diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 09:22:09 +0000 |
commit | 43a97878ce14b72f0981164f87f2e35e14151312 (patch) | |
tree | 620249daf56c0258faa40cbdcf9cfba06de2a846 /security/manager/ssl/AppSignatureVerification.cpp | |
parent | Initial commit. (diff) | |
download | firefox-upstream.tar.xz firefox-upstream.zip |
Adding upstream version 110.0.1.upstream/110.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'security/manager/ssl/AppSignatureVerification.cpp')
-rw-r--r-- | security/manager/ssl/AppSignatureVerification.cpp | 1410 |
1 files changed, 1410 insertions, 0 deletions
diff --git a/security/manager/ssl/AppSignatureVerification.cpp b/security/manager/ssl/AppSignatureVerification.cpp new file mode 100644 index 0000000000..399516dd9c --- /dev/null +++ b/security/manager/ssl/AppSignatureVerification.cpp @@ -0,0 +1,1410 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=2 et sw=2 tw=80: */ +/* 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 "nsNSSCertificateDB.h" + +#include "AppTrustDomain.h" +#include "CryptoTask.h" +#include "NSSCertDBTrustDomain.h" +#include "ScopedNSSTypes.h" +#include "SharedCertVerifier.h" +#include "certdb.h" +#include "cms.h" +#include "cosec.h" +#include "mozilla/Base64.h" +#include "mozilla/Casting.h" +#include "mozilla/Logging.h" +#include "mozilla/Preferences.h" +#include "mozilla/RefPtr.h" +#include "mozilla/UniquePtr.h" +#include "mozilla/Unused.h" +#include "nsCOMPtr.h" +#include "nsComponentManagerUtils.h" +#include "nsDependentString.h" +#include "nsHashKeys.h" +#include "nsIFile.h" +#include "nsIInputStream.h" +#include "nsIStringEnumerator.h" +#include "nsIZipReader.h" +#include "nsNSSCertificate.h" +#include "nsNetUtil.h" +#include "nsProxyRelease.h" +#include "nsString.h" +#include "nsTHashtable.h" +#include "mozpkix/pkix.h" +#include "mozpkix/pkixnss.h" +#include "mozpkix/pkixutil.h" +#include "secerr.h" +#include "secmime.h" + +using namespace mozilla::pkix; +using namespace mozilla; +using namespace mozilla::psm; + +extern mozilla::LazyLogModule gPIPNSSLog; + +namespace { + +// A convenient way to pair the bytes of a digest with the algorithm that +// purportedly produced those bytes. Only SHA-1 and SHA-256 are supported. +struct DigestWithAlgorithm { + nsresult ValidateLength() const { + size_t hashLen; + switch (mAlgorithm) { + case SEC_OID_SHA256: + hashLen = SHA256_LENGTH; + break; + case SEC_OID_SHA1: + hashLen = SHA1_LENGTH; + break; + default: + MOZ_ASSERT_UNREACHABLE( + "unsupported hash type in DigestWithAlgorithm::ValidateLength"); + return NS_ERROR_FAILURE; + } + if (mDigest.Length() != hashLen) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + return NS_OK; + } + + nsAutoCString mDigest; + SECOidTag mAlgorithm; +}; + +// The digest must have a lifetime greater than or equal to the returned string. +inline nsDependentCSubstring DigestToDependentString( + nsTArray<uint8_t>& digest) { + return nsDependentCSubstring(BitwiseCast<char*, uint8_t*>(digest.Elements()), + digest.Length()); +} + +// Reads a maximum of 8MB from a stream into the supplied buffer. +// The reason for the 8MB limit is because this function is used to read +// signature-related files and we want to avoid OOM. The uncompressed length of +// an entry can be hundreds of times larger than the compressed version, +// especially if someone has specifically crafted the entry to cause OOM or to +// consume massive amounts of disk space. +// +// @param stream The input stream to read from. +// @param buf The buffer that we read the stream into, which must have +// already been allocated. +nsresult ReadStream(const nsCOMPtr<nsIInputStream>& stream, + /*out*/ SECItem& buf) { + // The size returned by Available() might be inaccurate so we need + // to check that Available() matches up with the actual length of + // the file. + uint64_t length; + nsresult rv = stream->Available(&length); + if (NS_WARN_IF(NS_FAILED(rv))) { + return rv; + } + + // Cap the maximum accepted size of signature-related files at 8MB (which + // should be much larger than necessary for our purposes) to avoid OOM. + static const uint32_t MAX_LENGTH = 8 * 1000 * 1000; + if (length > MAX_LENGTH) { + return NS_ERROR_FILE_TOO_BIG; + } + + // With bug 164695 in mind we +1 to leave room for null-terminating + // the buffer. + SECITEM_AllocItem(buf, static_cast<uint32_t>(length + 1)); + + // buf.len == length + 1. We attempt to read length + 1 bytes + // instead of length, so that we can check whether the metadata for + // the entry is incorrect. + uint32_t bytesRead; + rv = stream->Read(BitwiseCast<char*, unsigned char*>(buf.data), buf.len, + &bytesRead); + if (NS_WARN_IF(NS_FAILED(rv))) { + return rv; + } + if (bytesRead != length) { + return NS_ERROR_FILE_CORRUPTED; + } + + buf.data[buf.len - 1] = 0; // null-terminate + + return NS_OK; +} + +// Finds exactly one (signature metadata) JAR entry that matches the given +// search pattern, and then loads it. Fails if there are no matches or if +// there is more than one match. If bufDigest is not null then on success +// bufDigest will contain the digeset of the entry using the given digest +// algorithm. +nsresult FindAndLoadOneEntry( + nsIZipReader* zip, const nsACString& searchPattern, + /*out*/ nsACString& filename, + /*out*/ SECItem& buf, + /*optional, in*/ SECOidTag digestAlgorithm = SEC_OID_SHA1, + /*optional, out*/ nsTArray<uint8_t>* bufDigest = nullptr) { + nsCOMPtr<nsIUTF8StringEnumerator> files; + nsresult rv = zip->FindEntries(searchPattern, getter_AddRefs(files)); + if (NS_FAILED(rv) || !files) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + