diff options
| -rw-r--r-- | .gitignore | 1 | ||||
| -rw-r--r-- | pbkdf2.c | 38 | ||||
| -rw-r--r-- | tests/test-pbkdf2.c | 3 |
3 files changed, 24 insertions, 18 deletions
@@ -7,4 +7,5 @@ config.log config.status tests/test-aes-key-wrap tests/test-hash +tests/test-pbkdf2 tests/test-rsa @@ -86,8 +86,12 @@ hal_error_t hal_pbkdf2(const hal_hash_descriptor_t * const descriptor, uint8_t * derived_key, size_t derived_key_length, unsigned iterations_desired) { - uint8_t statebuf[1024]; /* C99 may let us clean this up */ - uint32_t block_count; + uint8_t ac[HAL_MAX_HASH_DIGEST_LENGTH], mac[HAL_MAX_HASH_DIGEST_LENGTH]; + uint8_t statebuf[1024]; + unsigned iteration; + hal_error_t err; + uint32_t block; + int i; if (descriptor == NULL || password == NULL || salt == NULL || derived_key == NULL || derived_key_length == 0 || @@ -95,11 +99,16 @@ hal_error_t hal_pbkdf2(const hal_hash_descriptor_t * const descriptor, return HAL_ERROR_BAD_ARGUMENTS; assert(sizeof(statebuf) >= descriptor->hmac_state_length); + assert(sizeof(ac) >= descriptor->digest_length); + assert(sizeof(mac) >= descriptor->digest_length); /* Output length check per RFC 2989 5.2. */ if ((uint64_t) derived_key_length > ((uint64_t) 0xFFFFFFFF) * descriptor->block_length) return HAL_ERROR_UNSUPPORTED_KEY; + memset(ac, 0, sizeof(ac)); + memset(mac, 0, sizeof(mac)); + /* * We probably should check here to see whether the password is * longer than the HMAC block size, and, if so, we should hash the @@ -113,38 +122,33 @@ hal_error_t hal_pbkdf2(const hal_hash_descriptor_t * const descriptor, * Generate output blocks until we reach the requested length. */ - for (block_count = 1; ; block_count++) { - - uint8_t accumulator[HAL_MAX_HASH_DIGEST_LENGTH], mac[HAL_MAX_HASH_DIGEST_LENGTH]; - unsigned iteration; - hal_error_t err; - int i; + for (block = 1; ; block++) { /* - * Initialize the accumulator with the HMAC of the salt - * concatenated with the block count. + * Initial HMAC is of the salt concatenated with the block count. + * This seeds the accumulator, and constitutes iteration one. */ if ((err = do_hmac(descriptor, password, password_length, salt, salt_length, - block_count, accumulator, sizeof(accumulator))) != HAL_OK) + block, mac, sizeof(mac))) != HAL_OK) return err; + memcpy(ac, mac, descriptor->digest_length); + /* * Now iterate however many times the caller requested, XORing the * result back into the accumulator on each iteration. - * Initializing the accumulator counts as iteration 1, so we start - * with iteration 2. */ for (iteration = 2; iteration <= iterations_desired; iteration++) { if ((err = do_hmac(descriptor, password, password_length, - accumulator, descriptor->digest_length, + ac, descriptor->digest_length, 0, mac, sizeof(mac))) != HAL_OK) return err; for (i = 0; i < descriptor->digest_length; i++) - accumulator[i] ^= mac[i]; + ac[i] ^= mac[i]; } /* @@ -153,12 +157,12 @@ hal_error_t hal_pbkdf2(const hal_hash_descriptor_t * const descriptor, */ if (derived_key_length > descriptor->digest_length) { - memcpy(derived_key, accumulator, descriptor->digest_length); + memcpy(derived_key, ac, descriptor->digest_length); derived_key += descriptor->digest_length; derived_key_length -= descriptor->digest_length; } else { - memcpy(derived_key, accumulator, derived_key_length); + memcpy(derived_key, ac, derived_key_length); return HAL_OK; } } diff --git a/tests/test-pbkdf2.c b/tests/test-pbkdf2.c index 67940b4..477dfe2 100644 --- a/tests/test-pbkdf2.c +++ b/tests/test-pbkdf2.c @@ -153,7 +153,8 @@ static const uint8_t pbkdf2_tc_6_DK[] = { /* 16 bytes */ static void print_hex(const uint8_t * const val, const size_t len) { - for (size_t i = 0; i < len; i++) + size_t i; + for (i = 0; i < len; i++) printf(" %02x", val[i]); } |