Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

59 files changed, 5881 insertions, 0 deletions

diff --git a/modules/libmar/README b/modules/libmar/README
new file mode 100644
index 0000000000..422a289590
--- /dev/null
+++ b/modules/libmar/README
@@ -0,0 +1,6 @@
+This directory contains code for a simple archive file format, which
+is documented at http://wiki.mozilla.org/Software_Update:MAR
+
+The src directory builds a small static library used to create, read, and
+extract an archive file.  The tool directory builds a command line utility
+around the library.
diff --git a/modules/libmar/moz.build b/modules/libmar/moz.build
new file mode 100644
index 0000000000..d74a03de16
--- /dev/null
+++ b/modules/libmar/moz.build
@@ -0,0 +1,17 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+with Files("**"):
+    BUG_COMPONENT = ("Toolkit", "Application Update")
+
+DIRS += [
+    "src",
+    "sign",
+    "tool",
+    "verify",
+]
+
+TEST_DIRS += ["tests"]
diff --git a/modules/libmar/sign/mar_sign.c b/modules/libmar/sign/mar_sign.c
new file mode 100644
index 0000000000..87f67ca80c
--- /dev/null
+++ b/modules/libmar/sign/mar_sign.c
@@ -0,0 +1,1130 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifdef XP_WIN
+#  ifndef WIN32_LEAN_AND_MEAN
+#    define WIN32_LEAN_AND_MEAN
+#  endif
+#endif
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include "mar_private.h"
+#include "mar_cmdline.h"
+#include "mar.h"
+#include "cryptox.h"
+#ifndef XP_WIN
+#  include <unistd.h>
+#endif
+
+#include "nss_secutil.h"
+#include "base64.h"
+
+/**
+ * Initializes the NSS context.
+ *
+ * @param NSSConfigDir The config dir containing the private key to use
+ * @return 0 on success
+ *         -1 on error
+ */
+int NSSInitCryptoContext(const char* NSSConfigDir) {
+  SECStatus status =
+      NSS_Initialize(NSSConfigDir, "", "", SECMOD_DB, NSS_INIT_READONLY);
+  if (SECSuccess != status) {
+    fprintf(stderr, "ERROR: Could not initialize NSS\n");
+    return -1;
+  }
+
+  return 0;
+}
+
+/**
+ * Obtains a signing context.
+ *
+ * @param  ctx A pointer to the signing context to fill
+ * @return 0 on success
+ *         -1 on error
+ */
+int NSSSignBegin(const char* certName, SGNContext** ctx,
+                 SECKEYPrivateKey** privKey, CERTCertificate** cert,
+                 uint32_t* signatureLength) {
+  secuPWData pwdata = {PW_NONE, 0};
+  if (!certName || !ctx || !privKey || !cert || !signatureLength) {
+    fprintf(stderr, "ERROR: Invalid parameter passed to NSSSignBegin\n");
+    return -1;
+  }
+
+  /* Get the cert and embedded public key out of the database */
+  *cert = PK11_FindCertFromNickname(certName, &pwdata);
+  if (!*cert) {
+    fprintf(stderr, "ERROR: Could not find cert from nickname\n");
+    return -1;
+  }
+
+  /* Get the private key out of the database */
+  *privKey = PK11_FindKeyByAnyCert(*cert, &pwdata);
+  if (!*privKey) {
+    fprintf(stderr, "ERROR: Could not find private key\n");
+    return -1;
+  }
+
+  *signatureLength = PK11_SignatureLen(*privKey);
+
+  if (*signatureLength > BLOCKSIZE) {
+    fprintf(stderr,
+            "ERROR: Program must be compiled with a larger block size"
+            " to support signing with signatures this large: %u.\n",
+            *signatureLength);
+    return -1;
+  }
+
+  /* Check that the key length is large enough for our requirements */
+  if (*signatureLength < XP_MIN_SIGNATURE_LEN_IN_BYTES) {
+    fprintf(stderr, "ERROR: Key length must be >= %d bytes\n",
+            XP_MIN_SIGNATURE_LEN_IN_BYTES);
+    return -1;
+  }
+
+  *ctx = SGN_NewContext(SEC_OID_PKCS1_SHA384_WITH_RSA_ENCRYPTION, *privKey);
+  if (!*ctx) {
+    fprintf(stderr, "ERROR: Could not create signature context\n");
+    return -1;
+  }
+
+  if (SGN_Begin(*ctx) != SECSuccess) {
+    fprintf(stderr, "ERROR: Could not begin signature\n");
+    return -1;
+  }
+
+  return 0;
+}
+
+/**
+ * Writes the passed buffer to the file fp and updates the signature contexts.
+ *
+ * @param  fpDest   The file pointer to write to.
+ * @param  buffer   The buffer to write.
+ * @param  size     The size of the buffer to write.
+ * @param  ctxs     Pointer to the first element in an array of signature
+ *                  contexts to update.
+ * @param  ctxCount The number of signature contexts pointed to by ctxs
+ * @param  err    The name of what is being written to in case of error.
+ * @return  0 on success
+ *         -2 on write error
+ *         -3 on signature update error
+ */
+int WriteAndUpdateSignatures(FILE* fpDest, void* buffer, uint32_t size,
+                             SGNContext** ctxs, uint32_t ctxCount,
+                             const char* err) {
+  uint32_t k;
+  if (!size) {
+    return 0;
+  }
+
+  if (fwrite(buffer, size, 1, fpDest) != 1) {
+    fprintf(stderr, "ERROR: Could not write %s\n", err);
+    return -2;
+  }
+
+  for (k = 0; k < ctxCount; ++k) {
+    if (SGN_Update(ctxs[k], buffer, size) != SECSuccess) {
+      fprintf(stderr, "ERROR: Could not update signature context for %s\n",
+              err);
+      return -3;
+    }
+  }
+  return 0;
+}
+
+/**
+ * Adjusts each entry's content offset in the the passed in index by the
+ * specified amount.
+ *
+ * @param indexBuf     A buffer containing the MAR index
+ * @param indexLength  The length of the MAR index
+ * @param offsetAmount The amount to adjust each index entry by
+ */
+void AdjustIndexContentOffsets(char* indexBuf, uint32_t indexLength,
+                               uint32_t offsetAmount) {
+  uint32_t* offsetToContent;
+  char* indexBufLoc = indexBuf;
+
+  /* Consume the index and adjust each index by the specified amount */
+  while (indexBufLoc != (indexBuf + indexLength)) {
+    /* Adjust the offset */
+    offsetToContent = (uint32_t*)indexBufLoc;
+    *offsetToContent = ntohl(*offsetToContent);
+    *offsetToContent += offsetAmount;
+    *offsetToContent = htonl(*offsetToContent);
+    /* Skip past the offset, length, and flags */
+    indexBufLoc += 3 * sizeof(uint32_t);
+    indexBufLoc += strlen(indexBufLoc) + 1;
+  }
+}
+
+/**
+ * Reads from fpSrc, writes it to fpDest, and updates the signature contexts.
+ *
+ * @param  fpSrc    The file pointer to read from.
+ * @param  fpDest   The file pointer to write to.
+ * @param  buffer   The buffer to write.
+ * @param  size     The size of the buffer to write.
+ * @param  ctxs     Pointer to the first element in an array of signature
+ *                  contexts to update.
+ * @param  ctxCount The number of signature contexts pointed to by ctxs
+ * @param  err    The name of what is being written to in case of error.
+ * @return  0 on success
+ *         -1 on read error
+ *         -2 on write error
+ *         -3 on signature update error
+ */
+int ReadWriteAndUpdateSignatures(FILE* fpSrc, FILE* fpDest, void* buffer,
+                                 uint32_t size, SGNContext** ctxs,
+                                 uint32_t ctxCount, const char* err) {
+  if (!size) {
+    return 0;
+  }
+
+  if (fread(buffer, size, 1, fpSrc) != 1) {
+    fprintf(stderr, "ERROR: Could not read %s\n", err);
+    return -1;
+  }
+
+  return WriteAndUpdateSignatures(fpDest, buffer, size, ctxs, ctxCount, err);
+}
+
+/**
+ * Reads from fpSrc, writes it to fpDest.
+ *
+ * @param  fpSrc  The file pointer to read from.
+ * @param  fpDest The file pointer to write to.
+ * @param  buffer The buffer to write.
+ * @param  size   The size of the buffer to write.
+ * @param  err    The name of what is being written to in case of error.
+ * @return  0 on success
+ *         -1 on read error
+ *         -2 on write error
+ */
+int ReadAndWrite(FILE* fpSrc, FILE* fpDest, void* buffer, uint32_t size,
+                 const char* err) {
+  if (!size) {
+    return 0;
+  }
+
+  if (fread(buffer, size, 1, fpSrc) != 1) {
+    fprintf(stderr, "ERROR: Could not read %s\n", err);
+    return -1;
+  }
+
+  if (fwrite(buffer, size, 1, fpDest) != 1) {
+    fprintf(stderr, "ERROR: Could not write %s\n", err);
+    return -2;
+  }
+
+  return 0;
+}
+
+/**
+ * Writes out a copy of the MAR at src but with the signature block stripped.
+ *
+ * @param  src  The path of the source MAR file
+ * @param  dest The path of the MAR file to write out that
+                has no signature block
+ * @return 0 on success
+ *         -1 on error
+*/
+int strip_signature_block(const char* src, const char* dest) {
+  uint32_t offsetToIndex, dstOffsetToIndex, indexLength, numSignatures = 0,
+                                                         leftOver;
+  int32_t stripAmount = 0;
+  int64_t oldPos, numChunks, i, realSizeOfSrcMAR, numBytesToCopy,
+      sizeOfEntireMAR = 0;
+  FILE *fpSrc = NULL, *fpDest = NULL;
+  int rv = -1, hasSignatureBlock;
+  char buf[BLOCKSIZE];
+  char* indexBuf = NULL;
+
+  if (!src || !dest) {
+    fprintf(stderr, "ERROR: Invalid parameter passed in.\n");
+    return -1;
+  }
+
+  fpSrc = fopen(src, "rb");
+  if (!fpSrc) {
+    fprintf(stderr, "ERROR: could not open source file: %s\n", src);
+    goto failure;
+  }
+
+  fpDest = fopen(dest, "wb");
+  if (!fpDest) {
+    fprintf(stderr, "ERROR: could not create target file: %s\n", dest);
+    goto failure;
+  }
+
+  /* Determine if the source MAR file has the new fields for signing or not */
+  if (get_mar_file_info(src, &hasSignatureBlock, NULL, NULL, NULL, NULL)) {
+    fprintf(stderr, "ERROR: could not determine if MAR is old or new.\n");
+    goto failure;
+  }
+
+  /* MAR ID */
+  if (ReadAndWrite(fpSrc, fpDest, buf, MAR_ID_SIZE, "MAR ID")) {
+    goto failure;
+  }
+
+  /* Offset to index */
+  if (fread(&offsetToIndex, sizeof(offsetToIndex), 1, fpSrc) != 1) {
+    fprintf(stderr, "ERROR: Could not read offset\n");
+    goto failure;
+  }
+  offsetToIndex = ntohl(offsetToIndex);
+
+  /* Get the real size of the MAR */
+  oldPos = ftello(fpSrc);
+  if (fseeko(fpSrc, 0, SEEK_END)) {
+    fprintf(stderr, "ERROR: Could not seek to end of file.\n");
+    goto failure;
+  }
+  realSizeOfSrcMAR = ftello(fpSrc);
+  if (fseeko(fpSrc, oldPos, SEEK_SET)) {
+    fprintf(stderr, "ERROR: Could not seek back to current location.\n");
+    goto failure;
+  }
+
+  if (hasSignatureBlock) {
+    /* Get the MAR length and adjust its size */
+    if (fread(&sizeOfEntireMAR, sizeof(sizeOfEntireMAR), 1, fpSrc) != 1) {
+      fprintf(stderr, "ERROR: Could read mar size\n");
+      goto failure;
+    }
+    sizeOfEntireMAR = NETWORK_TO_HOST64(sizeOfEntireMAR);
+    if (sizeOfEntireMAR != realSizeOfSrcMAR) {
+      fprintf(stderr, "ERROR: Source MAR is not of the right size\n");
+      goto failure;
+    }
+
+    /* Get the num signatures in the source file so we know what to strip */
+    if (fread(&numSignatures, sizeof(numSignatures), 1, fpSrc) != 1) {
+      fprintf(stderr, "ERROR: Could read num signatures\n");
+      goto failure;
+    }
+    numSignatures = ntohl(numSignatures);
+
+    for (i = 0; i < numSignatures; i++) {
+      uint32_t signatureLen;
+
+      /* Skip past the signature algorithm ID */
+      if (fseeko(fpSrc, sizeof(uint32_t), SEEK_CUR)) {
+        fprintf(stderr, "ERROR: Could not skip past signature algorithm ID\n");
+      }
+
+      /* Read in the length of the signature so we know how far to skip */
+      if (fread(&signatureLen, sizeof(uint32_t), 1, fpSrc) != 1) {
+        fprintf(stderr, "ERROR: Could not read signatures length.\n");
+        return CryptoX_Error;
+      }
+      signatureLen = ntohl(signatureLen);
+
+      /* Skip past the signature */
+      if (fseeko(fpSrc, signatureLen, SEEK_CUR)) {
+        fprintf(stderr, "ERROR: Could not skip past signature algorithm ID\n");
+      }
+
+      stripAmount += sizeof(uint32_t) + sizeof(uint32_t) + signatureLen;
+    }
+
+  } else {
+    sizeOfEntireMAR = realSizeOfSrcMAR;
+    numSignatures = 0;
+  }
+
+  if (((int64_t)offsetToIndex) > sizeOfEntireMAR) {
+    fprintf(stderr, "ERROR: Offset to index is larger than the file size.\n");
+    goto failure;
+  }
+
+  dstOffsetToIndex = offsetToIndex;
+  if (!hasSignatureBlock) {
+    dstOffsetToIndex += sizeof(sizeOfEntireMAR) + sizeof(numSignatures);
+  }
+  dstOffsetToIndex -= stripAmount;
+
+  /* Write out the index offset */
+  dstOffsetToIndex = htonl(dstOffsetToIndex);
+  if (fwrite(&dstOffsetToIndex, sizeof(dstOffsetToIndex), 1, fpDest) != 1) {
+    fprintf(stderr, "ERROR: Could not write offset to index\n");
+    goto failure;
+  }
+  dstOffsetToIndex = ntohl(dstOffsetToIndex);
+
+  /* Write out the new MAR file size */
+  if (!hasSignatureBlock) {
+    sizeOfEntireMAR += sizeof(sizeOfEntireMAR) + sizeof(numSignatures);
+  }
+  sizeOfEntireMAR -= stripAmount;
+
+  /* Write out the MAR size */
+  sizeOfEntireMAR = HOST_TO_NETWORK64(sizeOfEntireMAR);
+  if (fwrite(&sizeOfEntireMAR, sizeof(sizeOfEntireMAR), 1, fpDest) != 1) {
+    fprintf(stderr, "ERROR: Could not write size of MAR\n");
+    goto failure;
+  }
+  sizeOfEntireMAR = NETWORK_TO_HOST64(sizeOfEntireMAR);
+
+  /* Write out the number of signatures, which is 0 */
+  numSignatures = 0;
+  if (fwrite(&numSignatures, sizeof(numSignatures), 1, fpDest) != 1) {
+    fprintf(stderr, "ERROR: Could not write out num signatures\n");
+    goto failure;
+  }
+
+  /* Write out the rest of the MAR excluding the index header and index
+     offsetToIndex unfortunately has to remain 32-bit because for backwards
+     compatibility with the old MAR file format. */
+  if (ftello(fpSrc) > ((int64_t)offsetToIndex)) {
+    fprintf(stderr, "ERROR: Index offset is too small.\n");
+    goto failure;
+  }
+  numBytesToCopy = ((int64_t)offsetToIndex) - ftello(fpSrc);
+  numChunks = numBytesToCopy / BLOCKSIZE;
+  leftOver = numBytesToCopy % BLOCKSIZE;
+
+  /* Read each file and write it to the MAR file */
+  for (i = 0; i < numChunks; ++i) {
+    if (ReadAndWrite(fpSrc, fpDest, buf, BLOCKSIZE, "content block")) {
+      goto failure;
+    }
+  }
+
+  /* Write out the left over */
+  if (ReadAndWrite(fpSrc, fpDest, buf, leftOver, "left over content block")) {
+    goto failure;
+  }
+
+  /* Length of the index */
+  if (ReadAndWrite(fpSrc, fpDest, &indexLength, sizeof(indexLength),
+                   "index length")) {
+    goto failure;
+  }
+  indexLength = ntohl(indexLength);
+
+  /* Consume the index and adjust each index by the difference */
+  indexBuf = malloc(indexLength);
+  if (fread(indexBuf, indexLength, 1, fpSrc) != 1) {
+    fprintf(stderr, "ERROR: Could not read index\n");
+    goto failure;
+  }
+
+  /* Adjust each entry in the index */
+  if (hasSignatureBlock) {
+    AdjustIndexContentOffsets(indexBuf, indexLength, -stripAmount);
+  } else {
+    AdjustIndexContentOffsets(
+        indexBuf, indexLength,
+        sizeof(sizeOfEntireMAR) + sizeof(numSignatures) - stripAmount);
+  }
+
+  if (fwrite(indexBuf, indexLength, 1, fpDest) != 1) {
+    fprintf(stderr, "ERROR: Could not write index\n");
+    goto failure;
+  }
+
+  rv = 0;
+failure:
+  if (fpSrc) {
+    fclose(fpSrc);
+  }
+
+  if (fpDest) {
+    fclose(fpDest);
+  }
+
+  if (rv) {
+    remove(dest);
+  }
+
+  if (indexBuf) {
+    free(indexBuf);
+  }
+
+  if (rv) {
+    remove(dest);
+  }
+  return rv;
+}
+
+/**
+ * Extracts a signature from a MAR file, base64 encodes it, and writes it out
+ *
+ * @param  src       The path of the source MAR file
+ * @param  sigIndex  The index of the signature to extract
+ * @param  dest      The path of file to write the signature to
+ * @return 0 on success
+ *         -1 on error
+ */
+int extract_signature(const char* src, uint32_t sigIndex, const char* dest) {
+  FILE *fpSrc = NULL, *fpDest = NULL;
+  uint32_t i;
+  uint32_t signatureCount;
+  uint32_t signatureLen;
+  uint8_t* extractedSignature = NULL;
+  char* base64Encoded = NULL;
+  int rv = -1;
+  if (!src || !dest) {
+    fprintf(stderr, "ERROR: Invalid parameter passed in.\n");
+    goto failure;
+  }
+
+  fpSrc = fopen(src, "rb");
+  if (!fpSrc) {
+    fprintf(stderr, "ERROR: could not open source file: %s\n", src);
+    goto failure;
+  }
+
+  fpDest = fopen(dest, "wb");
+  if (!fpDest) {
+    fprintf(stderr, "ERROR: could not create target file: %s\n", dest);
+    goto failure;
+  }
+
+  /* Skip to the start of the signature block */
+  if (fseeko(fpSrc, SIGNATURE_BLOCK_OFFSET, SEEK_SET)) {
+    fprintf(stderr, "ERROR: could not seek to signature block\n");
+    goto failure;
+  }
+
+  /* Get the number of signatures */
+  if (fread(&signatureCount, sizeof(signatureCount), 1, fpSrc) != 1) {
+    fprintf(stderr, "ERROR: could not read signature count\n");
+    goto failure;
+  }
+  signatureCount = ntohl(signatureCount);
+  if (sigIndex >= signatureCount) {
+    fprintf(stderr, "ERROR: Signature index was out of range\n");
+    goto failure;
+  }
+
+  /* Skip to the correct signature */
+  for (i = 0; i <= sigIndex; i++) {
+    /* Avoid leaking while skipping signatures */
+    free(extractedSignature);
+    extractedSignature = NULL;
+
+    /* skip past the signature algorithm ID */
+    if (fseeko(fpSrc, sizeof(uint32_t), SEEK_CUR)) {
+      fprintf(stderr, "ERROR: Could not seek past sig algorithm ID.\n");
+      goto failure;
+    }
+
+    /* Get the signature length */
+    if (fread(&signatureLen, sizeof(signatureLen), 1, fpSrc) != 1) {
+      fprintf(stderr, "ERROR: could not read signature length\n");
+      goto failure;
+    }
+    signatureLen = ntohl(signatureLen);
+
+    /* Get the signature */
+    extractedSignature = malloc(signatureLen);
+    if (fread(extractedSignature, signatureLen, 1, fpSrc) != 1) {
+      fprintf(stderr, "ERROR: could not read signature\n");
+      goto failure;
+    }
+  }
+
+  base64Encoded = BTOA_DataToAscii(extractedSignature, signatureLen);
+  if (!base64Encoded) {
+    fprintf(stderr, "ERROR: could not obtain base64 encoded data\n");
+    goto failure;
+  }
+
+  if (fwrite(base64Encoded, strlen(base64Encoded), 1, fpDest) != 1) {
+    fprintf(stderr, "ERROR: Could not write base64 encoded string\n");
+    goto failure;
+  }
+
+  rv = 0;
+failure:
+  if (base64Encoded) {
+    PORT_Free(base64Encoded);
+  }
+
+  if (extractedSignature) {
+    free(extractedSignature);
+  }
+
+  if (fpSrc) {
+    fclose(fpSrc);
+  }
+
+  if (fpDest) {
+    fclose(fpDest);
+  }
+
+  if (rv) {
+    remove(dest);
+  }
+
+  return rv;
+}
+
+/**
+ * Imports a base64 encoded signature into a MAR file
+ *
+ * @param  src           The path of the source MAR file
+ * @param  sigIndex      The index of the signature to import
+ * @param  base64SigFile A file which contains the signature to import
+ * @param  dest          The path of the destination MAR file with replaced
+ *                       signature
+ * @return 0 on success
+ *         -1 on error
+ */
+int import_signature(const char* src, uint32_t sigIndex,
+                     const char* base64SigFile, const char* dest) {
+  int rv = -1;
+  FILE* fpSrc = NULL;
+  FILE* fpDest = NULL;
+  FILE* fpSigFile = NULL;
+  uint32_t i;
+  uint32_t signatureCount, signatureLen, signatureAlgorithmID, numChunks,
+      leftOver;
+  char buf[BLOCKSIZE];
+  uint64_t sizeOfSrcMAR, sizeOfBase64EncodedFile;
+  char* passedInSignatureB64 = NULL;
+  uint8_t* passedInSignatureRaw = NULL;
+  uint8_t* extractedMARSignature = NULL;
+  unsigned int passedInSignatureLenRaw;
+
+  if (!src || !dest) {
+    fprintf(stderr, "ERROR: Invalid parameter passed in.\n");
+    goto failure;
+  }
+
+  fpSrc = fopen(src, "rb");
+  if (!fpSrc) {
+    fprintf(stderr, "ERROR: could not open source file: %s\n", src);
+    goto failure;
+  }
+
+  fpDest = fopen(dest, "wb");
+  if (!fpDest) {
+    fprintf(stderr, "ERROR: could not open dest file: %s\n", dest);
+    goto failure;
+  }
+
+  fpSigFile = fopen(base64SigFile, "rb");
+  if (!fpSigFile) {
+    fprintf(stderr, "ERROR: could not open sig file: %s\n", base64SigFile);
+    goto failure;
+  }
+
+  /* Get the src file size */
+  if (fseeko(fpSrc, 0, SEEK_END)) {
+    fprintf(stderr, "ERROR: Could not seek to end of src file.\n");
+    goto failure;
+  }
+  sizeOfSrcMAR = ftello(fpSrc);
+  if (fseeko(fpSrc, 0, SEEK_SET)) {
+    fprintf(stderr, "ERROR: Could not seek to start of src file.\n");
+    goto failure;
+  }
+
+  /* Get the sig file size */
+  if (fseeko(fpSigFile, 0, SEEK_END)) {
+    fprintf(stderr, "ERROR: Could not seek to end of sig file.\n");
+    goto failure;
+  }
+  sizeOfBase64EncodedFile = ftello(fpSigFile);
+  if (fseeko(fpSigFile, 0, SEEK_SET)) {
+    fprintf(stderr, "ERROR: Could not seek to start of sig file.\n");
+    goto failure;
+  }
+
+  /* Read in the base64 encoded signature to import */
+  passedInSignatureB64 = malloc(sizeOfBase64EncodedFile + 1);
+  passedInSignatureB64[sizeOfBase64EncodedFile] = '\0';
+  if (fread(passedInSignatureB64, sizeOfBase64EncodedFile, 1, fpSigFile) != 1) {
+    fprintf(stderr, "ERROR: Could read b64 sig file.\n");
+    goto failure;
+  }
+
+  /* Decode the base64 encoded data */
+  passedInSignatureRaw =
+      ATOB_AsciiToData(passedInSignatureB64, &passedInSignatureLenRaw);
+  if (!passedInSignatureRaw) {
+    fprintf(stderr, "ERROR: could not obtain base64 decoded data\n");
+    goto failure;
+  }
+
+  /* Read everything up until the signature block offset and write it out */
+  if (ReadAndWrite(fpSrc, fpDest, buf, SIGNATURE_BLOCK_OFFSET,
+                   "signature block offset")) {
+    goto failure;
+  }
+
+  /* Get the number of signatures */
+  if (ReadAndWrite(fpSrc, fpDest, &signatureCount, sizeof(signatureCount),
+                   "signature count")) {
+    goto failure;
+  }
+  signatureCount = ntohl(signatureCount);
+  if (signatureCount > MAX_SIGNATURES) {
+    fprintf(stderr, "ERROR: Signature count was out of range\n");
+    goto failure;
+  }
+
+  if (sigIndex >= signatureCount) {
+    fprintf(stderr, "ERROR: Signature index was out of range\n");
+    goto failure;
+  }
+
+  /* Read and write the whole signature block, but if we reach the
+     signature offset, then we should replace it with the specified
+     base64 decoded signature */
+  for (i = 0; i < signatureCount; i++) {
+    /* Read/Write the signature algorithm ID */
+    if (ReadAndWrite(fpSrc, fpDest, &signatureAlgorithmID,
+                     sizeof(signatureAlgorithmID), "sig algorithm ID")) {
+      goto failure;
+    }
+
+    /* Read/Write the signature length */
+    if (ReadAndWrite(fpSrc, fpDest, &signatureLen, sizeof(signatureLen),
+                     "sig length")) {
+      goto failure;
+    }
+    signatureLen = ntohl(signatureLen);
+
+    /* Get the signature */
+    if (extractedMARSignature) {
+      free(extractedMARSignature);
+    }
+    extractedMARSignature = malloc(signatureLen);
+
+    if (sigIndex == i) {
+      if (passedInSignatureLenRaw != signatureLen) {
+        fprintf(stderr, "ERROR: Signature length must be the same\n");
+        goto failure;
+      }
+
+      if (fread(extractedMARSignature, signatureLen, 1, fpSrc) != 1) {
+        fprintf(stderr, "ERROR: Could not read signature\n");
+        goto failure;
+      }
+
+      if (fwrite(passedInSignatureRaw, passedInSignatureLenRaw, 1, fpDest) !=
+          1) {
+        fprintf(stderr, "ERROR: Could not write signature\n");
+        goto failure;
+      }
+    } else {
+      if (ReadAndWrite(fpSrc, fpDest, extractedMARSignature, signatureLen,
+                       "signature")) {
+        goto failure;
+      }
+    }
+  }
+
+  /* We replaced the signature so let's just skip past the rest o the
+     file. */
+  numChunks = (sizeOfSrcMAR - ftello(fpSrc)) / BLOCKSIZE;
+  leftOver = (sizeOfSrcMAR - ftello(fpSrc)) % BLOCKSIZE;
+
+  /* Read each file and write it to the MAR file */
+  for (i = 0; i < numChunks; ++i) {
+    if (ReadAndWrite(fpSrc, fpDest, buf, BLOCKSIZE, "content block")) {
+      goto failure;
+    }
+  }
+
+  if (ReadAndWrite(fpSrc, fpDest, buf, leftOver, "left over content block")) {
+    goto failure;
+  }
+
+  rv = 0;
+
+failure:
+
+  if (fpSrc) {
+    fclose(fpSrc);
+  }
+
+  if (fpDest) {
+    fclose(fpDest);
+  }
+
+  if (fpSigFile) {
+    fclose(fpSigFile);
+  }
+
+  if (rv) {
+    remove(dest);
+  }
+
+  if (extractedMARSignature) {
+    free(extractedMARSignature);
+  }
+
+  if (passedInSignatureB64) {
+    free(passedInSignatureB64);
+  }
+
+  if (passedInSignatureRaw) {
+    PORT_Free(passedInSignatureRaw);
+  }
+
+  return rv;
+}
+
+/**
+ * Writes out a copy of the MAR at src but with embedded signatures.