bool more; + rv = files->HasMore(&more); + NS_ENSURE_SUCCESS(rv, rv); + if (!more) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + rv = files->GetNext(filename); + NS_ENSURE_SUCCESS(rv, rv); + + // Check if there is more than one match, if so then error! + rv = files->HasMore(&more); + NS_ENSURE_SUCCESS(rv, rv); + if (more) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + nsCOMPtr<nsIInputStream> stream; + rv = zip->GetInputStream(filename, getter_AddRefs(stream)); + NS_ENSURE_SUCCESS(rv, rv); + + rv = ReadStream(stream, buf); + if (NS_WARN_IF(NS_FAILED(rv))) { + return NS_ERROR_SIGNED_JAR_ENTRY_INVALID; + } + + if (bufDigest) { + rv = Digest::DigestBuf(digestAlgorithm, + Span<uint8_t>{buf.data, buf.len - 1}, *bufDigest); + NS_ENSURE_SUCCESS(rv, rv); + } + + return NS_OK; +} + +// Verify the digest of an entry. We avoid loading the entire entry into memory +// at once, which would require memory in proportion to the size of the largest +// entry. Instead, we require only a small, fixed amount of memory. +// +// @param stream an input stream from a JAR entry or file depending on whether +// it is from a signed archive or unpacked into a directory +// @param digestFromManifest The digest that we're supposed to check the file's +// contents against, from the manifest +// @param buf A scratch buffer that we use for doing the I/O, which must have +// already been allocated. The size of this buffer is the unit +// size of our I/O. +nsresult VerifyStreamContentDigest( + nsIInputStream* stream, const DigestWithAlgorithm& digestFromManifest, + SECItem& buf) { + MOZ_ASSERT(buf.len > 0); + nsresult rv = digestFromManifest.ValidateLength(); + if (NS_FAILED(rv)) { + return rv; + } + + uint64_t len64; + rv = stream->Available(&len64); + NS_ENSURE_SUCCESS(rv, rv); + if (len64 > UINT32_MAX) { + return NS_ERROR_SIGNED_JAR_ENTRY_TOO_LARGE; + } + + Digest digest; + + rv = digest.Begin(digestFromManifest.mAlgorithm); + NS_ENSURE_SUCCESS(rv, rv); + + uint64_t totalBytesRead = 0; + for (;;) { + uint32_t bytesRead; + rv = stream->Read(BitwiseCast<char*, unsigned char*>(buf.data), buf.len, + &bytesRead); + NS_ENSURE_SUCCESS(rv, rv); + + if (bytesRead == 0) { + break; // EOF + } + + totalBytesRead += bytesRead; + if (totalBytesRead >= UINT32_MAX) { + return NS_ERROR_SIGNED_JAR_ENTRY_TOO_LARGE; + } + + rv = digest.Update(buf.data, bytesRead); + NS_ENSURE_SUCCESS(rv, rv); + } + + if (totalBytesRead != len64) { + // The metadata we used for Available() doesn't match the actual size of + // the entry. + return NS_ERROR_SIGNED_JAR_ENTRY_INVALID; + } + + // Verify that the digests match. + nsTArray<uint8_t> outArray; + rv = digest.End(outArray); + NS_ENSURE_SUCCESS(rv, rv); + + nsDependentCSubstring digestStr(DigestToDependentString(outArray)); + if (!digestStr.Equals(digestFromManifest.mDigest)) { + return NS_ERROR_SIGNED_JAR_MODIFIED_ENTRY; + } + + return NS_OK; +} + +nsresult VerifyEntryContentDigest(nsIZipReader* zip, + const nsACString& aFilename, + const DigestWithAlgorithm& digestFromManifest, + SECItem& buf) { + nsCOMPtr<nsIInputStream> stream; + nsresult rv = zip->GetInputStream(aFilename, getter_AddRefs(stream)); + if (NS_FAILED(rv)) { + return NS_ERROR_SIGNED_JAR_ENTRY_MISSING; + } + + return VerifyStreamContentDigest(stream, digestFromManifest, buf); +} + +// On input, nextLineStart is the start of the current line. On output, +// nextLineStart is the start of the next line. +nsresult ReadLine(/*in/out*/ const char*& nextLineStart, + /*out*/ nsCString& line, bool allowContinuations = true) { + line.Truncate(); + size_t previousLength = 0; + size_t currentLength = 0; + for (;;) { + const char* eol = strpbrk(nextLineStart, "\r\n"); + + if (!eol) { // Reached end of file before newline + eol = nextLineStart + strlen(nextLineStart); + } + + previousLength = currentLength; + line.Append(nextLineStart, eol - nextLineStart); + currentLength = line.Length(); + + // The spec says "No line may be longer than 72 bytes (not characters)" + // in its UTF8-encoded form. + static const size_t lineLimit = 72; + if (currentLength - previousLength > lineLimit) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + // The spec says: "Implementations should support 65535-byte + // (not character) header values..." + if (currentLength > 65535) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + if (*eol == '\r') { + ++eol; + } + if (*eol == '\n') { + ++eol; + } + + nextLineStart = eol; + + if (*eol != ' ') { + // not a continuation + return NS_OK; + } + + // continuation + if (!allowContinuations) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + ++nextLineStart; // skip space and keep appending + } +} + +// The header strings are defined in the JAR specification. +#define JAR_MF_SEARCH_STRING "(M|/M)ETA-INF/(M|m)(ANIFEST|anifest).(MF|mf)$" +#define JAR_COSE_MF_SEARCH_STRING "(M|/M)ETA-INF/cose.manifest$" +#define JAR_SF_SEARCH_STRING "(M|/M)ETA-INF/*.(SF|sf)$" +#define JAR_RSA_SEARCH_STRING "(M|/M)ETA-INF/*.