/* * keylength in bits! * message length in bits! */ void hmac_sha1(void* dest, const void* key, uint16_t keylength_b, const void* msg, uint32_t msglength_b){ /* a one-shot*/ sha1_ctx_t s; uint8_t i; uint8_t buffer[SHA1_BLOCK_BYTES]; memset(buffer, 0, SHA1_BLOCK_BYTES); /* if key is larger than a block we have to hash it*/ if (keylength_b > SHA1_BLOCK_BITS){ sha1((void*)buffer, key, keylength_b); } else { memcpy(buffer, key, (keylength_b+7)/8); } for (i=0; i<SHA1_BLOCK_BYTES; ++i){ buffer[i] ^= IPAD; } sha1_init(&s); sha1_nextBlock(&s, buffer); while (msglength_b >= SHA1_BLOCK_BITS){ sha1_nextBlock(&s, msg); msg = (uint8_t*)msg + SHA1_BLOCK_BYTES; msglength_b -= SHA1_BLOCK_BITS; } sha1_lastBlock(&s, msg, msglength_b); /* since buffer still contains key xor ipad we can do ... */ for (i=0; i<SHA1_BLOCK_BYTES; ++i){ buffer[i] ^= IPAD ^ OPAD; } sha1_ctx2hash(dest, &s); /* save inner hash temporary to dest */ sha1_init(&s); sha1_nextBlock(&s, buffer); sha1_lastBlock(&s, dest, SHA1_HASH_BITS); sha1_ctx2hash(dest, &s); }
void hmac_sha1_init(hmac_sha1_ctx_t *s, const void* key, uint16_t keylength_b){ uint8_t buffer[SHA1_BLOCK_BYTES]; uint8_t i; memset(buffer, 0, SHA1_BLOCK_BYTES); if (keylength_b > SHA1_BLOCK_BITS){ sha1((void*)buffer, key, keylength_b); } else { memcpy(buffer, key, (keylength_b+7)/8); } for (i=0; i<SHA1_BLOCK_BYTES; ++i){ buffer[i] ^= IPAD; } sha1_init(&(s->a)); sha1_nextBlock(&(s->a), buffer); for (i=0; i<SHA1_BLOCK_BYTES; ++i){ buffer[i] ^= IPAD^OPAD; } sha1_init(&(s->b)); sha1_nextBlock(&(s->b), buffer); #if defined SECURE_WIPE_BUFFER memset(buffer, 0, SHA1_BLOCK_BYTES); #endif }
void hmac_sha1_lastBlock(hmac_sha1_ctx_t *s, const void* block, uint16_t length_b){ while(length_b>=SHA1_BLOCK_BITS){ sha1_nextBlock(&(s->a), block); block = (uint8_t*)block + SHA1_BLOCK_BYTES; length_b -= SHA1_BLOCK_BITS; } sha1_lastBlock(&(s->a), block, length_b); }
void shacal1_enc(void *buffer, void *key, uint16_t keysize_b){ sha1_ctx_t ctx, t_ctx; uint8_t i; memcpy(t_ctx.h, buffer, SHA1_HASH_BITS/8); uint8_t keybuffer[SHA1_BLOCK_BITS/8]; memset(keybuffer, 0, SHA1_BLOCK_BITS/8); if(keysize_b>SHA1_BLOCK_BITS) keysize_b=SHA1_BLOCK_BITS; memcpy(keybuffer, key, (keysize_b+7)/8); memcpy(t_ctx.h, buffer, SHA1_HASH_BITS/8); sha1_ctx2hash(&ctx.h[0], &t_ctx); memcpy(t_ctx.h, ctx.h, SHA1_HASH_BITS/8); sha1_nextBlock(&ctx, keybuffer); for(i=0; i<5; ++i) ctx.h[i] -= t_ctx.h[i]; sha1_ctx2hash(buffer, &ctx); }
void hmac_sha1_nextBlock(hmac_sha1_ctx_t *s, const void* block){ sha1_nextBlock(&(s->a), block); }