/src/hpn-ssh/ssh-ed25519.c
Line  | Count  | Source  | 
1  |  | /* $OpenBSD: ssh-ed25519.c,v 1.20 2025/07/24 06:12:08 djm Exp $ */  | 
2  |  | /*  | 
3  |  |  * Copyright (c) 2013 Markus Friedl <markus@openbsd.org>  | 
4  |  |  *  | 
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.  | 
8  |  |  *  | 
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.  | 
16  |  |  */  | 
17  |  |  | 
18  |  | #include "includes.h"  | 
19  |  |  | 
20  |  | #include <sys/types.h>  | 
21  |  | #include <limits.h>  | 
22  |  |  | 
23  |  | #include "crypto_api.h"  | 
24  |  |  | 
25  |  | #include <string.h>  | 
26  |  | #include <stdarg.h>  | 
27  |  |  | 
28  |  | #include "log.h"  | 
29  |  | #include "sshbuf.h"  | 
30  |  | #define SSHKEY_INTERNAL  | 
31  |  | #include "sshkey.h"  | 
32  |  | #include "ssherr.h"  | 
33  |  | #include "ssh.h"  | 
34  |  |  | 
35  |  | static void  | 
36  |  | ssh_ed25519_cleanup(struct sshkey *k)  | 
37  | 37.3k  | { | 
38  | 37.3k  |   freezero(k->ed25519_pk, ED25519_PK_SZ);  | 
39  | 37.3k  |   freezero(k->ed25519_sk, ED25519_SK_SZ);  | 
40  | 37.3k  |   k->ed25519_pk = NULL;  | 
41  | 37.3k  |   k->ed25519_sk = NULL;  | 
42  | 37.3k  | }  | 
43  |  |  | 
44  |  | static int  | 
45  |  | ssh_ed25519_equal(const struct sshkey *a, const struct sshkey *b)  | 
46  | 4.62k  | { | 
47  | 4.62k  |   if (a->ed25519_pk == NULL || b->ed25519_pk == NULL)  | 
48  | 0  |     return 0;  | 
49  | 4.62k  |   if (memcmp(a->ed25519_pk, b->ed25519_pk, ED25519_PK_SZ) != 0)  | 
50  | 0  |     return 0;  | 
51  | 4.62k  |   return 1;  | 
52  | 4.62k  | }  | 
53  |  |  | 
54  |  | static int  | 
55  |  | ssh_ed25519_serialize_public(const struct sshkey *key, struct sshbuf *b,  | 
56  |  |     enum sshkey_serialize_rep opts)  | 
57  | 12  | { | 
58  | 12  |   int r;  | 
59  |  |  | 
60  | 12  |   if (key->ed25519_pk == NULL)  | 
61  | 0  |     return SSH_ERR_INVALID_ARGUMENT;  | 
62  | 12  |   if ((r = sshbuf_put_string(b, key->ed25519_pk, ED25519_PK_SZ)) != 0)  | 
63  | 0  |     return r;  | 
64  |  |  | 
65  | 12  |   return 0;  | 
66  | 12  | }  | 
67  |  |  | 
68  |  | static int  | 
69  |  | ssh_ed25519_serialize_private(const struct sshkey *key, struct sshbuf *b,  | 
70  |  |     enum sshkey_serialize_rep opts)  | 
71  | 0  | { | 
72  | 0  |   int r;  | 
73  |  | 
  | 
74  | 0  |   if ((r = sshbuf_put_string(b, key->ed25519_pk, ED25519_PK_SZ)) != 0 ||  | 
75  | 0  |       (r = sshbuf_put_string(b, key->ed25519_sk, ED25519_SK_SZ)) != 0)  | 
76  | 0  |     return r;  | 
77  |  |  | 
78  | 0  |   return 0;  | 
79  | 0  | }  | 
80  |  |  | 
81  |  | static int  | 
82  |  | ssh_ed25519_generate(struct sshkey *k, int bits)  | 
