1 /* $OpenBSD: ssh-xmss.c,v 1.14 2022/10/28 00:44:44 djm Exp $*/
3 * Copyright (c) 2017 Stefan-Lukas Gazdag.
4 * Copyright (c) 2017 Markus Friedl.
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
21 #define SSHKEY_INTERNAL
22 #include <sys/types.h>
36 #include "sshkey-xmss.h"
40 #include "xmss_fast.h"
43 ssh_xmss_cleanup(struct sshkey *k)
45 freezero(k->xmss_pk, sshkey_xmss_pklen(k));
46 freezero(k->xmss_sk, sshkey_xmss_sklen(k));
47 sshkey_xmss_free_state(k);
49 free(k->xmss_filename);
53 k->xmss_filename = NULL;
57 ssh_xmss_equal(const struct sshkey *a, const struct sshkey *b)
59 if (a->xmss_pk == NULL || b->xmss_pk == NULL)
61 if (sshkey_xmss_pklen(a) != sshkey_xmss_pklen(b))
63 if (memcmp(a->xmss_pk, b->xmss_pk, sshkey_xmss_pklen(a)) != 0)
69 ssh_xmss_serialize_public(const struct sshkey *key, struct sshbuf *b,
70 enum sshkey_serialize_rep opts)
74 if (key->xmss_name == NULL || key->xmss_pk == NULL ||
75 sshkey_xmss_pklen(key) == 0)
76 return SSH_ERR_INVALID_ARGUMENT;
77 if ((r = sshbuf_put_cstring(b, key->xmss_name)) != 0 ||
78 (r = sshbuf_put_string(b, key->xmss_pk,
79 sshkey_xmss_pklen(key))) != 0 ||
80 (r = sshkey_xmss_serialize_pk_info(key, b, opts)) != 0)
87 ssh_xmss_serialize_private(const struct sshkey *key, struct sshbuf *b,
88 enum sshkey_serialize_rep opts)
92 if (key->xmss_name == NULL)
93 return SSH_ERR_INVALID_ARGUMENT;
94 /* Note: can't reuse ssh_xmss_serialize_public because of sk order */
95 if ((r = sshbuf_put_cstring(b, key->xmss_name)) != 0 ||
96 (r = sshbuf_put_string(b, key->xmss_pk,
97 sshkey_xmss_pklen(key))) != 0 ||
98 (r = sshbuf_put_string(b, key->xmss_sk,
99 sshkey_xmss_sklen(key))) != 0 ||
100 (r = sshkey_xmss_serialize_state_opt(key, b, opts)) != 0)
107 ssh_xmss_copy_public(const struct sshkey *from, struct sshkey *to)
109 int r = SSH_ERR_INTERNAL_ERROR;
113 if ((r = sshkey_xmss_init(to, from->xmss_name)) != 0)
115 if (from->xmss_pk == NULL)
116 return 0; /* XXX SSH_ERR_INTERNAL_ERROR ? */
118 if ((pklen = sshkey_xmss_pklen(from)) == 0 ||
119 sshkey_xmss_pklen(to) != pklen)
120 return SSH_ERR_INTERNAL_ERROR;
121 if ((to->xmss_pk = malloc(pklen)) == NULL)
122 return SSH_ERR_ALLOC_FAIL;
123 memcpy(to->xmss_pk, from->xmss_pk, pklen);
124 /* simulate number of signatures left on pubkey */
125 left = sshkey_xmss_signatures_left(from);
127 sshkey_xmss_enable_maxsign(to, left);
132 ssh_xmss_deserialize_public(const char *ktype, struct sshbuf *b,
136 char *xmss_name = NULL;
138 int ret = SSH_ERR_INTERNAL_ERROR;
140 if ((ret = sshbuf_get_cstring(b, &xmss_name, NULL)) != 0)
142 if ((ret = sshkey_xmss_init(key, xmss_name)) != 0)
144 if ((ret = sshbuf_get_string(b, &pk, &len)) != 0)
