crypto/openssh/mac.c

1 /* $OpenBSD: mac.c,v 1.35 2019/09/06 04:53:27 djm Exp $ */
37 #include "mac.h"
106 mac_setup_by_alg(struct sshmac *mac, const struct macalg *macalg)
108 	mac->type = macalg->type;
109 	if (mac->type == SSH_DIGEST) {
110 		if ((mac->hmac_ctx = ssh_hmac_start(macalg->alg)) == NULL)
112 		mac->key_len = mac->mac_len = ssh_hmac_bytes(macalg->alg);
114 		mac->mac_len = macalg->len / 8;
115 		mac->key_len = macalg->key_len / 8;
116 		mac->umac_ctx = NULL;
119 		mac->mac_len = macalg->truncatebits / 8;
120 	mac->etm = macalg->etm;
125 mac_setup(struct sshmac *mac, char *name)
132 		if (mac != NULL)
133 			return mac_setup_by_alg(mac, m);
140 mac_init(struct sshmac *mac)
142 	if (mac->key == NULL)
144 	switch (mac->type) {
146 		if (mac->hmac_ctx == NULL ||
147 		    ssh_hmac_init(mac->hmac_ctx, mac->key, mac->key_len) < 0)
151 		if ((mac->umac_ctx = umac_new(mac->key)) == NULL)
155 		if ((mac->umac_ctx = umac128_new(mac->key)) == NULL)
164 mac_compute(struct sshmac *mac, u_int32_t seqno,
175 	if (mac->mac_len > sizeof(u))
178 	switch (mac->type) {
182 		if (ssh_hmac_init(mac->hmac_ctx, NULL, 0) < 0 ||
183 		    ssh_hmac_update(mac->hmac_ctx, b, sizeof(b)) < 0 ||
184 		    ssh_hmac_update(mac->hmac_ctx, data, datalen) < 0 ||
185 		    ssh_hmac_final(mac->hmac_ctx, u.m, sizeof(u.m)) < 0)
190 		umac_update(mac->umac_ctx, data, datalen);
191 		umac_final(mac->umac_ctx, u.m, nonce);
195 		umac128_update(mac->umac_ctx, data, datalen);
196 		umac128_final(mac->umac_ctx, u.m, nonce);
202 		if (dlen > mac->mac_len)
203 			dlen = mac->mac_len;
210 mac_check(struct sshmac *mac, u_int32_t seqno,
217 	if (mac->mac_len > mlen)
219 	if ((r = mac_compute(mac, seqno, data, dlen,
222 	if (timingsafe_bcmp(ourmac, theirmac, mac->mac_len) != 0)
228 mac_clear(struct sshmac *mac)
230 	if (mac->type == SSH_UMAC) {
231 		if (mac->umac_ctx != NULL)
232 			umac_delete(mac->umac_ctx);
233 	} else if (mac->type == SSH_UMAC128) {
234 		if (mac->umac_ctx != NULL)
235 			umac128_delete(mac->umac_ctx);
236 	} else if (mac->hmac_ctx != NULL)
237 		ssh_hmac_free(mac->hmac_ctx);
238 	mac->hmac_ctx = NULL;
239 	mac->umac_ctx = NULL;