83  | 1  | { | 
84  | 1  |   if ((k->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL ||  | 
85  | 1  |       (k->ed25519_sk = malloc(ED25519_SK_SZ)) == NULL)  | 
86  | 0  |     return SSH_ERR_ALLOC_FAIL;  | 
87  | 1  |   crypto_sign_ed25519_keypair(k->ed25519_pk, k->ed25519_sk);  | 
88  | 1  |   return 0;  | 
89  | 1  | }  | 
90  |  |  | 
91  |  | static int  | 
92  |  | ssh_ed25519_copy_public(const struct sshkey *from, struct sshkey *to)  | 
93  | 15.0k  | { | 
94  | 15.0k  |   if (from->ed25519_pk == NULL)  | 
95  | 0  |     return 0; /* XXX SSH_ERR_INTERNAL_ERROR ? */  | 
96  | 15.0k  |   if ((to->ed25519_pk = malloc(ED25519_PK_SZ)) == NULL)  | 
97  | 0  |     return SSH_ERR_ALLOC_FAIL;  | 
98  | 15.0k  |   memcpy(to->ed25519_pk, from->ed25519_pk, ED25519_PK_SZ);  | 
99  | 15.0k  |   return 0;  | 
100  | 15.0k  | }  | 
101  |  |  | 
102  |  | static int  | 
103  |  | ssh_ed25519_deserialize_public(const char *ktype, struct sshbuf *b,  | 
104  |  |     struct sshkey *key)  | 
105  | 22.4k  | { | 
106  | 22.4k  |   u_char *pk = NULL;  | 
107  | 22.4k  |   size_t len = 0;  | 
108  | 22.4k  |   int r;  | 
109  |  |  | 
110  | 22.4k  |   if ((r = sshbuf_get_string(b, &pk, &len)) != 0)  | 
111  | 140  |     return r;  | 
112  | 22.3k  |   if (len != ED25519_PK_SZ) { | 
113  | 177  |     freezero(pk, len);  | 
114  | 177  |     return SSH_ERR_INVALID_FORMAT;  | 
115  | 177  |   }  | 
116  | 22.1k  |   key->ed25519_pk = pk;  | 
117  | 22.1k  |   return 0;  | 
118  | 22.3k  | }  | 
119  |  |  | 
120  |  | static int  | 
121  |  | ssh_ed25519_deserialize_private(const char *ktype, struct sshbuf *b,  | 
122  |  |     struct sshkey *key)  | 
123  | 2.59k  | { | 
124  | 2.59k  |   int r;  | 
125  | 2.59k  |   size_t sklen = 0;  | 
126  | 2.59k  |   u_char *ed25519_sk = NULL;  | 
127  |  |  | 
128  | 2.59k  |   if ((r = ssh_ed25519_deserialize_public(NULL, b, key)) != 0)  | 
129  | 125  |     goto out;  | 
130  | 2.46k  |   if ((r = sshbuf_get_string(b, &ed25519_sk, &sklen)) != 0)  | 
131  | 2  |     goto out;  | 
132  | 2.46k  |   if (sklen != ED25519_SK_SZ) { | 
133  | 27  |     r = SSH_ERR_INVALID_FORMAT;  | 
134  | 27  |     goto out;  | 
135  | 27  |   }  | 
136  | 2.43k  |   key->ed25519_sk = ed25519_sk;  | 
137  | 2.43k  |   ed25519_sk = NULL; /* transferred */  | 
138  |  |   /* success */  | 
139  | 2.43k  |   r = 0;  | 
140  | 2.59k  |  out:  | 
141  | 2.59k  |   freezero(ed25519_sk, sklen);  | 
142  | 2.59k  |   return r;  | 
143  | 2.43k  | }  | 
144  |  |  | 
145  |  | static int  | 
146  |  | ssh_ed25519_sign(struct sshkey *key,  | 
147  |  |     u_char **sigp, size_t *lenp,  | 
