1 /* $OpenBSD: ssh-ed25519-sk.c,v 1.15 2022/10/28 00:44:44 djm Exp $ */
3 * Copyright (c) 2019 Markus Friedl. All rights reserved.
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 /* #define DEBUG_SK 1 */
22 #define SSHKEY_INTERNAL
23 #include <sys/types.h>
26 #include "crypto_api.h"
38 /* Reuse some ED25519 internals */
39 extern struct sshkey_impl_funcs sshkey_ed25519_funcs
;
42 ssh_ed25519_sk_cleanup(struct sshkey
*k
)
45 sshkey_ed25519_funcs
.cleanup(k
);
49 ssh_ed25519_sk_equal(const struct sshkey
*a
, const struct sshkey
*b
)
51 if (!sshkey_sk_fields_equal(a
, b
))
53 if (!sshkey_ed25519_funcs
.equal(a
, b
))
59 ssh_ed25519_sk_serialize_public(const struct sshkey
*key
, struct sshbuf
*b
,
60 enum sshkey_serialize_rep opts
)
64 if ((r
= sshkey_ed25519_funcs
.serialize_public(key
, b
, opts
)) != 0)
66 if ((r
= sshkey_serialize_sk(key
, b
)) != 0)
73 ssh_ed25519_sk_serialize_private(const struct sshkey
*key
, struct sshbuf
*b
,
74 enum sshkey_serialize_rep opts
)
78 if ((r
= sshkey_ed25519_funcs
.serialize_public(key
, b
, opts
)) != 0)
80 if ((r
= sshkey_serialize_private_sk(key
, b
)) != 0)
87 ssh_ed25519_sk_copy_public(const struct sshkey
*from
, struct sshkey
*to
)
91 if ((r
= sshkey_ed25519_funcs
.copy_public(from
, to
)) != 0)
93 if ((r
= sshkey_copy_public_sk(from
, to
)) != 0)
99 ssh_ed25519_sk_deserialize_public(const char *ktype
, struct sshbuf
*b
,
104 if ((r
= sshkey_ed25519_funcs
.deserialize_public(ktype
, b
, key
)) != 0)
106 if ((r
= sshkey_deserialize_sk(b
, key
)) != 0)
112 ssh_ed25519_sk_deserialize_private(const char *ktype
, struct sshbuf
*b
,
117 if ((r
= sshkey_ed25519_funcs
.deserialize_public(ktype
, b
, key
)) != 0)
119 if ((r
= sshkey_private_deserialize_sk(b
, key
)) != 0)
125 ssh_ed25519_sk_verify(const struct sshkey
*key
,
126 const u_char
*sig
, size_t siglen
,
127 const u_char
*data
, size_t dlen
, const char *alg
, u_int compat
,
128 struct sshkey_sig_details
**detailsp
)
130 struct sshbuf
*b
= NULL
;
131 struct sshbuf
*encoded
= NULL
;
133 const u_char
*sigblob
;
141 unsigned long long smlen
= 0, mlen
= 0;
142 int r
= SSH_ERR_INTERNAL_ERROR
;
144 struct sshkey_sig_details
*details
= NULL
;
146 if (detailsp
!= NULL
)
150 sshkey_type_plain(key
->type
) != KEY_ED25519_SK
||
151 key
->ed25519_pk
== NULL
||
152 sig
== NULL
|| siglen
== 0)
153 return SSH_ERR_INVALID_ARGUMENT
;
155 if ((b
= sshbuf_from(sig
, siglen
)) == NULL
)
156 return SSH_ERR_ALLOC_FAIL
;
157 if (sshbuf_get_cstring(b
, &ktype
, NULL
) != 0 ||
158 sshbuf_get_string_direct(b
, &sigblob
, &len
) != 0 ||
159 sshbuf_get_u8(b
, &sig_flags
) != 0 ||
160 sshbuf_get_u32(b
, &sig_counter
) != 0) {
161 r
= SSH_ERR_INVALID_FORMAT
;
165 fprintf(stderr
, "%s: data:\n", __func__
);
166 /* sshbuf_dump_data(data, datalen, stderr); */
167 fprintf(stderr
, "%s: sigblob:\n", __func__
);
168 sshbuf_dump_data(sigblob
, len
, stderr
);
169 fprintf(stderr
, "%s: sig_flags = 0x%02x, sig_counter = %u\n",
170 __func__
, sig_flags
, sig_counter
);
172 if (strcmp(sshkey_ssh_name_plain(key
), ktype
) != 0) {
173 r