+ * The passed in MAR file must not already be signed or an error will
+ * be returned.
+ *
+ * @param  NSSConfigDir  The NSS directory containing the private key for
+ *                       signing
+ * @param  certNames     The nicknames of the certificate to use for signing
+ * @param  certCount     The number of certificate names contained in certNames.
+ *                       One signature will be produced for each certificate.
+ * @param  src           The path of the source MAR file to sign
+ * @param  dest          The path of the MAR file to write out that is signed
+ * @return 0 on success
+ *         -1 on error
+ */
+int mar_repackage_and_sign(const char* NSSConfigDir,
+                           const char* const* certNames, uint32_t certCount,
+                           const char* src, const char* dest) {
+  uint32_t offsetToIndex, dstOffsetToIndex, indexLength, leftOver,
+      signatureAlgorithmID, numSignatures = 0, signatureSectionLength = 0;
+  uint32_t signatureLengths[MAX_SIGNATURES];
+  int64_t oldPos, numChunks, i, realSizeOfSrcMAR, signaturePlaceholderOffset,
+      numBytesToCopy, sizeOfEntireMAR = 0;
+  FILE *fpSrc = NULL, *fpDest = NULL;
+  int rv = -1, hasSignatureBlock;
+  SGNContext* ctxs[MAX_SIGNATURES];
+  SECItem secItems[MAX_SIGNATURES];
+  char buf[BLOCKSIZE];
+  SECKEYPrivateKey* privKeys[MAX_SIGNATURES];
+  CERTCertificate* certs[MAX_SIGNATURES];
+  char* indexBuf = NULL;
+  uint32_t k;
+
+  memset(signatureLengths, 0, sizeof(signatureLengths));
+  memset(ctxs, 0, sizeof(ctxs));
+  memset(secItems, 0, sizeof(secItems));
+  memset(privKeys, 0, sizeof(privKeys));
+  memset(certs, 0, sizeof(certs));
+
+  if (!NSSConfigDir || !certNames || certCount == 0 || !src || !dest) {
+    fprintf(stderr, "ERROR: Invalid parameter passed in.\n");
+    return -1;
+  }
+
+  if (NSSInitCryptoContext(NSSConfigDir)) {
+    fprintf(stderr, "ERROR: Could not init config dir: %s\n", NSSConfigDir);
+    goto failure;
+  }
+
+  PK11_SetPasswordFunc(SECU_GetModulePassword);
+
+  fpSrc = fopen(src, "rb");
+  if (!fpSrc) {
+    fprintf(stderr, "ERROR: could not open source file: %s\n", src);
+    goto failure;
+  }
+
+  fpDest = fopen(dest, "wb");
+  if (!fpDest) {
+    fprintf(stderr, "ERROR: could not create target file: %s\n", dest);
+    goto failure;
+  }
+
+  /* Determine if the source MAR file has the new fields for signing or not */
+  if (get_mar_file_info(src, &hasSignatureBlock, NULL, NULL, NULL, NULL)) {
+    fprintf(stderr, "ERROR: could not determine if MAR is old or new.\n");
+    goto failure;
+  }
+
+  for (k = 0; k < certCount; k++) {
+    if (NSSSignBegin(certNames[k], &ctxs[k], &privKeys[k], &certs[k],
+                     &signatureLengths[k])) {
+      fprintf(stderr, "ERROR: NSSSignBegin failed\n");
+      goto failure;
+    }
+  }
+
+  /* MAR ID */
+  if (ReadWriteAndUpdateSignatures(fpSrc, fpDest, buf, MAR_ID_SIZE, ctxs,
+                                   certCount, "MAR ID")) {
+    goto failure;
+  }
+
+  /* Offset to index */
+  if (fread(&offsetToIndex, sizeof(offsetToIndex), 1, fpSrc) != 1) {
+    fprintf(stderr, "ERROR: Could not read offset\n");
+    goto failure;
+  }
+  offsetToIndex = ntohl(offsetToIndex);
+
+  /* Get the real size of the MAR */
+  oldPos = ftello(fpSrc);
+  if (fseeko(fpSrc, 0, SEEK_END)) {
+    fprintf(stderr, "ERROR: Could not seek to end of file.\n");
+    goto failure;
+  }
+  realSizeOfSrcMAR = ftello(fpSrc);
+  if (fseeko(fpSrc, oldPos, SEEK_SET)) {
+    fprintf(stderr, "ERROR: Could not seek back to current location.\n");
+    goto failure;
+  }
+
+  if (hasSignatureBlock) {
+    /* Get the MAR length and adjust its size */
+    if (fread(&sizeOfEntireMAR, sizeof(sizeOfEntireMAR), 1, fpSrc) != 1) {
+      fprintf(stderr, "ERROR: Could read mar size\n");
+      goto failure;
+    }
+    sizeOfEntireMAR = NETWORK_TO_HOST64(sizeOfEntireMAR);
+    if (sizeOfEntireMAR != realSizeOfSrcMAR) {
+      fprintf(stderr, "ERROR: Source MAR is not of the right size\n");
+      goto failure;
+    }
+
+    /* Get the num signatures in the source file */
+    if (fread(&numSignatures, sizeof(numSignatures), 1, fpSrc) != 1) {
+      fprintf(stderr, "ERROR: Could read num signatures\n");
+      goto failure;
+    }
+    numSignatures = ntohl(numSignatures);
+
+    /* We do not support resigning, if you have multiple signatures,
+       you must add them all at the same time. */
+    if (numSignatures) {
+      fprintf(stderr, "ERROR: MAR is already signed\n");
+      goto failure;
+    }
+  } else {
+    sizeOfEntireMAR = realSizeOfSrcMAR;
+  }
+
+  if (((int64_t)offsetToIndex) > sizeOfEntireMAR) {
+    fprintf(stderr, "ERROR: Offset to index is larger than the file size.\n");
+    goto failure;
+  }
+
+  /* Calculate the total signature block length */
+  for (k = 0; k < certCount; k++) {
+    signatureSectionLength += sizeof(signatureAlgorithmID) +
+                              sizeof(signatureLengths[k]) + signatureLengths[k];
+  }
+  dstOffsetToIndex = offsetToIndex;
+  if (!hasSignatureBlock) {
+    dstOffsetToIndex += sizeof(sizeOfEntireMAR) + sizeof(numSignatures);
+  }
+  dstOffsetToIndex += signatureSectionLength;
+
+  /* Write out the index offset */
+  dstOffsetToIndex = htonl(dstOffsetToIndex);
+  if (WriteAndUpdateSignatures(fpDest, &dstOffsetToIndex,
+                               sizeof(dstOffsetToIndex), ctxs, certCount,
+                               "index offset")) {
+    goto failure;
+  }
+  dstOffsetToIndex = ntohl(dstOffsetToIndex);
+
+  /* Write out the new MAR file size */
+  sizeOfEntireMAR += signatureSectionLength;
+  if (!hasSignatureBlock) {
+    sizeOfEntireMAR += sizeof(sizeOfEntireMAR) + sizeof(numSignatures);
+  }
+
+  /* Write out the MAR size */
+  sizeOfEntireMAR = HOST_TO_NETWORK64(sizeOfEntireMAR);
+  if (WriteAndUpdateSignatures(fpDest, &sizeOfEntireMAR,
+                               sizeof(sizeOfEntireMAR), ctxs, certCount,
+                               "size of MAR")) {
+    goto failure;
+  }
+  sizeOfEntireMAR = NETWORK_TO_HOST64(sizeOfEntireMAR);
+
+  /* Write out the number of signatures */
+  numSignatures = certCount;
+  numSignatures = htonl(numSignatures);
+  if (WriteAndUpdateSignatures(fpDest, &numSignatures, sizeof(numSignatures),
+                               ctxs, certCount, "num signatures")) {
+    goto failure;
+  }
+  numSignatures = ntohl(numSignatures);
+
+  signaturePlaceholderOffset = ftello(fpDest);
+
+  for (k = 0; k < certCount; k++) {
+    /* Write out the signature algorithm ID, Only an ID of 2 is supported */
+    signatureAlgorithmID = htonl(2);
+    if (WriteAndUpdateSignatures(fpDest, &signatureAlgorithmID,
+                                 sizeof(signatureAlgorithmID), ctxs, certCount,
+                                 "num signatures")) {
+      goto failure;
+    }
+    signatureAlgorithmID = ntohl(signatureAlgorithmID);
+
+    /* Write out the signature length */
+    signatureLengths[k] = htonl(signatureLengths[k]);
+    if (WriteAndUpdateSignatures(fpDest, &signatureLengths[k],
+                                 sizeof(signatureLengths[k]), ctxs, certCount,
+                                 "signature length")) {
+      goto failure;
+    }
+    signatureLengths[k] = ntohl(signatureLengths[k]);
+
+    /* Write out a placeholder for the signature, we'll come back to this later
+      *** THIS IS NOT SIGNED because it is a placeholder that will be replaced
+          below, plus it is going to be the signature itself. *** */
+    memset(buf, 0, sizeof(buf));
+    if (fwrite(buf, signatureLengths[k], 1, fpDest) != 1) {
+      fprintf(stderr, "ERROR: Could not write signature length\n");
+      goto failure;
+    }
+  }
+
+  /* Write out the rest of the MAR excluding the index header and index
+     offsetToIndex unfortunately has to remain 32-bit because for backwards
+     compatibility with the old MAR file format. */
+  if (ftello(fpSrc) > ((int64_t)offsetToIndex)) {
+    fprintf(stderr, "ERROR: Index offset is too small.\n");
+    goto failure;
+  }
+  numBytesToCopy = ((int64_t)offsetToIndex) - ftello(fpSrc);
+  numChunks = numBytesToCopy / BLOCKSIZE;
+  leftOver = numBytesToCopy % BLOCKSIZE;
+
+  /* Read each file and write it to the MAR file */
+  for (i = 0; i < numChunks; ++i) {
+    if (ReadWriteAndUpdateSignatures(fpSrc, fpDest, buf, BLOCKSIZE, ctxs,
+                                     certCount, "content block")) {
+      goto failure;
+    }
+  }
+
+  /* Write out the left over */
+  if (ReadWriteAndUpdateSignatures(fpSrc, fpDest, buf, leftOver, ctxs,
+                                   certCount, "left over content block")) {
+    goto failure;
+  }
+
+  /* Length of the index */
+  if (ReadWriteAndUpdateSignatures(fpSrc, fpDest, &indexLength,
+                                   sizeof(indexLength), ctxs, certCount,
+                                   "index length")) {
+    goto failure;
+  }
+  indexLength = ntohl(indexLength);
+
+  /* Consume the index and adjust each index by signatureSectionLength */
+  indexBuf = malloc(indexLength);
+  if (fread(indexBuf, indexLength, 1, fpSrc) != 1) {
+    fprintf(stderr, "ERROR: Could not read index\n");
+    goto failure;
+  }
+
+  /* Adjust each entry in the index */
+  if (hasSignatureBlock) {
+    AdjustIndexContentOffsets(indexBuf, indexLength, signatureSectionLength);
+  } else {
+    AdjustIndexContentOffsets(indexBuf, indexLength,
+                              sizeof(sizeOfEntireMAR) + sizeof(numSignatures) +
+                                  signatureSectionLength);
+  }
+
+  if (WriteAndUpdateSignatures(fpDest, indexBuf, indexLength, ctxs, certCount,
+                               "index")) {
+    goto failure;
+  }
+
+  /* Ensure that we don't sign a file that is too large to be accepted by
+     the verification function. */
+  if (ftello(fpDest) > MAX_SIZE_OF_MAR_FILE) {
+    goto failure;
+  }
+
+  for (k = 0; k < certCount; k++) {
+    /* Get the signature */
+    if (SGN_End(ctxs[k], &secItems[k]) != SECSuccess) {
+      fprintf(stderr, "ERROR: Could not end signature context\n");
+      goto failure;
+    }
+    if (signatureLengths[k] != secItems[k].len) {
+      fprintf(stderr, "ERROR: Signature is not the expected length\n");
+      goto failure;
+    }
+  }
+
+  /* Get back to the location of the signature placeholder */
+  if (fseeko(fpDest, signaturePlaceholderOffset, SEEK_SET)) {
+    fprintf(stderr, "ERROR: Could not seek to signature offset\n");
+    goto failure;
+  }
+
+  for (k = 0; k < certCount; k++) {
+    /* Skip to the position of the next signature */
+    if (fseeko(fpDest,
+               sizeof(signatureAlgorithmID) + sizeof(signatureLengths[k]),
+               SEEK_CUR)) {
+      fprintf(stderr, "ERROR: Could not seek to signature offset\n");
+      goto failure;
+    }
+
+    /* Write out the calculated signature.
+     *** THIS IS NOT SIGNED because it is the signature itself. *** */
+    if (fwrite(secItems[k].data, secItems[k].len, 1, fpDest) != 1) {
+      fprintf(stderr, "ERROR: Could not write signature\n");
+      goto failure;
+    }
+  }
+
+  rv = 0;
+failure:
+  if (fpSrc) {
+    fclose(fpSrc);
+  }
+
+  if (fpDest) {
+    fclose(fpDest);
+  }
+
+  if (rv) {
+    remove(dest);
+  }
+
+  if (indexBuf) {
+    free(indexBuf);
+  }
+
+  /* Cleanup */
+  for (k = 0; k < certCount; k++) {
+    if (ctxs[k]) {
+      SGN_DestroyContext(ctxs[k], PR_TRUE);
+    }
+
+    if (certs[k]) {
+      CERT_DestroyCertificate(certs[k]);
+    }
+
+    if (privKeys[k]) {
+      SECKEY_DestroyPrivateKey(privKeys[k]);
+    }
+
+    SECITEM_FreeItem(&secItems[k], PR_FALSE);
+  }
+
+  (void)NSS_Shutdown();
+
+  if (rv) {
+    remove(dest);
+  }
+
+  return rv;
+}
diff --git a/modules/libmar/sign/moz.build b/modules/libmar/sign/moz.build
new file mode 100644
index 0000000000..92f0d6cefd
--- /dev/null
+++ b/modules/libmar/sign/moz.build
@@ -0,0 +1,30 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+Library("signmar")
+
+UNIFIED_SOURCES += [
+    "mar_sign.c",
+    "nss_secutil.c",
+]
+
+FORCE_STATIC_LIB = True
+
+LOCAL_INCLUDES += [
+    "../src",
+    "../verify",
+]
+
+DEFINES["MAR_NSS"] = True
+
+if CONFIG["OS_ARCH"] == "WINNT":
+    USE_STATIC_LIBS = True
+
+# C11 for static_assert
+c11_flags = ["-std=gnu11"]
+if CONFIG["CC_TYPE"] == "clang-cl":
+    c11_flags.insert(0, "-Xclang")
+CFLAGS += c11_flags
diff --git a/modules/libmar/sign/nss_secutil.c b/modules/libmar/sign/nss_secutil.c
new file mode 100644
index 0000000000..02a298a6f7
--- /dev/null
+++ b/modules/libmar/sign/nss_secutil.c
@@ -0,0 +1,226 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* With the exception of GetPasswordString, this file was
+   copied from NSS's cmd/lib/secutil.c hg revision 8f011395145e */
+
+#include "nss_secutil.h"
+
+#include "prprf.h"
+#ifdef XP_WIN
+#  include <io.h>
+#else
+#  include <unistd.h>
+#endif
+
+#if defined(_WINDOWS)
+char* quiet_fgets(char* buf, int length, FILE* input) {
+  int c;
+  char* end = buf;
+
+  /* fflush (input); */
+  memset(buf, 0, length);
+
+  if (!isatty(fileno(input))) {
+    return fgets(buf, length, input);
+  }
+
+  while (1) {
+#  if defined(_WIN32_WCE)
+    c = getchar(); /* gets a character from stdin */
+#  else
+    c = getch(); /* getch gets a character from the console */
+#  endif
+    if (c == '\b') {
+      if (end > buf) end--;
+    }
+
+    else if (--length > 0)
+      *end++ = c;
+
+    if (!c || c == '\n' || c == '\r') break;
+  }
+
+  return buf;
+}
+#endif
+
+char* GetPasswordString(void* arg, char* prompt) {
+  FILE* input = stdin;
+  char phrase[200] = {'\0'};
+  int isInputTerminal = isatty(fileno(stdin));
+
+#ifndef _WINDOWS
+  if (isInputTerminal) {
+    static char consoleName[] = {
+#  ifdef XP_UNIX
+        "/dev/tty"
+#  else
+        "CON:"
+#  endif
+    };
+
+    input = fopen(consoleName, "r");
+    if (input == NULL) {
+      fprintf(stderr, "Error opening input terminal for read\n");
+      return NULL;
+    }
+  }
+#endif
+
+  if (isInputTerminal) {
+    fprintf(stdout, "Please enter your password:\n");
+    fflush(stdout);
+  }
+
+  if (!QUIET_FGETS(phrase, sizeof(phrase), input)) {
+    fprintf(stderr, "QUIET_FGETS failed\n");
+    return NULL;
+  }
+
+  if (isInputTerminal) {
+    fprintf(stdout, "\n");
+  }
+
+#ifndef _WINDOWS
+  if (isInputTerminal) {
+    fclose(input);
+  }
+#endif
+
+  /* Strip off the newlines if present */
+  if (phrase[PORT_Strlen(phrase) - 1] == '\n' ||
+      phrase[PORT_Strlen(phrase) - 1] == '\r') {
+    phrase[PORT_Strlen(phrase) - 1] = 0;
+  }
+  return (char*)PORT_Strdup(phrase);
+}
+
+char* SECU_FilePasswd(PK11SlotInfo* slot, PRBool retry, void* arg) {
+  char *phrases, *phrase;
+  PRFileDesc* fd;
+  int32_t nb;
+  char* pwFile = arg;
+  int i;
+  const long maxPwdFileSize = 4096;
+  char* tokenName = NULL;
+  int tokenLen = 0;
+
+  if (!pwFile) return 0;
+
+  if (retry) {
+    return 0; /* no good retrying - the files contents will be the same */
+  }
+
+  phrases = PORT_ZAlloc(maxPwdFileSize);
+
+  if (!phrases) {
+    return 0; /* out of memory */
+  }
+
+  fd = PR_Open(pwFile, PR_RDONLY, 0);
+  if (!fd) {
+    fprintf(stderr, "No password file \"%s\" exists.\n", pwFile);
+    PORT_Free(phrases);
+    return NULL;
+  }
+
+  nb = PR_Read(fd, phrases, maxPwdFileSize);
+
+  PR_Close(fd);
+
+  if (nb == 0) {
+    fprintf(stderr, "password file contains no data\n");
+    PORT_Free(phrases);
+    return NULL;
+  }
+
+  if (slot) {
+    tokenName = PK11_GetTokenName(slot);
+    if (tokenName) {
+      tokenLen = PORT_Strlen(tokenName);
+    }
+  }
+  i = 0;
+  do {
+    int startphrase = i;
+    int phraseLen;
+
+    /* handle the Windows EOL case */
+    while (phrases[i] != '\r' && phrases[i] != '\n' && i < nb) i++;
+    /* terminate passphrase */
+    if (i < nb) {
+      phrases[i++] = '\0';
+    }
+    /* clean up any EOL before the start of the next passphrase */
+    while ((i < nb) && (phrases[i] == '\r' || phrases[i] == '\n')) {
+      phrases[i++] = '\0';
+    }
+    /* now analyze the current passphrase */
+    phrase = &phrases[startphrase];
+    if (!tokenName) break;
+    if (PORT_Strncmp(phrase, tokenName, tokenLen)) continue;
+    phraseLen = PORT_Strlen(phrase);
+    if (phraseLen < (tokenLen + 1)) continue;
+    if (phrase[tokenLen] != ':') continue;
+    phrase = &phrase[tokenLen + 1];
+    break;
+
+  } while (i < nb);
+
+  phrase = PORT_Strdup((char*)phrase);
+  PORT_Free(phrases);
+  return phrase;
+}
+
+char* SECU_GetModulePassword(PK11SlotInfo* slot, PRBool retry, void* arg) {
+  char prompt[255];
+  secuPWData* pwdata = (secuPWData*)arg;
+  secuPWData pwnull = {PW_NONE, 0};
+  secuPWData pwxtrn = {PW_EXTERNAL, "external"};
+  char* pw;
+
+  if (pwdata == NULL) pwdata = &pwnull;
+
+  if (PK11_ProtectedAuthenticationPath(slot)) {
+    pwdata = &pwxtrn;
+  }
+  if (retry && pwdata->source != PW_NONE) {
+    PR_fprintf(PR_STDERR, "Incorrect password/PIN entered.\n");
+    return NULL;
+  }
+
+  switch (pwdata->source) {
+    case PW_NONE:
+      sprintf(prompt,
+              "Enter Password or Pin for \"%s\":", PK11_GetTokenName(slot));
+      return GetPasswordString(NULL, prompt);
+    case PW_FROMFILE:
+      /* Instead of opening and closing the file every time, get the pw
+       * once, then keep it in memory (duh).
+       */
+      pw = SECU_FilePasswd(slot, retry, pwdata->data);
+      pwdata->source = PW_PLAINTEXT;
+      pwdata->data = PL_strdup(pw);
+      /* it's already been dup'ed */
+      return pw;
+    case PW_EXTERNAL:
+      sprintf(prompt,
+              "Press Enter, then enter PIN for \"%s\" on external device.\n",
+              PK11_GetTokenName(slot));
+      pw = GetPasswordString(NULL, prompt);
+      if (pw) {
+        memset(pw, 0, PORT_Strlen(pw));
+        PORT_Free(pw);
+      }
+      /* Fall Through */
+    case PW_PLAINTEXT:
+      return PL_strdup(pwdata->data);
+    default:
+      break;
+  }
+
+  PR_fprintf(PR_STDERR, "Password check failed:  No password found.\n");
+  return NULL;
+}
diff --git a/modules/libmar/sign/nss_secutil.h b/modules/libmar/sign/nss_secutil.h
new file mode 100644
index 0000000000..c06d830a7d
--- /dev/null
+++ b/modules/libmar/sign/nss_secutil.h
@@ -0,0 +1,40 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* With the exception of GetPasswordString, this file was
+   copied from NSS's cmd/lib/secutil.h hg revision 8f011395145e */
+
+#ifndef NSS_SECUTIL_H_
+#define NSS_SECUTIL_H_
+
+#include "nss.h"
+#include "pk11pub.h"
+#include "cryptohi.h"
+#include "hasht.h"
+#include "cert.h"
+#include "keyhi.h"
+#include <stdint.h>
+
+typedef struct {
+  enum {
+    PW_NONE = 0,
+    PW_FROMFILE = 1,
+    PW_PLAINTEXT = 2,
+    PW_EXTERNAL = 3
+  } source;
+  char* data;
+} secuPWData;
+
+#if (defined(_WINDOWS) && !defined(_WIN32_WCE))
+#  include <conio.h>
+#  include <io.h>
+#  define QUIET_FGETS quiet_fgets
+char* quiet_fgets(char* buf, int length, FILE* input);
+#else
+#  define QUIET_FGETS fgets
+#endif
+
+char* SECU_GetModulePassword(PK11SlotInfo* slot, PRBool retry, void* arg);
+
+#endif
diff --git a/modules/libmar/src/mar.h b/modules/libmar/src/mar.h
new file mode 100644
index 0000000000..74ab7657f8
--- /dev/null
+++ b/modules/libmar/src/mar.h
@@ -0,0 +1,260 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MAR_H__
+#define MAR_H__
+
+#include <assert.h>  // for C11 static_assert
+#include <stdint.h>
+#include <stdio.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* We have a MAX_SIGNATURES limit so that an invalid MAR will never
+ * waste too much of either updater's or signmar's time.
+ * It is also used at various places internally and will affect memory usage.
+ * If you want to increase this value above 9 then you need to adjust parsing
+ * code in tool/mar.c.
+ */
+#define MAX_SIGNATURES 8
+static_assert(MAX_SIGNATURES <= 9, "too many signatures");
+
+struct ProductInformationBlock {
+  const char* MARChannelID;
+  const char* productVersion;
+};
+
+/**
+ * The MAR item data structure.
+ */
+typedef struct MarItem_ {
+  struct MarItem_* next; /* private field */
+  uint32_t offset;       /* offset into archive */
+  uint32_t length;       /* length of data in bytes */
+  uint32_t flags;        /* contains file mode bits */
+  char name[1];          /* file path */
+} MarItem;
+
+/**
+ * File offset and length for tracking access of byte indexes
+ */
+typedef struct SeenIndex_ {
+  struct SeenIndex_* next; /* private field */
+  uint32_t offset;         /* offset into archive */
+  uint32_t length;         /* length of the data in bytes */
+} SeenIndex;
+
+#define TABLESIZE 256
+
+/**
+ * Mozilla ARchive (MAR) file data structure
+ */
+struct MarFile_ {
+  unsigned char* buffer;          /* file buffer containing the entire MAR */
+  size_t data_len;                /* byte count of the data in the buffer */
+  MarItem* item_table[TABLESIZE]; /* hash table of files in the archive */
+  SeenIndex* index_list;          /* file indexes processed */
+  int item_table_is_valid;        /* header and index validation flag */
+};
+
+typedef struct MarFile_ MarFile;
+
+/**
+ * Signature of callback function passed to mar_enum_items.
+ * @param mar       The MAR file being visited.
+ * @param item      The MAR item being visited.
+ * @param data      The data parameter passed by the caller of mar_enum_items.
+ * @return          A non-zero value to stop enumerating.
+ */
+typedef int (*MarItemCallback)(MarFile* mar, const MarItem* item, void* data);
+
+enum MarReadResult_ {
+  MAR_READ_SUCCESS,
+  MAR_IO_ERROR,
+  MAR_MEM_ERROR,
+  MAR_FILE_TOO_BIG_ERROR,
+};
+
+typedef enum MarReadResult_ MarReadResult;
+
+/**
+ * Open a MAR file for reading.
+ * @param path      Specifies the path to the MAR file to open.  This path must
+ *                  be compatible with fopen.
+ * @param out_mar   Out-parameter through which the created MarFile structure is
+ *                  returned. Guaranteed to be a valid structure if
+ *                  MAR_READ_SUCCESS is returned. Otherwise NULL will be
+ *                  assigned.
+ * @return          NULL if an error occurs.
+ */
+MarReadResult mar_open(const char* path, MarFile** out_mar);
+
+#ifdef XP_WIN
+MarReadResult mar_wopen(const wchar_t* path, MarFile** out_mar);
+#endif
+
+/**
+ * Close a MAR file that was opened using mar_open.
+ * @param mar       The MarFile object to close.
+ */
+void mar_close(MarFile* mar);
+
+/**
+ * Reads the specified amount of data from the buffer in MarFile that contains
+ * the entirety of the MAR file data.
+ * @param mar       The MAR file to read from.
+ * @param dest      The buffer to read into.
+ * @param position  The byte index to start reading from the MAR at.
+ *                  On success, position will be incremented by size.
+ * @param size      The number of bytes to read.
+ * @return          0  If the specified amount of data was read.
+ *                  -1 If the buffer MAR is not large enough to read the
+ *                     specified amount of data at the specified position.
+ */
+int mar_read_buffer(MarFile* mar, void* dest, size_t* position, size_t size);
+
+/**
+ * Reads the specified amount of data from the buffer in MarFile that contains
+ * the entirety of the MAR file data. If there isn't that much data remaining,
+ * reads as much as possible.
+ * @param mar       The MAR file to read from.
+ * @param dest      The buffer to read into.
+ * @param position  The byte index to start reading from the MAR at.
+ *                  This function will increment position by the number of bytes
+ *                  copied.
+ * @param size      The maximum number of bytes to read.
+ * @return          The number of bytes copied into dest.
+ */
+int mar_read_buffer_max(MarFile* mar, void* dest, size_t* position,
+                        size_t size);
+
+/**
+ * Increments position by distance. Checks that the resulting position is still
+ * within the bounds of the buffer. Much like fseek, this will allow position to
+ * be successfully placed just after the end of the buffer.
+ * @param mar       The MAR file to read from.
+ * @param position  The byte index to start reading from the MAR at.
+ *                  On success, position will be incremented by size.
+ * @param distance  The number of bytes to move forward by.
+ * @return          0  If position was successfully moved.
+ *                  -1 If moving position by distance would move it outside the
+ *                     bounds of the buffer.