148  |  |     const u_char *data, size_t datalen,  | 
149  |  |     const char *alg, const char *sk_provider, const char *sk_pin, u_int compat)  | 
150  | 0  | { | 
151  | 0  |   u_char *sig = NULL;  | 
152  | 0  |   size_t slen = 0;  | 
153  | 0  |   unsigned long long smlen;  | 
154  | 0  |   int r, ret;  | 
155  |  | 
  | 
156  | 0  |   if (lenp != NULL)  | 
157  | 0  |     *lenp = 0;  | 
158  | 0  |   if (sigp != NULL)  | 
159  | 0  |     *sigp = NULL;  | 
160  |  | 
  | 
161  | 0  |   if (key == NULL ||  | 
162  | 0  |       sshkey_type_plain(key->type) != KEY_ED25519 ||  | 
163  | 0  |       key->ed25519_sk == NULL ||  | 
164  | 0  |       datalen >= INT_MAX - crypto_sign_ed25519_BYTES)  | 
165  | 0  |     return SSH_ERR_INVALID_ARGUMENT;  | 
166  | 0  |   smlen = slen = datalen + crypto_sign_ed25519_BYTES;  | 
167  | 0  |   if ((sig = malloc(slen)) == NULL)  | 
168  | 0  |     return SSH_ERR_ALLOC_FAIL;  | 
169  |  |  | 
170  | 0  |   if ((ret = crypto_sign_ed25519(sig, &smlen, data, datalen,  | 
171  | 0  |       key->ed25519_sk)) != 0 || smlen <= datalen) { | 
172  | 0  |     r = SSH_ERR_INVALID_ARGUMENT; /* XXX better error? */  | 
173  | 0  |     goto out;  | 
174  | 0  |   }  | 
175  | 0  |   if ((r = ssh_ed25519_encode_store_sig(sig, smlen - datalen,  | 
176  | 0  |       sigp, lenp)) != 0)  | 
177  | 0  |     goto out;  | 
178  |  |  | 
179  |  |   /* success */  | 
180  | 0  |   r = 0;  | 
181  | 0  |  out:  | 
182  | 0  |   freezero(sig, slen);  | 
183  | 0  |   return r;  | 
184  | 0  | }  | 
185  |  |  | 
186  |  | int  | 
187  |  | ssh_ed25519_encode_store_sig(const u_char *sig, size_t slen,  | 
188  |  |     u_char **sigp, size_t *lenp)  | 
189  | 0  | { | 
190  | 0  |   struct sshbuf *b = NULL;  | 
191  | 0  |   int r = -1;  | 
192  | 0  |   size_t len;  | 
193  |  | 
  | 
194  | 0  |   if (lenp != NULL)  | 
195  | 0  |     *lenp = 0;  | 
196  | 0  |   if (sigp != NULL)  | 
197  | 0  |     *sigp = NULL;  | 
198  |  | 
  | 
199  | 0  |   if (slen != crypto_sign_ed25519_BYTES)  | 
200  | 0  |     return SSH_ERR_INVALID_ARGUMENT;  | 
201  |  |  | 
202  |  |   /* encode signature */  | 
203  | 0  |   if ((b = sshbuf_new()) == NULL) { | 
204  | 0  |     r = SSH_ERR_ALLOC_FAIL;  | 
205  | 0  |     goto out;  | 
206  | 0  |   }  | 
207  | 0  |   if ((r = sshbuf_put_cstring(b, "ssh-ed25519")) != 0 ||  | 
208  | 0  |       (r = sshbuf_put_string(b, sig, slen)) != 0)  | 
209  | 0  |     goto out;  | 
210  | 0  |   len = sshbuf_len(b);  | 
211  | 0  |   if (sigp != NULL) { | 
212  | 0  |     if ((*sigp = malloc(len)) == NULL) { | 
213  | 0  |       r = SSH_ERR_ALLOC_FAIL;  | 
214  | 0  |       goto out;  | 
