Function padlock_authcompute

freebsd/crypto/via/padlock_hash.c:281–319

* Compute keyed-hash authenticator. */

 * Compute keyed-hash authenticator.
 */
static int
padlock_authcompute(struct padlock_session *ses, struct cryptop *crp)
{
	u_char hash[HASH_MAX_LEN], hash2[HASH_MAX_LEN];
	struct auth_hash *axf;
	union authctx ctx;
	int error;

	axf = ses->ses_axf;

	padlock_copy_ctx(axf, ses->ses_ictx, &ctx);
	error = crypto_apply(crp, crp->crp_aad_start, crp->crp_aad_length,
	    axf->Update, &ctx);
	if (error != 0) {
		padlock_free_ctx(axf, &ctx);
		return (error);
	}
	error = crypto_apply(crp, crp->crp_payload_start,
	    crp->crp_payload_length, axf->Update, &ctx);
	if (error != 0) {
		padlock_free_ctx(axf, &ctx);
		return (error);
	}
	axf->Final(hash, &ctx);

	padlock_copy_ctx(axf, ses->ses_octx, &ctx);
	axf->Update(&ctx, hash, axf->hashsize);
	axf->Final(hash, &ctx);

	if (crp->crp_op & CRYPTO_OP_VERIFY_DIGEST) {
		crypto_copydata(crp, crp->crp_digest_start, ses->ses_mlen,
		    hash2);
		if (timingsafe_bcmp(hash, hash2, ses->ses_mlen) != 0)
			return (EBADMSG);
	} else
		crypto_copyback(crp, crp->crp_digest_start, ses->ses_mlen,
		    hash);
	return (0);
}

/* Find software structure which describes HMAC algorithm. */
static struct auth_hash *