diff options
Diffstat (limited to 'mac.c')
| -rw-r--r-- | mac.c | 23 |
1 files changed, 21 insertions, 2 deletions
@@ -1,4 +1,4 @@ -/* $OpenBSD: mac.c,v 1.32 2015/01/15 18:32:54 naddy Exp $ */ +/* $OpenBSD: mac.c,v 1.33 2016/07/08 03:44:42 djm Exp $ */ /* * Copyright (c) 2001 Markus Friedl. All rights reserved. * @@ -167,7 +167,8 @@ mac_init(struct sshmac *mac) } int -mac_compute(struct sshmac *mac, u_int32_t seqno, const u_char *data, int datalen, +mac_compute(struct sshmac *mac, u_int32_t seqno, + const u_char *data, int datalen, u_char *digest, size_t dlen) { static union { @@ -211,6 +212,24 @@ mac_compute(struct sshmac *mac, u_int32_t seqno, const u_char *data, int datalen return 0; } +int +mac_check(struct sshmac *mac, u_int32_t seqno, + const u_char *data, size_t dlen, + const u_char *theirmac, size_t mlen) +{ + u_char ourmac[SSH_DIGEST_MAX_LENGTH]; + int r; + + if (mac->mac_len > mlen) + return SSH_ERR_INVALID_ARGUMENT; + if ((r = mac_compute(mac, seqno, data, dlen, + ourmac, sizeof(ourmac))) != 0) + return r; + if (timingsafe_bcmp(ourmac, theirmac, mac->mac_len) != 0) + return SSH_ERR_MAC_INVALID; + return 0; +} + void mac_clear(struct sshmac *mac) { |