+ */
+int mar_buffer_seek(MarFile* mar, size_t* position, size_t distance);
+
+/**
+ * Find an item in the MAR file by name.
+ * @param mar       The MarFile object to query.
+ * @param item      The name of the item to query.
+ * @return          A const reference to a MAR item or NULL if not found.
+ */
+const MarItem* mar_find_item(MarFile* mar, const char* item);
+
+/**
+ * Enumerate all MAR items via callback function.
+ * @param mar       The MAR file to enumerate.
+ * @param callback  The function to call for each MAR item.
+ * @param data      A caller specified value that is passed along to the
+ *                  callback function.
+ * @return          0 if the enumeration ran to completion.  Otherwise, any
+ *                  non-zero return value from the callback is returned.
+ */
+int mar_enum_items(MarFile* mar, MarItemCallback callback, void* data);
+
+/**
+ * Read from MAR item at given offset up to bufsize bytes.
+ * @param mar       The MAR file to read.
+ * @param item      The MAR item to read.
+ * @param offset    The byte offset relative to the start of the item.
+ * @param buf       A pointer to a buffer to copy the data into.
+ * @param bufsize   The length of the buffer to copy the data into.
+ * @return          The number of bytes written or a negative value if an
+ *                  error occurs.
+ */
+int mar_read(MarFile* mar, const MarItem* item, int offset, uint8_t* buf,
+             int bufsize);
+
+/**
+ * Create a MAR file from a set of files.
+ * @param dest      The path to the file to create.  This path must be
+ *                  compatible with fopen.
+ * @param numfiles  The number of files to store in the archive.
+ * @param files     The list of null-terminated file paths.  Each file
+ *                  path must be compatible with fopen.
+ * @param infoBlock The information to store in the product information block.
+ * @return          A non-zero value if an error occurs.
+ */
+int mar_create(const char* dest, int numfiles, char** files,
+               struct ProductInformationBlock* infoBlock);
+
+/**
+ * Extract a MAR file to the current working directory.
+ * @param path      The path to the MAR file to extract.  This path must be
+ *                  compatible with fopen.
+ * @return          A non-zero value if an error occurs.
+ */
+int mar_extract(const char* path);
+
+#define MAR_MAX_CERT_SIZE (16 * 1024)  // Way larger than necessary
+
+/* Read the entire file (not a MAR file) into a newly-allocated buffer.
+ * This function does not write to stderr. Instead, the caller should
+ * write whatever error messages it sees fit. The caller must free the returned
+ * buffer using free().
+ *
+ * @param filePath The path to the file that should be read.
+ * @param maxSize  The maximum valid file size.
+ * @param data     On success, *data will point to a newly-allocated buffer
+ *                 with the file's contents in it.
+ * @param size     On success, *size will be the size of the created buffer.
+ *
+ * @return 0 on success, -1 on error
+ */
+int mar_read_entire_file(const char* filePath, uint32_t maxSize,
+                         /*out*/ const uint8_t** data,
+                         /*out*/ uint32_t* size);
+
+/**
+ * Verifies a MAR file by verifying each signature with the corresponding
+ * certificate. That is, the first signature will be verified using the first
+ * certificate given, the second signature will be verified using the second
+ * certificate given, etc. The signature count must exactly match the number of
+ * certificates given, and all signature verifications must succeed.
+ * We do not check that the certificate was issued by any trusted authority.
+ * We assume it to be self-signed.  We do not check whether the certificate
+ * is valid for this usage.
+ *
+ * @param mar            The already opened MAR file.
+ * @param certData       Pointer to the first element in an array of certificate
+ *                       file data.
+ * @param certDataSizes  Pointer to the first element in an array for size of
+ *                       the cert data.
+ * @param certCount      The number of elements in certData and certDataSizes
+ * @return 0 on success
+ *         a negative number if there was an error
+ *         a positive number if the signature does not verify
+ */
+int mar_verify_signatures(MarFile* mar, const uint8_t* const* certData,
+                          const uint32_t* certDataSizes, uint32_t certCount);
+
+/**
+ * Reads the product info block from the MAR file's additional block section.
+ * The caller is responsible for freeing the fields in infoBlock
+ * if the return is successful.
+ *
+ * @param infoBlock Out parameter for where to store the result to
+ * @return 0 on success, -1 on failure
+ */
+int mar_read_product_info_block(MarFile* mar,
+                                struct ProductInformationBlock* infoBlock);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* MAR_H__ */
diff --git a/modules/libmar/src/mar_cmdline.h b/modules/libmar/src/mar_cmdline.h
new file mode 100644
index 0000000000..4b9302f0b1
--- /dev/null
+++ b/modules/libmar/src/mar_cmdline.h
@@ -0,0 +1,102 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MAR_CMDLINE_H__
+#define MAR_CMDLINE_H__
+
+/* We use NSPR here just to import the definition of uint32_t */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct ProductInformationBlock;
+
+/**
+ * Determines MAR file information.
+ *
+ * @param path                   The path of the MAR file to check.
+ * @param hasSignatureBlock      Optional out parameter specifying if the MAR
+ *                               file has a signature block or not.
+ * @param numSignatures          Optional out parameter for storing the number
+ *                               of signatures in the MAR file.
+ * @param hasAdditionalBlocks    Optional out parameter specifying if the MAR
+ *                               file has additional blocks or not.
+ * @param offsetAdditionalBlocks Optional out parameter for the offset to the
+ *                               first additional block. Value is only valid if
+ *                               hasAdditionalBlocks is not equal to 0.
+ * @param numAdditionalBlocks    Optional out parameter for the number of
+ *                               additional blocks.  Value is only valid if
+ *                               has_additional_blocks is not equal to 0.
+ * @return 0 on success and non-zero on failure.
+ */
+int get_mar_file_info(const char* path, int* hasSignatureBlock,
+                      uint32_t* numSignatures, int* hasAdditionalBlocks,
+                      uint32_t* offsetAdditionalBlocks,
+                      uint32_t* numAdditionalBlocks);
+
+/**
+ * Reads the product info block from the MAR file's additional block section.
+ * The caller is responsible for freeing the fields in infoBlock
+ * if the return is successful.
+ *
+ * @param infoBlock Out parameter for where to store the result to
+ * @return 0 on success, -1 on failure
+ */
+int read_product_info_block(char* path,
+                            struct ProductInformationBlock* infoBlock);
+
+/**
+ * Refreshes the product information block with the new information.
+ * The input MAR must not be signed or the function call will fail.
+ *
+ * @param path             The path to the MAR file whose product info block
+ *                         should be refreshed.
+ * @param infoBlock        Out parameter for where to store the result to
+ * @return 0 on success, -1 on failure
+ */
+int refresh_product_info_block(const char* path,
+                               struct ProductInformationBlock* infoBlock);
+
+/**
+ * Writes out a copy of the MAR at src but with the signature block stripped.
+ *
+ * @param  src  The path of the source MAR file
+ * @param  dest The path of the MAR file to write out that
+                has no signature block
+ * @return 0 on success
+ *         -1 on error
+*/
+int strip_signature_block(const char* src, const char* dest);
+
+/**
+ * Extracts a signature from a MAR file, base64 encodes it, and writes it out
+ *
+ * @param  src       The path of the source MAR file
+ * @param  sigIndex  The index of the signature to extract
+ * @param  dest      The path of file to write the signature to
+ * @return 0 on success
+ *         -1 on error
+ */
+int extract_signature(const char* src, uint32_t sigIndex, const char* dest);
+
+/**
+ * Imports a base64 encoded signature into a MAR file
+ *
+ * @param  src           The path of the source MAR file
+ * @param  sigIndex      The index of the signature to import
+ * @param  base64SigFile A file which contains the signature to import
+ * @param  dest          The path of the destination MAR file with replaced
+ *                       signature
+ * @return 0 on success
+ *         -1 on error
+ */
+int import_signature(const char* src, uint32_t sigIndex,
+                     const char* base64SigFile, const char* dest);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* MAR_CMDLINE_H__ */
diff --git a/modules/libmar/src/mar_create.c b/modules/libmar/src/mar_create.c
new file mode 100644
index 0000000000..0ac2bf7b2c
--- /dev/null
+++ b/modules/libmar/src/mar_create.c
@@ -0,0 +1,391 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include "mar_private.h"
+#include "mar_cmdline.h"
+#include "mar.h"
+
+#ifdef XP_WIN
+#  include <winsock2.h>
+#else
+#  include <netinet/in.h>
+#  include <unistd.h>
+#endif
+
+struct MarItemStack {
+  void* head;
+  uint32_t size_used;
+  uint32_t size_allocated;
+  uint32_t last_offset;
+};
+
+/**
+ * Push a new item onto the stack of items.  The stack is a single block
+ * of memory.
+ */
+static int mar_push(struct MarItemStack* stack, uint32_t length, uint32_t flags,
+                    const char* name) {
+  int namelen;
+  uint32_t n_offset, n_length, n_flags;
+  uint32_t size;
+  char* data;
+
+  namelen = strlen(name);
+  size = MAR_ITEM_SIZE(namelen);
+
+  if (stack->size_allocated - stack->size_used < size) {
+    /* increase size of stack */
+    size_t size_needed = ROUND_UP(stack->size_used + size, BLOCKSIZE);
+    stack->head = realloc(stack->head, size_needed);
+    if (!stack->head) {
+      return -1;
+    }
+    stack->size_allocated = size_needed;
+  }
+
+  data = (((char*)stack->head) + stack->size_used);
+
+  n_offset = htonl(stack->last_offset);
+  n_length = htonl(length);
+  n_flags = htonl(flags);
+
+  memcpy(data, &n_offset, sizeof(n_offset));
+  data += sizeof(n_offset);
+
+  memcpy(data, &n_length, sizeof(n_length));
+  data += sizeof(n_length);
+
+  memcpy(data, &n_flags, sizeof(n_flags));
+  data += sizeof(n_flags);
+
+  memcpy(data, name, namelen + 1);
+
+  stack->size_used += size;
+  stack->last_offset += length;
+  return 0;
+}
+
+static int mar_concat_file(FILE* fp, const char* path) {
+  FILE* in;
+  char buf[BLOCKSIZE];
+  size_t len;
+  int rv = 0;
+
+  in = fopen(path, "rb");
+  if (!in) {
+    fprintf(stderr, "ERROR: could not open file in mar_concat_file()\n");
+    perror(path);
+    return -1;
+  }
+
+  while ((len = fread(buf, 1, BLOCKSIZE, in)) > 0) {
+    if (fwrite(buf, len, 1, fp) != 1) {
+      rv = -1;
+      break;
+    }
+  }
+
+  fclose(in);
+  return rv;
+}
+
+/**
+ * Writes out the product information block to the specified file.
+ *
+ * @param fp           The opened MAR file being created.
+ * @param stack        A pointer to the MAR item stack being used to create
+ *                     the MAR
+ * @param infoBlock    The product info block to store in the file.
+ * @return 0 on success.
+ */
+static int mar_concat_product_info_block(
+    FILE* fp, struct MarItemStack* stack,
+    struct ProductInformationBlock* infoBlock) {
+  char buf[PIB_MAX_MAR_CHANNEL_ID_SIZE + PIB_MAX_PRODUCT_VERSION_SIZE];
+  uint32_t additionalBlockID = 1, infoBlockSize, unused;
+  if (!fp || !infoBlock || !infoBlock->MARChannelID ||
+      !infoBlock->productVersion) {
+    return -1;
+  }
+
+  /* The MAR channel name must be < 64 bytes per the spec */
+  if (strlen(infoBlock->MARChannelID) > PIB_MAX_MAR_CHANNEL_ID_SIZE) {
+    return -1;
+  }
+
+  /* The product version must be < 32 bytes per the spec */
+  if (strlen(infoBlock->productVersion) > PIB_MAX_PRODUCT_VERSION_SIZE) {
+    return -1;
+  }
+
+  /* Although we don't need the product information block size to include the
+     maximum MAR channel name and product version, we allocate the maximum
+     amount to make it easier to modify the MAR file for repurposing MAR files
+     to different MAR channels. + 2 is for the NULL terminators. */
+  infoBlockSize = sizeof(infoBlockSize) + sizeof(additionalBlockID) +
+                  PIB_MAX_MAR_CHANNEL_ID_SIZE + PIB_MAX_PRODUCT_VERSION_SIZE +
+                  2;
+  if (stack) {
+    stack->last_offset += infoBlockSize;
+  }
+
+  /* Write out the product info block size */
+  infoBlockSize = htonl(infoBlockSize);
+  if (fwrite(&infoBlockSize, sizeof(infoBlockSize), 1, fp) != 1) {
+    return -1;
+  }
+  infoBlockSize = ntohl(infoBlockSize);
+
+  /* Write out the product info block ID */
+  additionalBlockID = htonl(additionalBlockID);
+  if (fwrite(&additionalBlockID, sizeof(additionalBlockID), 1, fp) != 1) {
+    return -1;
+  }
+  additionalBlockID = ntohl(additionalBlockID);
+
+  /* Write out the channel name and NULL terminator */
+  if (fwrite(infoBlock->MARChannelID, strlen(infoBlock->MARChannelID) + 1, 1,
+             fp) != 1) {
+    return -1;
+  }
+
+  /* Write out the product version string and NULL terminator */
+  if (fwrite(infoBlock->productVersion, strlen(infoBlock->productVersion) + 1,
+             1, fp) != 1) {
+    return -1;
+  }
+
+  /* Write out the rest of the block that is unused */
+  unused = infoBlockSize - (sizeof(infoBlockSize) + sizeof(additionalBlockID) +
+                            strlen(infoBlock->MARChannelID) +
+                            strlen(infoBlock->productVersion) + 2);
+  memset(buf, 0, sizeof(buf));
+  if (fwrite(buf, unused, 1, fp) != 1) {
+    return -1;
+  }
+  return 0;
+}
+
+/**
+ * Refreshes the product information block with the new information.
+ * The input MAR must not be signed or the function call will fail.
+ *
+ * @param path             The path to the MAR file whose product info block
+ *                         should be refreshed.
+ * @param infoBlock        Out parameter for where to store the result to
+ * @return 0 on success, -1 on failure
+ */
+int refresh_product_info_block(const char* path,
+                               struct ProductInformationBlock* infoBlock) {
+  FILE* fp;
+  int rv;
+  uint32_t numSignatures, additionalBlockSize, additionalBlockID,
+      offsetAdditionalBlocks, numAdditionalBlocks, i;
+  int additionalBlocks, hasSignatureBlock;
+  int64_t oldPos;
+
+  rv = get_mar_file_info(path, &hasSignatureBlock, &numSignatures,
+                         &additionalBlocks, &offsetAdditionalBlocks,
+                         &numAdditionalBlocks);
+  if (rv) {
+    fprintf(stderr, "ERROR: Could not obtain MAR information.\n");
+    return -1;
+  }
+
+  if (hasSignatureBlock && numSignatures) {
+    fprintf(stderr, "ERROR: Cannot refresh a signed MAR\n");
+    return -1;
+  }
+
+  fp = fopen(path, "r+b");
+  if (!fp) {
+    fprintf(stderr, "ERROR: could not open target file: %s\n", path);
+    return -1;
+  }
+
+  if (fseeko(fp, offsetAdditionalBlocks, SEEK_SET)) {
+    fprintf(stderr, "ERROR: could not seek to additional blocks\n");
+    fclose(fp);
+    return -1;
+  }
+
+  for (i = 0; i < numAdditionalBlocks; ++i) {
+    /* Get the position of the start of this block */
+    oldPos = ftello(fp);
+
+    /* Read the additional block size */
+    if (fread(&additionalBlockSize, sizeof(additionalBlockSize), 1, fp) != 1) {
+      fclose(fp);
+      return -1;
+    }
+    additionalBlockSize = ntohl(additionalBlockSize);
+
+    /* Read the additional block ID */
+    if (fread(&additionalBlockID, sizeof(additionalBlockID), 1, fp) != 1) {
+      fclose(fp);
+      return -1;
+    }
+    additionalBlockID = ntohl(additionalBlockID);
+
+    if (PRODUCT_INFO_BLOCK_ID == additionalBlockID) {
+      if (fseeko(fp, oldPos, SEEK_SET)) {
+        fprintf(stderr, "Could not seek back to Product Information Block\n");
+        fclose(fp);
+        return -1;
+      }
+
+      if (mar_concat_product_info_block(fp, NULL, infoBlock)) {
+        fprintf(stderr, "Could not concat Product Information Block\n");
+        fclose(fp);
+        return -1;
+      }
+
+      fclose(fp);
+      return 0;
+    } else {
+      /* This is not the additional block you're looking for. Move along. */
+      if (fseek(fp, additionalBlockSize, SEEK_CUR)) {
+        fprintf(stderr, "ERROR: Could not seek past current block.\n");
+        fclose(fp);
+        return -1;
+      }
+    }
+  }
+
+  /* If we had a product info block we would have already returned */
+  fclose(fp);
+  fprintf(stderr, "ERROR: Could not refresh because block does not exist\n");
+  return -1;
+}
+
+/**
+ * Create a MAR file from a set of files.
+ * @param dest      The path to the file to create.  This path must be
+ *                  compatible with fopen.
+ * @param numfiles  The number of files to store in the archive.
+ * @param files     The list of null-terminated file paths.  Each file
+ *                  path must be compatible with fopen.
+ * @param infoBlock The information to store in the product information block.
+ * @return A non-zero value if an error occurs.
+ */
+int mar_create(const char* dest, int num_files, char** files,
+               struct ProductInformationBlock* infoBlock) {
+  struct MarItemStack stack;
+  uint32_t offset_to_index = 0, size_of_index, numSignatures,
+           numAdditionalSections;
+  uint64_t sizeOfEntireMAR = 0;
+  struct stat st;
+  FILE* fp;
+  int i, rv = -1;
+
+  memset(&stack, 0, sizeof(stack));
+
+  fp = fopen(dest, "wb");
+  if (!fp) {
+    fprintf(stderr, "ERROR: could not create target file: %s\n", dest);
+    return -1;
+  }
+
+  if (fwrite(MAR_ID, MAR_ID_SIZE, 1, fp) != 1) {
+    goto failure;
+  }
+  if (fwrite(&offset_to_index, sizeof(uint32_t), 1, fp) != 1) {
+    goto failure;
+  }
+
+  stack.last_offset = MAR_ID_SIZE + sizeof(offset_to_index) +
+                      sizeof(numSignatures) + sizeof(numAdditionalSections) +
+                      sizeof(sizeOfEntireMAR);
+
+  /* We will circle back on this at the end of the MAR creation to fill it */
+  if (fwrite(&sizeOfEntireMAR, sizeof(sizeOfEntireMAR), 1, fp) != 1) {
+    goto failure;
+  }
+
+  /* Write out the number of signatures, for now only at most 1 is supported */
+  numSignatures = 0;
+  if (fwrite(&numSignatures, sizeof(numSignatures), 1, fp) != 1) {
+    goto failure;
+  }
+
+  /* Write out the number of additional sections, for now just 1
+     for the product info block */
+  numAdditionalSections = htonl(1);
+  if (fwrite(&numAdditionalSections, sizeof(numAdditionalSections), 1, fp) !=
+      1) {
+    goto failure;
+  }
+  numAdditionalSections = ntohl(numAdditionalSections);
+
+  if (mar_concat_product_info_block(fp, &stack, infoBlock)) {
+    goto failure;
+  }
+
+  for (i = 0; i < num_files; ++i) {
+    if (stat(files[i], &st)) {
+      fprintf(stderr, "ERROR: file not found: %s\n", files[i]);
+      goto failure;
+    }
+
+    if (mar_push(&stack, st.st_size, st.st_mode & 0777, files[i])) {
+      goto failure;
+    }
+
+    /* concatenate input file to archive */
+    if (mar_concat_file(fp, files[i])) {
+      goto failure;
+    }
+  }
+
+  /* write out the index (prefixed with length of index) */
+  size_of_index = htonl(stack.size_used);
+  if (fwrite(&size_of_index, sizeof(size_of_index), 1, fp) != 1) {
+    goto failure;
+  }
+  if (fwrite(stack.head, stack.size_used, 1, fp) != 1) {
+    goto failure;
+  }
+
+  /* To protect against invalid MAR files, we assumes that the MAR file
+     size is less than or equal to MAX_SIZE_OF_MAR_FILE. */
+  if (ftell(fp) > MAX_SIZE_OF_MAR_FILE) {
+    goto failure;
+  }
+
+  /* write out offset to index file in network byte order */
+  offset_to_index = htonl(stack.last_offset);
+  if (fseek(fp, MAR_ID_SIZE, SEEK_SET)) {
+    goto failure;
+  }
+  if (fwrite(&offset_to_index, sizeof(offset_to_index), 1, fp) != 1) {
+    goto failure;
+  }
+  offset_to_index = ntohl(stack.last_offset);
+
+  sizeOfEntireMAR =
+      ((uint64_t)stack.last_offset) + stack.size_used + sizeof(size_of_index);
+  sizeOfEntireMAR = HOST_TO_NETWORK64(sizeOfEntireMAR);
+  if (fwrite(&sizeOfEntireMAR, sizeof(sizeOfEntireMAR), 1, fp) != 1) {
+    goto failure;
+  }
+  sizeOfEntireMAR = NETWORK_TO_HOST64(sizeOfEntireMAR);
+
+  rv = 0;
+failure:
+  if (stack.head) {
+    free(stack.head);
+  }
+  fclose(fp);
+  if (rv) {
+    remove(dest);
+  }
+  return rv;
+}
diff --git a/modules/libmar/src/mar_extract.c b/modules/libmar/src/mar_extract.c
new file mode 100644
index 0000000000..9b4a3fa26d
--- /dev/null
+++ b/modules/libmar/src/mar_extract.c
@@ -0,0 +1,87 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+#include <stdlib.h>
+#include "mar_private.h"
+#include "mar.h"
+
+#ifdef XP_WIN
+#  include <io.h>
+#  include <direct.h>
+#  define fdopen _fdopen
+#endif
+
+/* Ensure that the directory containing this file exists */
+static int mar_ensure_parent_dir(const char* path) {
+  char* slash = strrchr(path, '/');
+  if (slash) {
+    *slash = '\0';
+    mar_ensure_parent_dir(path);
+#ifdef XP_WIN
+    _mkdir(path);
+#else
+    mkdir(path, 0755);
+#endif
+    *slash = '/';
+  }
+  return 0;
+}
+
+static int mar_test_callback(MarFile* mar, const MarItem* item, void* unused) {
+  FILE* fp;
+  uint8_t buf[BLOCKSIZE];
+  int fd, len, offset = 0;
+
+  if (mar_ensure_parent_dir(item->name)) {
+    return -1;
+  }
+
+#ifdef XP_WIN
+  fd = _open(item->name, _O_BINARY | _O_CREAT | _O_TRUNC | _O_WRONLY,
+             item->flags);
+#else
+  fd = creat(item->name, item->flags);
+#endif
+  if (fd == -1) {
+    fprintf(stderr, "ERROR: could not create file in mar_test_callback()\n");
+    perror(item->name);
+    return -1;
+  }
+
+  fp = fdopen(fd, "wb");
+  if (!fp) {
+    return -1;
+  }
+
+  while ((len = mar_read(mar, item, offset, buf, sizeof(buf))) > 0) {
+    if (fwrite(buf, len, 1, fp) != 1) {
+      break;
+    }
+    offset += len;
+  }
+
+  fclose(fp);
+  return len == 0 ? 0 : -1;
+}
+
+int mar_extract(const char* path) {
+  MarFile* mar;
+  int rv;
+
+  MarReadResult result = mar_open(path, &mar);
+  if (result != MAR_READ_SUCCESS) {
+    return -1;
+  }
+
+  rv = mar_enum_items(mar, mar_test_callback, NULL);
+
+  mar_close(mar);
+  return rv;
+}
diff --git a/modules/libmar/src/mar_private.h b/modules/libmar/src/mar_private.h
new file mode 100644
index 0000000000..bd9d4386fe
--- /dev/null
+++ b/modules/libmar/src/mar_private.h
@@ -0,0 +1,78 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef MAR_PRIVATE_H__
+#define MAR_PRIVATE_H__
+
+#include <assert.h>  // for C11 static_assert
+#include "limits.h"
+#include <stdint.h>
+
+#define BLOCKSIZE 4096
+#define ROUND_UP(n, incr) (((n) / (incr) + 1) * (incr))
+
+#define MAR_ID "MAR1"
+#define MAR_ID_SIZE 4
+
+/* The signature block comes directly after the header block
+   which is 16 bytes */
+#define SIGNATURE_BLOCK_OFFSET 16
+
+/* Make sure the file is less than 500MB.  We do this to protect against
+   invalid MAR files. */
+#define MAX_SIZE_OF_MAR_FILE ((int64_t)524288000)
+
+/* Existing code makes assumptions that the file size is
+   smaller than LONG_MAX. */
+static_assert(MAX_SIZE_OF_MAR_FILE < ((int64_t)LONG_MAX),
+              "max mar file size is too big");
+
+/* We store at most the size up to the signature block + 4
+   bytes per BLOCKSIZE bytes */
+static_assert(sizeof(BLOCKSIZE) < (SIGNATURE_BLOCK_OFFSET + sizeof(uint32_t)),
+              "BLOCKSIZE is too big");
+
+/* The maximum size of any signature supported by current and future
+   implementations of the signmar program. */
+#define MAX_SIGNATURE_LENGTH 2048
+
+/* Each additional block has a unique ID.
+   The product information block has an ID of 1. */
+#define PRODUCT_INFO_BLOCK_ID 1
+
+#define MAR_ITEM_SIZE(namelen) (3 * sizeof(uint32_t) + (namelen) + 1)
+
+/* Product Information Block (PIB) constants */
+#define PIB_MAX_MAR_CHANNEL_ID_SIZE 63
+#define PIB_MAX_PRODUCT_VERSION_SIZE 31
+
+/* The mar program is compiled as a host bin so we don't have access to NSPR at
+   runtime.  For that reason we use ntohl, htonl, and define HOST_TO_NETWORK64
+   instead of the NSPR equivalents. */
+#ifdef XP_WIN
+#  include <winsock2.h>
+/* Include stdio.h before redefining ftello and fseeko to avoid clobbering
+ * the ftello() and fseeko() function declarations in MinGW's stdio.h. */
+#  include <stdio.h>
+#  define ftello _ftelli64
+#  define fseeko _fseeki64
+#else
+#  define _FILE_OFFSET_BITS 64
+#  include <netinet/in.h>
+#  include <unistd.h>
+#  include <stdio.h>
+#endif
+
+#define HOST_TO_NETWORK64(x)                                               \
+  (((((uint64_t)x) & 0xFF) << 56) | ((((uint64_t)x) >> 8) & 0xFF) << 48) | \
+      (((((uint64_t)x) >> 16) & 0xFF) << 40) |                             \
+      (((((uint64_t)x) >> 24) & 0xFF) << 32) |                             \
+      (((((uint64_t)x) >> 32) & 0xFF) << 24) |                             \
+      (((((uint64_t)x) >> 40) & 0xFF) << 16) |                             \
+      (((((uint64_t)x) >> 48) & 0xFF) << 8) | (((uint64_t)x) >> 56)
+#define NETWORK_TO_HOST64 HOST_TO_NETWORK64
+
+#endif /* MAR_PRIVATE_H__ */
diff --git a/modules/libmar/src/mar_read.c b/modules/libmar/src/mar_read.c
new file mode 100644
index 0000000000..679dc258d6
--- /dev/null
+++ b/modules/libmar/src/mar_read.c
@@ -0,0 +1,787 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <sys/types.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include "city.h"
+#include "mar_private.h"
+#include "mar.h"
+#ifdef XP_WIN
+#  define strdup _strdup
+#endif
+
+/* This block must be at most 104 bytes.
