From 636c3b627cc964f65e5b38bb005d50f2841d6966 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Mon, 3 Apr 2017 17:43:44 +0200 Subject: [PATCH] tls: merge sha1 and sha256 hmac functions function old new delta hmac_begin - 196 +196 hmac_sha256 61 68 +7 hmac 250 87 -163 hmac_sha256_begin 190 - -190 ------------------------------------------------------------------------------ (add/remove: 1/1 grow/shrink: 1/1 up/down: 203/-353) Total: -150 bytes Signed-off-by: Denys Vlasenko --- networking/tls.c | 56 +++++++++++------------------------------------- 1 file changed, 12 insertions(+), 44 deletions(-) diff --git a/networking/tls.c b/networking/tls.c index cb6b09476..bbf2b158f 100644 --- a/networking/tls.c +++ b/networking/tls.c @@ -367,11 +367,12 @@ static unsigned hmac_sha_precomputed_v( return sha_end(&pre->hashed_key_xor_opad, out); } -static void hmac_sha256_begin(hmac_precomputed_t *pre, uint8_t *key, unsigned key_size) +typedef void md5sha_begin_func(md5sha_ctx_t *ctx) FAST_FUNC; +static void hmac_begin(hmac_precomputed_t *pre, uint8_t *key, unsigned key_size, md5sha_begin_func *begin) { uint8_t key_xor_ipad[SHA_INSIZE]; uint8_t key_xor_opad[SHA_INSIZE]; - uint8_t tempkey[SHA256_OUTSIZE]; + uint8_t tempkey[SHA1_OUTSIZE < SHA256_OUTSIZE ? SHA256_OUTSIZE : SHA1_OUTSIZE]; unsigned i; // "The authentication key can be of any length up to INSIZE, the @@ -380,7 +381,7 @@ static void hmac_sha256_begin(hmac_precomputed_t *pre, uint8_t *key, unsigned ke // resultant OUTSIZE byte string as the actual key to HMAC." if (key_size > SHA_INSIZE) { md5sha_ctx_t ctx; - sha256_begin(&ctx); + begin(&ctx); md5sha_hash(&ctx, key, key_size); key_size = sha_end(&ctx, tempkey); } @@ -394,41 +395,8 @@ static void hmac_sha256_begin(hmac_precomputed_t *pre, uint8_t *key, unsigned ke key_xor_opad[i] = 0x5c; } - sha256_begin(&pre->hashed_key_xor_ipad); - sha256_begin(&pre->hashed_key_xor_opad); - md5sha_hash(&pre->hashed_key_xor_ipad, key_xor_ipad, SHA_INSIZE); - md5sha_hash(&pre->hashed_key_xor_opad, key_xor_opad, SHA_INSIZE); -} -// TODO: ^^^ vvv merge? -static void hmac_sha1_begin(hmac_precomputed_t *pre, uint8_t *key, unsigned key_size) -{ - uint8_t key_xor_ipad[SHA_INSIZE]; - uint8_t key_xor_opad[SHA_INSIZE]; - uint8_t tempkey[SHA1_OUTSIZE]; - unsigned i; - - // "The authentication key can be of any length up to INSIZE, the - // block length of the hash function. Applications that use keys longer - // than INSIZE bytes will first hash the key using H and then use the - // resultant OUTSIZE byte string as the actual key to HMAC." - if (key_size > SHA_INSIZE) { - md5sha_ctx_t ctx; - sha1_begin(&ctx); - md5sha_hash(&ctx, key, key_size); - key_size = sha_end(&ctx, tempkey); - } - - for (i = 0; i < key_size; i++) { - key_xor_ipad[i] = key[i] ^ 0x36; - key_xor_opad[i] = key[i] ^ 0x5c; - } - for (; i < SHA_INSIZE; i++) { - key_xor_ipad[i] = 0x36; - key_xor_opad[i] = 0x5c; - } - - sha1_begin(&pre->hashed_key_xor_ipad); - sha1_begin(&pre->hashed_key_xor_opad); + begin(&pre->hashed_key_xor_ipad); + begin(&pre->hashed_key_xor_opad); md5sha_hash(&pre->hashed_key_xor_ipad, key_xor_ipad, SHA_INSIZE); md5sha_hash(&pre->hashed_key_xor_opad, key_xor_opad, SHA_INSIZE); } @@ -441,11 +409,11 @@ static unsigned hmac(tls_state_t *tls, uint8_t *out, uint8_t *key, unsigned key_ va_start(va, key_size); - if (tls->MAC_size == SHA256_OUTSIZE) - hmac_sha256_begin(&pre, key, key_size); - else - hmac_sha1_begin(&pre, key, key_size); - + hmac_begin(&pre, key, key_size, + (tls->MAC_size == SHA256_OUTSIZE) + ? sha256_begin + : sha1_begin + ); len = hmac_sha_precomputed_v(&pre, out, va); va_end(va); @@ -460,7 +428,7 @@ static unsigned hmac_sha256(/*tls_state_t *tls,*/ uint8_t *out, uint8_t *key, un va_start(va, key_size); - hmac_sha256_begin(&pre, key, key_size); + hmac_begin(&pre, key, key_size, sha256_begin); len = hmac_sha_precomputed_v(&pre, out, va); va_end(va);