diff options
Diffstat (limited to 'modules/libmar/verify/mar_verify.c')
| -rw-r--r-- | modules/libmar/verify/mar_verify.c | 416 |
1 files changed, 416 insertions, 0 deletions
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; +} |