+   MAR channel name < 64 bytes, and product version < 32 bytes + 3 NULL
+   terminator bytes. We only check for 96 though because we remove 8
+   bytes above from the additionalBlockSize: We subtract
+   sizeof(additionalBlockSize) and sizeof(additionalBlockID) */
+#define MAXADDITIONALBLOCKSIZE 96
+
+static uint32_t mar_hash_name(const char* name) {
+  return CityHash64(name, strlen(name)) % TABLESIZE;
+}
+
+static int mar_insert_item(MarFile* mar, const char* name, uint32_t namelen,
+                           uint32_t offset, uint32_t length, uint32_t flags) {
+  MarItem *item, *root;
+  uint32_t hash;
+
+  item = (MarItem*)malloc(sizeof(MarItem) + namelen);
+  if (!item) {
+    return -1;
+  }
+  item->next = NULL;
+  item->offset = offset;
+  item->length = length;
+  item->flags = flags;
+  memcpy(item->name, name, namelen + 1);
+
+  hash = mar_hash_name(name);
+
+  root = mar->item_table[hash];
+  if (!root) {
+    mar->item_table[hash] = item;
+  } else {
+    /* append item */
+    while (root->next) root = root->next;
+    root->next = item;
+  }
+  return 0;
+}
+
+static int mar_consume_index(MarFile* mar, char** buf, const char* buf_end) {
+  /*
+   * Each item has the following structure:
+   *   uint32_t offset      (network byte order)
+   *   uint32_t length      (network byte order)
+   *   uint32_t flags       (network byte order)
+   *   char     name[N]     (where N >= 1)
+   *   char     null_byte;
+   */
+  uint32_t offset;
+  uint32_t length;
+  uint32_t flags;
+  const char* name;
+  int namelen;
+
+  if ((buf_end - *buf) < (int)(3 * sizeof(uint32_t) + 2)) {
+    return -1;
+  }
+
+  memcpy(&offset, *buf, sizeof(offset));
+  *buf += sizeof(offset);
+
+  memcpy(&length, *buf, sizeof(length));
+  *buf += sizeof(length);
+
+  memcpy(&flags, *buf, sizeof(flags));
+  *buf += sizeof(flags);
+
+  offset = ntohl(offset);
+  length = ntohl(length);
+  flags = ntohl(flags);
+
+  name = *buf;
+  /* find namelen; must take care not to read beyond buf_end */
+  while (**buf) {
+    /* buf_end points one byte past the end of buf's allocation */
+    if (*buf == (buf_end - 1)) {
+      return -1;
+    }
+    ++(*buf);
+  }
+  namelen = (*buf - name);
+  /* must ensure that namelen is valid */
+  if (namelen < 0) {
+    return -1;
+  }
+  /* consume null byte */
+  if (*buf == buf_end) {
+    return -1;
+  }
+  ++(*buf);
+
+  return mar_insert_item(mar, name, namelen, offset, length, flags);
+}
+
+static int mar_read_index(MarFile* mar) {
+  char id[MAR_ID_SIZE], *buf, *bufptr, *bufend;
+  uint32_t offset_to_index, size_of_index;
+  size_t mar_position = 0;
+
+  /* verify MAR ID */
+  if (mar_read_buffer(mar, id, &mar_position, MAR_ID_SIZE) != 0) {
+    return -1;
+  }
+  if (memcmp(id, MAR_ID, MAR_ID_SIZE) != 0) {
+    return -1;
+  }
+
+  if (mar_read_buffer(mar, &offset_to_index, &mar_position, sizeof(uint32_t)) !=
+      0) {
+    return -1;
+  }
+  offset_to_index = ntohl(offset_to_index);
+
+  mar_position = 0;
+  if (mar_buffer_seek(mar, &mar_position, offset_to_index) != 0) {
+    return -1;
+  }
+  if (mar_read_buffer(mar, &size_of_index, &mar_position, sizeof(uint32_t)) !=
+      0) {
+    return -1;
+  }
+  size_of_index = ntohl(size_of_index);
+
+  buf = (char*)malloc(size_of_index);
+  if (!buf) {
+    return -1;
+  }
+  if (mar_read_buffer(mar, buf, &mar_position, size_of_index) != 0) {
+    free(buf);
+    return -1;
+  }
+
+  bufptr = buf;
+  bufend = buf + size_of_index;
+  while (bufptr < bufend && mar_consume_index(mar, &bufptr, bufend) == 0)
+    ;
+
+  free(buf);
+  return (bufptr == bufend) ? 0 : -1;
+}
+
+/**
+ * Adds an offset and length to the MarFile's index_list
+ * @param mar     The MarFile that owns this offset length pair
+ * @param offset  The byte offset in the archive to be marked as processed
+ * @param length  The length corresponding to this byte offset
+ * @return int    1 on success, 0 if offset has been previously processed
+ *                -1 if unable to allocate space for the SeenIndexes
+ */
+static int mar_insert_offset(MarFile* mar, uint32_t offset, uint32_t length) {
+  /* Ignore files with no length */
+  if (length == 0) {
+    return 1;
+  }
+
+  SeenIndex* index = (SeenIndex*)malloc(sizeof(SeenIndex));
+  if (!index) {
+    return -1;
+  }
+  index->next = NULL;
+  index->offset = offset;
+  index->length = length;
+  uint32_t index_end = index->offset + index->length - 1;
+
+  /* If this is our first index store it at the front */
+  if (mar->index_list == NULL) {
+    mar->index_list = index;
+    return 1;
+  }
+
+  /* Search for matching indexes in the list of those previously visited */
+  SeenIndex* previous;
+  SeenIndex* current = mar->index_list;
+  while (current != NULL) {
+    uint32_t current_end = current->offset + current->length - 1;
+
+    /* If index has collided with the front or end of current or if current has
+       collided with the front or end of index return false */
+    if ((index->offset >= current->offset && index->offset <= current_end) ||
+        (index_end >= current->offset && index_end <= current_end) ||
+        (current->offset >= index->offset && current->offset <= index_end) ||
+        (current_end >= index->offset && current_end <= index_end)) {
+      free(index);
+      return 0;
+    }
+
+    /* else move to the next in the list */
+    previous = current;
+    current = current->next;
+  }
+
+  /* These indexes are valid, track them */
+  previous->next = index;
+  return 1;
+}
+
+/**
+ * Internal shared code for mar_open and mar_wopen.
+ * Reads the entire MAR into memory. Fails if it is bigger than
+ * MAX_SIZE_OF_MAR_FILE bytes.
+ */
+static MarReadResult mar_fpopen(FILE* fp, MarFile** out_mar) {
+  *out_mar = NULL;
+  MarFile* mar;
+
+  mar = (MarFile*)malloc(sizeof(*mar));
+  if (!mar) {
+    return MAR_MEM_ERROR;
+  }
+
+  off_t buffer_size = -1;
+  if (fseeko(fp, 0, SEEK_END) == 0) {
+    buffer_size = ftello(fp);
+  }
+  rewind(fp);
+  if (buffer_size < 0) {
+    fprintf(stderr, "Warning: MAR size could not be determined\n");
+    buffer_size = MAX_SIZE_OF_MAR_FILE;
+  }
+  if (buffer_size > MAX_SIZE_OF_MAR_FILE) {
+    fprintf(stderr, "ERROR: MAR exceeds maximum size (%lli)\n",
+            (long long int)buffer_size);
+    free(mar);
+    return MAR_FILE_TOO_BIG_ERROR;
+  }
+
+  mar->buffer = malloc(buffer_size);
+  if (!mar->buffer) {
+    fprintf(stderr, "ERROR: MAR buffer could not be allocated\n");
+    free(mar);
+    return MAR_MEM_ERROR;
+  }
+  mar->data_len = fread(mar->buffer, 1, buffer_size, fp);
+  if (fgetc(fp) != EOF) {
+    fprintf(stderr, "ERROR: File is larger than buffer (%lli)\n",
+            (long long int)buffer_size);
+    free(mar->buffer);
+    free(mar);
+    return MAR_IO_ERROR;
+  }
+  if (ferror(fp)) {
+    fprintf(stderr, "ERROR: Failed to read MAR\n");
+    free(mar->buffer);
+    free(mar);
+    return MAR_IO_ERROR;
+  }
+
+  mar->item_table_is_valid = 0;
+  memset(mar->item_table, 0, sizeof(mar->item_table));
+  mar->index_list = NULL;
+
+  *out_mar = mar;
+  return MAR_READ_SUCCESS;
+}
+
+MarReadResult mar_open(const char* path, MarFile** out_mar) {
+  *out_mar = NULL;
+
+  FILE* fp;
+
+  fp = fopen(path, "rb");
+  if (!fp) {
+    fprintf(stderr, "ERROR: could not open file in mar_open()\n");
+    perror(path);
+    return MAR_IO_ERROR;
+  }
+
+  MarReadResult result = mar_fpopen(fp, out_mar);
+  fclose(fp);
+  return result;
+}
+
+#ifdef XP_WIN
+MarReadResult mar_wopen(const wchar_t* path, MarFile** out_mar) {
+  *out_mar = NULL;
+
+  FILE* fp;
+
+  _wfopen_s(&fp, path, L"rb");
+  if (!fp) {
+    fprintf(stderr, "ERROR: could not open file in mar_wopen()\n");
+    _wperror(path);
+    return MAR_IO_ERROR;
+  }
+
+  MarReadResult result = mar_fpopen(fp, out_mar);
+  fclose(fp);
+  return result;
+}
+#endif
+
+void mar_close(MarFile* mar) {
+  MarItem* item;
+  SeenIndex* index;
+  int i;
+
+  free(mar->buffer);
+
+  for (i = 0; i < TABLESIZE; ++i) {
+    item = mar->item_table[i];
+    while (item) {
+      MarItem* temp = item;
+      item = item->next;
+      free(temp);
+    }
+  }
+
+  while (mar->index_list != NULL) {
+    index = mar->index_list;
+    mar->index_list = index->next;
+    free(index);
+  }
+
+  free(mar);
+}
+
+int mar_read_buffer(MarFile* mar, void* dest, size_t* position, size_t size) {
+  // size may be provided by the MAR, which we may not have finished validating
+  // the signature on yet. Make sure not to trust it in a way that could
+  // cause an overflow.
+  if (size > mar->data_len) {
+    return -1;
+  }
+  if (*position > mar->data_len - size) {
+    return -1;
+  }
+  memcpy(dest, mar->buffer + *position, size);
+  *position += size;
+  return 0;
+}
+
+int mar_read_buffer_max(MarFile* mar, void* dest, size_t* position,
+                        size_t size) {
+  // size may be provided by the MAR, which we may not have finished validating
+  // the signature on yet. Make sure not to trust it in a way that could
+  // cause an overflow.
+  if (mar->data_len <= *position) {
+    return 0;
+  }
+  size_t read_count = mar->data_len - *position;
+  if (read_count > size) {
+    read_count = size;
+  }
+  memcpy(dest, mar->buffer + *position, read_count);
+  *position += read_count;
+  return read_count;
+}
+
+int mar_buffer_seek(MarFile* mar, size_t* position, size_t distance) {
+  // distance may be provided by the MAR, which we may not have finished
+  // validating the signature on yet. Make sure not to trust it in a way that
+  // could cause an overflow.
+  if (distance > mar->data_len) {
+    return -1;
+  }
+  if (*position > mar->data_len - distance) {
+    return -1;
+  }
+  *position += distance;
+  return 0;
+}
+
+/**
+ * Determines the MAR file information.
+ *
+ * @param mar                    An open MAR file.
+ * @param mar_position           The current position in the MAR.
+ *                               Its value will be updated to the current
+ *                               position in the MAR after the function exits.
+ *                               Since its initial value will never actually be
+ *                               used, this is effectively an outparam.
+ * @param hasSignatureBlock      Optional out parameter specifying if the MAR
+ *                               file has a signature block or not.
+ * @param numSignatures          Optional out parameter for storing the number
+ *                               of signatures in the MAR file.
+ * @param hasAdditionalBlocks    Optional out parameter specifying if the MAR
+ *                               file has additional blocks or not.
+ * @param offsetAdditionalBlocks Optional out parameter for the offset to the
+ *                               first additional block. Value is only valid if
+ *                               hasAdditionalBlocks is not equal to 0.
+ * @param numAdditionalBlocks    Optional out parameter for the number of
+ *                               additional blocks.  Value is only valid if
+ *                               hasAdditionalBlocks is not equal to 0.
+ * @return 0 on success and non-zero on failure.
+ */
+int get_open_mar_file_info(MarFile* mar, size_t* mar_position,
+                           int* hasSignatureBlock, uint32_t* numSignatures,
+                           int* hasAdditionalBlocks,
+                           uint32_t* offsetAdditionalBlocks,
+                           uint32_t* numAdditionalBlocks) {
+  uint32_t offsetToIndex, offsetToContent, signatureCount, signatureLen, i;
+
+  /* One of hasSignatureBlock or hasAdditionalBlocks must be non NULL */
+  if (!hasSignatureBlock && !hasAdditionalBlocks) {
+    return -1;
+  }
+
+  /* Skip to the start of the offset index */
+  *mar_position = 0;
+  if (mar_buffer_seek(mar, mar_position, MAR_ID_SIZE) != 0) {
+    return -1;
+  }
+
+  /* Read the offset to the index. */
+  if (mar_read_buffer(mar, &offsetToIndex, mar_position,
+                      sizeof(offsetToIndex)) != 0) {
+    return -1;
+  }
+  offsetToIndex = ntohl(offsetToIndex);
+
+  if (numSignatures) {
+    /* Skip past the MAR file size field */
+    if (mar_buffer_seek(mar, mar_position, sizeof(uint64_t)) != 0) {
+      return -1;
+    }
+
+    /* Read the number of signatures field */
+    if (mar_read_buffer(mar, numSignatures, mar_position,
+                        sizeof(*numSignatures)) != 0) {
+      return -1;
+    }
+    *numSignatures = ntohl(*numSignatures);
+  }
+
+  /* Skip to the first index entry past the index size field
+     We do it in 2 calls because offsetToIndex + sizeof(uint32_t)
+     could overflow in theory. */
+  *mar_position = 0;
+  if (mar_buffer_seek(mar, mar_position, offsetToIndex) != 0) {
+    return -1;
+  }
+
+  if (mar_buffer_seek(mar, mar_position, sizeof(uint32_t)) != 0) {
+    return -1;
+  }
+
+  /* Read the first offset to content field. */
+  if (mar_read_buffer(mar, &offsetToContent, mar_position,
+                      sizeof(offsetToContent)) != 0) {
+    return -1;
+  }
+  offsetToContent = ntohl(offsetToContent);
+
+  /* Check if we have a new or old MAR file */
+  if (hasSignatureBlock) {
+    if (offsetToContent == MAR_ID_SIZE + sizeof(uint32_t)) {
+      *hasSignatureBlock = 0;
+    } else {
+      *hasSignatureBlock = 1;
+    }
+  }
+
+  /* If the caller doesn't care about the product info block
+     value, then just return */
+  if (!hasAdditionalBlocks) {
+    return 0;
+  }
+
+  /* Skip to the start of the signature block */
+  *mar_position = 0;
+  if (mar_buffer_seek(mar, mar_position, SIGNATURE_BLOCK_OFFSET) != 0) {
+    return -1;
+  }
+
+  /* Get the number of signatures */
+  if (mar_read_buffer(mar, &signatureCount, mar_position,
+                      sizeof(signatureCount)) != 0) {
+    return -1;
+  }
+  signatureCount = ntohl(signatureCount);
+
+  /* Check that we have less than the max amount of signatures so we don't
+     waste too much of either updater's or signmar's time. */
+  if (signatureCount > MAX_SIGNATURES) {
+    return -1;
+  }
+
+  /* Skip past the whole signature block */
+  for (i = 0; i < signatureCount; i++) {
+    /* Skip past the signature algorithm ID */
+    if (mar_buffer_seek(mar, mar_position, sizeof(uint32_t)) != 0) {
+      return -1;
+    }
+
+    /* Read the signature length and skip past the signature */
+    if (mar_read_buffer(mar, &signatureLen, mar_position, sizeof(uint32_t)) !=
+        0) {
+      return -1;
+    }
+    signatureLen = ntohl(signatureLen);
+    if (mar_buffer_seek(mar, mar_position, signatureLen) != 0) {
+      return -1;
+    }
+  }
+
+  if (*mar_position <= (size_t)INT64_MAX &&
+      (int64_t)mar_position == (int64_t)offsetToContent) {
+    *hasAdditionalBlocks = 0;
+  } else {
+    if (numAdditionalBlocks) {
+      /* We have an additional block, so read in the number of additional blocks
+         and set the offset. */
+      *hasAdditionalBlocks = 1;
+      if (mar_read_buffer(mar, numAdditionalBlocks, mar_position,
+                          sizeof(uint32_t)) != 0) {
+        return -1;
+      }
+      *numAdditionalBlocks = ntohl(*numAdditionalBlocks);
+      if (offsetAdditionalBlocks) {
+        if (*mar_position > (size_t)UINT32_MAX) {
+          return -1;
+        }
+        *offsetAdditionalBlocks = (uint32_t)*mar_position;
+      }
+    } else if (offsetAdditionalBlocks) {
+      /* numAdditionalBlocks is not specified but offsetAdditionalBlocks
+         is, so fill it! */
+      if (mar_buffer_seek(mar, mar_position, sizeof(uint32_t)) != 0) {
+        return -1;
+      }
+      if (*mar_position > (size_t)UINT32_MAX) {
+        return -1;
+      }
+      *offsetAdditionalBlocks = (uint32_t)*mar_position;
+    }
+  }
+
+  return 0;
+}
+
+/**
+ * Reads the product info block from the MAR file's additional block section.
+ * The caller is responsible for freeing the fields in infoBlock
+ * if the return is successful.
+ *
+ * @param infoBlock Out parameter for where to store the result to
+ * @return 0 on success, -1 on failure
+ */
+int read_product_info_block(char* path,
+                            struct ProductInformationBlock* infoBlock) {
+  int rv;
+  MarFile* mar;
+  MarReadResult result = mar_open(path, &mar);
+  if (result != MAR_READ_SUCCESS) {
+    fprintf(stderr,
+            "ERROR: could not open file in read_product_info_block()\n");
+    return -1;
+  }
+  rv = mar_read_product_info_block(mar, infoBlock);
+  mar_close(mar);
+  return rv;
+}
+
+/**
+ * Reads the product info block from the MAR file's additional block section.
+ * The caller is responsible for freeing the fields in infoBlock
+ * if the return is successful.
+ *
+ * @param infoBlock Out parameter for where to store the result to
+ * @return 0 on success, -1 on failure
+ */
+int mar_read_product_info_block(MarFile* mar,
+                                struct ProductInformationBlock* infoBlock) {
+  uint32_t offsetAdditionalBlocks, numAdditionalBlocks, additionalBlockSize,
+      additionalBlockID;
+  int hasAdditionalBlocks;
+  size_t mar_position = 0;
+
+  /* The buffer size is 97 bytes because the MAR channel name < 64 bytes, and
+     product version < 32 bytes + 3 NULL terminator bytes. */
+  char buf[MAXADDITIONALBLOCKSIZE + 1] = {'\0'};
+  if (get_open_mar_file_info(mar, &mar_position, NULL, NULL,
+                             &hasAdditionalBlocks, &offsetAdditionalBlocks,
+                             &numAdditionalBlocks) != 0) {
+    return -1;
+  }
+
+  /* We only have the one additional block type and only one is expected to be
+     in a MAR file so check if any exist and process the first found */
+  if (numAdditionalBlocks > 0) {
+    /* Read the additional block size */
+    if (mar_read_buffer(mar, &additionalBlockSize, &mar_position,
+                        sizeof(additionalBlockSize)) != 0) {
+      return -1;
+    }
+    additionalBlockSize = ntohl(additionalBlockSize) -
+                          sizeof(additionalBlockSize) -
+                          sizeof(additionalBlockID);
+
+    /* Additional Block sizes should only be 96 bytes long */
+    if (additionalBlockSize > MAXADDITIONALBLOCKSIZE) {
+      return -1;
+    }
+
+    /* Read the additional block ID */
+    if (mar_read_buffer(mar, &additionalBlockID, &mar_position,
+                        sizeof(additionalBlockID)) != 0) {
+      return -1;
+    }
+    additionalBlockID = ntohl(additionalBlockID);
+
+    if (PRODUCT_INFO_BLOCK_ID == additionalBlockID) {
+      const char* location;
+      int len;
+
+      if (mar_read_buffer(mar, buf, &mar_position, additionalBlockSize) != 0) {
+        return -1;
+      }
+
+      /* Extract the MAR channel name from the buffer.  For now we
+         point to the stack allocated buffer but we strdup this
+         if we are within bounds of each field's max length. */
+      location = buf;
+      len = strlen(location);
+      infoBlock->MARChannelID = location;
+      location += len + 1;
+      if (len >= 64) {
+        infoBlock->MARChannelID = NULL;
+        return -1;
+      }
+
+      /* Extract the version from the buffer */
+      len = strlen(location);
+      infoBlock->productVersion = location;
+      if (len >= 32) {
+        infoBlock->MARChannelID = NULL;
+        infoBlock->productVersion = NULL;
+        return -1;
+      }
+      infoBlock->MARChannelID = strdup(infoBlock->MARChannelID);
+      infoBlock->productVersion = strdup(infoBlock->productVersion);
+      return 0;
+    } else {
+      /* This is not the additional block you're looking for. Move along. */
+      if (mar_buffer_seek(mar, &mar_position, additionalBlockSize) != 0) {
+        return -1;
+      }
+    }
+  }
+
+  /* If we had a product info block we would have already returned */
+  return -1;
+}
+
+const MarItem* mar_find_item(MarFile* mar, const char* name) {
+  uint32_t hash;
+  const MarItem* item;
+
+  if (!mar->item_table_is_valid) {
+    if (mar_read_index(mar)) {
+      return NULL;
+    } else {
+      mar->item_table_is_valid = 1;
+    }
+  }
+
+  hash = mar_hash_name(name);
+
+  item = mar->item_table[hash];
+  while (item && strcmp(item->name, name) != 0) {
+    item = item->next;
+  }
+
+  /* If this is the first time seeing this item's indexes, return it */
+  if (mar_insert_offset(mar, item->offset, item->length) == 1) {
+    return item;
+  } else {
+    fprintf(stderr, "ERROR: file content collision in mar_find_item()\n");
+    return NULL;
+  }
+}
+
+int mar_enum_items(MarFile* mar, MarItemCallback callback, void* closure) {
+  MarItem* item;
+  int i, rv;
+
+  if (!mar->item_table_is_valid) {
+    if (mar_read_index(mar)) {
+      return -1;
+    } else {
+      mar->item_table_is_valid = 1;
+    }
+  }
+
+  for (i = 0; i < TABLESIZE; ++i) {
+    item = mar->item_table[i];
+    while (item) {
+      /* if this is the first time seeing this item's indexes, process it */
+      if (mar_insert_offset(mar, item->offset, item->length) == 1) {
+        rv = callback(mar, item, closure);
+        if (rv) {
+          return rv;
+        }
+      } else {
+        fprintf(stderr, "ERROR: file content collision in mar_enum_items()\n");
+        return 1;
+      }
+      item = item->next;
+    }
+  }
+
+  return 0;
+}
+
+int mar_read(MarFile* mar, const MarItem* item, int offset, uint8_t* buf,
+             int bufsize) {
+  int nr;
+  size_t mar_position = 0;
+
+  if (offset == (int)item->length) {
+    return 0;
+  }
+  if (offset > (int)item->length) {
+    return -1;
+  }
+
+  nr = item->length - offset;
+  if (nr > bufsize) {
+    nr = bufsize;
+  }
+
+  // Avoid adding item->offset and offset directly, just in case of overflow.
+  if (mar_buffer_seek(mar, &mar_position, item->offset)) {
+    return -1;
+  }
+  if (mar_buffer_seek(mar, &mar_position, offset)) {
+    return -1;
+  }
+
+  return mar_read_buffer_max(mar, buf, &mar_position, nr);
+}
+
+/**
+ * Determines the MAR file information.
+ *
+ * @param path                   The path of the MAR file to check.
+ * @param hasSignatureBlock      Optional out parameter specifying if the MAR
+ *                               file has a signature block or not.
+ * @param numSignatures          Optional out parameter for storing the number
+ *                               of signatures in the MAR file.
+ * @param hasAdditionalBlocks    Optional out parameter specifying if the MAR
+ *                               file has additional blocks or not.
+ * @param offsetAdditionalBlocks Optional out parameter for the offset to the
+ *                               first additional block. Value is only valid if
+ *                               hasAdditionalBlocks is not equal to 0.
+ * @param numAdditionalBlocks    Optional out parameter for the number of
+ *                               additional blocks.  Value is only valid if
+ *                               has_additional_blocks is not equal to 0.
+ * @return 0 on success and non-zero on failure.