= SSH_ERR_KEY_TYPE_MISMATCH
;
176 if (sshbuf_len(b
) != 0) {
177 r
= SSH_ERR_UNEXPECTED_TRAILING_DATA
;
180 if (len
> crypto_sign_ed25519_BYTES
) {
181 r
= SSH_ERR_INVALID_FORMAT
;
184 if (ssh_digest_memory(SSH_DIGEST_SHA256
, key
->sk_application
,
185 strlen(key
->sk_application
), apphash
, sizeof(apphash
)) != 0 ||
186 ssh_digest_memory(SSH_DIGEST_SHA256
, data
, dlen
,
187 msghash
, sizeof(msghash
)) != 0) {
188 r
= SSH_ERR_INVALID_ARGUMENT
;
192 fprintf(stderr
, "%s: hashed application:\n", __func__
);
193 sshbuf_dump_data(apphash
, sizeof(apphash
), stderr
);
194 fprintf(stderr
, "%s: hashed message:\n", __func__
);
195 sshbuf_dump_data(msghash
, sizeof(msghash
), stderr
);
197 if ((details
= calloc(1, sizeof(*details
))) == NULL
) {
198 r
= SSH_ERR_ALLOC_FAIL
;
201 details
->sk_counter
= sig_counter
;
202 details
->sk_flags
= sig_flags
;
203 if ((encoded
= sshbuf_new()) == NULL
) {
204 r
= SSH_ERR_ALLOC_FAIL
;
207 if (sshbuf_put(encoded
, sigblob
, len
) != 0 ||
208 sshbuf_put(encoded
, apphash
, sizeof(apphash
)) != 0 ||
209 sshbuf_put_u8(encoded
, sig_flags
) != 0 ||
210 sshbuf_put_u32(encoded
, sig_counter
) != 0 ||
211 sshbuf_put(encoded
, msghash
, sizeof(msghash
)) != 0) {
212 r
= SSH_ERR_ALLOC_FAIL
;
216 fprintf(stderr
, "%s: signed buf:\n", __func__
);
217 sshbuf_dump(encoded
, stderr
);
219 sm
= sshbuf_ptr(encoded
);
220 smlen
= sshbuf_len(encoded
);
222 if ((m
= malloc(smlen
)) == NULL
) {
223 r
= SSH_ERR_ALLOC_FAIL
;
226 if ((ret
= crypto_sign_ed25519_open(m
, &mlen
, sm
, smlen
,
227 key
->ed25519_pk
)) != 0) {
228 debug2_f("crypto_sign_ed25519_open failed: %d", ret
);
230 if (ret
!= 0 || mlen
!= smlen
- len
) {
231 r
= SSH_ERR_SIGNATURE_INVALID
;
234 /* XXX compare 'm' and 'sm + len' ? */
237 if (detailsp
!= NULL
) {
243 freezero(m
, smlen
); /* NB mlen may be invalid if r != 0 */
244 sshkey_sig_details_free(details
);
246 sshbuf_free(encoded
);
251 static const struct sshkey_impl_funcs sshkey_ed25519_sk_funcs
= {
254 /* .cleanup = */ ssh_ed25519_sk_cleanup
,
255 /* .equal = */ ssh_ed25519_sk_equal
,
256 /* .ssh_serialize_public = */ ssh_ed25519_sk_serialize_public
,
257 /* .ssh_deserialize_public = */ ssh_ed25519_sk_deserialize_public
,
258 /* .ssh_serialize_private = */ ssh_ed25519_sk_serialize_private
,
259 /* .ssh_deserialize_private = */ ssh_ed25519_sk_deserialize_private
,
260 /* .generate = */ NULL
,
261 /* .copy_public = */ ssh_ed25519_sk_copy_public
,
263 /* .verify = */ ssh_ed25519_sk_verify
,
266 const struct sshkey_impl sshkey_ed25519_sk_impl
= {
267 /* .name = */ "sk-ssh-ed25519@openssh.com",
268 /* .shortname = */ "ED25519-SK",
269 /* .sigalg = */ NULL
,
270 /* .type = */ KEY_ED25519_SK
,
274 /* .keybits = */ 256,
275 /* .funcs = */ &sshkey_ed25519_sk_funcs
,
278 const struct sshkey_impl sshkey_ed25519_sk_cert_impl
= {
279 /* .name = */ "sk-ssh-ed25519-cert-v01@openssh.com",
280 /* .shortname = */ "ED25519-SK-CERT",
281 /* .sigalg = */ NULL
,
282 /* .type = */ KEY_ED25519_SK_CERT
,
286 /* .keybits = */ 256,
287 /* .funcs = */ &sshkey_ed25519_sk_funcs
,