/* 'do it all in one go' subroutine */
void hmac_sha1(const unsigned char key[], unsigned int key_len,
const unsigned char data[], unsigned int data_len,
unsigned char mac[], unsigned int mac_len)
{ hmac_ctx cx[1];
hmac_sha1_begin(cx);
hmac_sha1_key(key, key_len, cx);
hmac_sha1_data(data, data_len, cx);
hmac_sha1_end(mac, mac_len, cx);
}
void authenticate_decrypt(void* buf, u32 len)
{
#ifdef GLADMAN_HMAC
hmac_sha1_data(buf, len, &hmac);
#else
if (hmac_process(&hmac, buf, len) != CRYPT_OK)
Z_ERROR("Failed to authenticate");
#endif
if (ctr_decrypt(buf, buf, len, &ctr) != CRYPT_OK)
Z_ERROR("Failed to decrypt");
}
/* compute and output the MAC value */
void hmac_sha1_end(unsigned char mac[], unsigned long mac_len, hmac_ctx cx[1])
{ unsigned char dig[OUT_BLOCK_LENGTH];
unsigned int i;
/* if no data has been entered perform a null data phase */
if(cx->klen != HMAC_IN_DATA)
hmac_sha1_data((const unsigned char*)0, 0, cx);
sha1_end(dig, cx->ctx); /* complete the inner hash */
/* set outer key value using opad and removing ipad */
for(i = 0; i < IN_BLOCK_LENGTH / sizeof(ARCH_WORD_32); ++i)
cx->key[i] ^= 0x36363636 ^ 0x5c5c5c5c;
/* perform the outer hash operation */
sha1_begin(cx->ctx);
sha1_hash(cx->key, IN_BLOCK_LENGTH, cx->ctx);
sha1_hash(dig, OUT_BLOCK_LENGTH, cx->ctx);
sha1_end(dig, cx->ctx);
/* output the hash value */
for(i = 0; i < mac_len; ++i)
mac[i] = dig[i];
}