+ */
+int get_mar_file_info(const char* path, int* hasSignatureBlock,
+                      uint32_t* numSignatures, int* hasAdditionalBlocks,
+                      uint32_t* offsetAdditionalBlocks,
+                      uint32_t* numAdditionalBlocks) {
+  int rv;
+  MarFile* mar;
+  size_t mar_position = 0;
+  MarReadResult result = mar_open(path, &mar);
+  if (result != MAR_READ_SUCCESS) {
+    fprintf(stderr, "ERROR: could not read file in get_mar_file_info()\n");
+    return -1;
+  }
+
+  rv = get_open_mar_file_info(mar, &mar_position, hasSignatureBlock,
+                              numSignatures, hasAdditionalBlocks,
+                              offsetAdditionalBlocks, numAdditionalBlocks);
+
+  mar_close(mar);
+  return rv;
+}
diff --git a/modules/libmar/src/moz.build b/modules/libmar/src/moz.build
new file mode 100644
index 0000000000..5c40291e92
--- /dev/null
+++ b/modules/libmar/src/moz.build
@@ -0,0 +1,39 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+EXPORTS += [
+    "mar.h",
+    "mar_cmdline.h",
+]
+
+HOST_SOURCES += [
+    "mar_create.c",
+    "mar_extract.c",
+    "mar_read.c",
+]
+HostLibrary("hostmar")
+
+# C11 for static_assert
+c11_flags = ["-std=gnu11"]
+if CONFIG["CC_TYPE"] == "clang-cl":
+    c11_flags.insert(0, "-Xclang")
+HOST_CFLAGS += c11_flags
+
+LOCAL_INCLUDES += [
+    "../../../other-licenses/nsis/Contrib/CityHash/cityhash",
+]
+
+if CONFIG["MOZ_BUILD_APP"] != "tools/update-packaging":
+    Library("mar")
+
+    UNIFIED_SOURCES += HOST_SOURCES
+
+    CFLAGS += c11_flags
+
+    FORCE_STATIC_LIB = True
+
+    if CONFIG["OS_ARCH"] == "WINNT":
+        USE_STATIC_LIBS = True
diff --git a/modules/libmar/tests/moz.build b/modules/libmar/tests/moz.build
new file mode 100644
index 0000000000..7b96d8dfd3
--- /dev/null
+++ b/modules/libmar/tests/moz.build
@@ -0,0 +1,12 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+if CONFIG["OS_TARGET"] != "Android" and CONFIG["COMPILE_ENVIRONMENT"]:
+    XPCSHELL_TESTS_MANIFESTS += ["unit/xpcshell.ini"]
+
+    TEST_HARNESS_FILES.xpcshell.modules.libmar.tests.unit += [
+        "!/dist/bin/signmar%s" % CONFIG["BIN_SUFFIX"],
+    ]
diff --git a/modules/libmar/tests/unit/data/0_sized.mar b/modules/libmar/tests/unit/data/0_sized.mar
new file mode 100644
index 0000000000..357eeb9a87
--- /dev/null
+++ b/modules/libmar/tests/unit/data/0_sized.mar
diff --git a/modules/libmar/tests/unit/data/0_sized_file b/modules/libmar/tests/unit/data/0_sized_file
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/modules/libmar/tests/unit/data/0_sized_file
diff --git a/modules/libmar/tests/unit/data/1_byte.mar b/modules/libmar/tests/unit/data/1_byte.mar
new file mode 100644
index 0000000000..a137f11adc
--- /dev/null
+++ b/modules/libmar/tests/unit/data/1_byte.mar
diff --git a/modules/libmar/tests/unit/data/1_byte_file b/modules/libmar/tests/unit/data/1_byte_file
new file mode 100644
index 0000000000..56a6051ca2
--- /dev/null
+++ b/modules/libmar/tests/unit/data/1_byte_file
@@ -0,0 +1 @@
+1
\ No newline at end of file
diff --git a/modules/libmar/tests/unit/data/binary_data.mar b/modules/libmar/tests/unit/data/binary_data.mar
new file mode 100644
index 0000000000..7fef469898
--- /dev/null
+++ b/modules/libmar/tests/unit/data/binary_data.mar
diff --git a/modules/libmar/tests/unit/data/binary_data_file b/modules/libmar/tests/unit/data/binary_data_file
new file mode 100644
index 0000000000..a0d7369e45
--- /dev/null
+++ b/modules/libmar/tests/unit/data/binary_data_file
diff --git a/modules/libmar/tests/unit/data/cert9.db b/modules/libmar/tests/unit/data/cert9.db
new file mode 100644
index 0000000000..e0d6191e64
--- /dev/null
+++ b/modules/libmar/tests/unit/data/cert9.db
diff --git a/modules/libmar/tests/unit/data/key4.db b/modules/libmar/tests/unit/data/key4.db
new file mode 100644
index 0000000000..85c9c5a215
--- /dev/null
+++ b/modules/libmar/tests/unit/data/key4.db
diff --git a/modules/libmar/tests/unit/data/manipulated_backend_collision.mar b/modules/libmar/tests/unit/data/manipulated_backend_collision.mar
new file mode 100644
index 0000000000..41d4f78482
--- /dev/null
+++ b/modules/libmar/tests/unit/data/manipulated_backend_collision.mar
diff --git a/modules/libmar/tests/unit/data/manipulated_frontend_collision.mar b/modules/libmar/tests/unit/data/manipulated_frontend_collision.mar
new file mode 100644
index 0000000000..582af58b59
--- /dev/null
+++ b/modules/libmar/tests/unit/data/manipulated_frontend_collision.mar
diff --git a/modules/libmar/tests/unit/data/manipulated_is_contained.mar b/modules/libmar/tests/unit/data/manipulated_is_contained.mar
new file mode 100644
index 0000000000..d51b23587d
--- /dev/null
+++ b/modules/libmar/tests/unit/data/manipulated_is_contained.mar
diff --git a/modules/libmar/tests/unit/data/manipulated_is_container.mar b/modules/libmar/tests/unit/data/manipulated_is_container.mar
new file mode 100644
index 0000000000..98b33ce9e5
--- /dev/null
+++ b/modules/libmar/tests/unit/data/manipulated_is_container.mar
diff --git a/modules/libmar/tests/unit/data/manipulated_multiple_collision.mar b/modules/libmar/tests/unit/data/manipulated_multiple_collision.mar
new file mode 100644
index 0000000000..7e0a3dd724
--- /dev/null
+++ b/modules/libmar/tests/unit/data/manipulated_multiple_collision.mar
diff --git a/modules/libmar/tests/unit/data/manipulated_multiple_collision_first.mar b/modules/libmar/tests/unit/data/manipulated_multiple_collision_first.mar
new file mode 100644
index 0000000000..a10d3eb53b
--- /dev/null
+++ b/modules/libmar/tests/unit/data/manipulated_multiple_collision_first.mar
diff --git a/modules/libmar/tests/unit/data/manipulated_multiple_collision_last.mar b/modules/libmar/tests/unit/data/manipulated_multiple_collision_last.mar
new file mode 100644
index 0000000000..bfbb9ba853
--- /dev/null
+++ b/modules/libmar/tests/unit/data/manipulated_multiple_collision_last.mar
diff --git a/modules/libmar/tests/unit/data/manipulated_same_offset.mar b/modules/libmar/tests/unit/data/manipulated_same_offset.mar
new file mode 100644
index 0000000000..1326d1afd8
--- /dev/null
+++ b/modules/libmar/tests/unit/data/manipulated_same_offset.mar
diff --git a/modules/libmar/tests/unit/data/manipulated_signed.mar b/modules/libmar/tests/unit/data/manipulated_signed.mar
new file mode 100644
index 0000000000..df8b3b5dbb
--- /dev/null
+++ b/modules/libmar/tests/unit/data/manipulated_signed.mar
diff --git a/modules/libmar/tests/unit/data/multiple_file.mar b/modules/libmar/tests/unit/data/multiple_file.mar
new file mode 100644
index 0000000000..183493a368
--- /dev/null
+++ b/modules/libmar/tests/unit/data/multiple_file.mar
diff --git a/modules/libmar/tests/unit/data/multiple_signed_no_pib.mar b/modules/libmar/tests/unit/data/multiple_signed_no_pib.mar
new file mode 100644
index 0000000000..fb56eef98e
--- /dev/null
+++ b/modules/libmar/tests/unit/data/multiple_signed_no_pib.mar
diff --git a/modules/libmar/tests/unit/data/multiple_signed_pib.mar b/modules/libmar/tests/unit/data/multiple_signed_pib.mar
new file mode 100644
index 0000000000..3624436cf5
--- /dev/null
+++ b/modules/libmar/tests/unit/data/multiple_signed_pib.mar
diff --git a/modules/libmar/tests/unit/data/multiple_signed_pib_2.mar b/modules/libmar/tests/unit/data/multiple_signed_pib_2.mar
new file mode 100644
index 0000000000..edce42b854
--- /dev/null
+++ b/modules/libmar/tests/unit/data/multiple_signed_pib_2.mar
diff --git a/modules/libmar/tests/unit/data/multiple_signed_pib_mar.sig.0 b/modules/libmar/tests/unit/data/multiple_signed_pib_mar.sig.0
new file mode 100644
index 0000000000..fa75b9f231
--- /dev/null
+++ b/modules/libmar/tests/unit/data/multiple_signed_pib_mar.sig.0
@@ -0,0 +1,11 @@
+biW+t1VP/UUp/B+xnQNKRDib3r4ZYP/HX/O5ZVPaTalCIZJfeGjoGK8TAlNUQUPZ

+rHK/SZqr7rzsWlqb6rAGBWphnaZ3202luiaCBtb1Vi/MS7tPIssC6m2gvy5rwhMA

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\ No newline at end of file
diff --git a/modules/libmar/tests/unit/data/multiple_signed_pib_mar.sig.1 b/modules/libmar/tests/unit/data/multiple_signed_pib_mar.sig.1
new file mode 100644
index 0000000000..3ab4cef5f4
--- /dev/null
+++ b/modules/libmar/tests/unit/data/multiple_signed_pib_mar.sig.1
@@ -0,0 +1,11 @@
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+mhYiy+v/27LfonFX0ak9+HlANsV96ixf3mrkVz7Tfc4=
\ No newline at end of file
diff --git a/modules/libmar/tests/unit/data/multiple_signed_pib_mar.sig.2 b/modules/libmar/tests/unit/data/multiple_signed_pib_mar.sig.2
new file mode 100644
index 0000000000..974a425137
--- /dev/null
+++ b/modules/libmar/tests/unit/data/multiple_signed_pib_mar.sig.2
@@ -0,0 +1,11 @@
+F6F1LmabkmheGolLdYlWkaSnM782EoJnZAiDYOszsetXWltFLCd/SrfKaAABBUJZ

+jPS5EeEAFtNK6INCs/ULujohnQwhiMWwcLm7f5CGEaC7UzKB4tP5ZvnBASTDhAMj

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++t//Y5PZTktwjxIELbGYvVXoJYYHW7Jr5PlxvUxqq7WRHwOd9nL4Bs8gqr64I9sB

+8yMnjffnl5ZL53pS6SjIzPgymYNOYN1KpDuNoSBuXN8=
\ No newline at end of file
diff --git a/modules/libmar/tests/unit/data/mycert.der b/modules/libmar/tests/unit/data/mycert.der
new file mode 100644
index 0000000000..ea1fd47faa
--- /dev/null
+++ b/modules/libmar/tests/unit/data/mycert.der
diff --git a/modules/libmar/tests/unit/data/mycert2.der b/modules/libmar/tests/unit/data/mycert2.der
new file mode 100644
index 0000000000..d8cdfea972
--- /dev/null
+++ b/modules/libmar/tests/unit/data/mycert2.der
diff --git a/modules/libmar/tests/unit/data/mycert3.der b/modules/libmar/tests/unit/data/mycert3.der
new file mode 100644
index 0000000000..b942d4d795
--- /dev/null
+++ b/modules/libmar/tests/unit/data/mycert3.der
diff --git a/modules/libmar/tests/unit/data/no_pib.mar b/modules/libmar/tests/unit/data/no_pib.mar
new file mode 100644
index 0000000000..8976e7d737
--- /dev/null
+++ b/modules/libmar/tests/unit/data/no_pib.mar
diff --git a/modules/libmar/tests/unit/data/signed_no_pib.mar b/modules/libmar/tests/unit/data/signed_no_pib.mar
new file mode 100644
index 0000000000..92d97fec51
--- /dev/null
+++ b/modules/libmar/tests/unit/data/signed_no_pib.mar
diff --git a/modules/libmar/tests/unit/data/signed_pib.mar b/modules/libmar/tests/unit/data/signed_pib.mar
new file mode 100644
index 0000000000..1b8baa7969
--- /dev/null
+++ b/modules/libmar/tests/unit/data/signed_pib.mar
diff --git a/modules/libmar/tests/unit/data/signed_pib_mar.signature.0 b/modules/libmar/tests/unit/data/signed_pib_mar.signature.0
new file mode 100644
index 0000000000..d597fa5491
--- /dev/null
+++ b/modules/libmar/tests/unit/data/signed_pib_mar.signature.0
@@ -0,0 +1,11 @@
+Qv7nfMB5+ri3errM8NqkCl7LwWFHu3DXBFAHaw3Rl27hGyZw4xR+oKbQMkwvdrY7

+GxWZ0vBNSI4nte+Ii6XjDQcnzQgqINEZkL5EVMs1re1zA8OzuItxtXWeCoAPGgMg

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+Zrhi/BNkQstX7Bdqe58adzRAv/O80DH8ErKBqvqh17HXwMmGx6i+EGyNt8DfFLSm

+xEzxnsmFnOaBytzpth4pltEEpioQPS7/CSdRydi/29w=
\ No newline at end of file
diff --git a/modules/libmar/tests/unit/data/signed_pib_mar.signature.mycert2 b/modules/libmar/tests/unit/data/signed_pib_mar.signature.mycert2
new file mode 100644
index 0000000000..045fc80be1
--- /dev/null
+++ b/modules/libmar/tests/unit/data/signed_pib_mar.signature.mycert2
@@ -0,0 +1,11 @@
+i6oFIDMnyZ5CUaYUCg8MEL48puCQdZMH9s2ZoGKzxK4YO6a/2Yhur4jNRfoxgQm3

+2o4qO4gUCjcwZmQHoSmseELJWP+6I929SZ4KUc/bXsIOMlZLcq+YSQSCbmkM/AeV

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+FSbVjBI+ie7oTFeInJ7eWgJ7/XTMtHsCAw+RHN1drFo=
\ No newline at end of file
diff --git a/modules/libmar/tests/unit/data/signed_pib_with_mycert2.mar b/modules/libmar/tests/unit/data/signed_pib_with_mycert2.mar
new file mode 100644
index 0000000000..22a998e227
--- /dev/null
+++ b/modules/libmar/tests/unit/data/signed_pib_with_mycert2.mar
diff --git a/modules/libmar/tests/unit/head_libmar.js b/modules/libmar/tests/unit/head_libmar.js
new file mode 100644
index 0000000000..49ce2e8ba6
--- /dev/null
+++ b/modules/libmar/tests/unit/head_libmar.js
@@ -0,0 +1,162 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const BIN_SUFFIX = mozinfo.bin_suffix;
+const tempDir = do_get_tempdir();
+
+/**
+ * Compares binary data of 2 arrays and throws if they aren't the same.
+ * Throws on mismatch, does nothing on match.
+ *
+ * @param arr1 The first array to compare
+ * @param arr2 The second array to compare
+ */
+function compareBinaryData(arr1, arr2) {
+  Assert.equal(arr1.length, arr2.length);
+  for (let i = 0; i < arr1.length; i++) {
+    if (arr1[i] != arr2[i]) {
+      throw new Error(
+        `Data differs at index ${i}, arr1: ${arr1[i]}, arr2: ${arr2[i]}`
+      );
+    }
+  }
+}
+
+/**
+ * Reads a file's data and returns it
+ *
+ * @param file The file to read the data from
+ * @return a byte array for the data in the file.
+ */
+function getBinaryFileData(file) {
+  let fileStream = Cc[
+    "@mozilla.org/network/file-input-stream;1"
+  ].createInstance(Ci.nsIFileInputStream);
+  // Open as RD_ONLY with default permissions.
+  fileStream.init(file, -1, -1, null);
+
+  // Check the returned size versus the expected size.
+  let stream = Cc["@mozilla.org/binaryinputstream;1"].createInstance(
+    Ci.nsIBinaryInputStream
+  );
+  stream.setInputStream(fileStream);
+  let bytes = stream.readByteArray(stream.available());
+  fileStream.close();
+  return bytes;
+}
+
+/**
+ * Runs each method in the passed in object
+ * Every method of the passed in object that starts with test_ will be ran
+ * The cleanup_per_test method of the object will be run right away, it will be
+ * registered to be the cleanup function, and it will be run between each test.
+ *
+ * @return The number of tests ran
+ */
+function run_tests(obj) {
+  let cleanup_per_test = obj.cleanup_per_test;
+  if (cleanup_per_test === undefined) {
+    cleanup_per_test = function __cleanup_per_test() {};
+  }
+
+  registerCleanupFunction(cleanup_per_test);
+
+  // Make sure there's nothing left over from a preious failed test
+  cleanup_per_test();
+
+  let ranCount = 0;
+  // hasOwnProperty ensures we only see direct properties and not all
+  for (let f in obj) {
+    if (
+      typeof obj[f] === "function" &&
+      obj.hasOwnProperty(f) &&
+      f.toString().indexOf("test_") === 0
+    ) {
+      obj[f]();
+      cleanup_per_test();
+      ranCount++;
+    }
+  }
+  return ranCount;
+}
+
+/**
+ * Creates a MAR file with the content of files.
+ *
+ * @param outMAR  The file where the MAR should be created to
+ * @param dataDir The directory where the relative file paths exist
+ * @param files   The relative file paths of the files to include in the MAR
+ */
+function createMAR(outMAR, dataDir, files) {
+  // You cannot create an empy MAR.
+  Assert.ok(!!files.length);
+
+  // Get an nsIProcess to the signmar binary.
+  let process = Cc["@mozilla.org/process/util;1"].createInstance(Ci.nsIProcess);
+  let signmarBin = do_get_file("signmar" + BIN_SUFFIX);
+
+  // Make sure the signmar binary exists and is an executable.
+  Assert.ok(signmarBin.exists());
+  Assert.ok(signmarBin.isExecutable());
+
+  // Ensure on non Windows platforms we encode the same permissions
+  // as the refernence MARs contain.  On Windows this is also safe.
+  // The reference MAR files have permissions of 0o664, so in case
+  // someone is running these tests locally with another permission
+  // (perhaps 0o777), make sure that we encode them as 0o664.
+  for (let filePath of files) {
+    let f = dataDir.clone();
+    f.append(filePath);
+    f.permissions = 0o664;
+  }
+
+  // Setup the command line arguments to create the MAR.
+  let args = [
+    "-C",
+    dataDir.path,
+    "-H",
+    "@MAR_CHANNEL_ID@",
+    "-V",
+    "13.0a1",
+    "-c",
+    outMAR.path,
+  ];
+  args = args.concat(files);
+
+  info("Running: " + signmarBin.path + " " + args.join(" "));
+  process.init(signmarBin);
+  process.run(true, args, args.length);
+
+  // Verify signmar returned 0 for success.
+  Assert.equal(process.exitValue, 0);
+
+  // Verify the out MAR file actually exists.
+  Assert.ok(outMAR.exists());
+}
+
+/**
+ * Extracts a MAR file to the specified output directory.
+ *
+ * @param mar     The MAR file that should be matched
+ * @param dataDir The directory to extract to
+ */
+function extractMAR(mar, dataDir) {
+  // Get an nsIProcess to the signmar binary.
+  let process = Cc["@mozilla.org/process/util;1"].createInstance(Ci.nsIProcess);
+  let signmarBin = do_get_file("signmar" + BIN_SUFFIX);
+
+  // Make sure the signmar binary exists and is an executable.
+  Assert.ok(signmarBin.exists());
+  Assert.ok(signmarBin.isExecutable());
+
+  // Setup the command line arguments to extract the MAR.
+  let args = ["-C", dataDir.path, "-x", mar.path];
+
+  info("Running: " + signmarBin.path + " " + args.join(" "));
+  process.init(signmarBin);
+  process.run(true, args, args.length);
+
+  return process.exitValue;
+}
diff --git a/modules/libmar/tests/unit/test_create.js b/modules/libmar/tests/unit/test_create.js
new file mode 100644
index 0000000000..224364b419
--- /dev/null
+++ b/modules/libmar/tests/unit/test_create.js
@@ -0,0 +1,112 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function run_test() {
+  /**
+   * Creates MAR from the passed files, compares it to the reference MAR.
+   *
+   * @param refMARFileName The name of the MAR file that should match
+   * @param files          The files that should go in the created MAR
+   * @param checkNoMAR     If true return an error if a file already exists
+   */
+  function run_one_test(refMARFileName, files, checkNoMAR) {
+    if (checkNoMAR === undefined) {
+      checkNoMAR = true;
+    }
+
+    // Ensure the MAR we will create doesn't already exist.
+    let outMAR = tempDir.clone();
+    outMAR.append("out.mar");
+    if (checkNoMAR) {
+      Assert.ok(!outMAR.exists());
+    }
+
+    // Create the actual MAR file.
+    createMAR(outMAR, do_get_file("data"), files);
+
+    // Get the reference MAR data.
+    let refMAR = do_get_file("data/" + refMARFileName);
+    let refMARData = getBinaryFileData(refMAR);
+
+    // Verify the data of the MAR is what it should be.
+    let outMARData = getBinaryFileData(outMAR);
+    if (mozinfo.os != "win") {
+      // Modify the array index that contains the file permission in this mar so
+      // the comparison succeeds. This value is only changed when the value is
+      // the expected value on non-Windows platforms since the MAR files are
+      // created on Windows. This makes it possible to use the same MAR files for
+      // all platforms.
+      switch (refMARFileName) {
+        case "0_sized.mar":
+          if (outMARData[143] == 180) {
+            outMARData[143] = 182;
+          }
+          break;
+        case "1_byte.mar":
+          if (outMARData[144] == 180) {
+            outMARData[144] = 182;
+          }
+          break;
+        case "binary_data.mar":
+          if (outMARData[655] == 180) {
+            outMARData[655] = 182;
+          }
+          break;
+        case "multiple_file.mar":
+          if (outMARData[656] == 180) {
+            outMARData[656] = 182;
+          }
+          if (outMARData[681] == 180) {
+            outMARData[681] = 182;
+          }
+          if (outMARData[705] == 180) {
+            outMARData[705] = 182;
+          }
+      }
+    }
+    compareBinaryData(outMARData, refMARData);
+  }
+
+  // Define the unit tests to run.
+  let tests = {
+    // Test creating a MAR file with a 0 byte file.
+    test_zero_sized: function _test_zero_sized() {
+      return run_one_test("0_sized.mar", ["0_sized_file"]);
+    },
+    // Test creating a MAR file with a 1 byte file.
+    test_one_byte: function _test_one_byte() {
+      return run_one_test("1_byte.mar", ["1_byte_file"]);
+    },
+    // Test creating a MAR file with binary data.
+    test_binary_data: function _test_binary_data() {
+      return run_one_test("binary_data.mar", ["binary_data_file"]);
+    },
+    // Test creating a MAR file with multiple files inside of it.
+    test_multiple_file: function _test_multiple_file() {
+      return run_one_test("multiple_file.mar", [
+        "0_sized_file",
+        "1_byte_file",
+        "binary_data_file",
+      ]);
+    },
+    // Test creating a MAR file on top of a different one that already exists
+    // at the location the new one will be created at.
+    test_overwrite_already_exists: function _test_overwrite_already_exists() {
+      let differentFile = do_get_file("data/1_byte.mar");
+      let outMARDir = tempDir.clone();
+      differentFile.copyTo(outMARDir, "out.mar");
+      return run_one_test("binary_data.mar", ["binary_data_file"], false);
+    },
+    // Between each test make sure the out MAR does not exist.
+    cleanup_per_test: function _cleanup_per_test() {
+      let outMAR = tempDir.clone();
+      outMAR.append("out.mar");
+      if (outMAR.exists()) {
+        outMAR.remove(false);
+      }
+    },
+  };
+
+  // Run all the tests
+  Assert.equal(run_tests(tests), Object.keys(tests).length - 1);
+}
diff --git a/modules/libmar/tests/unit/test_extract.js b/modules/libmar/tests/unit/test_extract.js
new file mode 100644
index 0000000000..46cbbcbbee
--- /dev/null
+++ b/modules/libmar/tests/unit/test_extract.js
@@ -0,0 +1,147 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function run_test() {
+  /**
+   * Extracts a MAR and makes sure each file matches the reference files.
+   *
+   * @param marFileName The name of the MAR file to extract
+   * @param files       The files that the extracted MAR should contain
+   */
+  function extract_and_compare(marFileName, files) {
+    // Get the MAR file that we will be extracting
+    let mar = do_get_file("data/" + marFileName);
+
+    // Get the path that we will extract to
+    let outDir = tempDir.clone();
+    outDir.append("out");
+    Assert.ok(!outDir.exists());
+    outDir.create(Ci.nsIFile.DIRECTORY_TYPE, 0o777);
+
+    // Get the ref files and the files that will be extracted.
+    let outFiles = [];
+    let refFiles = [];
+    for (let i = 0; i < files.length; i++) {
+      let outFile = outDir.clone();
+      outFile.append(files[i]);
+      Assert.ok(!outFile.exists());
+
+      outFiles.push(outFile);
+      refFiles.push(do_get_file("data/" + files[i]));
+    }
+
+    // Extract the MAR contents to ./out dir and verify 0 for success.
+    Assert.equal(extractMAR(mar, outDir), 0);
+
+    // Compare to make sure the extracted files are the same.
+    for (let i = 0; i < files.length; i++) {
+      Assert.ok(outFiles[i].exists());
+      let refFileData = getBinaryFileData(refFiles[i]);
+      let outFileData = getBinaryFileData(outFiles[i]);
+      compareBinaryData(refFileData, outFileData);
+    }
+  }
+
+  /**
+   * Attempts to extract a MAR and expects a failure
+   *
+   * @param marFileName The name of the MAR file to extract
+   */
+  function extract_and_fail(marFileName) {
+    // Get the MAR file that we will be extracting
+    let mar = do_get_file("data/" + marFileName);
+
+    // Get the path that we will extract to
+    let outDir = tempDir.clone();
+    outDir.append("out");
+    Assert.ok(!outDir.exists());
+    outDir.create(Ci.nsIFile.DIRECTORY_TYPE, 0o777);
+
+    // Extract the MAR contents to ./out dir and verify -1 (255 from the
+    // nsIprocess) for failure
+    Assert.equal(extractMAR(mar, outDir), 1);
+  }
+
+  // Define the unit tests to run.
+  let tests = {
+    // Test extracting a MAR file with a 0 byte file.
+    test_zero_sized: function _test_zero_sized() {
+      return extract_and_compare("0_sized.mar", ["0_sized_file"]);
+    },
+    // Test extracting a MAR file with a 1 byte file.
+    test_one_byte: function _test_one_byte() {
+      return extract_and_compare("1_byte.mar", ["1_byte_file"]);
+    },
+    // Test extracting a MAR file with binary data.
+    test_binary_data: function _test_binary_data() {
+      return extract_and_compare("binary_data.mar", ["binary_data_file"]);
+    },
+    // Test extracting a MAR without a product information block (PIB) which
+    // contains binary data.
+    test_no_pib: function _test_no_pib() {
+      return extract_and_compare("no_pib.mar", ["binary_data_file"]);
+    },
+    // Test extracting a MAR without a product information block (PIB) that is
+    // signed and which contains binary data.
+    test_no_pib_signed: function _test_no_pib_signed() {
+      return extract_and_compare("signed_no_pib.mar", ["binary_data_file"]);
+    },
+    // Test extracting a MAR with a product information block (PIB) that is
+    // signed and which contains binary data.
+    test_pib_signed: function _test_pib_signed() {
+      return extract_and_compare("signed_pib.mar", ["binary_data_file"]);
+    },
+    // Test extracting a MAR file with multiple files inside of it.
+    test_multiple_file: function _test_multiple_file() {
+      return extract_and_compare("multiple_file.mar", [
+        "0_sized_file",
+        "1_byte_file",
+        "binary_data_file",
+      ]);
+    },
+    // Test collision detection where file A + B are the same offset
+    test_collision_same_offset: function test_collision_same_offset() {
+      return extract_and_fail("manipulated_same_offset.mar");
+    },
+    // Test collision detection where file A's indexes are a subset of file B's
+    test_collision_is_contained: function test_collision_is_contained() {
+      return extract_and_fail("manipulated_is_container.mar");
+    },
+    // Test collision detection where file B's indexes are a subset of file A's
+    test_collision_contained_by: function test_collision_contained_by() {
+      return extract_and_fail("manipulated_is_contained.mar");
+    },
+    // Test collision detection where file A ends in file B's indexes
+    test_collision_a_onto_b: function test_collision_a_onto_b() {
+      return extract_and_fail("manipulated_frontend_collision.mar");
+    },
+    // Test collision detection where file B ends in file A's indexes
+    test_collsion_b_onto_a: function test_collsion_b_onto_a() {
+      return extract_and_fail("manipulated_backend_collision.mar");
+    },
+    // Test collision detection where file C shares indexes with both file A & B
+    test_collision_multiple: function test_collision_multiple() {
+      return extract_and_fail("manipulated_multiple_collision.mar");
+    },
+    // Test collision detection where A is the last file in the list
+    test_collision_last: function test_collision_multiple_last() {
+      return extract_and_fail("manipulated_multiple_collision_last.mar");
+    },
+    // Test collision detection where A is the first file in the list
+    test_collision_first: function test_collision_multiple_first() {
+      return extract_and_fail("manipulated_multiple_collision_first.mar");
+    },
+    // Between each test make sure the out directory and its subfiles do
+    // not exist.
+    cleanup_per_test: function _cleanup_per_test() {
+      let outDir = tempDir.clone();
+      outDir.append("out");
+      if (outDir.exists()) {
+        outDir.remove(true);
+      }
+    },
+  };
+
+  // Run all the tests
+  Assert.equal(run_tests(tests), Object.keys(tests).length - 1);
+}
diff --git a/modules/libmar/tests/unit/test_sign_verify.js b/modules/libmar/tests/unit/test_sign_verify.js
new file mode 100644
index 0000000000..20f0d691ac
--- /dev/null
+++ b/modules/libmar/tests/unit/test_sign_verify.js
@@ -0,0 +1,591 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function run_test() {
+  /**
+   * Signs a MAR file.
+   *
+   * @param inMAR The MAR file that should be signed
+   * @param outMAR The MAR file to create
+   */
+  function signMAR(inMAR, outMAR, certs, wantSuccess, useShortHandCmdLine) {
+    // Get a process to the signmar binary from the dist/bin directory.
+    let process = Cc["@mozilla.org/process/util;1"].createInstance(
+      Ci.nsIProcess
+    );
+    let signmarBin = do_get_file("signmar" + BIN_SUFFIX);
+
+    // Make sure the signmar binary exists and is an executable.
+    Assert.ok(signmarBin.exists());
+    Assert.ok(signmarBin.isExecutable());
+
+    // Setup the command line arguments to sign the MAR.
+    let NSSConfigDir = do_get_file("data");
+    let args = ["-d", NSSConfigDir.path];
+    if (certs.length == 1 && useShortHandCmdLine) {
+      args.push("-n", certs[0]);
+    } else {
+      for (let i = 0; i < certs.length; i++) {
+        args.push("-n" + i, certs[i]);
+      }
+    }
+    args.push("-s", inMAR.path, outMAR.path);
+
+    let exitValue;
+    process.init(signmarBin);
+    try {
+      process.run(true, args, args.length);
+      exitValue = process.exitValue;
+    } catch (e) {
+      // On Windows negative return value throws an exception
+      exitValue = -1;
+    }
+
+    // Verify signmar returned 0 for success.
+    if (wantSuccess) {
+      Assert.equal(exitValue, 0);
+    } else {
+      Assert.notEqual(exitValue, 0);
+    }
+  }
+
+  /**
+   * Extract a MAR signature.
+   *
+   * @param inMAR        The MAR file who's signature should be extracted
+   * @param sigIndex     The index of the signature to extract
+   * @param extractedSig The file where the extracted signature will be stored
+   * @param wantSuccess  True if a successful signmar return code is desired
+   */
+  function extractMARSignature(inMAR, sigIndex, extractedSig, wantSuccess) {
+    // Get a process to the signmar binary from the dist/bin directory.
+    let process = Cc["@mozilla.org/process/util;1"].createInstance(
+      Ci.nsIProcess
+    );
+    let signmarBin = do_get_file("signmar" + BIN_SUFFIX);
+
+    // Make sure the signmar binary exists and is an executable.
+    Assert.ok(signmarBin.exists());
+    Assert.ok(signmarBin.isExecutable());
+
+    // Setup the command line arguments to extract the signature in the MAR.