146 if (len == 0 || len != sshkey_xmss_pklen(key)) {
147 ret = SSH_ERR_INVALID_FORMAT;
152 if (!sshkey_is_cert(key) &&
153 (ret = sshkey_xmss_deserialize_pk_info(key, b)) != 0)
164 ssh_xmss_deserialize_private(const char *ktype, struct sshbuf *b,
168 char *xmss_name = NULL;
169 size_t pklen = 0, sklen = 0;
170 u_char *xmss_pk = NULL, *xmss_sk = NULL;
172 /* Note: can't reuse ssh_xmss_deserialize_public because of sk order */
173 if ((r = sshbuf_get_cstring(b, &xmss_name, NULL)) != 0 ||
174 (r = sshbuf_get_string(b, &xmss_pk, &pklen)) != 0 ||
175 (r = sshbuf_get_string(b, &xmss_sk, &sklen)) != 0)
177 if (!sshkey_is_cert(key) &&
178 (r = sshkey_xmss_init(key, xmss_name)) != 0)
180 if (pklen != sshkey_xmss_pklen(key) ||
181 sklen != sshkey_xmss_sklen(key)) {
182 r = SSH_ERR_INVALID_FORMAT;
185 key->xmss_pk = xmss_pk;
186 key->xmss_sk = xmss_sk;
187 xmss_pk = xmss_sk = NULL;
188 /* optional internal state */
189 if ((r = sshkey_xmss_deserialize_state_opt(key, b)) != 0)
195 freezero(xmss_pk, pklen);
196 freezero(xmss_sk, sklen);
201 ssh_xmss_sign(struct sshkey *key,
202 u_char **sigp, size_t *lenp,
203 const u_char *data, size_t datalen,
204 const char *alg, const char *sk_provider, const char *sk_pin, u_int compat)
207 size_t slen = 0, len = 0, required_siglen;
208 unsigned long long smlen;
210 struct sshbuf *b = NULL;
218 sshkey_type_plain(key->type) != KEY_XMSS ||
219 key->xmss_sk == NULL ||
220 sshkey_xmss_params(key) == NULL)
221 return SSH_ERR_INVALID_ARGUMENT;
222 if ((r = sshkey_xmss_siglen(key, &required_siglen)) != 0)
224 if (datalen >= INT_MAX - required_siglen)
225 return SSH_ERR_INVALID_ARGUMENT;
226 smlen = slen = datalen + required_siglen;
227 if ((sig = malloc(slen)) == NULL)
228 return SSH_ERR_ALLOC_FAIL;
229 if ((r = sshkey_xmss_get_state(key, 1)) != 0)
231 if ((ret = xmss_sign(key->xmss_sk, sshkey_xmss_bds_state(key), sig, &smlen,
232 data, datalen, sshkey_xmss_params(key))) != 0 || smlen <= datalen) {
233 r = SSH_ERR_INVALID_ARGUMENT; /* XXX better error? */
236 /* encode signature */
237 if ((b = sshbuf_new()) == NULL) {
238 r = SSH_ERR_ALLOC_FAIL;
241 if ((r = sshbuf_put_cstring(b, "ssh-xmss@openssh.com")) != 0 ||
242 (r = sshbuf_put_string(b, sig, smlen - datalen)) != 0)
246 if ((*sigp = malloc(len)) == NULL) {
247 r = SSH_ERR_ALLOC_FAIL;
250 memcpy(*sigp, sshbuf_ptr(b), len);
257 if ((ret = sshkey_xmss_update_state(key, 1)) != 0) {
258 /* discard signature since we cannot update the state */
259 if (r == 0 && sigp != NULL && *sigp != NULL) {
260 explicit_bzero(*sigp, len);
277 ssh_xmss_verify(const struct sshkey *key,
278 const u_char *sig, size_t siglen,
