size_t hmac_sha(const hash_t *key, const hash_t *msg, hash_t *hash, const evp_md_t *md)
{
size_t len;
hash_t buff[MAX_LEN];
hmac_ctx_t ctx;
hmac_ctx_init(&ctx);
hmac_init(&ctx, key, strlen((char *)key), md);
hmac_update(&ctx, msg, strlen((char *)msg));
hmac_final(&ctx, buff, (unsigned int *)&len);
hmac_ctx_cleanup(&ctx);
memcpy(hash, buff, len);
return len;
}
/* given a key and key_type, build a key_ctx */
void
init_key_ctx (struct key_ctx *ctx, struct key *key,
const struct key_type *kt, int enc,
const char *prefix)
{
struct gc_arena gc = gc_new ();
CLEAR (*ctx);
if (kt->cipher && kt->cipher_length > 0)
{
ALLOC_OBJ(ctx->cipher, cipher_ctx_t);
cipher_ctx_init (ctx->cipher, key->cipher, kt->cipher_length,
kt->cipher, enc);
msg (D_HANDSHAKE, "%s: Cipher '%s' initialized with %d bit key",
prefix,
cipher_kt_name(kt->cipher),
kt->cipher_length *8);
dmsg (D_SHOW_KEYS, "%s: CIPHER KEY: %s", prefix,
format_hex (key->cipher, kt->cipher_length, 0, &gc));
dmsg (D_CRYPTO_DEBUG, "%s: CIPHER block_size=%d iv_size=%d",
prefix,
cipher_kt_block_size(kt->cipher),
cipher_kt_iv_size(kt->cipher));
}
if (kt->digest && kt->hmac_length > 0)
{
ALLOC_OBJ(ctx->hmac, hmac_ctx_t);
hmac_ctx_init (ctx->hmac, key->hmac, kt->hmac_length, kt->digest);
msg (D_HANDSHAKE,
"%s: Using %d bit message hash '%s' for HMAC authentication",
prefix, md_kt_size(kt->digest) * 8, md_kt_name(kt->digest));
dmsg (D_SHOW_KEYS, "%s: HMAC KEY: %s", prefix,
format_hex (key->hmac, kt->hmac_length, 0, &gc));
dmsg (D_CRYPTO_DEBUG, "%s: HMAC size=%d block_size=%d",
prefix,
md_kt_size(kt->digest),
hmac_ctx_size(ctx->hmac));
}
gc_free (&gc);
}