+    let args = ["-n" + sigIndex, "-X", inMAR.path, extractedSig.path];
+
+    let exitValue;
+    process.init(signmarBin);
+    try {
+      process.run(true, args, args.length);
+      exitValue = process.exitValue;
+    } catch (e) {
+      // On Windows negative return value throws an exception
+      exitValue = -1;
+    }
+
+    // Verify signmar returned 0 for success.
+    if (wantSuccess) {
+      Assert.equal(exitValue, 0);
+    } else {
+      Assert.notEqual(exitValue, 0);
+    }
+  }
+
+  /**
+   * Import a MAR signature.
+   *
+   * @param inMAR        The MAR file who's signature should be imported to
+   * @param sigIndex     The index of the signature to import to
+   * @param sigFile      The file where the base64 signature exists
+   * @param outMAR       The same as inMAR but with the specified signature
+   *                     swapped at the specified index.
+   * @param wantSuccess  True if a successful signmar return code is desired
+   */
+  function importMARSignature(inMAR, sigIndex, sigFile, outMAR, wantSuccess) {
+    // Get a process to the signmar binary from the dist/bin directory.
+    let process = Cc["@mozilla.org/process/util;1"].createInstance(
+      Ci.nsIProcess
+    );
+    let signmarBin = do_get_file("signmar" + BIN_SUFFIX);
+
+    // Make sure the signmar binary exists and is an executable.
+    Assert.ok(signmarBin.exists());
+    Assert.ok(signmarBin.isExecutable());
+
+    // Setup the command line arguments to import the signature in the MAR.
+    let args = ["-n" + sigIndex, "-I", inMAR.path, sigFile.path, outMAR.path];
+
+    let exitValue;
+    process.init(signmarBin);
+    try {
+      process.run(true, args, args.length);
+      exitValue = process.exitValue;
+    } catch (e) {
+      // On Windows negative return value throws an exception
+      exitValue = -1;
+    }
+
+    // Verify signmar returned 0 for success.
+    if (wantSuccess) {
+      Assert.equal(exitValue, 0);
+    } else {
+      Assert.notEqual(exitValue, 0);
+    }
+  }
+
+  /**
+   * Verifies a MAR file.
+   *
+   * @param signedMAR Verifies a MAR file
+   */
+  function verifyMAR(signedMAR, wantSuccess, certs, useShortHandCmdLine) {
+    // Get a process to the signmar binary from the dist/bin directory.
+    let process = Cc["@mozilla.org/process/util;1"].createInstance(
+      Ci.nsIProcess
+    );
+    let signmarBin = do_get_file("signmar" + BIN_SUFFIX);
+
+    // Make sure the signmar binary exists and is an executable.
+    Assert.ok(signmarBin.exists());
+    Assert.ok(signmarBin.isExecutable());
+
+    // Will reference the arguments to use for verification in signmar
+    let args = [];
+
+    // Setup the command line arguments to create the MAR.
+    // Windows & Mac vs. Linux/... have different command line for verification
+    // since on Windows we verify with CryptoAPI, on Mac with Security
+    // Transforms or CDSA/CSSM and on all other platforms we verify with NSS. So
+    // on Windows and Mac we use an exported DER file and on other platforms we
+    // use the NSS config db.
+    if (mozinfo.os == "win" || mozinfo.os == "mac") {
+      if (certs.length == 1 && useShortHandCmdLine) {
+        args.push("-D", "data/" + certs[0] + ".der");
+      } else {
+        for (let i = 0; i < certs.length; i++) {
+          args.push("-D" + i, "data/" + certs[i] + ".der");
+        }
+      }
+    } else {
+      let NSSConfigDir = do_get_file("data");
+      args = ["-d", NSSConfigDir.path];
+      if (certs.length == 1 && useShortHandCmdLine) {
+        args.push("-n", certs[0]);
+      } else {
+        for (let i = 0; i < certs.length; i++) {
+          args.push("-n" + i, certs[i]);
+        }
+      }
+    }
+    args.push("-v", signedMAR.path);
+
+    let exitValue;
+    process.init(signmarBin);
+    try {
+      // We put this in a try block because nsIProcess doesn't like -1 returns
+      process.run(true, args, args.length);
+      exitValue = process.exitValue;
+    } catch (e) {
+      // On Windows negative return value throws an exception
+      exitValue = -1;
+    }
+
+    // Verify signmar returned 0 for success.
+    if (wantSuccess) {
+      Assert.equal(exitValue, 0);
+    } else {
+      Assert.notEqual(exitValue, 0);
+    }
+  }
+
+  /**
+   * Strips a MAR signature.
+   *
+   * @param signedMAR The MAR file that should be signed
+   * @param outMAR The MAR file to write to with signature stripped
+   */
+  function stripMARSignature(signedMAR, outMAR, wantSuccess) {
+    // Get a process to the signmar binary from the dist/bin directory.
+    let process = Cc["@mozilla.org/process/util;1"].createInstance(
+      Ci.nsIProcess
+    );
+    let signmarBin = do_get_file("signmar" + BIN_SUFFIX);
+
+    // Make sure the signmar binary exists and is an executable.
+    Assert.ok(signmarBin.exists());
+    Assert.ok(signmarBin.isExecutable());
+
+    // Setup the command line arguments to create the MAR.
+    let args = ["-r", signedMAR.path, outMAR.path];
+
+    let exitValue;
+    process.init(signmarBin);
+    try {
+      process.run(true, args, args.length);
+      exitValue = process.exitValue;
+    } catch (e) {
+      // On Windows negative return value throws an exception
+      exitValue = -1;
+    }
+
+    // Verify signmar returned 0 for success.
+    if (wantSuccess) {
+      Assert.equal(exitValue, 0);
+    } else {
+      Assert.notEqual(exitValue, 0);
+    }
+  }
+
+  function cleanup() {
+    let outMAR = tempDir.clone();
+    outMAR.append("signed_out.mar");
+    if (outMAR.exists()) {
+      outMAR.remove(false);
+    }
+    outMAR = tempDir.clone();
+    outMAR.append("multiple_signed_out.mar");
+    if (outMAR.exists()) {
+      outMAR.remove(false);
+    }
+    outMAR = tempDir.clone();
+    outMAR.append("out.mar");
+    if (outMAR.exists()) {
+      outMAR.remove(false);
+    }
+
+    let outDir = tempDir.clone();
+    outDir.append("out");
+    if (outDir.exists()) {
+      outDir.remove(true);
+    }
+  }
+
+  const wantFailure = false;
+  const wantSuccess = true;
+  // Define the unit tests to run.
+  let tests = {
+    // Test signing a MAR file with a single signature
+    test_sign_single: function _test_sign_single() {
+      let inMAR = do_get_file("data/binary_data.mar");
+      let outMAR = tempDir.clone();
+      outMAR.append("signed_out.mar");
+      if (outMAR.exists()) {
+        outMAR.remove(false);
+      }
+      signMAR(inMAR, outMAR, ["mycert"], wantSuccess, true);
+      Assert.ok(outMAR.exists());
+      let outMARData = getBinaryFileData(outMAR);
+      let refMAR = do_get_file("data/signed_pib.mar");
+      let refMARData = getBinaryFileData(refMAR);
+      compareBinaryData(outMARData, refMARData);
+    },
+    // Test signing a MAR file with multiple signatures
+    test_sign_multiple: function _test_sign_multiple() {
+      let inMAR = do_get_file("data/binary_data.mar");
+      let outMAR = tempDir.clone();
+      outMAR.append("multiple_signed_out.mar");
+      if (outMAR.exists()) {
+        outMAR.remove(false);
+      }
+      Assert.ok(!outMAR.exists());
+      signMAR(
+        inMAR,
+        outMAR,
+        ["mycert", "mycert2", "mycert3"],
+        wantSuccess,
+        true
+      );
+      Assert.ok(outMAR.exists());
+      let outMARData = getBinaryFileData(outMAR);
+      let refMAR = do_get_file("data/multiple_signed_pib.mar");
+      let refMARData = getBinaryFileData(refMAR);
+      compareBinaryData(outMARData, refMARData);
+    },
+    // Test verifying a signed MAR file
+    test_verify_single: function _test_verify_single() {
+      let signedMAR = do_get_file("data/signed_pib.mar");
+      verifyMAR(signedMAR, wantSuccess, ["mycert"], true);
+      verifyMAR(signedMAR, wantSuccess, ["mycert"], false);
+    },
+    // Test verifying a signed MAR file with too many certs fails.
+    // Or if you want to look at it another way, One mycert signature
+    // is missing.
+    test_verify_single_too_many_certs:
+      function _test_verify_single_too_many_certs() {
+        let signedMAR = do_get_file("data/signed_pib.mar");
+        verifyMAR(signedMAR, wantFailure, ["mycert", "mycert"], true);
+        verifyMAR(signedMAR, wantFailure, ["mycert", "mycert"], false);
+      },
+    // Test verifying a signed MAR file fails when using a wrong cert
+    test_verify_single_wrong_cert: function _test_verify_single_wrong_cert() {
+      let signedMAR = do_get_file("data/signed_pib.mar");
+      verifyMAR(signedMAR, wantFailure, ["mycert2"], true);
+      verifyMAR(signedMAR, wantFailure, ["mycert2"], false);
+    },
+    // Test verifying a signed MAR file with multiple signatures
+    test_verify_multiple: function _test_verify_multiple() {
+      let signedMAR = do_get_file("data/multiple_signed_pib.mar");
+      verifyMAR(signedMAR, wantSuccess, ["mycert", "mycert2", "mycert3"]);
+    },
+    // Test verifying an unsigned MAR file fails
+    test_verify_unsigned_mar_file_fails:
+      function _test_verify_unsigned_mar_file_fails() {
+        let unsignedMAR = do_get_file("data/binary_data.mar");
+        verifyMAR(unsignedMAR, wantFailure, ["mycert", "mycert2", "mycert3"]);
+      },
+    // Test verifying a signed MAR file with the same signature multiple
+    // times fails.  The input MAR has: mycert, mycert2, mycert3.
+    // we're checking to make sure the number of verified signatures
+    // is only 1 and not 3.  Each signature should be verified once.
+    test_verify_multiple_same_cert: function _test_verify_multiple_same_cert() {
+      let signedMAR = do_get_file("data/multiple_signed_pib.mar");
+      verifyMAR(signedMAR, wantFailure, ["mycert", "mycert", "mycert"]);
+    },
+    // Test verifying a signed MAR file with the correct signatures but in
+    // a different order fails
+    test_verify_multiple_wrong_order:
+      function _test_verify_multiple_wrong_order() {
+        let signedMAR = do_get_file("data/multiple_signed_pib.mar");
+        verifyMAR(signedMAR, wantSuccess, ["mycert", "mycert2", "mycert3"]);
+        verifyMAR(signedMAR, wantFailure, ["mycert", "mycert3", "mycert2"]);
+        verifyMAR(signedMAR, wantFailure, ["mycert2", "mycert", "mycert3"]);
+        verifyMAR(signedMAR, wantFailure, ["mycert2", "mycert3", "mycert"]);
+        verifyMAR(signedMAR, wantFailure, ["mycert3", "mycert", "mycert2"]);
+        verifyMAR(signedMAR, wantFailure, ["mycert3", "mycert2", "mycert"]);
+      },
+    // Test verifying a signed MAR file without a PIB
+    test_verify_no_pib: function _test_verify_no_pib() {
+      let signedMAR = do_get_file("data/signed_no_pib.mar");
+      verifyMAR(signedMAR, wantSuccess, ["mycert"], true);
+      verifyMAR(signedMAR, wantSuccess, ["mycert"], false);
+    },
+    // Test verifying a signed MAR file with multiple signatures without a PIB
+    test_verify_no_pib_multiple: function _test_verify_no_pib_multiple() {
+      let signedMAR = do_get_file("data/multiple_signed_no_pib.mar");
+      verifyMAR(signedMAR, wantSuccess, ["mycert", "mycert2", "mycert3"]);
+    },
+    // Test verifying a crafted MAR file where the attacker tried to adjust
+    // the version number manually.
+    test_crafted_mar: function _test_crafted_mar() {
+      let signedBadMAR = do_get_file("data/manipulated_signed.mar");
+      verifyMAR(signedBadMAR, wantFailure, ["mycert"], true);
+      verifyMAR(signedBadMAR, wantFailure, ["mycert"], false);
+    },
+    // Test verifying a file that doesn't exist fails
+    test_bad_path_verify_fails: function _test_bad_path_verify_fails() {
+      let noMAR = do_get_file("data/does_not_exist.mar", true);
+      Assert.ok(!noMAR.exists());
+      verifyMAR(noMAR, wantFailure, ["mycert"], true);
+    },
+    // Test to make sure a stripped MAR is the same as the original MAR
+    test_strip_signature: function _test_strip_signature() {
+      let originalMAR = do_get_file("data/binary_data.mar");
+      let signedMAR = tempDir.clone();
+      signedMAR.append("signed_out.mar");
+      let outMAR = tempDir.clone();
+      outMAR.append("out.mar", true);
+      stripMARSignature(signedMAR, outMAR, wantSuccess);
+
+      // Verify that the stripped MAR matches the original data MAR exactly
+      let outMARData = getBinaryFileData(outMAR);
+      let originalMARData = getBinaryFileData(originalMAR);
+      compareBinaryData(outMARData, originalMARData);
+    },
+    // Test to make sure a stripped multi-signature-MAR is the same as the original MAR
+    test_strip_multiple_signatures: function _test_strip_multiple_signatures() {
+      let originalMAR = do_get_file("data/binary_data.mar");
+      let signedMAR = tempDir.clone();
+      signedMAR.append("multiple_signed_out.mar");
+      let outMAR = tempDir.clone();
+      outMAR.append("out.mar");
+      stripMARSignature(signedMAR, outMAR, wantSuccess);
+
+      // Verify that the stripped MAR matches the original data MAR exactly
+      let outMARData = getBinaryFileData(outMAR);
+      let originalMARData = getBinaryFileData(originalMAR);
+      compareBinaryData(outMARData, originalMARData);
+    },
+    // Test extracting the first signature in a MAR that has only a single signature
+    test_extract_sig_single: function _test_extract_sig_single() {
+      let inMAR = do_get_file("data/signed_pib.mar");
+      let extractedSig = do_get_file("extracted_signature", true);
+      if (extractedSig.exists()) {
+        extractedSig.remove(false);
+      }
+      extractMARSignature(inMAR, 0, extractedSig, wantSuccess);
+      Assert.ok(extractedSig.exists());
+
+      let referenceSig = do_get_file("data/signed_pib_mar.signature.0");
+      compareBinaryData(extractedSig, referenceSig);
+    },
+    // Test extracting the all signatures in a multi signature MAR
+    // The input MAR has 3 signatures.
+    test_extract_sig_multi: function _test_extract_sig_multi() {
+      for (let i = 0; i < 3; i++) {
+        let inMAR = do_get_file("data/multiple_signed_pib.mar");
+        let extractedSig = do_get_file("extracted_signature", true);
+        if (extractedSig.exists()) {
+          extractedSig.remove(false);
+        }
+        extractMARSignature(inMAR, i, extractedSig, wantSuccess);
+        Assert.ok(extractedSig.exists());
+
+        let referenceSig = do_get_file("data/multiple_signed_pib_mar.sig." + i);
+        compareBinaryData(extractedSig, referenceSig);
+      }
+    },
+    // Test extracting a signature that is out of range fails
+    test_extract_sig_out_of_range: function _test_extract_sig_out_of_range() {
+      let inMAR = do_get_file("data/signed_pib.mar");
+      let extractedSig = do_get_file("extracted_signature", true);
+      if (extractedSig.exists()) {
+        extractedSig.remove(false);
+      }
+      const outOfBoundsIndex = 5;
+      extractMARSignature(inMAR, outOfBoundsIndex, extractedSig, wantFailure);
+      Assert.ok(!extractedSig.exists());
+    },
+    // Test signing a file that doesn't exist fails
+    test_bad_path_sign_fails: function _test_bad_path_sign_fails() {
+      let inMAR = do_get_file("data/does_not_exist.mar", true);
+      let outMAR = tempDir.clone();
+      outMAR.append("signed_out.mar");
+      Assert.ok(!inMAR.exists());
+      signMAR(inMAR, outMAR, ["mycert"], wantFailure, true);
+      Assert.ok(!outMAR.exists());
+    },
+    // Test verifying only a subset of the signatures fails.
+    // The input MAR has: mycert, mycert2, mycert3.
+    // We're only verifying 2 of the 3 signatures and that should fail.
+    test_verify_multiple_subset: function _test_verify_multiple_subset() {
+      let signedMAR = do_get_file("data/multiple_signed_pib.mar");
+      verifyMAR(signedMAR, wantFailure, ["mycert", "mycert2"]);
+    },
+    // Test importing the first signature in a MAR that has only
+    // a single signature
+    test_import_sig_single: function _test_import_sig_single() {
+      // Make sure the input MAR was signed with mycert only
+      let inMAR = do_get_file("data/signed_pib.mar");
+      verifyMAR(inMAR, wantSuccess, ["mycert"], false);
+      verifyMAR(inMAR, wantFailure, ["mycert2"], false);
+      verifyMAR(inMAR, wantFailure, ["mycert3"], false);
+
+      // Get the signature file for this MAR signed with the key from mycert2
+      let sigFile = do_get_file("data/signed_pib_mar.signature.mycert2");
+      Assert.ok(sigFile.exists());
+      let outMAR = tempDir.clone();
+      outMAR.append("sigchanged_signed_pib.mar");
+      if (outMAR.exists()) {
+        outMAR.remove(false);
+      }
+
+      // Run the import operation
+      importMARSignature(inMAR, 0, sigFile, outMAR, wantSuccess);
+
+      // Verify we have a new MAR file, that mycert no longer verifies and that,
+      // mycert2 does verify
+      Assert.ok(outMAR.exists());
+      verifyMAR(outMAR, wantFailure, ["mycert"], false);
+      verifyMAR(outMAR, wantSuccess, ["mycert2"], false);
+      verifyMAR(outMAR, wantFailure, ["mycert3"], false);
+
+      // Compare the binary data to something that was signed originally
+      // with the private key from mycert2
+      let refMAR = do_get_file("data/signed_pib_with_mycert2.mar");
+      Assert.ok(refMAR.exists());
+      let refMARData = getBinaryFileData(refMAR);
+      let outMARData = getBinaryFileData(outMAR);
+      compareBinaryData(outMARData, refMARData);
+    },
+    // Test importing a signature that doesn't belong to the file
+    // fails to verify.
+    test_import_wrong_sig: function _test_import_wrong_sig() {
+      // Make sure the input MAR was signed with mycert only
+      let inMAR = do_get_file("data/signed_pib.mar");
+      verifyMAR(inMAR, wantSuccess, ["mycert"], false);
+      verifyMAR(inMAR, wantFailure, ["mycert2"], false);
+      verifyMAR(inMAR, wantFailure, ["mycert3"], false);
+
+      // Get the signature file for multiple_signed_pib.mar signed with the
+      // key from mycert
+      let sigFile = do_get_file("data/multiple_signed_pib_mar.sig.0");
+      Assert.ok(sigFile.exists());
+      let outMAR = tempDir.clone();
+      outMAR.append("sigchanged_signed_pib.mar");
+      if (outMAR.exists()) {
+        outMAR.remove(false);
+      }
+
+      // Run the import operation
+      importMARSignature(inMAR, 0, sigFile, outMAR, wantSuccess);
+
+      // Verify we have a new MAR file and that the mar file fails to verify
+      // when using a signature for another mar file.
+      Assert.ok(outMAR.exists());
+      verifyMAR(outMAR, wantFailure, ["mycert"], false);
+      verifyMAR(outMAR, wantFailure, ["mycert2"], false);
+      verifyMAR(outMAR, wantFailure, ["mycert3"], false);
+    },
+    // Test importing to the second signature in a MAR that has multiple
+    // signature
+    test_import_sig_multiple: function _test_import_sig_multiple() {
+      // Make sure the input MAR was signed with mycert only
+      let inMAR = do_get_file("data/multiple_signed_pib.mar");
+      verifyMAR(inMAR, wantSuccess, ["mycert", "mycert2", "mycert3"], false);
+      verifyMAR(inMAR, wantFailure, ["mycert", "mycert", "mycert3"], false);
+
+      // Get the signature file for this MAR signed with the key from mycert
+      let sigFile = do_get_file("data/multiple_signed_pib_mar.sig.0");
+      Assert.ok(sigFile.exists());
+      let outMAR = tempDir.clone();
+      outMAR.append("sigchanged_signed_pib.mar");
+      if (outMAR.exists()) {
+        outMAR.remove(false);
+      }
+
+      // Run the import operation
+      const secondSigPos = 1;
+      importMARSignature(inMAR, secondSigPos, sigFile, outMAR, wantSuccess);
+
+      // Verify we have a new MAR file and that mycert no longer verifies
+      // and that mycert2 does verify
+      Assert.ok(outMAR.exists());
+      verifyMAR(outMAR, wantSuccess, ["mycert", "mycert", "mycert3"], false);
+      verifyMAR(outMAR, wantFailure, ["mycert", "mycert2", "mycert3"], false);
+
+      // Compare the binary data to something that was signed originally
+      // with the private keys from mycert, mycert, mycert3
+      let refMAR = do_get_file("data/multiple_signed_pib_2.mar");
+      Assert.ok(refMAR.exists());
+      let refMARData = getBinaryFileData(refMAR);
+      let outMARData = getBinaryFileData(outMAR);
+      compareBinaryData(outMARData, refMARData);
+    },
+    // Test stripping a MAR that doesn't exist fails
+    test_bad_path_strip_fails: function _test_bad_path_strip_fails() {
+      let noMAR = do_get_file("data/does_not_exist.mar", true);
+      Assert.ok(!noMAR.exists());
+      let outMAR = tempDir.clone();
+      outMAR.append("out.mar");
+      stripMARSignature(noMAR, outMAR, wantFailure);
+    },
+    // Test extracting from a bad path fails
+    test_extract_bad_path: function _test_extract_bad_path() {
+      let noMAR = do_get_file("data/does_not_exist.mar", true);
+      let extractedSig = do_get_file("extracted_signature", true);
+      Assert.ok(!noMAR.exists());
+      if (extractedSig.exists()) {
+        extractedSig.remove(false);
+      }
+      extractMARSignature(noMAR, 0, extractedSig, wantFailure);
+      Assert.ok(!extractedSig.exists());
+    },
+    // Between each test make sure the out MAR does not exist.