(RSA|rsa)$" +#define JAR_COSE_SEARCH_STRING "(M|/M)ETA-INF/cose.sig$" +#define JAR_META_DIR "META-INF" +#define JAR_MF_HEADER "Manifest-Version: 1.0" +#define JAR_SF_HEADER "Signature-Version: 1.0" + +nsresult ParseAttribute(const nsAutoCString& curLine, + /*out*/ nsAutoCString& attrName, + /*out*/ nsAutoCString& attrValue) { + // Find the colon that separates the name from the value. + int32_t colonPos = curLine.FindChar(':'); + if (colonPos == kNotFound) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + // set attrName to the name, skipping spaces between the name and colon + int32_t nameEnd = colonPos; + for (;;) { + if (nameEnd == 0) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; // colon with no name + } + if (curLine[nameEnd - 1] != ' ') break; + --nameEnd; + } + curLine.Left(attrName, nameEnd); + + // Set attrValue to the value, skipping spaces between the colon and the + // value. The value may be empty. + int32_t valueStart = colonPos + 1; + int32_t curLineLength = curLine.Length(); + while (valueStart != curLineLength && curLine[valueStart] == ' ') { + ++valueStart; + } + curLine.Right(attrValue, curLineLength - valueStart); + + return NS_OK; +} + +// Parses the version line of the MF or SF header. +nsresult CheckManifestVersion(const char*& nextLineStart, + const nsACString& expectedHeader) { + // The JAR spec says: "Manifest-Version and Signature-Version must be first, + // and in exactly that case (so that they can be recognized easily as magic + // strings)." + nsAutoCString curLine; + nsresult rv = ReadLine(nextLineStart, curLine, false); + if (NS_FAILED(rv)) { + return rv; + } + if (!curLine.Equals(expectedHeader)) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + return NS_OK; +} + +// Parses a signature file (SF) based on the JDK 8 JAR Specification. +// +// The SF file must contain a SHA*-Digest-Manifest attribute in the main +// section (where the * is either 1 or 256, depending on the given digest +// algorithm). All other sections are ignored. This means that this will NOT +// parse old-style signature files that have separate digests per entry. +// The JDK8 x-Digest-Manifest variant is better because: +// +// (1) It allows us to follow the principle that we should minimize the +// processing of data that we do before we verify its signature. In +// particular, with the x-Digest-Manifest style, we can verify the digest +// of MANIFEST.MF before we parse it, which prevents malicious JARs +// exploiting our MANIFEST.MF parser. +// (2) It is more time-efficient and space-efficient to have one +// x-Digest-Manifest instead of multiple x-Digest values. +// +// filebuf must be null-terminated. On output, mfDigest will contain the +// decoded value of the appropriate SHA*-DigestManifest, if found. +nsresult ParseSF(const char* filebuf, SECOidTag digestAlgorithm, + /*out*/ nsAutoCString& mfDigest) { + const char* digestNameToFind = nullptr; + switch (digestAlgorithm) { + case SEC_OID_SHA256: + digestNameToFind = "sha256-digest-manifest"; + break; + case SEC_OID_SHA1: + digestNameToFind = "sha1-digest-manifest"; + break; + default: + MOZ_ASSERT_UNREACHABLE("bad argument to ParseSF"); + return NS_ERROR_FAILURE; + } + + const char* nextLineStart = filebuf; + nsresult rv = + CheckManifestVersion(nextLineStart, nsLiteralCString(JAR_SF_HEADER)); + if (NS_FAILED(rv)) { + return rv; + } + + for (;;) { + nsAutoCString curLine; + rv = ReadLine(nextLineStart, curLine); + if (NS_FAILED(rv)) { + return rv; + } + + if (curLine.Length() == 0) { + // End of main section (blank line or end-of-file). We didn't find the + // SHA*-Digest-Manifest we were looking for. + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + nsAutoCString attrName; + nsAutoCString attrValue; + rv = ParseAttribute(curLine, attrName, attrValue); + if (NS_FAILED(rv)) { + return rv; + } + + if (attrName.EqualsIgnoreCase(digestNameToFind)) { + rv = Base64Decode(attrValue, mfDigest); + if (NS_FAILED(rv)) { + return rv; + } + + // There could be multiple SHA*-Digest-Manifest attributes, which + // would be an error, but it's better to just skip any erroneous + // duplicate entries rather than trying to detect them, because: + // + // (1) It's simpler, and simpler generally means more secure + // (2) An attacker can't make us accept a JAR we would otherwise + // reject just by adding additional SHA*-Digest-Manifest + // attributes. + return NS_OK; + } + + // ignore unrecognized attributes + } + + MOZ_ASSERT_UNREACHABLE("somehow exited loop in ParseSF without returning"); + return NS_ERROR_FAILURE; +} + +// Parses MANIFEST.MF. The filenames of all entries will be returned in +// mfItems. buf must be a pre-allocated scratch buffer that is used for doing +// I/O. Each file's contents are verified against the entry in the manifest with +// the digest algorithm that matches the given one. This algorithm comes from +// the signature file. If the signature file has a SHA-256 digest, then SHA-256 +// entries must be present in the manifest file. If the signature file only has +// a SHA-1 digest, then only SHA-1 digests will be used in the manifest file. +nsresult ParseMF(const char* filebuf, nsIZipReader* zip, + SECOidTag digestAlgorithm, + /*out*/ nsTHashtable<nsCStringHashKey>& mfItems, + ScopedAutoSECItem& buf) { + const char* digestNameToFind = nullptr; + switch (digestAlgorithm) { + case SEC_OID_SHA256: + digestNameToFind = "sha256-digest"; + break; + case SEC_OID_SHA1: + digestNameToFind = "sha1-digest"; + break; + default: + MOZ_ASSERT_UNREACHABLE("bad argument to ParseMF"); + return NS_ERROR_FAILURE; + } + + const char* nextLineStart = filebuf; + nsresult rv = + CheckManifestVersion(nextLineStart, nsLiteralCString(JAR_MF_HEADER)); + if (NS_FAILED(rv)) { + return rv; + } + + // Skip the rest of the header section, which ends with a blank line. + { + nsAutoCString line; + do { + rv = ReadLine(nextLineStart, line); + if (NS_FAILED(rv)) { + return rv; + } + } while (line.Length() > 0); + + // Manifest containing no file entries is OK, though useless. + if (*nextLineStart == '\0') { + return NS_OK; + } + } + + nsAutoCString curItemName; + nsAutoCString digest; + + for (;;) { + nsAutoCString curLine; + rv = ReadLine(nextLineStart, curLine); + if (NS_FAILED(rv)) { + return