215  | 0  |     }  | 
216  | 0  |     memcpy(*sigp, sshbuf_ptr(b), len);  | 
217  | 0  |   }  | 
218  | 0  |   if (lenp != NULL)  | 
219  | 0  |     *lenp = len;  | 
220  |  |   /* success */  | 
221  | 0  |   r = 0;  | 
222  | 0  |  out:  | 
223  | 0  |   sshbuf_free(b);  | 
224  | 0  |   return r;  | 
225  | 0  | }  | 
226  |  |  | 
227  |  | static int  | 
228  |  | ssh_ed25519_verify(const struct sshkey *key,  | 
229  |  |     const u_char *sig, size_t siglen,  | 
230  |  |     const u_char *data, size_t dlen, const char *alg, u_int compat,  | 
231  |  |     struct sshkey_sig_details **detailsp)  | 
232  | 7.63k  | { | 
233  | 7.63k  |   struct sshbuf *b = NULL;  | 
234  | 7.63k  |   char *ktype = NULL;  | 
235  | 7.63k  |   const u_char *sigblob;  | 
236  | 7.63k  |   u_char *sm = NULL, *m = NULL;  | 
237  | 7.63k  |   size_t len;  | 
238  | 7.63k  |   unsigned long long smlen = 0, mlen = 0;  | 
239  | 7.63k  |   int r, ret;  | 
240  |  |  | 
241  | 7.63k  |   if (key == NULL ||  | 
242  | 7.63k  |       sshkey_type_plain(key->type) != KEY_ED25519 ||  | 
243  | 7.63k  |       key->ed25519_pk == NULL ||  | 
244  | 7.63k  |       dlen >= INT_MAX - crypto_sign_ed25519_BYTES ||  | 
245  | 7.63k  |       sig == NULL || siglen == 0)  | 
246  | 0  |     return SSH_ERR_INVALID_ARGUMENT;  | 
247  |  |  | 
248  | 7.63k  |   if ((b = sshbuf_from(sig, siglen)) == NULL)  | 
249  | 0  |     return SSH_ERR_ALLOC_FAIL;  | 
250  | 7.63k  |   if ((r = sshbuf_get_cstring(b, &ktype, NULL)) != 0 ||  | 
251  | 7.50k  |       (r = sshbuf_get_string_direct(b, &sigblob, &len)) != 0)  | 
252  | 532  |     goto out;  | 
253  | 7.09k  |   if (strcmp("ssh-ed25519", ktype) != 0) { | 
254  | 924  |     r = SSH_ERR_KEY_TYPE_MISMATCH;  | 
255  | 924  |     goto out;  | 
256  | 924  |   }  | 
257  | 6.17k  |   if (sshbuf_len(b) != 0) { | 
258  | 42  |     r = SSH_ERR_UNEXPECTED_TRAILING_DATA;  | 
259  | 42  |     goto out;  | 
260  | 42  |   }  | 
261  | 6.13k  |   if (len > crypto_sign_ed25519_BYTES) { | 
262  | 5  |     r = SSH_ERR_INVALID_FORMAT;  | 
263  | 5  |     goto out;  | 
264  | 5  |   }  | 
265  | 6.12k  |   if (dlen >= SIZE_MAX - len) { | 
266  | 0  |     r = SSH_ERR_INVALID_ARGUMENT;  | 
267  | 0  |     goto out;  | 
268  | 0  |   }  | 
269  | 6.12k  |   smlen = len + dlen;  | 
270  | 6.12k  |   mlen = smlen;  | 
271  | 6.12k  |   if ((sm = malloc(smlen)) == NULL || (m = malloc(mlen)) == NULL) { | 
272  | 0  |     r = SSH_ERR_ALLOC_FAIL;  | 
273  | 0  |     goto out;  | 
274  | 0  |   }  | 
275  | 6.12k  |   memcpy(sm, sigblob, len);  | 
276  | 6.12k  |   memcpy(sm+len, data, dlen);  | 
277  | 6.12k  |   if ((ret = crypto_sign_ed25519_open(m, &mlen, sm, smlen,  | 