+    cleanup_per_test: function _cleanup_per_test() {},
+  };
+
+  cleanup();
+
+  // Run all the tests
+  Assert.equal(run_tests(tests), Object.keys(tests).length - 1);
+
+  registerCleanupFunction(cleanup);
+}
diff --git a/modules/libmar/tests/unit/xpcshell.ini b/modules/libmar/tests/unit/xpcshell.ini
new file mode 100644
index 0000000000..c677d46438
--- /dev/null
+++ b/modules/libmar/tests/unit/xpcshell.ini
@@ -0,0 +1,8 @@
+[DEFAULT]
+head = head_libmar.js
+support-files = data/**
+skip-if = os == 'win' && msix # Updates are disabled for MSIX builds
+
+[test_create.js]
+[test_extract.js]
+[test_sign_verify.js]
diff --git a/modules/libmar/tool/mar.c b/modules/libmar/tool/mar.c
new file mode 100644
index 0000000000..449c9f7efc
--- /dev/null
+++ b/modules/libmar/tool/mar.c
@@ -0,0 +1,447 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "mar.h"
+#include "mar_cmdline.h"
+
+#ifdef XP_WIN
+#  include <windows.h>
+#  include <direct.h>
+#  define chdir _chdir
+#else
+#  include <unistd.h>
+#endif
+
+#if !defined(NO_SIGN_VERIFY) && (!defined(XP_WIN) || defined(MAR_NSS))
+#  include "cert.h"
+#  include "nss.h"
+#  include "pk11pub.h"
+int NSSInitCryptoContext(const char* NSSConfigDir);
+#endif
+
+int mar_repackage_and_sign(const char* NSSConfigDir,
+                           const char* const* certNames, uint32_t certCount,
+                           const char* src, const char* dest);
+
+static void print_version() {
+  printf("Version: %s\n", MOZ_APP_VERSION);
+  printf("Default Channel ID: %s\n", MAR_CHANNEL_ID);
+}
+
+static void print_usage() {
+  printf("usage:\n");
+  printf("Create a MAR file:\n");
+  printf(
+      "  mar -H MARChannelID -V ProductVersion [-C workingDir] "
+      "-c archive.mar [files...]\n");
+
+  printf("Extract a MAR file:\n");
+  printf("  mar [-C workingDir] -x archive.mar\n");
+#ifndef NO_SIGN_VERIFY
+  printf("Sign a MAR file:\n");
+  printf(
+      "  mar [-C workingDir] -d NSSConfigDir -n certname -s "
+      "archive.mar out_signed_archive.mar\n");
+
+  printf("Strip a MAR signature:\n");
+  printf(
+      "  mar [-C workingDir] -r "
+      "signed_input_archive.mar output_archive.mar\n");
+
+  printf("Extract a MAR signature:\n");
+  printf(
+      "  mar [-C workingDir] -n(i) -X "
+      "signed_input_archive.mar base_64_encoded_signature_file\n");
+
+  printf("Import a MAR signature:\n");
+  printf(
+      "  mar [-C workingDir] -n(i) -I "
+      "signed_input_archive.mar base_64_encoded_signature_file "
+      "changed_signed_output.mar\n");
+  printf("(i) is the index of the certificate to extract\n");
+#  if defined(XP_MACOSX) || (defined(XP_WIN) && !defined(MAR_NSS))
+  printf("Verify a MAR file:\n");
+  printf("  mar [-C workingDir] -D DERFilePath -v signed_archive.mar\n");
+  printf(
+      "At most %d signature certificate DER files are specified by "
+      "-D0 DERFilePath1 -D1 DERFilePath2, ...\n",
+      MAX_SIGNATURES);
+#  else
+  printf("Verify a MAR file:\n");
+  printf(
+      "  mar [-C workingDir] -d NSSConfigDir -n certname "
+      "-v signed_archive.mar\n");
+  printf(
+      "At most %d signature certificate names are specified by "
+      "-n0 certName -n1 certName2, ...\n",
+      MAX_SIGNATURES);
+#  endif
+  printf(
+      "At most %d verification certificate names are specified by "
+      "-n0 certName -n1 certName2, ...\n",
+      MAX_SIGNATURES);
+#endif
+  printf("Print information on a MAR file:\n");
+  printf("  mar -t archive.mar\n");
+
+  printf("Print detailed information on a MAR file including signatures:\n");
+  printf("  mar -T archive.mar\n");
+
+  printf("Refresh the product information block of a MAR file:\n");
+  printf(
+      "  mar -H MARChannelID -V ProductVersion [-C workingDir] "
+      "-i unsigned_archive_to_refresh.mar\n");
+
+  printf("Print executable version:\n");
+  printf("  mar --version\n");
+  printf("This program does not handle unicode file paths properly\n");
+}
+
+static int mar_test_callback(MarFile* mar, const MarItem* item, void* unused) {
+  printf("%u\t0%o\t%s\n", item->length, item->flags, item->name);
+  return 0;
+}
+
+static int mar_test(const char* path) {
+  MarFile* mar;
+
+  MarReadResult result = mar_open(path, &mar);
+  if (result != MAR_READ_SUCCESS) {
+    return -1;
+  }
+
+  printf("SIZE\tMODE\tNAME\n");
+  mar_enum_items(mar, mar_test_callback, NULL);
+
+  mar_close(mar);
+  return 0;
+}
+
+int main(int argc, char** argv) {
+  const char* certNames[MAX_SIGNATURES];
+  char* MARChannelID = NULL;
+  char* productVersion = NULL;
+  int rv = -1;
+#if !defined(NO_SIGN_VERIFY)
+  char* NSSConfigDir = NULL;
+  uint32_t k;
+  uint32_t certCount = 0;
+  int32_t sigIndex = -1;
+  uint32_t fileSizes[MAX_SIGNATURES];
+  const uint8_t* certBuffers[MAX_SIGNATURES];
+#  if ((!defined(MAR_NSS) && defined(XP_WIN)) || defined(XP_MACOSX)) || \
+      ((defined(XP_WIN) || defined(XP_MACOSX)) && !defined(MAR_NSS))
+  char* DERFilePaths[MAX_SIGNATURES];
+#  endif
+#  if (!defined(XP_WIN) && !defined(XP_MACOSX)) || defined(MAR_NSS)
+  CERTCertificate* certs[MAX_SIGNATURES];
+#  endif
+#endif
+
+  memset((void*)certNames, 0, sizeof(certNames));
+#if defined(XP_WIN) && !defined(MAR_NSS) && !defined(NO_SIGN_VERIFY)
+  memset((void*)certBuffers, 0, sizeof(certBuffers));
+#endif
+#if !defined(NO_SIGN_VERIFY) && \
+    ((!defined(MAR_NSS) && defined(XP_WIN)) || defined(XP_MACOSX))
+  memset(DERFilePaths, 0, sizeof(DERFilePaths));
+  memset(fileSizes, 0, sizeof(fileSizes));
+#endif
+
+  if (argc > 1 && 0 == strcmp(argv[1], "--version")) {
+    print_version();
+    return 0;
+  }
+
+  if (argc < 3) {
+    print_usage();
+    return -1;
+  }
+
+  while (argc > 0) {
+    if (argv[1][0] == '-' &&
+        (argv[1][1] == 'c' || argv[1][1] == 't' || argv[1][1] == 'x' ||
+         argv[1][1] == 'v' || argv[1][1] == 's' || argv[1][1] == 'i' ||
+         argv[1][1] == 'T' || argv[1][1] == 'r' || argv[1][1] == 'X' ||
+         argv[1][1] == 'I')) {
+      break;
+      /* -C workingdirectory */
+    }
+    if (argv[1][0] == '-' && argv[1][1] == 'C') {
+      if (chdir(argv[2]) != 0) {
+        return -1;
+      }
+      argv += 2;
+      argc -= 2;
+    }
+#if !defined(NO_SIGN_VERIFY)
+#  if (!defined(MAR_NSS) && defined(XP_WIN)) || defined(XP_MACOSX)
+    /* -D DERFilePath, also matches -D[index] DERFilePath
+       We allow an index for verifying to be symmetric
+       with the import and export command line arguments. */
+    else if (argv[1][0] == '-' && argv[1][1] == 'D' &&
+             (argv[1][2] == (char)('0' + certCount) || argv[1][2] == '\0')) {
+      if (certCount >= MAX_SIGNATURES) {
+        print_usage();
+        return -1;
+      }
+      DERFilePaths[certCount++] = argv[2];
+      argv += 2;
+      argc -= 2;
+    }
+#  endif
+    /* -d NSSConfigdir */
+    else if (argv[1][0] == '-' && argv[1][1] == 'd') {
+      NSSConfigDir = argv[2];
+      argv += 2;
+      argc -= 2;
+      /* -n certName, also matches -n[index] certName
+         We allow an index for verifying to be symmetric
+         with the import and export command line arguments. */
+    } else if (argv[1][0] == '-' && argv[1][1] == 'n' &&
+               (argv[1][2] == (char)('0' + certCount) || argv[1][2] == '\0' ||
+                !strcmp(argv[2], "-X") || !strcmp(argv[2], "-I"))) {
+      if (certCount >= MAX_SIGNATURES) {
+        print_usage();
+        return -1;
+      }
+      certNames[certCount++] = argv[2];
+      if (strlen(argv[1]) > 2 &&
+          (!strcmp(argv[2], "-X") || !strcmp(argv[2], "-I")) &&
+          argv[1][2] >= '0' && argv[1][2] <= '9') {
+        sigIndex = argv[1][2] - '0';
+        argv++;
+        argc--;
+      } else {
+        argv += 2;
+        argc -= 2;
+      }
+    }
+#endif
+    else if (argv[1][0] == '-' && argv[1][1] == 'H') {  // MAR channel ID
+      MARChannelID = argv[2];
+      argv += 2;
+      argc -= 2;
+    } else if (argv[1][0] == '-' && argv[1][1] == 'V') {  // Product Version
+      productVersion = argv[2];
+      argv += 2;
+      argc -= 2;
+    } else {
+      print_usage();
+      return -1;
+    }
+  }
+
+  if (argv[1][0] != '-') {
+    print_usage();
+    return -1;
+  }
+
+  switch (argv[1][1]) {
+    case 'c': {
+      struct ProductInformationBlock infoBlock;
+      if (!productVersion) {
+        fprintf(stderr,
+                "ERROR: Version not specified (pass `-V <version>`).\n");
+        return -1;
+      }
+      if (!MARChannelID) {
+        fprintf(stderr,
+                "ERROR: MAR channel ID not specified (pass `-H "
+                "<mar-channel-id>`).\n");
+        return -1;
+      }
+      infoBlock.MARChannelID = MARChannelID;
+      infoBlock.productVersion = productVersion;
+      return mar_create(argv[2], argc - 3, argv + 3, &infoBlock);
+    }
+    case 'i': {
+      if (!productVersion) {
+        fprintf(stderr,
+                "ERROR: Version not specified (pass `-V <version>`).\n");
+        return -1;
+      }
+      if (!MARChannelID) {
+        fprintf(stderr,
+                "ERROR: MAR channel ID not specified (pass `-H "
+                "<mar-channel-id>`).\n");
+        return -1;
+      }
+      struct ProductInformationBlock infoBlock;
+      infoBlock.MARChannelID = MARChannelID;
+      infoBlock.productVersion = productVersion;
+      return refresh_product_info_block(argv[2], &infoBlock);
+    }
+    case 'T': {
+      struct ProductInformationBlock infoBlock;
+      uint32_t numSignatures, numAdditionalBlocks;
+      int hasSignatureBlock, hasAdditionalBlock;
+      if (!get_mar_file_info(argv[2], &hasSignatureBlock, &numSignatures,
+                             &hasAdditionalBlock, NULL, &numAdditionalBlocks)) {
+        if (hasSignatureBlock) {
+          printf("Signature block found with %d signature%s\n", numSignatures,
+                 numSignatures != 1 ? "s" : "");
+        }
+        if (hasAdditionalBlock) {
+          printf("%d additional block%s found:\n", numAdditionalBlocks,
+                 numAdditionalBlocks != 1 ? "s" : "");
+        }
+
+        rv = read_product_info_block(argv[2], &infoBlock);
+        if (!rv) {
+          printf("  - Product Information Block:\n");
+          printf(
+              "    - MAR channel name: %s\n"
+              "    - Product version: %s\n",
+              infoBlock.MARChannelID, infoBlock.productVersion);
+          free((void*)infoBlock.MARChannelID);
+          free((void*)infoBlock.productVersion);
+        }
+      }
+      printf("\n");
+      /* The fall through from 'T' to 't' is intentional */
+    }
+    case 't':
+      return mar_test(argv[2]);
+
+    case 'x':  // Extract a MAR file
+      return mar_extract(argv[2]);
+
+#ifndef NO_SIGN_VERIFY
+    case 'X':  // Extract a MAR signature
+      if (sigIndex == -1) {
+        fprintf(stderr, "ERROR: Signature index was not passed.\n");
+        return -1;
+      }
+      if (sigIndex >= MAX_SIGNATURES || sigIndex < -1) {
+        fprintf(stderr, "ERROR: Signature index is out of range: %d.\n",
+                sigIndex);
+        return -1;
+      }
+      return extract_signature(argv[2], sigIndex, argv[3]);
+
+    case 'I':  // Import a MAR signature
+      if (sigIndex == -1) {
+        fprintf(stderr, "ERROR: signature index was not passed.\n");
+        return -1;
+      }
+      if (sigIndex >= MAX_SIGNATURES || sigIndex < -1) {
+        fprintf(stderr, "ERROR: Signature index is out of range: %d.\n",
+                sigIndex);
+        return -1;
+      }
+      if (argc < 5) {
+        print_usage();
+        return -1;
+      }
+      return import_signature(argv[2], sigIndex, argv[3], argv[4]);
+
+    case 'v':
+      if (certCount == 0) {
+        print_usage();
+        return -1;
+      }
+
+#  if (!defined(XP_WIN) && !defined(XP_MACOSX)) || defined(MAR_NSS)
+      if (!NSSConfigDir || certCount == 0) {
+        print_usage();
+        return -1;
+      }
+
+      if (NSSInitCryptoContext(NSSConfigDir)) {
+        fprintf(stderr, "ERROR: Could not initialize crypto library.\n");
+        return -1;
+      }
+#  endif
+
+      rv = 0;
+      for (k = 0; k < certCount; ++k) {
+#  if (defined(XP_WIN) || defined(XP_MACOSX)) && !defined(MAR_NSS)
+        rv = mar_read_entire_file(DERFilePaths[k], MAR_MAX_CERT_SIZE,
+                                  &certBuffers[k], &fileSizes[k]);
+
+        if (rv) {
+          fprintf(stderr, "ERROR: could not read file %s", DERFilePaths[k]);
+          break;
+        }
+#  else
+        /* It is somewhat circuitous to look up a CERTCertificate and then pass
+         * in its DER encoding just so we can later re-create that
+         * CERTCertificate to extract the public key out of it. However, by
+         * doing things this way, we maximize the reuse of the
+         * mar_verify_signatures function and also we keep the control flow as
+         * similar as possible between programs and operating systems, at least
+         * for the functions that are critically important to security.
+         */
+        certs[k] = PK11_FindCertFromNickname(certNames[k], NULL);
+        if (certs[k]) {
+          certBuffers[k] = certs[k]->derCert.data;
+          fileSizes[k] = certs[k]->derCert.len;
+        } else {
+          rv = -1;
+          fprintf(stderr, "ERROR: could not find cert from nickname %s",
+                  certNames[k]);
+          break;
+        }
+#  endif
+      }
+
+      if (!rv) {
+        MarFile* mar;
+        MarReadResult result = mar_open(argv[2], &mar);
+        if (result == MAR_READ_SUCCESS) {
+          rv = mar_verify_signatures(mar, certBuffers, fileSizes, certCount);
+          mar_close(mar);
+        } else {
+          fprintf(stderr, "ERROR: Could not open MAR file.\n");
+          rv = -1;
+        }
+      }
+      for (k = 0; k < certCount; ++k) {
+#  if (defined(XP_WIN) || defined(XP_MACOSX)) && !defined(MAR_NSS)
+        free((void*)certBuffers[k]);
+#  else
+        /* certBuffers[k] is owned by certs[k] so don't free it */
+        CERT_DestroyCertificate(certs[k]);
+#  endif
+      }
+      if (rv) {
+        /* Determine if the source MAR file has the new fields for signing */
+        int hasSignatureBlock;
+        if (get_mar_file_info(argv[2], &hasSignatureBlock, NULL, NULL, NULL,
+                              NULL)) {
+          fprintf(stderr, "ERROR: could not determine if MAR is old or new.\n");
+        } else if (!hasSignatureBlock) {
+          fprintf(stderr,
+                  "ERROR: The MAR file is in the old format so has"
+                  " no signature to verify.\n");
+        }
+      }
+#  if (!defined(XP_WIN) && !defined(XP_MACOSX)) || defined(MAR_NSS)
+      (void)NSS_Shutdown();
+#  endif
+      return rv ? -1 : 0;
+
+    case 's':
+      if (!NSSConfigDir || certCount == 0 || argc < 4) {
+        print_usage();
+        return -1;
+      }
+      return mar_repackage_and_sign(NSSConfigDir, certNames, certCount, argv[2],
+                                    argv[3]);
+
+    case 'r':
+      return strip_signature_block(argv[2], argv[3]);
+#endif /* endif NO_SIGN_VERIFY disabled */
+
+    default:
+      print_usage();
+      return -1;
+  }
+}
diff --git a/modules/libmar/tool/moz.build b/modules/libmar/tool/moz.build
new file mode 100644
index 0000000000..0f25dcc10a
--- /dev/null
+++ b/modules/libmar/tool/moz.build
@@ -0,0 +1,66 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+HOST_SOURCES += [
+    "/other-licenses/nsis/Contrib/CityHash/cityhash/city.cpp",
+    "mar.c",
+]
+
+HostProgram("mar")
+
+HOST_USE_LIBS += [
+    "hostmar",
+]
+
+if CONFIG["HOST_OS_ARCH"] == "WINNT":
+    HOST_OS_LIBS += [
+        "ws2_32",
+    ]
+
+# C11 for static_assert
+c11_flags = ["-std=gnu11"]
+if CONFIG["CC_TYPE"] == "clang-cl":
+    c11_flags.insert(0, "-Xclang")
+HOST_CFLAGS += c11_flags
+
+HOST_DEFINES["NO_SIGN_VERIFY"] = True
+
+if CONFIG["MOZ_BUILD_APP"] != "tools/update-packaging":
+    Program("signmar")
+
+    SOURCES += HOST_SOURCES
+
+    CFLAGS += c11_flags
+
+    USE_LIBS += [
+        "mar",
+        "nspr",
+        "nss",
+        "signmar",
+        "verifymar",
+    ]
+
+    if CONFIG["OS_ARCH"] == "WINNT":
+        USE_STATIC_LIBS = True
+
+        OS_LIBS += [
+            "ws2_32",
+            "crypt32",
+            "advapi32",
+        ]
+    elif CONFIG["OS_ARCH"] == "Darwin":
+        OS_LIBS += [
+            "-framework CoreFoundation",
+            "-framework Security",
+        ]
+
+    DisableStlWrapping()
+
+
+for var in ("MAR_CHANNEL_ID", "MOZ_APP_VERSION"):
+    HOST_DEFINES[var] = '"%s"' % CONFIG[var]
+    if SOURCES:
+        DEFINES[var] = HOST_DEFINES[var]
diff --git a/modules/libmar/verify/MacVerifyCrypto.cpp b/modules/libmar/verify/MacVerifyCrypto.cpp
new file mode 100644
index 0000000000..d1d1200fef
--- /dev/null
+++ b/modules/libmar/verify/MacVerifyCrypto.cpp
@@ -0,0 +1,218 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <CoreFoundation/CoreFoundation.h>
+#include <Security/Security.h>
+#include <dlfcn.h>
+
+#include "cryptox.h"
+
+// We declare the necessary parts of the Security Transforms API here since
+// we're building with the 10.6 SDK, which doesn't know about Security
+// Transforms.
+#if defined(__cplusplus)
+extern "C" {
+#endif
+const CFStringRef kSecTransformInputAttributeName = CFSTR("INPUT");
+typedef CFTypeRef SecTransformRef;
+typedef OpaqueSecKeyRef* SecKeyRef;
+
+typedef SecTransformRef (*SecTransformCreateReadTransformWithReadStreamFunc)(
+    CFReadStreamRef inputStream);
+SecTransformCreateReadTransformWithReadStreamFunc
+    SecTransformCreateReadTransformWithReadStreamPtr = NULL;
+typedef CFTypeRef (*SecTransformExecuteFunc)(SecTransformRef transform,
+                                             CFErrorRef* error);
+SecTransformExecuteFunc SecTransformExecutePtr = NULL;
+typedef SecTransformRef (*SecVerifyTransformCreateFunc)(SecKeyRef key,
+                                                        CFDataRef signature,
+                                                        CFErrorRef* error);
+SecVerifyTransformCreateFunc SecVerifyTransformCreatePtr = NULL;
+typedef Boolean (*SecTransformSetAttributeFunc)(SecTransformRef transform,
+                                                CFStringRef key,
+                                                CFTypeRef value,
+                                                CFErrorRef* error);
+SecTransformSetAttributeFunc SecTransformSetAttributePtr = NULL;
+#if defined(__cplusplus)
+}
+#endif
+
+CryptoX_Result CryptoMac_InitCryptoProvider() {
+  if (!SecTransformCreateReadTransformWithReadStreamPtr) {
+    SecTransformCreateReadTransformWithReadStreamPtr =
+        (SecTransformCreateReadTransformWithReadStreamFunc)dlsym(
+            RTLD_DEFAULT, "SecTransformCreateReadTransformWithReadStream");
+  }
+  if (!SecTransformExecutePtr) {
+    SecTransformExecutePtr =
+        (SecTransformExecuteFunc)dlsym(RTLD_DEFAULT, "SecTransformExecute");
+  }
+  if (!SecVerifyTransformCreatePtr) {
+    SecVerifyTransformCreatePtr = (SecVerifyTransformCreateFunc)dlsym(
+        RTLD_DEFAULT, "SecVerifyTransformCreate");
+  }
+  if (!SecTransformSetAttributePtr) {
+    SecTransformSetAttributePtr = (SecTransformSetAttributeFunc)dlsym(
+        RTLD_DEFAULT, "SecTransformSetAttribute");
+  }
+  if (!SecTransformCreateReadTransformWithReadStreamPtr ||
+      !SecTransformExecutePtr || !SecVerifyTransformCreatePtr ||
+      !SecTransformSetAttributePtr) {
+    return CryptoX_Error;
+  }
+  return CryptoX_Success;
+}
+
+CryptoX_Result CryptoMac_VerifyBegin(CryptoX_SignatureHandle* aInputData) {
+  if (!aInputData) {
+    return CryptoX_Error;
+  }
+
+  void* inputData = CFDataCreateMutable(kCFAllocatorDefault, 0);
+  if (!inputData) {
+    return CryptoX_Error;
+  }
+
+  *aInputData = inputData;
+  return CryptoX_Success;
+}
+
+CryptoX_Result CryptoMac_VerifyUpdate(CryptoX_SignatureHandle* aInputData,
+                                      void* aBuf, unsigned int aLen) {
+  if (aLen == 0) {
+    return CryptoX_Success;
+  }
+  if (!aInputData || !*aInputData) {
+    return CryptoX_Error;
+  }
+
+  CFMutableDataRef inputData = (CFMutableDataRef)*aInputData;
+
+  CFDataAppendBytes(inputData, (const uint8*)aBuf, aLen);
+  return CryptoX_Success;
+}
+
+CryptoX_Result CryptoMac_LoadPublicKey(const unsigned char* aCertData,
+                                       unsigned int aDataSize,
+                                       CryptoX_PublicKey* aPublicKey) {
+  if (!aCertData || aDataSize == 0 || !aPublicKey) {
+    return CryptoX_Error;
+  }
+  *aPublicKey = NULL;
+  CFDataRef certData = CFDataCreate(kCFAllocatorDefault, aCertData, aDataSize);
+  if (!certData) {
+    return CryptoX_Error;
+  }
+
+  SecCertificateRef cert =
+      SecCertificateCreateWithData(kCFAllocatorDefault, certData);
+  CFRelease(certData);
+  if (!cert) {
+    return CryptoX_Error;
+  }
+
+  OSStatus status = SecCertificateCopyPublicKey(cert, (SecKeyRef*)aPublicKey);
+  CFRelease(cert);
+  if (status != 0) {
+    return CryptoX_Error;
+  }
+
+  return CryptoX_Success;
+}
+
+CryptoX_Result CryptoMac_VerifySignature(CryptoX_SignatureHandle* aInputData,
+                                         CryptoX_PublicKey* aPublicKey,
+                                         const unsigned char* aSignature,
+                                         unsigned int aSignatureLen) {
+  if (!aInputData || !*aInputData || !aPublicKey || !*aPublicKey ||
+      !aSignature || aSignatureLen == 0) {
+    return CryptoX_Error;
+  }
+
+  CFDataRef signatureData =
+      CFDataCreate(kCFAllocatorDefault, aSignature, aSignatureLen);
+  if (!signatureData) {
+    return CryptoX_Error;
+  }
+
+  CFErrorRef error;
+  SecTransformRef verifier = SecVerifyTransformCreatePtr((SecKeyRef)*aPublicKey,
+                                                         signatureData, &error);
+  if (!verifier || error) {
+    if (error) {
+      CFRelease(error);
+    }
+    CFRelease(signatureData);
+    return CryptoX_Error;
+  }
+
+  SecTransformSetAttributePtr(verifier, kSecDigestTypeAttribute, kSecDigestSHA2,
+                              &error);
+  if (error) {
+    CFRelease(error);
+    CFRelease(signatureData);
+    CFRelease(verifier);
+    return CryptoX_Error;
+  }
+
+  int digestLength = 384;
+  CFNumberRef dLen =
+      CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &digestLength);
+  SecTransformSetAttributePtr(verifier, kSecDigestLengthAttribute, dLen,
+                              &error);
+  CFRelease(dLen);
+  if (error) {
+    CFRelease(error);
+    CFRelease(signatureData);
+    CFRelease(verifier);
+    return CryptoX_Error;
+  }
+
+  SecTransformSetAttributePtr(verifier, kSecTransformInputAttributeName,
+                              (CFDataRef)*aInputData, &error);
+  if (error) {
+    CFRelease(error);
+    CFRelease(signatureData);
+    CFRelease(verifier);
+    return CryptoX_Error;
+  }
+
+  CryptoX_Result result = CryptoX_Error;
+  CFTypeRef rv = SecTransformExecutePtr(verifier, &error);
+  if (error) {
+    CFRelease(error);
+    CFRelease(signatureData);
+    CFRelease(verifier);
+    return CryptoX_Error;
+  }
+
+  if (CFGetTypeID(rv) == CFBooleanGetTypeID() &&
+      CFBooleanGetValue((CFBooleanRef)rv) == true) {
+    result = CryptoX_Success;
+  }
+
+  CFRelease(signatureData);
+  CFRelease(verifier);
+
+  return result;
+}
+
+void CryptoMac_FreeSignatureHandle(CryptoX_SignatureHandle* aInputData) {
+  if (!aInputData || !*aInputData) {
+    return;
+  }
+
+  CFMutableDataRef inputData = NULL;
+  inputData = (CFMutableDataRef)*aInputData;
+
+  CFRelease(inputData);
+}
+
+void CryptoMac_FreePublicKey(CryptoX_PublicKey* aPublicKey) {
+  if (!aPublicKey || !*aPublicKey) {
+    return;
+  }
+
+  CFRelease((SecKeyRef)*aPublicKey);
+}
diff --git a/modules/libmar/verify/cryptox.c b/modules/libmar/verify/cryptox.c
new file mode 100644
index 0000000000..8afc13e5e9
--- /dev/null
+++ b/modules/libmar/verify/cryptox.c
@@ -0,0 +1,239 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifdef XP_WIN
+#  ifndef WIN32_LEAN_AND_MEAN
+#    define WIN32_LEAN_AND_MEAN
+#  endif
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include "cryptox.h"
+
+#if defined(MAR_NSS)
+
+/**
+ * Loads the public key for the specified cert name from the NSS store.
+ *
+ * @param certData  The DER-encoded X509 certificate to extract the key from.
+ * @param certDataSize The size of certData.
+ * @param publicKey Out parameter for the public key to use.
+ * @return CryptoX_Success on success, CryptoX_Error on error.
+ */
+CryptoX_Result NSS_LoadPublicKey(const unsigned char* certData,
+                                 unsigned int certDataSize,
+                                 SECKEYPublicKey** publicKey) {
+  CERTCertificate* cert;
+  SECItem certDataItem = {siBuffer, (unsigned char*)certData, certDataSize};
+
+  if (!certData || !publicKey) {
+    return CryptoX_Error;
+  }
+
+  cert = CERT_NewTempCertificate(CERT_GetDefaultCertDB(), &certDataItem, NULL,
+                                 PR_FALSE, PR_TRUE);
+  /* Get the cert and embedded public key out of the database */
+  if (!cert) {
+    return CryptoX_Error;
+  }
+  *publicKey = CERT_ExtractPublicKey(cert);
+  CERT_DestroyCertificate(cert);
+
+  if (!*publicKey) {
+    return CryptoX_Error;
+  }
+  return CryptoX_Success;
+}
+
+CryptoX_Result NSS_VerifyBegin(VFYContext** ctx,
+                               SECKEYPublicKey* const* publicKey) {
+  SECStatus status;
+  if (!ctx || !publicKey || !*publicKey) {
+    return CryptoX_Error;
+  }
+
+  /* Check that the key length is large enough for our requirements */
+  if ((SECKEY_PublicKeyStrength(*publicKey) * 8) <
+      XP_MIN_SIGNATURE_LEN_IN_BYTES) {
+    fprintf(stderr, "ERROR: Key length must be >= %d bytes\n",
+            XP_MIN_SIGNATURE_LEN_IN_BYTES);
+    return CryptoX_Error;
+  }
+
+  *ctx = VFY_CreateContext(*publicKey, NULL,
+                           SEC_OID_PKCS1_SHA384_WITH_RSA_ENCRYPTION, NULL);
+  if (*ctx == NULL) {
+    return CryptoX_Error;
+  }
+
+  status = VFY_Begin(*ctx);
+  return SECSuccess == status ? CryptoX_Success : CryptoX_Error;
+}
+
+/**
+ * Verifies if a verify context matches the passed in signature.
+ *
+ * @param ctx          The verify context that the signature should match.
+ * @param signature    The signature to match.
+ * @param signatureLen The length of the signature.
+ * @return CryptoX_Success on success, CryptoX_Error on error.
+ */
+CryptoX_Result NSS_VerifySignature(VFYContext* const* ctx,
+                                   const unsigned char* signature,
+                                   unsigned int signatureLen) {
+  SECItem signedItem;
+  SECStatus status;
+  if (!ctx || !signature || !*ctx) {
+    return CryptoX_Error;
+  }
+
+  signedItem.len = signatureLen;
+  signedItem.data = (unsigned char*)signature;
+  status = VFY_EndWithSignature(*ctx, &signedItem);
+  return SECSuccess == status ? CryptoX_Success : CryptoX_Error;
+}
+
+#elif defined(XP_WIN)
+/**
+ * Verifies if a signature + public key matches a hash context.
+ *
+ * @param hash      The hash context that the signature should match.
+ * @param pubKey    The public key to use on the signature.
+ * @param signature The signature to check.
+ * @param signatureLen The length of the signature.
+ * @return CryptoX_Success on success, CryptoX_Error on error.
+ */
+CryptoX_Result CryptoAPI_VerifySignature(HCRYPTHASH* hash, HCRYPTKEY* pubKey,
+                                         const BYTE* signature,
+                                         DWORD signatureLen) {
+  DWORD i;
+  BOOL result;
+  /* Windows APIs expect the bytes in the signature to be in little-endian
+   * order, but we write the signature in big-endian order.  Other APIs like
+   * NSS and OpenSSL expect big-endian order.
+   */
+  BYTE* signatureReversed;
+  if (!hash || !pubKey || !signature || signatureLen < 1) {
+    return CryptoX_Error;
+  }
+
+  signatureReversed = malloc(signatureLen);
+  if (!signatureReversed) {
+    return CryptoX_Error;
+  }
+
+  for (i = 0; i < signatureLen; i++) {
+    signatureReversed[i] = signature[signatureLen - 1 - i];
+  }
+  result = CryptVerifySignature(*hash, signatureReversed, signatureLen, *pubKey,
+                                NULL, 0);
+  free(signatureReversed);
+  return result ? CryptoX_Success : CryptoX_Error;
+}
+
+/**
+ * Obtains the public key for the passed in cert data
+ *
+ * @param provider       The cyrto provider
+ * @param certData       Data of the certificate to extract the public key from
+ * @param sizeOfCertData The size of the certData buffer
+ * @param certStore      Pointer to the handle of the certificate store to use
+ * @param CryptoX_Success on success
+ */
+CryptoX_Result CryptoAPI_LoadPublicKey(HCRYPTPROV provider, BYTE* certData,
+                                       DWORD sizeOfCertData,
+                                       HCRYPTKEY* publicKey) {
+  CRYPT_DATA_BLOB blob;
+  CERT_CONTEXT* context;
+  if (!provider || !certData || !publicKey) {
+    return CryptoX_Error;
+  }
+
+  blob.cbData = sizeOfCertData;
+  blob.pbData = certData;
+  if (!CryptQueryObject(CERT_QUERY_OBJECT_BLOB, &blob,
+                        CERT_QUERY_CONTENT_FLAG_CERT,
+                        CERT_QUERY_FORMAT_FLAG_BINARY, 0, NULL, NULL, NULL,
+                        NULL, NULL, (const void**)&context)) {
+    return CryptoX_Error;
+  }
+
+  if (!CryptImportPublicKeyInfo(
+          provider, PKCS_7_ASN_ENCODING | X509_ASN_ENCODING,
+          &context->pCertInfo->SubjectPublicKeyInfo, publicKey)) {
+    CertFreeCertificateContext(context);
+    return CryptoX_Error;
+  }
+
+  CertFreeCertificateContext(context);
+  return CryptoX_Success;
+}
+
+/* Try to acquire context in this way:
+ * 1. Enhanced provider without creating a new key set
+ * 2. Enhanced provider with creating a new key set
+ * 3. Default provider without creating a new key set
+ * 4. Default provider without creating a new key set
+ * #2 and #4 should not be needed because of the CRYPT_VERIFYCONTEXT,
+ * but we add it just in case.
+ *
+ * @param provider Out parameter containing the provider handle.
+ * @return CryptoX_Success on success, CryptoX_Error on error.