rv; + } + + if (curLine.Length() == 0) { + // end of section (blank line or end-of-file) + + if (curItemName.Length() == 0) { + // '...Each section must start with an attribute with the name as + // "Name",...', so every section must have a Name attribute. + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + if (digest.IsEmpty()) { + // We require every entry to have a digest, since we require every + // entry to be signed and we don't allow duplicate entries. + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + if (mfItems.Contains(curItemName)) { + // Duplicate entry + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + // Verify that the entry's content digest matches the digest from this + // MF section. + DigestWithAlgorithm digestWithAlgorithm = {digest, digestAlgorithm}; + rv = VerifyEntryContentDigest(zip, curItemName, digestWithAlgorithm, buf); + if (NS_FAILED(rv)) { + return rv; + } + + mfItems.PutEntry(curItemName); + + if (*nextLineStart == '\0') { + // end-of-file + break; + } + + // reset so we know we haven't encountered either of these for the next + // item yet. + curItemName.Truncate(); + digest.Truncate(); + + continue; // skip the rest of the loop below + } + + nsAutoCString attrName; + nsAutoCString attrValue; + rv = ParseAttribute(curLine, attrName, attrValue); + if (NS_FAILED(rv)) { + return rv; + } + + // Lines to look for: + + // (1) Digest: + if (attrName.EqualsIgnoreCase(digestNameToFind)) { + if (!digest.IsEmpty()) { // multiple SHA* digests in section + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + rv = Base64Decode(attrValue, digest); + if (NS_FAILED(rv)) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + continue; + } + + // (2) Name: associates this manifest section with a file in the jar. + if (attrName.LowerCaseEqualsLiteral("name")) { + if (MOZ_UNLIKELY(curItemName.Length() > 0)) // multiple names in section + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + + if (MOZ_UNLIKELY(attrValue.Length() == 0)) + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + + curItemName = attrValue; + + continue; + } + + // (3) Magic: the only other must-understand attribute + if (attrName.LowerCaseEqualsLiteral("magic")) { + // We don't understand any magic, so we can't verify an entry that + // requires magic. Since we require every entry to have a valid + // signature, we have no choice but to reject the entry. + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + // unrecognized attributes must be ignored + } + + return NS_OK; +} + +nsresult VerifyCertificate(Span<const uint8_t> signerCert, + AppTrustedRoot trustedRoot, + nsTArray<Span<const uint8_t>>&& collectedCerts) { + AppTrustDomain trustDomain(std::move(collectedCerts)); + nsresult rv = trustDomain.SetTrustedRoot(trustedRoot); + if (NS_FAILED(rv)) { + return rv; + } + Input certDER; + mozilla::pkix::Result result = + certDER.Init(signerCert.Elements(), signerCert.Length()); + if (result != Success) { + return mozilla::psm::GetXPCOMFromNSSError(MapResultToPRErrorCode(result)); + } + + result = BuildCertChain( + trustDomain, certDER, Now(), EndEntityOrCA::MustBeEndEntity, + KeyUsage::digitalSignature, KeyPurposeId::id_kp_codeSigning, + CertPolicyId::anyPolicy, nullptr /*stapledOCSPResponse*/); + if (result == mozilla::pkix::Result::ERROR_EXPIRED_CERTIFICATE || + result == mozilla::pkix::Result::ERROR_NOT_YET_VALID_CERTIFICATE) { + // For code-signing you normally need trusted 3rd-party timestamps to + // handle expiration properly. The signer could always mess with their + // system clock so you can't trust the certificate was un-expired when + // the signing took place. The choice is either to ignore expiration + // or to enforce expiration at time of use. The latter leads to the + // user-hostile result that perfectly good code stops working. + // + // Our package format doesn't support timestamps (nor do we have a + // trusted 3rd party timestamper), but since we sign all of our apps and + // add-ons ourselves we can trust ourselves not to mess with the clock + // on the signing systems. We also have a revocation mechanism if we + // need it. Under these conditions it's OK to ignore cert errors related + // to time validity (expiration and "not yet valid"). + // + // This is an invalid approach if + // * we issue certs to let others sign their own packages + // * mozilla::pkix returns "expired" when there are "worse" problems + // with the certificate or chain. + // (see bug 1267318) + result = Success; + } + if (result != Success) { + return mozilla::psm::GetXPCOMFromNSSError(MapResultToPRErrorCode(result)); + } + + return NS_OK; +} + +// Given a SECOidTag representing a digest algorithm (either SEC_OID_SHA1 or +// SEC_OID_SHA256), returns the first signerInfo in the given signedData that +// purports to have been created using that digest algorithm, or nullptr if +// there is none. +// The returned signerInfo is owned by signedData, so the caller must ensure +// that the lifetime of the signerInfo is contained by the lifetime of the +// signedData. +NSSCMSSignerInfo* GetSignerInfoForDigestAlgorithm(NSSCMSSignedData* signedData, + SECOidTag digestAlgorithm) { + MOZ_ASSERT(digestAlgorithm == SEC_OID_SHA1 || + digestAlgorithm == SEC_OID_SHA256); + if (digestAlgorithm != SEC_OID_SHA1 && digestAlgorithm != SEC_OID_SHA256) { + return nullptr; + } + + int numSigners = NSS_CMSSignedData_SignerInfoCount(signedData); + if (numSigners < 1) { + return nullptr; + } + for (int i = 0; i < numSigners; i++) { + NSSCMSSignerInfo* signerInfo = + NSS_CMSSignedData_GetSignerInfo(signedData, i); + // NSS_CMSSignerInfo_GetDigestAlgTag