278  | 6.12k  |       key->ed25519_pk)) != 0) { | 
279  | 199  |     debug2_f("crypto_sign_ed25519_open failed: %d", ret); | 
280  | 199  |   }  | 
281  | 6.12k  |   if (ret != 0 || mlen != dlen) { | 
282  | 215  |     r = SSH_ERR_SIGNATURE_INVALID;  | 
283  | 215  |     goto out;  | 
284  | 215  |   }  | 
285  |  |   /* XXX compare 'm' and 'data' ? */  | 
286  |  |   /* success */  | 
287  | 5.91k  |   r = 0;  | 
288  | 7.63k  |  out:  | 
289  | 7.63k  |   if (sm != NULL)  | 
290  | 6.12k  |     freezero(sm, smlen);  | 
291  | 7.63k  |   if (m != NULL)  | 
292  | 6.12k  |     freezero(m, smlen); /* NB mlen may be invalid if r != 0 */  | 
293  | 7.63k  |   sshbuf_free(b);  | 
294  | 7.63k  |   free(ktype);  | 
295  | 7.63k  |   return r;  | 
296  | 5.91k  | }  | 
297  |  |  | 
298  |  | /* NB. not static; used by ED25519-SK */  | 
299  |  | const struct sshkey_impl_funcs sshkey_ed25519_funcs = { | 
300  |  |   /* .size = */   NULL,  | 
301  |  |   /* .alloc = */    NULL,  | 
302  |  |   /* .cleanup = */  ssh_ed25519_cleanup,  | 
303  |  |   /* .equal = */    ssh_ed25519_equal,  | 
304  |  |   /* .ssh_serialize_public = */ ssh_ed25519_serialize_public,  | 
305  |  |   /* .ssh_deserialize_public = */ ssh_ed25519_deserialize_public,  | 
306  |  |   /* .ssh_serialize_private = */ ssh_ed25519_serialize_private,  | 
307  |  |   /* .ssh_deserialize_private = */ ssh_ed25519_deserialize_private,  | 
308  |  |   /* .generate = */ ssh_ed25519_generate,  | 
309  |  |   /* .copy_public = */  ssh_ed25519_copy_public,  | 
310  |  |   /* .sign = */   ssh_ed25519_sign,  | 
311  |  |   /* .verify = */   ssh_ed25519_verify,  | 
312  |  | };  | 
313  |  |  | 
314  |  | const struct sshkey_impl sshkey_ed25519_impl = { | 
315  |  |   /* .name = */   "ssh-ed25519",  | 
316  |  |   /* .shortname = */  "ED25519",  | 
317  |  |   /* .sigalg = */   NULL,  | 
318  |  |   /* .type = */   KEY_ED25519,  | 
319  |  |   /* .nid = */    0,  | 
320  |  |   /* .cert = */   0,  | 
321  |  |   /* .sigonly = */  0,  | 
322  |  |   /* .keybits = */  256,  | 
323  |  |   /* .funcs = */    &sshkey_ed25519_funcs,  | 
324  |  | };  | 
325  |  |  | 
326  |  | const struct sshkey_impl sshkey_ed25519_cert_impl = { | 
327  |  |   /* .name = */   "ssh-ed25519-cert-v01@openssh.com",  | 
328  |  |   /* .shortname = */  "ED25519-CERT",  | 
329  |  |   /* .sigalg = */   NULL,  | 
330  |  |   /* .type = */   KEY_ED25519_CERT,  | 
331  |  |   /* .nid = */    0,  | 
332  |  |   /* .cert = */   1,  | 
333  |  |   /* .sigonly = */  0,  | 
334  |  |   /* .keybits = */  256,  | 
335  |  |   /* .funcs = */    &sshkey_ed25519_funcs,  | 
336  |  | };  |