+ */
+CryptoX_Result CryptoAPI_InitCryptoContext(HCRYPTPROV* provider) {
+  if (!CryptAcquireContext(provider, NULL, MS_ENH_RSA_AES_PROV, PROV_RSA_AES,
+                           CRYPT_VERIFYCONTEXT)) {
+    if (!CryptAcquireContext(provider, NULL, MS_ENH_RSA_AES_PROV, PROV_RSA_AES,
+                             CRYPT_NEWKEYSET | CRYPT_VERIFYCONTEXT)) {
+      if (!CryptAcquireContext(provider, NULL, NULL, PROV_RSA_AES,
+                               CRYPT_VERIFYCONTEXT)) {
+        if (!CryptAcquireContext(provider, NULL, NULL, PROV_RSA_AES,
+                                 CRYPT_NEWKEYSET | CRYPT_VERIFYCONTEXT)) {
+          *provider = CryptoX_InvalidHandleValue;
+          return CryptoX_Error;
+        }
+      }
+    }
+  }
+  return CryptoX_Success;
+}
+
+/**
+ * Begins a signature verification hash context
+ *
+ * @param provider The crypt provider to use
+ * @param hash     Out parameter for a handle to the hash context
+ * @return CryptoX_Success on success, CryptoX_Error on error.
+ */
+CryptoX_Result CryptoAPI_VerifyBegin(HCRYPTPROV provider, HCRYPTHASH* hash) {
+  BOOL result;
+  if (!provider || !hash) {
+    return CryptoX_Error;
+  }
+
+  *hash = (HCRYPTHASH)NULL;
+  result = CryptCreateHash(provider, CALG_SHA_384, 0, 0, hash);
+  return result ? CryptoX_Success : CryptoX_Error;
+}
+
+/**
+ * Updates a signature verification hash context
+ *
+ * @param hash The hash context to udpate
+ * @param buf  The buffer to update the hash context with
+ * @param len The size of the passed in buffer
+ * @return CryptoX_Success on success, CryptoX_Error on error.
+ */
+CryptoX_Result CryptoAPI_VerifyUpdate(HCRYPTHASH* hash, BYTE* buf, DWORD len) {
+  BOOL result;
+  if (!hash || !buf) {
+    return CryptoX_Error;
+  }
+
+  result = CryptHashData(*hash, buf, len, 0);
+  return result ? CryptoX_Success : CryptoX_Error;
+}
+
+#endif
diff --git a/modules/libmar/verify/cryptox.h b/modules/libmar/verify/cryptox.h
new file mode 100644
index 0000000000..9d7b1f04bc
--- /dev/null
+++ b/modules/libmar/verify/cryptox.h
@@ -0,0 +1,165 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef CRYPTOX_H
+#define CRYPTOX_H
+
+#define XP_MIN_SIGNATURE_LEN_IN_BYTES 256
+
+#define CryptoX_Result int
+#define CryptoX_Success 0
+#define CryptoX_Error (-1)
+#define CryptoX_Succeeded(X) ((X) == CryptoX_Success)
+#define CryptoX_Failed(X) ((X) != CryptoX_Success)
+
+#if defined(MAR_NSS)
+
+#  include "cert.h"
+#  include "keyhi.h"
+#  include "cryptohi.h"
+
+#  define CryptoX_InvalidHandleValue NULL
+#  define CryptoX_ProviderHandle void*
+#  define CryptoX_SignatureHandle VFYContext*
+#  define CryptoX_PublicKey SECKEYPublicKey*
+#  define CryptoX_Certificate CERTCertificate*
+
+#  ifdef __cplusplus
+extern "C" {
+#  endif
+CryptoX_Result NSS_LoadPublicKey(const unsigned char* certData,
+                                 unsigned int certDataSize,
+                                 SECKEYPublicKey** publicKey);
+CryptoX_Result NSS_VerifyBegin(VFYContext** ctx,
+                               SECKEYPublicKey* const* publicKey);
+CryptoX_Result NSS_VerifySignature(VFYContext* const* ctx,
+                                   const unsigned char* signature,
+                                   unsigned int signatureLen);
+#  ifdef __cplusplus
+}  // extern "C"
+#  endif
+
+#  define CryptoX_InitCryptoProvider(CryptoHandle) CryptoX_Success
+#  define CryptoX_VerifyBegin(CryptoHandle, SignatureHandle, PublicKey) \
+    NSS_VerifyBegin(SignatureHandle, PublicKey)
+#  define CryptoX_FreeSignatureHandle(SignatureHandle) \
+    VFY_DestroyContext(*SignatureHandle, PR_TRUE)
+#  define CryptoX_VerifyUpdate(SignatureHandle, buf, len) \
+    VFY_Update(*SignatureHandle, (const unsigned char*)(buf), len)
+#  define CryptoX_LoadPublicKey(CryptoHandle, certData, dataSize, publicKey) \
+    NSS_LoadPublicKey(certData, dataSize, publicKey)
+#  define CryptoX_VerifySignature(hash, publicKey, signedData, len) \
+    NSS_VerifySignature(hash, (const unsigned char*)(signedData), len)
+#  define CryptoX_FreePublicKey(key) SECKEY_DestroyPublicKey(*key)
+#  define CryptoX_FreeCertificate(cert) CERT_DestroyCertificate(*cert)
+
+#elif XP_MACOSX
+
+#  define CryptoX_InvalidHandleValue NULL
+#  define CryptoX_ProviderHandle void*
+#  define CryptoX_SignatureHandle void*
+#  define CryptoX_PublicKey void*
+#  define CryptoX_Certificate void*
+
+// Forward-declare Objective-C functions implemented in MacVerifyCrypto.mm.
+#  ifdef __cplusplus
+extern "C" {
+#  endif
+CryptoX_Result CryptoMac_InitCryptoProvider();
+CryptoX_Result CryptoMac_VerifyBegin(CryptoX_SignatureHandle* aInputData);
+CryptoX_Result CryptoMac_VerifyUpdate(CryptoX_SignatureHandle* aInputData,
+                                      void* aBuf, unsigned int aLen);
+CryptoX_Result CryptoMac_LoadPublicKey(const unsigned char* aCertData,
+                                       unsigned int aDataSize,
+                                       CryptoX_PublicKey* aPublicKey);
+CryptoX_Result CryptoMac_VerifySignature(CryptoX_SignatureHandle* aInputData,
+                                         CryptoX_PublicKey* aPublicKey,
+                                         const unsigned char* aSignature,
+                                         unsigned int aSignatureLen);
+void CryptoMac_FreeSignatureHandle(CryptoX_SignatureHandle* aInputData);
+void CryptoMac_FreePublicKey(CryptoX_PublicKey* aPublicKey);
+#  ifdef __cplusplus
+}  // extern "C"
+#  endif
+
+#  define CryptoX_InitCryptoProvider(aProviderHandle) \
+    CryptoMac_InitCryptoProvider()
+#  define CryptoX_VerifyBegin(aCryptoHandle, aInputData, aPublicKey) \
+    CryptoMac_VerifyBegin(aInputData)
+#  define CryptoX_VerifyUpdate(aInputData, aBuf, aLen) \
+    CryptoMac_VerifyUpdate(aInputData, aBuf, aLen)
+#  define CryptoX_LoadPublicKey(aProviderHandle, aCertData, aDataSize, \
+                                aPublicKey)                            \
+    CryptoMac_LoadPublicKey(aCertData, aDataSize, aPublicKey)
+#  define CryptoX_VerifySignature(aInputData, aPublicKey, aSignature, \
+                                  aSignatureLen)                      \
+    CryptoMac_VerifySignature(aInputData, aPublicKey, aSignature, aSignatureLen)
+#  define CryptoX_FreeSignatureHandle(aInputData) \
+    CryptoMac_FreeSignatureHandle(aInputData)
+#  define CryptoX_FreePublicKey(aPublicKey) CryptoMac_FreePublicKey(aPublicKey)
+#  define CryptoX_FreeCertificate(aCertificate)
+
+#elif defined(XP_WIN)
+
+#  include <windows.h>
+#  include <wincrypt.h>
+
+CryptoX_Result CryptoAPI_InitCryptoContext(HCRYPTPROV* provider);
+CryptoX_Result CryptoAPI_LoadPublicKey(HCRYPTPROV hProv, BYTE* certData,
+                                       DWORD sizeOfCertData,
+                                       HCRYPTKEY* publicKey);
+CryptoX_Result CryptoAPI_VerifyBegin(HCRYPTPROV provider, HCRYPTHASH* hash);
+CryptoX_Result CryptoAPI_VerifyUpdate(HCRYPTHASH* hash, BYTE* buf, DWORD len);
+CryptoX_Result CryptoAPI_VerifySignature(HCRYPTHASH* hash, HCRYPTKEY* pubKey,
+                                         const BYTE* signature,
+                                         DWORD signatureLen);
+
+#  define CryptoX_InvalidHandleValue ((ULONG_PTR)NULL)
+#  define CryptoX_ProviderHandle HCRYPTPROV
+#  define CryptoX_SignatureHandle HCRYPTHASH
+#  define CryptoX_PublicKey HCRYPTKEY
+#  define CryptoX_Certificate HCERTSTORE
+#  define CryptoX_InitCryptoProvider(CryptoHandle) \
+    CryptoAPI_InitCryptoContext(CryptoHandle)
+#  define CryptoX_VerifyBegin(CryptoHandle, SignatureHandle, PublicKey) \
+    CryptoAPI_VerifyBegin(CryptoHandle, SignatureHandle)
+#  define CryptoX_FreeSignatureHandle(SignatureHandle)
+#  define CryptoX_VerifyUpdate(SignatureHandle, buf, len) \
+    CryptoAPI_VerifyUpdate(SignatureHandle, (BYTE*)(buf), len)
+#  define CryptoX_LoadPublicKey(CryptoHandle, certData, dataSize, publicKey) \
+    CryptoAPI_LoadPublicKey(CryptoHandle, (BYTE*)(certData), dataSize,       \
+                            publicKey)
+#  define CryptoX_VerifySignature(hash, publicKey, signedData, len) \
+    CryptoAPI_VerifySignature(hash, publicKey, signedData, len)
+#  define CryptoX_FreePublicKey(key) CryptDestroyKey(*(key))
+#  define CryptoX_FreeCertificate(cert) \
+    CertCloseStore(*(cert), CERT_CLOSE_STORE_FORCE_FLAG);
+
+#else
+
+/* This default implementation is necessary because we don't want to
+ * link to NSS from updater code on non Windows platforms.  On Windows
+ * we use CyrptoAPI instead of NSS.  We don't call any function as they
+ * would just fail, but this simplifies linking.
+ */
+
+#  define CryptoX_InvalidHandleValue NULL
+#  define CryptoX_ProviderHandle void*
+#  define CryptoX_SignatureHandle void*
+#  define CryptoX_PublicKey void*
+#  define CryptoX_Certificate void*
+#  define CryptoX_InitCryptoProvider(CryptoHandle) CryptoX_Error
+#  define CryptoX_VerifyBegin(CryptoHandle, SignatureHandle, PublicKey) \
+    CryptoX_Error
+#  define CryptoX_FreeSignatureHandle(SignatureHandle)
+#  define CryptoX_VerifyUpdate(SignatureHandle, buf, len) CryptoX_Error
+#  define CryptoX_LoadPublicKey(CryptoHandle, certData, dataSize, publicKey) \
+    CryptoX_Error
+#  define CryptoX_VerifySignature(hash, publicKey, signedData, len) \
+    CryptoX_Error
+#  define CryptoX_FreePublicKey(key) CryptoX_Error
+
+#endif
+
+#endif
diff --git a/modules/libmar/verify/mar_verify.c b/modules/libmar/verify/mar_verify.c
new file mode 100644
index 0000000000..5272bb585b
--- /dev/null
+++ b/modules/libmar/verify/mar_verify.c
@@ -0,0 +1,416 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifdef XP_WIN
+#  ifndef WIN32_LEAN_AND_MEAN
+#    define WIN32_LEAN_AND_MEAN
+#  endif
+#endif
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include "mar_private.h"
+#include "mar.h"
+#include "cryptox.h"
+
+int mar_read_entire_file(const char* filePath, uint32_t maxSize,
+                         /*out*/ const uint8_t** data,
+                         /*out*/ uint32_t* size) {
+  int result;
+  FILE* f;
+
+  if (!filePath || !data || !size) {
+    return -1;
+  }
+
+  f = fopen(filePath, "rb");
+  if (!f) {
+    return -1;
+  }
+
+  result = -1;
+  if (!fseeko(f, 0, SEEK_END)) {
+    int64_t fileSize = ftello(f);
+    if (fileSize > 0 && fileSize <= maxSize && !fseeko(f, 0, SEEK_SET)) {
+      unsigned char* fileData;
+
+      *size = (unsigned int)fileSize;
+      fileData = malloc(*size);
+      if (fileData) {
+        if (fread(fileData, *size, 1, f) == 1) {
+          *data = fileData;
+          result = 0;
+        } else {
+          free(fileData);
+        }
+      }
+    }
+  }
+
+  fclose(f);
+
+  return result;
+}
+
+int mar_extract_and_verify_signatures(MarFile* mar,
+                                      CryptoX_ProviderHandle provider,
+                                      CryptoX_PublicKey* keys,
+                                      uint32_t keyCount);
+int mar_verify_extracted_signatures(MarFile* mar,
+                                    CryptoX_ProviderHandle provider,
+                                    CryptoX_PublicKey* keys,
+                                    const uint8_t* const* extractedSignatures,
+                                    uint32_t keyCount, uint32_t* numVerified);
+
+/**
+ * Reads the specified number of bytes from the MAR buffer and
+ * stores them in the passed buffer.
+ *
+ * @param  mar    An opened MAR
+ * @param  mar_position
+ *                Our current position within the MAR file buffer.
+ * @param  buffer The buffer to store the read results.
+ * @param  size   The number of bytes to read, buffer must be
+ *                at least of this size.
+ * @param  ctxs   Pointer to the first element in an array of verify context.
+ * @param  count  The number of elements in ctxs
+ * @param  err    The name of what is being written to in case of error.
+ * @return  CryptoX_Success on success
+ *          CryptoX_Error   on error
+ */
+CryptoX_Result ReadAndUpdateVerifyContext(MarFile* mar, size_t* mar_position,
+                                          void* buffer, uint32_t size,
+                                          CryptoX_SignatureHandle* ctxs,
+                                          uint32_t count, const char* err) {
+  uint32_t k;
+  if (!mar || !mar_position || !buffer || !ctxs || count == 0 || !err) {
+    fprintf(stderr, "ERROR: Invalid parameter specified.\n");
+    return CryptoX_Error;
+  }
+
+  if (!size) {
+    return CryptoX_Success;
+  }
+
+  if (mar_read_buffer(mar, buffer, mar_position, size) != 0) {
+    fprintf(stderr, "ERROR: Could not read %s\n", err);
+    return CryptoX_Error;
+  }
+
+  for (k = 0; k < count; k++) {
+    if (CryptoX_Failed(CryptoX_VerifyUpdate(&ctxs[k], buffer, size))) {
+      fprintf(stderr, "ERROR: Could not update verify context for %s\n", err);
+      return CryptoX_Error;
+    }
+  }
+  return CryptoX_Success;
+}
+
+/**
+ * Verifies a MAR file by verifying each signature with the corresponding
+ * certificate. That is, the first signature will be verified using the first
+ * certificate given, the second signature will be verified using the second
+ * certificate given, etc. The signature count must exactly match the number of
+ * certificates given, and all signature verifications must succeed.
+ *
+ * @param  mar            The file who's signature should be calculated
+ * @param  certData       Pointer to the first element in an array of
+ *                        certificate data
+ * @param  certDataSizes  Pointer to the first element in an array for size of
+ *                        the data stored
+ * @param  certCount      The number of elements in certData and certDataSizes
+ * @return 0 on success
+ */
+int mar_verify_signatures(MarFile* mar, const uint8_t* const* certData,
+                          const uint32_t* certDataSizes, uint32_t certCount) {
+  int rv = -1;
+  CryptoX_ProviderHandle provider = CryptoX_InvalidHandleValue;
+  CryptoX_PublicKey keys[MAX_SIGNATURES];
+  uint32_t k;
+
+  memset(keys, 0, sizeof(keys));
+
+  if (!mar || !certData || !certDataSizes || certCount == 0) {
+    fprintf(stderr, "ERROR: Invalid parameter specified.\n");
+    goto failure;
+  }
+
+  if (CryptoX_Failed(CryptoX_InitCryptoProvider(&provider))) {
+    fprintf(stderr, "ERROR: Could not init crytpo library.\n");
+    goto failure;
+  }
+
+  for (k = 0; k < certCount; ++k) {
+    if (CryptoX_Failed(CryptoX_LoadPublicKey(provider, certData[k],
+                                             certDataSizes[k], &keys[k]))) {
+      fprintf(stderr, "ERROR: Could not load public key.\n");
+      goto failure;
+    }
+  }
+
+  rv = mar_extract_and_verify_signatures(mar, provider, keys, certCount);
+
+failure:
+
+  for (k = 0; k < certCount; ++k) {
+    if (keys[k]) {
+      CryptoX_FreePublicKey(&keys[k]);
+    }
+  }
+
+  return rv;
+}
+
+/**
+ * Extracts each signature from the specified MAR file,
+ * then calls mar_verify_extracted_signatures to verify each signature.
+ *
+ * @param  mar      An opened MAR
+ * @param  provider A library provider
+ * @param  keys     The public keys to use to verify the MAR
+ * @param  keyCount The number of keys pointed to by keys
+ * @return 0 on success
+ */
+int mar_extract_and_verify_signatures(MarFile* mar,
+                                      CryptoX_ProviderHandle provider,
+                                      CryptoX_PublicKey* keys,
+                                      uint32_t keyCount) {
+  uint32_t signatureCount, signatureLen, numVerified = 0;
+  uint32_t signatureAlgorithmIDs[MAX_SIGNATURES];
+  uint8_t* extractedSignatures[MAX_SIGNATURES];
+  uint32_t i;
+  size_t mar_position = 0;
+
+  memset(signatureAlgorithmIDs, 0, sizeof(signatureAlgorithmIDs));
+  memset(extractedSignatures, 0, sizeof(extractedSignatures));
+
+  if (!mar) {
+    fprintf(stderr, "ERROR: Invalid file pointer passed.\n");
+    return CryptoX_Error;
+  }
+
+  /* Skip to the start of the signature block */
+  if (mar_buffer_seek(mar, &mar_position, SIGNATURE_BLOCK_OFFSET) != 0) {
+    fprintf(stderr, "ERROR: Could not seek to the signature block.\n");
+    return CryptoX_Error;
+  }
+
+  /* Get the number of signatures */
+  if (mar_read_buffer(mar, &signatureCount, &mar_position,
+                      sizeof(signatureCount)) != 0) {
+    fprintf(stderr, "ERROR: Could not read number of signatures.\n");
+    return CryptoX_Error;
+  }
+  signatureCount = ntohl(signatureCount);
+
+  /* Check that we have less than the max amount of signatures so we don't
+     waste too much of either updater's or signmar's time. */
+  if (signatureCount > MAX_SIGNATURES) {
+    fprintf(stderr, "ERROR: At most %d signatures can be specified.\n",
+            MAX_SIGNATURES);
+    return CryptoX_Error;
+  }
+
+  for (i = 0; i < signatureCount; i++) {
+    /* Get the signature algorithm ID */
+    if (mar_read_buffer(mar, &signatureAlgorithmIDs[i], &mar_position,
+                        sizeof(uint32_t)) != 0) {
+      fprintf(stderr, "ERROR: Could not read signatures algorithm ID.\n");
+      return CryptoX_Error;
+    }
+    signatureAlgorithmIDs[i] = ntohl(signatureAlgorithmIDs[i]);
+
+    if (mar_read_buffer(mar, &signatureLen, &mar_position, sizeof(uint32_t)) !=
+        0) {
+      fprintf(stderr, "ERROR: Could not read signatures length.\n");
+      return CryptoX_Error;
+    }
+    signatureLen = ntohl(signatureLen);
+
+    /* To protect against invalid input make sure the signature length
+       isn't too big. */
+    if (signatureLen > MAX_SIGNATURE_LENGTH) {
+      fprintf(stderr, "ERROR: Signature length is too large to verify.\n");
+      return CryptoX_Error;
+    }
+
+    extractedSignatures[i] = malloc(signatureLen);
+    if (!extractedSignatures[i]) {
+      fprintf(stderr, "ERROR: Could not allocate buffer for signature.\n");
+      return CryptoX_Error;
+    }
+    if (mar_read_buffer(mar, extractedSignatures[i], &mar_position,
+                        signatureLen) != 0) {
+      fprintf(stderr, "ERROR: Could not read extracted signature.\n");
+      for (i = 0; i < signatureCount; ++i) {
+        free(extractedSignatures[i]);
+      }
+      return CryptoX_Error;
+    }
+
+    /* We don't try to verify signatures we don't know about */
+    if (signatureAlgorithmIDs[i] != 2) {
+      fprintf(stderr, "ERROR: Unknown signature algorithm ID.\n");
+      for (i = 0; i < signatureCount; ++i) {
+        free(extractedSignatures[i]);
+      }
+      return CryptoX_Error;
+    }
+  }
+
+  if (mar_verify_extracted_signatures(
+          mar, provider, keys, (const uint8_t* const*)extractedSignatures,
+          signatureCount, &numVerified) == CryptoX_Error) {
+    return CryptoX_Error;
+  }
+  for (i = 0; i < signatureCount; ++i) {
+    free(extractedSignatures[i]);
+  }
+
+  /* If we reached here and we verified every
+     signature, return success. */
+  if (numVerified == signatureCount && keyCount == numVerified) {
+    return CryptoX_Success;
+  }
+
+  if (numVerified == 0) {
+    fprintf(stderr, "ERROR: Not all signatures were verified.\n");
+  } else {
+    fprintf(stderr, "ERROR: Only %d of %d signatures were verified.\n",
+            numVerified, signatureCount);
+  }
+  return CryptoX_Error;
+}
+
+/**
+ * Verifies a MAR file by verifying each signature with the corresponding
+ * certificate. That is, the first signature will be verified using the first
+ * certificate given, the second signature will be verified using the second
+ * certificate given, etc. The signature count must exactly match the number of
+ * certificates given, and all signature verifications must succeed.
+ *
+ * @param  mar                  An opened MAR
+ * @param  provider             A library provider
+ * @param  keys                 A pointer to the first element in an
+ *                              array of keys.
+ * @param  extractedSignatures  Pointer to the first element in an array
+ *                              of extracted signatures.
+ * @param  signatureCount       The number of signatures in the MAR file
+ * @param numVerified           Out parameter which will be filled with
+ *                              the number of verified signatures.
+ *                              This information can be useful for printing
+ *                              error messages.
+ * @return  CryptoX_Success on success, *numVerified == signatureCount.
+ */
+CryptoX_Result mar_verify_extracted_signatures(
+    MarFile* mar, CryptoX_ProviderHandle provider, CryptoX_PublicKey* keys,
+    const uint8_t* const* extractedSignatures, uint32_t signatureCount,
+    uint32_t* numVerified) {
+  CryptoX_SignatureHandle signatureHandles[MAX_SIGNATURES];
+  char buf[BLOCKSIZE];
+  uint32_t signatureLengths[MAX_SIGNATURES];
+  uint32_t i;
+  int rv = CryptoX_Error;
+  size_t mar_position = 0;
+
+  memset(signatureHandles, 0, sizeof(signatureHandles));
+  memset(signatureLengths, 0, sizeof(signatureLengths));
+
+  if (!extractedSignatures || !numVerified) {
+    fprintf(stderr, "ERROR: Invalid parameter specified.\n");
+    goto failure;
+  }
+
+  *numVerified = 0;
+
+  /* This function is only called when we have at least one signature,
+     but to protected against future people who call this function we
+     make sure a non zero value is passed in.
+   */
+  if (!signatureCount) {
+    fprintf(stderr, "ERROR: There must be at least one signature.\n");
+    goto failure;
+  }
+
+  for (i = 0; i < signatureCount; i++) {
+    if (CryptoX_Failed(
+            CryptoX_VerifyBegin(provider, &signatureHandles[i], &keys[i]))) {
+      fprintf(stderr, "ERROR: Could not initialize signature handle.\n");
+      goto failure;
+    }
+  }
+
+  /* Bytes 0-3: MAR1
+     Bytes 4-7: index offset
+     Bytes 8-15: size of entire MAR
+   */
+  if (CryptoX_Failed(ReadAndUpdateVerifyContext(
+          mar, &mar_position, buf, SIGNATURE_BLOCK_OFFSET + sizeof(uint32_t),
+          signatureHandles, signatureCount, "signature block"))) {
+    goto failure;
+  }
+
+  /* Read the signature block */
+  for (i = 0; i < signatureCount; i++) {
+    /* Get the signature algorithm ID */
+    if (CryptoX_Failed(ReadAndUpdateVerifyContext(
+            mar, &mar_position, &buf, sizeof(uint32_t), signatureHandles,
+            signatureCount, "signature algorithm ID"))) {
+      goto failure;
+    }
+
+    if (CryptoX_Failed(ReadAndUpdateVerifyContext(
+            mar, &mar_position, &signatureLengths[i], sizeof(uint32_t),
+            signatureHandles, signatureCount, "signature length"))) {
+      goto failure;
+    }
+    signatureLengths[i] = ntohl(signatureLengths[i]);
+    if (signatureLengths[i] > MAX_SIGNATURE_LENGTH) {
+      fprintf(stderr, "ERROR: Embedded signature length is too large.\n");
+      goto failure;
+    }
+
+    /* Skip past the signature itself as those are not included */
+    if (mar_buffer_seek(mar, &mar_position, signatureLengths[i]) != 0) {
+      fprintf(stderr, "ERROR: Could not seek past signature.\n");
+      goto failure;
+    }
+  }
+
+  /* Read the rest of the file after the signature block */
+  while (mar_position < mar->data_len) {
+    int numRead = mar_read_buffer_max(mar, buf, &mar_position, BLOCKSIZE);
+    for (i = 0; i < signatureCount; i++) {
+      if (CryptoX_Failed(
+              CryptoX_VerifyUpdate(&signatureHandles[i], buf, numRead))) {
+        fprintf(stderr,
+                "ERROR: Error updating verify context with"
+                " data block.\n");
+        goto failure;
+      }
+    }
+  }
+
+  /* Verify the signatures */
+  for (i = 0; i < signatureCount; i++) {
+    if (CryptoX_Failed(CryptoX_VerifySignature(&signatureHandles[i], &keys[i],
+                                               extractedSignatures[i],
+                                               signatureLengths[i]))) {
+      fprintf(stderr, "ERROR: Error verifying signature.\n");
+      goto failure;
+    }
+    ++*numVerified;
+  }
+
+  rv = CryptoX_Success;
+failure:
+  for (i = 0; i < signatureCount; i++) {
+    CryptoX_FreeSignatureHandle(&signatureHandles[i]);
+  }
+
+  return rv;
+}
diff --git a/modules/libmar/verify/moz.build b/modules/libmar/verify/moz.build
new file mode 100644
index 0000000000..b07475655f
--- /dev/null
+++ b/modules/libmar/verify/moz.build
@@ -0,0 +1,49 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+Library("verifymar")
+
+UNIFIED_SOURCES += [
+    "cryptox.c",
+    "mar_verify.c",
+]
+
+FORCE_STATIC_LIB = True
+
+if CONFIG["OS_ARCH"] == "WINNT":
+    USE_STATIC_LIBS = True
+elif CONFIG["OS_ARCH"] == "Darwin":
+    UNIFIED_SOURCES += [
+        "MacVerifyCrypto.cpp",
+    ]
+    OS_LIBS += [
+        "-framework Security",
+    ]
+else:
+    DEFINES["MAR_NSS"] = True
+    LOCAL_INCLUDES += ["../sign"]
+    USE_LIBS += [
+        "nspr",
+        "nss",
+        "signmar",
+    ]
+    # Ideally, this would be '-Wl,-rpath=$ORIGIN', but the build system
+    # doesn't do the right escaping yet. Even more ideally, this would
+    # be LDFLAGS, but the build system doesn't propagate those like USE_LIBS
+    # and OS_LIBS. Bug #1041943.
+    OS_LIBS += [
+        "-Wl,-rpath=\\$$ORIGIN",
+    ]
+
+LOCAL_INCLUDES += [
+    "../src",
+]
+
+# C11 for static_assert
+c11_flags = ["-std=gnu11"]
+if CONFIG["CC_TYPE"] == "clang-cl":
+    c11_flags.insert(0, "-Xclang")
+CFLAGS += c11_flags