isn't exported from NSS. + SECOidData* digestAlgOID = SECOID_FindOID(&signerInfo->digestAlg.algorithm); + if (!digestAlgOID) { + continue; + } + if (digestAlgorithm == digestAlgOID->offset) { + return signerInfo; + } + } + return nullptr; +} + +Span<const uint8_t> GetPKCS7SignerCert( + NSSCMSSignerInfo* signerInfo, + nsTArray<Span<const uint8_t>>& collectedCerts) { + if (!signerInfo) { + return {}; + } + // The NSS APIs use the term "CMS", but since these are all signed by Mozilla + // infrastructure, we know they are actually PKCS7. This means that this only + // needs to handle issuer/serial number signer identifiers. + if (signerInfo->signerIdentifier.identifierType != NSSCMSSignerID_IssuerSN) { + return {}; + } + CERTIssuerAndSN* issuerAndSN = signerInfo->signerIdentifier.id.issuerAndSN; + if (!issuerAndSN) { + return {}; + } + Input issuer; + mozilla::pkix::Result result = + issuer.Init(issuerAndSN->derIssuer.data, issuerAndSN->derIssuer.len); + if (result != Success) { + return {}; + } + Input serialNumber; + result = serialNumber.Init(issuerAndSN->serialNumber.data, + issuerAndSN->serialNumber.len); + if (result != Success) { + return {}; + } + for (const auto& certDER : collectedCerts) { + Input certInput; + result = certInput.Init(certDER.Elements(), certDER.Length()); + if (result != Success) { + continue; // probably too big + } + // Since this only decodes the certificate and doesn't attempt to build a + // verified chain with it, the EndEntityOrCA parameter doesn't matter. + BackCert cert(certInput, EndEntityOrCA::MustBeEndEntity, nullptr); + result = cert.Init(); + if (result != Success) { + continue; + } + if (InputsAreEqual(issuer, cert.GetIssuer()) && + InputsAreEqual(serialNumber, cert.GetSerialNumber())) { + return certDER; + } + } + return {}; +} + +nsresult VerifySignature(AppTrustedRoot trustedRoot, const SECItem& buffer, + nsTArray<uint8_t>& detachedSHA1Digest, + nsTArray<uint8_t>& detachedSHA256Digest, + /*out*/ SECOidTag& digestAlgorithm, + /*out*/ nsTArray<uint8_t>& signerCert) { + if (NS_WARN_IF(!buffer.data || buffer.len == 0 || + detachedSHA1Digest.Length() == 0 || + detachedSHA256Digest.Length() == 0)) { + return NS_ERROR_INVALID_ARG; + } + + UniqueNSSCMSMessage cmsMsg(NSS_CMSMessage_CreateFromDER( + const_cast<SECItem*>(&buffer), nullptr, nullptr, nullptr, nullptr, + nullptr, nullptr)); + if (!cmsMsg) { + return NS_ERROR_CMS_VERIFY_NOT_SIGNED; + } + + if (!NSS_CMSMessage_IsSigned(cmsMsg.get())) { + return NS_ERROR_CMS_VERIFY_NOT_SIGNED; + } + + NSSCMSContentInfo* cinfo = NSS_CMSMessage_ContentLevel(cmsMsg.get(), 0); + if (!cinfo) { + return NS_ERROR_CMS_VERIFY_NO_CONTENT_INFO; + } + + // We're expecting this to be a PKCS#7 signedData content info. + if (NSS_CMSContentInfo_GetContentTypeTag(cinfo) != + SEC_OID_PKCS7_SIGNED_DATA) { + return NS_ERROR_CMS_VERIFY_NO_CONTENT_INFO; + } + + // signedData is non-owning + NSSCMSSignedData* signedData = + static_cast<NSSCMSSignedData*>(NSS_CMSContentInfo_GetContent(cinfo)); + if (!signedData) { + return NS_ERROR_CMS_VERIFY_NO_CONTENT_INFO; + } + + nsTArray<Span<const uint8_t>> collectedCerts; + if (signedData->rawCerts) { + for (size_t i = 0; signedData->rawCerts[i]; ++i) { + Span<const uint8_t> cert(signedData->rawCerts[i]->data, + signedData->rawCerts[i]->len); + collectedCerts.AppendElement(std::move(cert)); + } + } + + NSSCMSSignerInfo* signerInfo = + GetSignerInfoForDigestAlgorithm(signedData, SEC_OID_SHA256); + nsTArray<uint8_t>* tmpDetachedDigest = &detachedSHA256Digest; + digestAlgorithm = SEC_OID_SHA256; + if (!signerInfo) { + signerInfo = GetSignerInfoForDigestAlgorithm(signedData, SEC_OID_SHA1); + if (!signerInfo) { + return NS_ERROR_CMS_VERIFY_NOT_SIGNED; + } + tmpDetachedDigest = &detachedSHA1Digest; + digestAlgorithm = SEC_OID_SHA1; + } + + const SECItem detachedDigest = { + siBuffer, tmpDetachedDigest->Elements(), + static_cast<unsigned int>(tmpDetachedDigest->Length())}; + + // Get the certificate that issued the PKCS7 signature. + Span<const uint8_t> signerCertSpan = + GetPKCS7SignerCert(signerInfo, collectedCerts); + if (signerCertSpan.IsEmpty()) { + return NS_ERROR_CMS_VERIFY_ERROR_PROCESSING; + } + + nsresult rv = + VerifyCertificate(signerCertSpan, trustedRoot, std::move(collectedCerts)); + if (NS_FAILED(rv)) { + return rv; + } + signerCert.Clear(); + signerCert.AppendElements(signerCertSpan); + + // Ensure that the PKCS#7 data OID is present as the PKCS#9 contentType. + const char* pkcs7DataOidString = "1.2.840.113549.1.7.1"; + ScopedAutoSECItem pkcs7DataOid; + if (SEC_StringToOID(nullptr, &pkcs7DataOid, pkcs7DataOidString, 0) != + SECSuccess) { + return NS_ERROR_CMS_VERIFY_ERROR_PROCESSING; + } + + // NSS_CMSSignerInfo_Verify relies on NSS_CMSSignerInfo_GetSigningCertificate + // having been called already. This relies on the signing certificate being + // decoded as a CERTCertificate. + // This assertion should never fail, as this certificate has been + // successfully verified, which means it fits in the size of an unsigned int. + SECItem signingCertificateItem = { + siBuffer, const_cast<unsigned char*>(signerCertSpan.Elements()), + AssertedCast<unsigned int>(signerCertSpan.Length())}; + UniqueCERTCertificate signingCertificateHandle(CERT_NewTempCertificate( + CERT_GetDefaultCertDB(), &signingCertificateItem, nullptr, false, true)); + if (!signingCertificateHandle) { + return mozilla::psm::GetXPCOMFromNSSError(SEC_ERROR_PKCS7_BAD_SIGNATURE); + } + // NB: This function does not return an owning reference, unlike with many + // other NSS APIs. + if (!NSS_CMSSignerInfo_GetSigningCertificate(signerInfo, + CERT_GetDefaultCertDB())) { + return