diff options
Diffstat (limited to 'src/common/crypto.c')
| -rw-r--r-- | src/common/crypto.c | 50 |
1 files changed, 49 insertions, 1 deletions
diff --git a/src/common/crypto.c b/src/common/crypto.c index 6c1dae9a73..8762840a54 100644 --- a/src/common/crypto.c +++ b/src/common/crypto.c @@ -1261,7 +1261,7 @@ void crypto_digest_get_digest(crypto_digest_env_t *digest, char *out, size_t out_len) { - static unsigned char r[DIGEST_LEN]; + static unsigned char r[DIGEST_LEN]; /*XXXXX020 why static? */ SHA_CTX tmpctx; tor_assert(digest); tor_assert(out); @@ -1297,6 +1297,54 @@ crypto_digest_assign(crypto_digest_env_t *into, memcpy(into,from,sizeof(crypto_digest_env_t)); } +/**DOCDOC */ +#define DIGEST_BLOCKSIZE 64 + +/** Compute the HMAC-SHA-1 of the <b>msg_len</b> bytes in <b>msg</b>, using + * the <b>key</b> of length <b>key_len</b>. Store the DIGEST_LEN-byte result + * in <b>hmac_out</b>. + */ +void +crypto_hmac_sha1(char *hmac_out, + const char *key, size_t key_len, + const char *msg, size_t msg_len) +{ + SHA_CTX sha; + uint8_t K[DIGEST_BLOCKSIZE], D[DIGEST_LEN], K_SHORT[DIGEST_LEN]; + const uint8_t *real_key; + unsigned int i; + + if (key_len > DIGEST_BLOCKSIZE) { + SHA1((const unsigned char*)key, key_len, K_SHORT); + key_len = DIGEST_LEN; + real_key = K_SHORT; + } else { + real_key = (const uint8_t*)key; + } + + memset(K, 0, sizeof(K)); + memcpy(K, real_key, key_len); + for (i=0; i < sizeof(K); ++i) + K[i] ^= 0x36; + SHA1_Init(&sha); + SHA1_Update(&sha, K, sizeof(K)); + SHA1_Update(&sha, msg, msg_len); + SHA1_Final(D, &sha); + + /* + memset(K, 0, sizeof(K)); + memcpy(K, real_key, key_len); + for (i=0; i < sizeof(K); ++i) + K[i] ^= 0x5c; + */ + for (i=0; i < sizeof(K); ++i) + K[i] ^= (0x36 ^ 0x5c); + SHA1_Init(&sha); + SHA1_Update(&sha, K, sizeof(K)); + SHA1_Update(&sha, D, sizeof(D)); + SHA1_Final((unsigned char*)hmac_out, &sha); +} + /* DH */ /** Shared P parameter for our DH key exchanged. */ |