diff options
Diffstat (limited to 'verifier.cpp')
| -rw-r--r-- | verifier.cpp | 80 |
1 files changed, 63 insertions, 17 deletions
diff --git a/verifier.cpp b/verifier.cpp index 5f4c981e5..782a83863 100644 --- a/verifier.cpp +++ b/verifier.cpp @@ -20,6 +20,7 @@ #include "mincrypt/rsa.h" #include "mincrypt/sha.h" +#include "mincrypt/sha256.h" #include <string.h> #include <stdio.h> @@ -34,7 +35,7 @@ extern RecoveryUI* ui; // Return VERIFY_SUCCESS, VERIFY_FAILURE (if any error is encountered // or no key matches the signature). -int verify_file(const char* path, const RSAPublicKey *pKeys, unsigned int numKeys) { +int verify_file(const char* path, const Certificate* pKeys, unsigned int numKeys) { ui->SetProgress(0.0); FILE* f = fopen(path, "rb"); @@ -68,6 +69,7 @@ int verify_file(const char* path, const RSAPublicKey *pKeys, unsigned int numKey } if (footer[2] != 0xff || footer[3] != 0xff) { + LOGE("footer is wrong\n"); fclose(f); return VERIFY_FAILURE; } @@ -139,8 +141,19 @@ int verify_file(const char* path, const RSAPublicKey *pKeys, unsigned int numKey #define BUFFER_SIZE 4096 - SHA_CTX ctx; - SHA_init(&ctx); + bool need_sha1 = false; + bool need_sha256 = false; + for (i = 0; i < numKeys; ++i) { + switch (pKeys[i].hash_len) { + case SHA_DIGEST_SIZE: need_sha1 = true; break; + case SHA256_DIGEST_SIZE: need_sha256 = true; break; + } + } + + SHA_CTX sha1_ctx; + 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"); @@ -159,7 +172,8 @@ int verify_file(const char* path, const RSAPublicKey *pKeys, unsigned int numKey fclose(f); return VERIFY_FAILURE; } - SHA_update(&ctx, buffer, size); + if (need_sha1) SHA_update(&sha1_ctx, buffer, size); + if (need_sha256) SHA256_update(&sha256_ctx, buffer, size); so_far += size; double f = so_far / (double)signed_len; if (f > frac + 0.02 || size == so_far) { @@ -170,12 +184,21 @@ int verify_file(const char* path, const RSAPublicKey *pKeys, unsigned int numKey fclose(f); free(buffer); - const uint8_t* sha1 = SHA_final(&ctx); + const uint8_t* sha1 = SHA_final(&sha1_ctx); + const uint8_t* sha256 = SHA256_final(&sha256_ctx); + for (i = 0; i < numKeys; ++i) { + const uint8_t* hash; + switch (pKeys[i].hash_len) { + case SHA_DIGEST_SIZE: hash = sha1; break; + case SHA256_DIGEST_SIZE: hash = sha256; break; + default: continue; + } + // The 6 bytes is the "(signature_start) $ff $ff (comment_size)" that // the signing tool appends after the signature itself. - if (RSA_verify(pKeys+i, eocd + eocd_size - 6 - RSANUMBYTES, - RSANUMBYTES, sha1)) { + if (RSA_verify(pKeys[i].public_key, eocd + eocd_size - 6 - RSANUMBYTES, + RSANUMBYTES, hash, pKeys[i].hash_len)) { LOGI("whole-file signature verified against key %d\n", i); free(eocd); return VERIFY_SUCCESS; @@ -207,10 +230,19 @@ int verify_file(const char* path, const RSAPublicKey *pKeys, unsigned int numKey // The file may contain multiple keys in this format, separated by // commas. The last key must not be followed by a comma. // +// A Certificate is a pair of an RSAPublicKey and a particular hash +// (we support SHA-1 and SHA-256; we store the hash length to signify +// which is being used). The hash used is implied by the version number. +// +// 1: 2048-bit RSA key with e=3 and SHA-1 hash +// 2: 2048-bit RSA key with e=65537 and SHA-1 hash +// 3: 2048-bit RSA key with e=3 and SHA-256 hash +// 4: 2048-bit RSA key with e=65537 and SHA-256 hash +// // Returns NULL if the file failed to parse, or if it contain zero keys. -RSAPublicKey* +Certificate* load_keys(const char* filename, int* numKeys) { - RSAPublicKey* out = NULL; + Certificate* out = NULL; *numKeys = 0; FILE* f = fopen(filename, "r"); @@ -224,24 +256,38 @@ load_keys(const char* filename, int* numKeys) { bool done = false; while (!done) { ++*numKeys; - out = (RSAPublicKey*)realloc(out, *numKeys * sizeof(RSAPublicKey)); - RSAPublicKey* key = out + (*numKeys - 1); + out = (Certificate*)realloc(out, *numKeys * sizeof(Certificate)); + Certificate* cert = out + (*numKeys - 1); + cert->public_key = (RSAPublicKey*)malloc(sizeof(RSAPublicKey)); char start_char; if (fscanf(f, " %c", &start_char) != 1) goto exit; if (start_char == '{') { // a version 1 key has no version specifier. - key->exponent = 3; + cert->public_key->exponent = 3; + cert->hash_len = SHA_DIGEST_SIZE; } else if (start_char == 'v') { int version; if (fscanf(f, "%d {", &version) != 1) goto exit; - if (version == 2) { - key->exponent = 65537; - } else { - goto exit; + switch (version) { + case 2: + cert->public_key->exponent = 65537; + cert->hash_len = SHA_DIGEST_SIZE; + break; + case 3: + cert->public_key->exponent = 3; + cert->hash_len = SHA256_DIGEST_SIZE; + break; + case 4: + cert->public_key->exponent = 65537; + cert->hash_len = SHA256_DIGEST_SIZE; + break; + default: + goto exit; } } + RSAPublicKey* key = cert->public_key; if (fscanf(f, " %i , 0x%x , { %u", &(key->len), &(key->n0inv), &(key->n[0])) != 3) { goto exit; @@ -274,7 +320,7 @@ load_keys(const char* filename, int* numKeys) { goto exit; } - LOGI("read key e=%d\n", key->exponent); + LOGI("read key e=%d hash=%d\n", key->exponent, cert->hash_len); } } |