mozilla::psm::GetXPCOMFromNSSError(SEC_ERROR_PKCS7_BAD_SIGNATURE); + } + return MapSECStatus(NSS_CMSSignerInfo_Verify( + signerInfo, const_cast<SECItem*>(&detachedDigest), &pkcs7DataOid)); +} + +class CoseVerificationContext { + public: + explicit CoseVerificationContext(AppTrustedRoot aTrustedRoot) + : mTrustedRoot(aTrustedRoot) {} + ~CoseVerificationContext() = default; + + AppTrustedRoot GetTrustedRoot() { return mTrustedRoot; } + void SetCert(Span<const uint8_t> certDER) { + mCertDER.Clear(); + mCertDER.AppendElements(certDER); + } + + nsTArray<uint8_t> TakeCert() { return std::move(mCertDER); } + + private: + AppTrustedRoot mTrustedRoot; + nsTArray<uint8_t> mCertDER; +}; + +// Verification function called from cose-rust. +// Returns true if everything goes well and the signature and certificate chain +// are good, false in any other case. +bool CoseVerificationCallback(const uint8_t* aPayload, size_t aPayloadLen, + const uint8_t** aCertChain, size_t aCertChainLen, + const size_t* aCertsLen, const uint8_t* aEECert, + size_t aEECertLen, const uint8_t* aSignature, + size_t aSignatureLen, uint8_t aSignatureAlgorithm, + void* ctx) { + if (!ctx || !aPayload || !aEECert || !aSignature) { + return false; + } + // The ctx here is a pointer to a CoseVerificationContext object + CoseVerificationContext* context = static_cast<CoseVerificationContext*>(ctx); + AppTrustedRoot aTrustedRoot = context->GetTrustedRoot(); + + CK_MECHANISM_TYPE mechanism; + SECOidTag oid; + uint32_t hash_length; + SECItem param = {siBuffer, nullptr, 0}; + switch (aSignatureAlgorithm) { + case ES256: + mechanism = CKM_ECDSA; + oid = SEC_OID_SHA256; + hash_length = SHA256_LENGTH; + break; + case ES384: + mechanism = CKM_ECDSA; + oid = SEC_OID_SHA384; + hash_length = SHA384_LENGTH; + break; + case ES512: + mechanism = CKM_ECDSA; + oid = SEC_OID_SHA512; + hash_length = SHA512_LENGTH; + break; + default: + return false; + } + + uint8_t hashBuf[HASH_LENGTH_MAX]; + SECStatus rv = PK11_HashBuf(oid, hashBuf, aPayload, aPayloadLen); + if (rv != SECSuccess) { + return false; + } + SECItem hashItem = {siBuffer, hashBuf, hash_length}; + Input certInput; + if (certInput.Init(aEECert, aEECertLen) != Success) { + return false; + } + // Since this only decodes the certificate and doesn't attempt to build a + // verified chain with it, the EndEntityOrCA parameter doesn't matter. + BackCert backCert(certInput, EndEntityOrCA::MustBeEndEntity, nullptr); + if (backCert.Init() != Success) { + return false; + } + Input spkiInput = backCert.GetSubjectPublicKeyInfo(); + SECItem spkiItem = {siBuffer, const_cast<uint8_t*>(spkiInput.UnsafeGetData()), + spkiInput.GetLength()}; + UniqueCERTSubjectPublicKeyInfo spki( + SECKEY_DecodeDERSubjectPublicKeyInfo(&spkiItem)); + if (!spki) { + return false; + } + UniqueSECKEYPublicKey key(SECKEY_ExtractPublicKey(spki.get())); + SECItem signatureItem = {siBuffer, const_cast<uint8_t*>(aSignature), + static_cast<unsigned int>(aSignatureLen)}; + rv = PK11_VerifyWithMechanism(key.get(), mechanism, ¶m, &signatureItem, + &hashItem, nullptr); + if (rv != SECSuccess) { + return false; + } + + nsTArray<Span<const uint8_t>> collectedCerts; + for (size_t i = 0; i < aCertChainLen; ++i) { + Span<const uint8_t> cert(aCertChain[i], aCertsLen[i]); + collectedCerts.AppendElement(std::move(cert)); + } + + Span<const uint8_t> certSpan = {aEECert, aEECertLen}; + nsresult nrv = + VerifyCertificate(certSpan, aTrustedRoot, std::move(collectedCerts)); + bool result = true; + if (NS_FAILED(nrv)) { + result = false; + } + + // Passing back the signing certificate in form of the DER cert. + context->SetCert(certSpan); + if (NS_FAILED(nrv)) { + result = false; + } + + return result; +} + +nsresult VerifyAppManifest(SECOidTag aDigestToUse, nsCOMPtr<nsIZipReader> aZip, + nsTHashtable<nsCStringHashKey>& aIgnoredFiles, + const SECItem& aManifestBuffer) { + // Allocate the I/O buffer only once per JAR, instead of once per entry, in + // order to minimize malloc/free calls and in order to avoid fragmenting + // memory. + ScopedAutoSECItem buf(128 * 1024); + + nsTHashtable<nsCStringHashKey> items; + + nsresult rv = + ParseMF(BitwiseCast<char*, unsigned char*>(aManifestBuffer.data), aZip, + aDigestToUse, items, buf); + if (NS_FAILED(rv)) { + return rv; + } + + // Verify every entry in the file. + nsCOMPtr<nsIUTF8StringEnumerator> entries; + rv = aZip->FindEntries(""_ns, getter_AddRefs(entries)); + if (NS_FAILED(rv)) { + return rv; + } + if (!entries) { + return NS_ERROR_UNEXPECTED; + } + + for (;;) { + bool hasMore; + rv = entries->HasMore(&hasMore); + NS_ENSURE_SUCCESS(rv, rv); + + if (!hasMore) { + break; + } + + nsAutoCString entryFilename; + rv = entries->GetNext(entryFilename); + NS_ENSURE_SUCCESS(rv, rv); + + MOZ_LOG(gPIPNSSLog, LogLevel::Debug, + ("Verifying digests for %s", entryFilename.get())); + + if (entryFilename.Length() == 0) { + return NS_ERROR_SIGNED_JAR_ENTRY_INVALID; + } + + // The files that comprise the signature mechanism are not covered by the + // signature. Ignore these files. + if (aIgnoredFiles.Contains(entryFilename)) { + continue; + } + + // Entries with names that end in "/" are directory entries, which are not + // signed. + // + // Since bug 1415991 we don't support unpacked JARs. The "/" entries are + // therefore harmless. + if (entryFilename.Last() == '/') { + continue; + } + + nsCStringHashKey* item = items.GetEntry(entryFilename); + if (!item) { + return NS_ERROR_SIGNED_JAR_UNSIGNED_ENTRY; + } + + // Remove the item so we can check for leftover items later + items.RemoveEntry(item); + } + + // We