sshkey.h revision 1.25 1 /* $NetBSD: sshkey.h,v 1.25 2025/12/28 09:54:07 nia Exp $ */
2 /* $OpenBSD: sshkey.h,v 1.70 2025/08/29 03:50:38 djm Exp $ */
3
4 /*
5 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27 #ifndef SSHKEY_H
28 #define SSHKEY_H
29
30 #include "includes.h"
31 #include <sys/types.h>
32
33 #ifdef WITH_OPENSSL
34 #include <openssl/rsa.h>
35 #include <openssl/ec.h>
36 #include <openssl/ecdsa.h>
37 #include <openssl/evp.h>
38 #define SSH_OPENSSL_VERSION OpenSSL_version(OPENSSL_VERSION)
39 #else /* OPENSSL */
40 #define BIGNUM void
41 #define RSA void
42 #define EC_KEY void
43 #define EC_GROUP void
44 #define EC_POINT void
45 #define EVP_PKEY void
46 #define SSH_OPENSSL_VERSION "without OpenSSL"
47 #endif /* WITH_OPENSSL */
48
49 #define SSH_RSA_MINIMUM_MODULUS_SIZE 1024
50 #define SSH_KEY_MAX_SIGN_DATA_SIZE (1 << 20)
51
52 struct sshbuf;
53
54 /* Key types */
55 enum sshkey_types {
56 KEY_RSA,
57 KEY_ECDSA,
58 KEY_ED25519,
59 KEY_RSA_CERT,
60 KEY_ECDSA_CERT,
61 KEY_ED25519_CERT,
62 KEY_ECDSA_SK,
63 KEY_ECDSA_SK_CERT,
64 KEY_ED25519_SK,
65 KEY_ED25519_SK_CERT,
66 KEY_UNSPEC
67 };
68
69 /* Default fingerprint hash */
70 #define SSH_FP_HASH_DEFAULT SSH_DIGEST_SHA256
71
72 /* Fingerprint representation formats */
73 enum sshkey_fp_rep {
74 SSH_FP_DEFAULT = 0,
75 SSH_FP_HEX,
76 SSH_FP_BASE64,
77 SSH_FP_BUBBLEBABBLE,
78 SSH_FP_RANDOMART
79 };
80
81 /* Private key serialisation formats, used on the wire */
82 enum sshkey_serialize_rep {
83 SSHKEY_SERIALIZE_DEFAULT = 0,
84 };
85
86 /* Private key disk formats */
87 enum sshkey_private_format {
88 SSHKEY_PRIVATE_OPENSSH = 0,
89 SSHKEY_PRIVATE_PEM = 1,
90 SSHKEY_PRIVATE_PKCS8 = 2,
91 };
92
93 /* key is stored in external hardware */
94 #define SSHKEY_FLAG_EXT 0x0001
95
96 #define SSHKEY_CERT_MAX_PRINCIPALS 256
97 /* XXX opaquify? */
98 struct sshkey_cert {
99 struct sshbuf *certblob; /* Kept around for use on wire */
100 u_int type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */
101 u_int64_t serial;
102 char *key_id;
103 u_int nprincipals;
104 char **principals;
105 u_int64_t valid_after, valid_before;
106 struct sshbuf *critical;
107 struct sshbuf *extensions;
108 struct sshkey *signature_key;
109 char *signature_type;
110 };
111
112 /* XXX opaquify? */
113 struct sshkey {
114 int type;
115 int flags;
116 /* KEY_ECDSA and KEY_ECDSA_SK */
117 int ecdsa_nid; /* NID of curve */
118 /* libcrypto-backed keys */
119 EVP_PKEY *pkey;
120 /* KEY_ED25519 and KEY_ED25519_SK */
121 u_char *ed25519_sk;
122 u_char *ed25519_pk;
123 /* KEY_ECDSA_SK and KEY_ED25519_SK */
124 char *sk_application;
125 uint8_t sk_flags;
126 struct sshbuf *sk_key_handle;
127 struct sshbuf *sk_reserved;
128 /* Certificates */
129 struct sshkey_cert *cert;
130 /* Private key shielding */
131 u_char *shielded_private;
132 size_t shielded_len;
133 u_char *shield_prekey;
134 size_t shield_prekey_len;
135 };
136
137 #define ED25519_SK_SZ crypto_sign_ed25519_SECRETKEYBYTES
138 #define ED25519_PK_SZ crypto_sign_ed25519_PUBLICKEYBYTES
139
140 /* Additional fields contained in signature */
141 struct sshkey_sig_details {
142 uint32_t sk_counter; /* U2F signature counter */
143 uint8_t sk_flags; /* U2F signature flags; see ssh-sk.h */
144 };
145
146 struct sshkey_impl_funcs {
147 u_int (*size)(const struct sshkey *); /* optional */
148 int (*alloc)(struct sshkey *); /* optional */
149 void (*cleanup)(struct sshkey *); /* optional */
150 int (*equal)(const struct sshkey *, const struct sshkey *);
151 int (*serialize_public)(const struct sshkey *, struct sshbuf *,
152 enum sshkey_serialize_rep);
153 int (*deserialize_public)(const char *, struct sshbuf *,
154 struct sshkey *);
155 int (*serialize_private)(const struct sshkey *, struct sshbuf *,
156 enum sshkey_serialize_rep);
157 int (*deserialize_private)(const char *, struct sshbuf *,
158 struct sshkey *);
159 int (*generate)(struct sshkey *, int); /* optional */
160 int (*copy_public)(const struct sshkey *, struct sshkey *);
