diff options
Diffstat (limited to 'verifier.cpp')
| -rw-r--r-- | verifier.cpp | 90 |
1 files changed, 28 insertions, 62 deletions
diff --git a/verifier.cpp b/verifier.cpp index 0930fbd15..3d4f603a2 100644 --- a/verifier.cpp +++ b/verifier.cpp @@ -111,15 +111,10 @@ static bool read_pkcs7(uint8_t* pkcs7_der, size_t pkcs7_der_len, uint8_t** sig_d // Return VERIFY_SUCCESS, VERIFY_FAILURE (if any error is encountered // or no key matches the signature). -int verify_file(const char* path, const Certificate* pKeys, unsigned int numKeys) { +int verify_file(unsigned char* addr, size_t length, + const Certificate* pKeys, unsigned int numKeys) { ui->SetProgress(0.0); - FILE* f = fopen(path, "rb"); - if (f == NULL) { - LOGE("failed to open %s (%s)\n", path, strerror(errno)); - return VERIFY_FAILURE; - } - // An archive with a whole-file signature will end in six bytes: // // (2-byte signature start) $ff $ff (2-byte comment size) @@ -131,33 +126,31 @@ int verify_file(const char* path, const Certificate* pKeys, unsigned int numKeys #define FOOTER_SIZE 6 - if (fseek(f, -FOOTER_SIZE, SEEK_END) != 0) { - LOGE("failed to seek in %s (%s)\n", path, strerror(errno)); - fclose(f); + if (length < FOOTER_SIZE) { + LOGE("not big enough to contain footer\n"); return VERIFY_FAILURE; } - unsigned char footer[FOOTER_SIZE]; - if (fread(footer, 1, FOOTER_SIZE, f) != FOOTER_SIZE) { - LOGE("failed to read footer from %s (%s)\n", path, strerror(errno)); - fclose(f); - return VERIFY_FAILURE; - } + unsigned char* footer = addr + length - FOOTER_SIZE; if (footer[2] != 0xff || footer[3] != 0xff) { LOGE("footer is wrong\n"); - fclose(f); return VERIFY_FAILURE; } size_t comment_size = footer[4] + (footer[5] << 8); size_t signature_start = footer[0] + (footer[1] << 8); - LOGI("comment is %d bytes; signature %d bytes from end\n", + LOGI("comment is %zu bytes; signature %zu bytes from end\n", comment_size, signature_start); + if (signature_start > comment_size) { + LOGE("signature start: %zu is larger than comment size: %zu\n", signature_start, + comment_size); + return VERIFY_FAILURE; + } + if (signature_start <= FOOTER_SIZE) { LOGE("Signature start is in the footer"); - fclose(f); return VERIFY_FAILURE; } @@ -167,9 +160,8 @@ int verify_file(const char* path, const Certificate* pKeys, unsigned int numKeys // comment length. size_t eocd_size = comment_size + EOCD_HEADER_SIZE; - if (fseek(f, -eocd_size, SEEK_END) != 0) { - LOGE("failed to seek in %s (%s)\n", path, strerror(errno)); - fclose(f); + if (length < eocd_size) { + LOGE("not big enough to contain EOCD\n"); return VERIFY_FAILURE; } @@ -177,26 +169,15 @@ int verify_file(const char* path, const Certificate* pKeys, unsigned int numKeys // This is everything except the signature data and length, which // includes all of the EOCD except for the comment length field (2 // bytes) and the comment data. - size_t signed_len = ftell(f) + EOCD_HEADER_SIZE - 2; + size_t signed_len = length - eocd_size + EOCD_HEADER_SIZE - 2; - unsigned char* eocd = (unsigned char*)malloc(eocd_size); - if (eocd == NULL) { - LOGE("malloc for EOCD record failed\n"); - fclose(f); - return VERIFY_FAILURE; - } - if (fread(eocd, 1, eocd_size, f) != eocd_size) { - LOGE("failed to read eocd from %s (%s)\n", path, strerror(errno)); - fclose(f); - return VERIFY_FAILURE; - } + unsigned char* eocd = addr + length - eocd_size; // If this is really is the EOCD record, it will begin with the // magic number $50 $4b $05 $06. if (eocd[0] != 0x50 || eocd[1] != 0x4b || eocd[2] != 0x05 || eocd[3] != 0x06) { LOGE("signature length