verified that every entry that we require to be signed is signed. But, + // were there any missing entries--that is, entries that are mentioned in the + // manifest but missing from the archive? + if (items.Count() != 0) { + return NS_ERROR_SIGNED_JAR_ENTRY_MISSING; + } + + return NS_OK; +} + +// This corresponds to the preference "security.signed_app_signatures.policy". +// The lowest order bit determines which PKCS#7 algorithms are accepted. +// xxx_0_: SHA-1 and/or SHA-256 PKCS#7 allowed +// xxx_1_: SHA-256 PKCS#7 allowed +// The next two bits determine whether COSE is required and PKCS#7 is allowed +// x_00_x: COSE disabled, ignore files, PKCS#7 must verify +// x_01_x: COSE is verified if present, PKCS#7 must verify +// x_10_x: COSE is required, PKCS#7 must verify if present +// x_11_x: COSE is required, PKCS#7 disabled (fail when present) +class SignaturePolicy { + public: + explicit SignaturePolicy(int32_t preference) + : mProcessCose(true), + mCoseRequired(false), + mProcessPK7(true), + mPK7Required(true), + mSHA1Allowed(true), + mSHA256Allowed(true) { + mCoseRequired = (preference & 0b100) != 0; + mProcessCose = (preference & 0b110) != 0; + mPK7Required = (preference & 0b100) == 0; + mProcessPK7 = (preference & 0b110) != 0b110; + if ((preference & 0b1) == 0) { + mSHA1Allowed = true; + mSHA256Allowed = true; + } else { + mSHA1Allowed = false; + mSHA256Allowed = true; + } + } + ~SignaturePolicy() = default; + bool ProcessCOSE() { return mProcessCose; } + bool COSERequired() { return mCoseRequired; } + bool PK7Required() { return mPK7Required; } + bool ProcessPK7() { return mProcessPK7; } + bool IsPK7HashAllowed(SECOidTag aHashAlg) { + if (aHashAlg == SEC_OID_SHA256 && mSHA256Allowed) { + return true; + } + if (aHashAlg == SEC_OID_SHA1 && mSHA1Allowed) { + return true; + } + return false; + } + + private: + bool mProcessCose; + bool mCoseRequired; + bool mProcessPK7; + bool mPK7Required; + bool mSHA1Allowed; + bool mSHA256Allowed; +}; + +nsresult VerifyCOSESignature(AppTrustedRoot aTrustedRoot, nsIZipReader* aZip, + SignaturePolicy& aPolicy, + nsTHashtable<nsCStringHashKey>& aIgnoredFiles, + /* out */ bool& aVerified, + /* out */ nsTArray<uint8_t>& aCoseCertDER) { + NS_ENSURE_ARG_POINTER(aZip); + bool required = aPolicy.COSERequired(); + aVerified = false; + + // Read COSE signature file. + nsAutoCString coseFilename; + ScopedAutoSECItem coseBuffer; + nsresult rv = FindAndLoadOneEntry( + aZip, nsLiteralCString(JAR_COSE_SEARCH_STRING), coseFilename, coseBuffer); + if (NS_FAILED(rv)) { + return required ? NS_ERROR_SIGNED_JAR_WRONG_SIGNATURE : NS_OK; + } + + // Verify COSE signature. + nsAutoCString mfFilename; + ScopedAutoSECItem manifestBuffer; + rv = FindAndLoadOneEntry(aZip, nsLiteralCString(JAR_COSE_MF_SEARCH_STRING), + mfFilename, manifestBuffer); + if (NS_FAILED(rv)) { + return required ? NS_ERROR_SIGNED_JAR_WRONG_SIGNATURE : rv; + } + MOZ_ASSERT(manifestBuffer.len >= 1); + MOZ_ASSERT(coseBuffer.len >= 1); + CoseVerificationContext context(aTrustedRoot); + bool coseVerification = verify_cose_signature_ffi( + manifestBuffer.data, manifestBuffer.len - 1, coseBuffer.data, + coseBuffer.len - 1, &context, CoseVerificationCallback); + if (!coseVerification) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + // CoseVerificationCallback sets the context certificate to the first cert + // it encounters. + aCoseCertDER = context.TakeCert(); + + // aIgnoredFiles contains the PKCS#7 manifest and signature files iff the + // PKCS#7 verification was successful. + aIgnoredFiles.PutEntry(mfFilename); + aIgnoredFiles.PutEntry(coseFilename); + rv = VerifyAppManifest(SEC_OID_SHA256, aZip, aIgnoredFiles, manifestBuffer); + if (NS_FAILED(rv)) { + return rv; + } + + aVerified = true; + return NS_OK; +} + +nsresult VerifyPK7Signature( + AppTrustedRoot aTrustedRoot, nsIZipReader* aZip, SignaturePolicy& aPolicy, + /* out */ nsTHashtable<nsCStringHashKey>& aIgnoredFiles, + /* out */ bool& aVerified, + /* out */ nsTArray<uint8_t>& aSignerCert) { + NS_ENSURE_ARG_POINTER(aZip); + bool required = aPolicy.PK7Required(); + aVerified = false; + + // Signature (RSA) file + nsAutoCString sigFilename; + ScopedAutoSECItem sigBuffer; + nsresult rv = FindAndLoadOneEntry( + aZip, nsLiteralCString(JAR_RSA_SEARCH_STRING), sigFilename, sigBuffer); + if (NS_FAILED(rv)) { + return required ? NS_ERROR_SIGNED_JAR_NOT_SIGNED : NS_OK; + } + + // Signature (SF) file + nsAutoCString sfFilename; + ScopedAutoSECItem sfBuffer; + rv = FindAndLoadOneEntry(aZip, nsLiteralCString(JAR_SF_SEARCH_STRING), + sfFilename, sfBuffer); + if (NS_FAILED(rv)) { + return required ? NS_ERROR_SIGNED_JAR_MANIFEST_INVALID : NS_OK; + } + + // Calculate both the SHA-1 and SHA-256 hashes of the signature file - we + // don't know what algorithm the PKCS#7 signature used. + nsTArray<uint8_t> sfCalculatedSHA1Digest; + rv = Digest::DigestBuf(SEC_OID_SHA1, sfBuffer.data, sfBuffer.len - 1, + sfCalculatedSHA1Digest); + if (NS_FAILED(rv)) { + return rv; + } + + nsTArray<uint8_t> sfCalculatedSHA256Digest; + rv = Digest::DigestBuf(SEC_OID_SHA256, sfBuffer.data, sfBuffer.len - 1, + sfCalculatedSHA256Digest); + if (NS_FAILED(rv)) { + return rv; + } + + // Verify PKCS#7 signature. + // If we get here, the signature has to verify even if PKCS#7 is not required. + sigBuffer.type = siBuffer; + SECOidTag digestToUse; + rv = VerifySignature(aTrustedRoot, sigBuffer, sfCalculatedSHA1Digest, + sfCalculatedSHA256Digest, digestToUse, aSignerCert); + if (NS_FAILED(rv)) { + return rv; + } + + // Check the digest used for the signature against the policy. + if (!aPolicy.IsPK7HashAllowed(digestToUse)) { + return