279 const u_char *data, size_t dlen, const char *alg, u_int compat,
280 struct sshkey_sig_details **detailsp)
282 struct sshbuf *b = NULL;
284 const u_char *sigblob;
285 u_char *sm = NULL, *m = NULL;
286 size_t len, required_siglen;
287 unsigned long long smlen = 0, mlen = 0;
291 sshkey_type_plain(key->type) != KEY_XMSS ||
292 key->xmss_pk == NULL ||
293 sshkey_xmss_params(key) == NULL ||
294 sig == NULL || siglen == 0)
295 return SSH_ERR_INVALID_ARGUMENT;
296 if ((r = sshkey_xmss_siglen(key, &required_siglen)) != 0)
298 if (dlen >= INT_MAX - required_siglen)
299 return SSH_ERR_INVALID_ARGUMENT;
301 if ((b = sshbuf_from(sig, siglen)) == NULL)
302 return SSH_ERR_ALLOC_FAIL;
303 if ((r = sshbuf_get_cstring(b, &ktype, NULL)) != 0 ||
304 (r = sshbuf_get_string_direct(b, &sigblob, &len)) != 0)
306 if (strcmp("ssh-xmss@openssh.com", ktype) != 0) {
307 r = SSH_ERR_KEY_TYPE_MISMATCH;
310 if (sshbuf_len(b) != 0) {
311 r = SSH_ERR_UNEXPECTED_TRAILING_DATA;
314 if (len != required_siglen) {
315 r = SSH_ERR_INVALID_FORMAT;
318 if (dlen >= SIZE_MAX - len) {
319 r = SSH_ERR_INVALID_ARGUMENT;
324 if ((sm = malloc(smlen)) == NULL || (m = malloc(mlen)) == NULL) {
325 r = SSH_ERR_ALLOC_FAIL;
328 memcpy(sm, sigblob, len);
329 memcpy(sm+len, data, dlen);
330 if ((ret = xmss_sign_open(m, &mlen, sm, smlen,
331 key->xmss_pk, sshkey_xmss_params(key))) != 0) {
332 debug2_f("xmss_sign_open failed: %d", ret);
334 if (ret != 0 || mlen != dlen) {
335 r = SSH_ERR_SIGNATURE_INVALID;
338 /* XXX compare 'm' and 'data' ? */
351 static const struct sshkey_impl_funcs sshkey_xmss_funcs = {
354 /* .cleanup = */ ssh_xmss_cleanup,
355 /* .equal = */ ssh_xmss_equal,
356 /* .ssh_serialize_public = */ ssh_xmss_serialize_public,
357 /* .ssh_deserialize_public = */ ssh_xmss_deserialize_public,
358 /* .ssh_serialize_private = */ ssh_xmss_serialize_private,
359 /* .ssh_deserialize_private = */ ssh_xmss_deserialize_private,
360 /* .generate = */ sshkey_xmss_generate_private_key,
361 /* .copy_public = */ ssh_xmss_copy_public,
362 /* .sign = */ ssh_xmss_sign,
363 /* .verify = */ ssh_xmss_verify,
366 const struct sshkey_impl sshkey_xmss_impl = {
367 /* .name = */ "ssh-xmss@openssh.com",
368 /* .shortname = */ "XMSS",
369 /* .sigalg = */ NULL,
370 /* .type = */ KEY_XMSS,
374 /* .keybits = */ 256,
375 /* .funcs = */ &sshkey_xmss_funcs,
378 const struct sshkey_impl sshkey_xmss_cert_impl = {
379 /* .name = */ "ssh-xmss-cert-v01@openssh.com",
380 /* .shortname = */ "XMSS-CERT",
381 /* .sigalg = */ NULL,
382 /* .type = */ KEY_XMSS_CERT,
386 /* .keybits = */ 256,
387 /* .funcs = */ &sshkey_xmss_funcs,
389 #endif /* WITH_XMSS */