doesn't match EOCD marker\n"); - fclose(f); return VERIFY_FAILURE; } @@ -209,7 +190,6 @@ int verify_file(const char* path, const Certificate* pKeys, unsigned int numKeys // which could be exploitable. Fail verification if // this sequence occurs anywhere after the real one. LOGE("EOCD marker occurs after start of EOCD\n"); - fclose(f); return VERIFY_FAILURE; } } @@ -229,35 +209,23 @@ int verify_file(const char* path, const Certificate* pKeys, unsigned int numKeys SHA256_CTX sha256_ctx; SHA_init(&sha1_ctx); SHA256_init(&sha256_ctx); - unsigned char* buffer = (unsigned char*)malloc(BUFFER_SIZE); - if (buffer == NULL) { - LOGE("failed to alloc memory for sha1 buffer\n"); - fclose(f); - return VERIFY_FAILURE; - } double frac = -1.0; size_t so_far = 0; - fseek(f, 0, SEEK_SET); while (so_far < signed_len) { - size_t size = BUFFER_SIZE; - if (signed_len - so_far < size) size = signed_len - so_far; - if (fread(buffer, 1, size, f) != size) { - LOGE("failed to read data from %s (%s)\n", path, strerror(errno)); - fclose(f); - return VERIFY_FAILURE; - } - if (need_sha1) SHA_update(&sha1_ctx, buffer, size); - if (need_sha256) SHA256_update(&sha256_ctx, buffer, size); + size_t size = signed_len - so_far; + if (size > BUFFER_SIZE) size = BUFFER_SIZE; + + if (need_sha1) SHA_update(&sha1_ctx, addr + so_far, size); + if (need_sha256) SHA256_update(&sha256_ctx, addr + so_far, size); so_far += size; + double f = so_far / (double)signed_len; if (f > frac + 0.02 || size == so_far) { ui->SetProgress(f); frac = f; } } - fclose(f); - free(buffer); const uint8_t* sha1 = SHA_final(&sha1_ctx); const uint8_t* sha256 = SHA256_final(&sha256_ctx); @@ -269,10 +237,8 @@ int verify_file(const char* path, const Certificate* pKeys, unsigned int numKeys if (!read_pkcs7(eocd + eocd_size - signature_start, signature_size, &sig_der, &sig_der_length)) { LOGE("Could not find signature DER block\n"); - free(eocd); return VERIFY_FAILURE; } - free(eocd); /* * Check to make sure at least one of the keys matches the signature. Since @@ -292,24 +258,24 @@ int verify_file(const char* path, const Certificate* pKeys, unsigned int numKeys if (pKeys[i].key_type == Certificate::RSA) { if (sig_der_length < RSANUMBYTES) { // "signature" block isn't big enough to contain an RSA block. - LOGI("signature is too short for RSA key %d\n", i); + LOGI("signature is too short for RSA key %zu\n", i); continue; } if (!RSA_verify(pKeys[i].rsa, sig_der, RSANUMBYTES, hash, pKeys[i].hash_len)) { - LOGI("failed to verify against RSA key %d\n", i); + LOGI("failed to verify against RSA key %zu\n", i); continue; } - LOGI("whole-file signature verified against RSA key %d\n", i); + LOGI("whole-file signature verified against RSA key %zu\n", i); free(sig_der); return VERIFY_SUCCESS; } else if (pKeys[i].key_type == Certificate::EC && pKeys[i].hash_len == SHA256_DIGEST_SIZE) { p256_int r, s; if (!dsa_sig_unpack(sig_der, sig_der_length, &r, &s)) { - LOGI("Not a DSA signature block for EC key %d\n", i); + LOGI("Not a DSA signature block for EC key %zu\n", i); continue; } @@ -317,11 +283,11 @@ int verify_file(const char* path, const Certificate* pKeys, unsigned int numKeys p256_from_bin(hash, &p256_hash); if (!p256_ecdsa_verify(&(pKeys[i].ec->x), &(pKeys[i].ec->y), &p256_hash, &r, &s)) { - LOGI("failed to verify against EC key %d\n", i); + LOGI("failed to verify against EC key %zu\n", i); continue; } - LOGI("whole-file signature verified against EC key %d\n", i); + LOGI("whole-file signature verified against EC key %zu\n", i); free(sig_der); return VERIFY_SUCCESS; } else { |