NS_ERROR_SIGNED_JAR_WRONG_SIGNATURE; + } + + nsAutoCString mfDigest; + rv = ParseSF(BitwiseCast<char*, unsigned char*>(sfBuffer.data), digestToUse, + mfDigest); + if (NS_FAILED(rv)) { + return rv; + } + + // Read PK7 manifest (MF) file. + ScopedAutoSECItem manifestBuffer; + nsTArray<uint8_t> digestArray; + nsAutoCString mfFilename; + rv = FindAndLoadOneEntry(aZip, nsLiteralCString(JAR_MF_SEARCH_STRING), + mfFilename, manifestBuffer, digestToUse, + &digestArray); + if (NS_FAILED(rv)) { + return rv; + } + + nsDependentCSubstring calculatedDigest( + BitwiseCast<char*, uint8_t*>(digestArray.Elements()), + digestArray.Length()); + if (!mfDigest.Equals(calculatedDigest)) { + return NS_ERROR_SIGNED_JAR_MANIFEST_INVALID; + } + + // Verify PKCS7 manifest file hashes. + aIgnoredFiles.PutEntry(sfFilename); + aIgnoredFiles.PutEntry(sigFilename); + aIgnoredFiles.PutEntry(mfFilename); + rv = VerifyAppManifest(digestToUse, aZip, aIgnoredFiles, manifestBuffer); + if (NS_FAILED(rv)) { + aIgnoredFiles.Clear(); + return rv; + } + + aVerified = true; + return NS_OK; +} + +nsresult OpenSignedAppFile(AppTrustedRoot aTrustedRoot, nsIFile* aJarFile, + SignaturePolicy aPolicy, + /* out, optional */ nsIZipReader** aZipReader, + /* out, optional */ nsIX509Cert** aSignerCert) { + NS_ENSURE_ARG_POINTER(aJarFile); + + if (aZipReader) { + *aZipReader = nullptr; + } + + if (aSignerCert) { + *aSignerCert = nullptr; + } + + nsresult rv; + + static NS_DEFINE_CID(kZipReaderCID, NS_ZIPREADER_CID); + nsCOMPtr<nsIZipReader> zip = do_CreateInstance(kZipReaderCID, &rv); + NS_ENSURE_SUCCESS(rv, rv); + + rv = zip->Open(aJarFile); + NS_ENSURE_SUCCESS(rv, rv); + + bool pk7Verified = false; + bool coseVerified = false; + nsTHashtable<nsCStringHashKey> ignoredFiles; + nsTArray<uint8_t> pkcs7CertDER; + nsTArray<uint8_t> coseCertDER; + + // First we have to verify the PKCS#7 signature if there is one. + // This signature covers all files (except for the signature files itself), + // including the COSE signature files. Only when this verification is + // successful the respective files will be ignored in the subsequent COSE + // signature verification. + if (aPolicy.ProcessPK7()) { + rv = VerifyPK7Signature(aTrustedRoot, zip, aPolicy, ignoredFiles, + pk7Verified, pkcs7CertDER); + if (NS_FAILED(rv)) { + return rv; + } + } + + if (aPolicy.ProcessCOSE()) { + rv = VerifyCOSESignature(aTrustedRoot, zip, aPolicy, ignoredFiles, + coseVerified, coseCertDER); + if (NS_FAILED(rv)) { + return rv; + } + } + + // Bits 1 and 2 + // 00 = Didn't Process PKCS#7 signatures + // 01 = Processed but no valid cert or signature + // 10 = Processed and valid cert found, but addon didn't match manifest + // 11 = Processed and valid. + // Bits 3 and 4 are the same but for COSE. + uint32_t bucket = 0; + bucket += aPolicy.ProcessCOSE(); + bucket += !coseCertDER.IsEmpty(); + bucket += coseVerified; + bucket <<= 2; + bucket += aPolicy.ProcessPK7(); + bucket += !pkcs7CertDER.IsEmpty(); + bucket += pk7Verified; + Telemetry::Accumulate(Telemetry::ADDON_SIGNATURE_VERIFICATION_STATUS, bucket); + + if ((aPolicy.PK7Required() && !pk7Verified) || + (aPolicy.COSERequired() && !coseVerified)) { + return NS_ERROR_SIGNED_JAR_WRONG_SIGNATURE; + } + + // Return the reader to the caller if they want it + if (aZipReader) { + zip.forget(aZipReader); + } + + // Return the signer's certificate to the reader if they want it. + if (aSignerCert) { + // The COSE certificate is authoritative. + if (aPolicy.COSERequired() || !coseCertDER.IsEmpty()) { + if (coseCertDER.IsEmpty()) { + return NS_ERROR_FAILURE; + } + nsCOMPtr<nsIX509Cert> signerCert( + new nsNSSCertificate(std::move(coseCertDER))); + signerCert.forget(aSignerCert); + } else { + if (pkcs7CertDER.IsEmpty()) { + return NS_ERROR_FAILURE; + } + nsCOMPtr<nsIX509Cert> signerCert( + new nsNSSCertificate(std::move(pkcs7CertDER))); + signerCert.forget(aSignerCert); + } + } + + return NS_OK; +} + +class OpenSignedAppFileTask final : public CryptoTask { + public: + OpenSignedAppFileTask(AppTrustedRoot aTrustedRoot, nsIFile* aJarFile, + SignaturePolicy aPolicy, + nsIOpenSignedAppFileCallback* aCallback) + : mTrustedRoot(aTrustedRoot), + mJarFile(aJarFile), + mPolicy(aPolicy), + mCallback(new nsMainThreadPtrHolder<nsIOpenSignedAppFileCallback>( + "OpenSignedAppFileTask::mCallback", aCallback)) {} + + private: + virtual nsresult CalculateResult() override { + return OpenSignedAppFile(mTrustedRoot, mJarFile, mPolicy, + getter_AddRefs(mZipReader), + getter_AddRefs(mSignerCert)); + } + + virtual void CallCallback(nsresult rv) override { + (void)mCallback->OpenSignedAppFileFinished(rv, mZipReader, mSignerCert); + } + + const AppTrustedRoot mTrustedRoot; + const nsCOMPtr<nsIFile> mJarFile; + const SignaturePolicy mPolicy; + nsMainThreadPtrHandle<nsIOpenSignedAppFileCallback> mCallback; + nsCOMPtr<nsIZipReader> mZipReader; // out + nsCOMPtr<nsIX509Cert> mSignerCert; // out +}; + +static const int32_t sDefaultSignaturePolicy = 0b10; + +} // unnamed namespace + +NS_IMETHODIMP +nsNSSCertificateDB::OpenSignedAppFileAsync( + AppTrustedRoot aTrustedRoot, nsIFile* aJarFile, + nsIOpenSignedAppFileCallback* aCallback) { + NS_ENSURE_ARG_POINTER(aJarFile); + NS_ENSURE_ARG_POINTER(aCallback); + if (!NS_IsMainThread()) { + return NS_ERROR_NOT_SAME_THREAD; + } + int32_t policyInt = + Preferences::GetInt("security.signed_app_signatures.policy", + static_cast<int32_t>(sDefaultSignaturePolicy)); + SignaturePolicy policy(policyInt); + RefPtr<OpenSignedAppFileTask> task( + new OpenSignedAppFileTask(aTrustedRoot, aJarFile, policy, aCallback)); + return task->Dispatch(); +} |