161 int (*sign)(struct sshkey *, u_char **, size_t *,
162 const u_char *, size_t, const char *,
163 const char *, const char *, u_int); /* optional */
164 int (*verify)(const struct sshkey *, const u_char *, size_t,
165 const u_char *, size_t, const char *, u_int,
166 struct sshkey_sig_details **);
167 };
168
169 struct sshkey_impl {
170 const char *name;
171 const char *shortname;
172 const char *sigalg;
173 int type;
174 int nid;
175 int cert;
176 int sigonly;
177 int keybits;
178 const struct sshkey_impl_funcs *funcs;
179 };
180
181 struct sshkey *sshkey_new(int);
182 void sshkey_free(struct sshkey *);
183 int sshkey_equal_public(const struct sshkey *,
184 const struct sshkey *);
185 int sshkey_equal(const struct sshkey *, const struct sshkey *);
186 char *sshkey_fingerprint(const struct sshkey *,
187 int, enum sshkey_fp_rep);
188 int sshkey_fingerprint_raw(const struct sshkey *k,
189 int, u_char **retp, size_t *lenp);
190 const char *sshkey_type(const struct sshkey *);
191 const char *sshkey_cert_type(const struct sshkey *);
192 int sshkey_format_text(const struct sshkey *, struct sshbuf *);
193 int sshkey_write(const struct sshkey *, FILE *);
194 int sshkey_read(struct sshkey *, char **);
195 u_int sshkey_size(const struct sshkey *);
196
197 int sshkey_generate(int type, u_int bits, struct sshkey **keyp);
198 int sshkey_from_private(const struct sshkey *, struct sshkey **);
199
200 int sshkey_is_shielded(struct sshkey *);
201 int sshkey_shield_private(struct sshkey *);
202 int sshkey_unshield_private(struct sshkey *);
203
204 int sshkey_type_from_name(const char *);
205 int sshkey_type_from_shortname(const char *);
206 int sshkey_is_cert(const struct sshkey *);
207 int sshkey_is_sk(const struct sshkey *);
208 int sshkey_type_is_cert(int);
209 int sshkey_type_plain(int);
210
211 /* Returns non-zero if key name match sigalgs pattern list. (handles RSA) */
212 int sshkey_match_keyname_to_sigalgs(const char *, const char *);
213
214 int sshkey_to_certified(struct sshkey *);
215 int sshkey_drop_cert(struct sshkey *);
216 int sshkey_cert_copy(const struct sshkey *, struct sshkey *);
217 int sshkey_cert_check_authority(const struct sshkey *, int, int, int,
218 uint64_t, const char *, const char **);
219 int sshkey_cert_check_authority_now(const struct sshkey *, int, int, int,
220 const char *, const char **);
221 int sshkey_cert_check_host(const struct sshkey *, const char *,
222 int , const char *, const char **);
223 size_t sshkey_format_cert_validity(const struct sshkey_cert *,
224 char *, size_t) __attribute__((__bounded__(__string__, 2, 3)));
225 int sshkey_check_cert_sigtype(const struct sshkey *, const char *);
226
227 int sshkey_certify(struct sshkey *, struct sshkey *,
228 const char *, const char *, const char *);
229 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */
230 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *,
231 const u_char *, size_t, const char *, const char *, const char *,
232 u_int, void *);
233 int sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *,
234 const char *, const char *, sshkey_certify_signer *, void *);
235
236 int sshkey_ecdsa_nid_from_name(const char *);
237 int sshkey_curve_name_to_nid(const char *);
238 const char * sshkey_curve_nid_to_name(int);
239 u_int sshkey_curve_nid_to_bits(int);
240 int sshkey_ecdsa_bits_to_nid(int);
241 int sshkey_ecdsa_key_to_nid(const EC_KEY *);
242 int sshkey_ecdsa_pkey_to_nid(EVP_PKEY *);
243 int sshkey_ec_nid_to_hash_alg(int nid);
244 int sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *);
245 int sshkey_ec_validate_private(const EC_KEY *);
246 const char *sshkey_ssh_name(const struct sshkey *);
247 const char *sshkey_ssh_name_plain(const struct sshkey *);
248 int sshkey_names_valid2(const char *, int, int);
249 char *sshkey_alg_list(int, int, int, char);
250
251 int sshkey_from_blob(const u_char *, size_t, struct sshkey **);
252 int sshkey_fromb(struct sshbuf *, struct sshkey **);
253 int sshkey_froms(struct sshbuf *, struct sshkey **);
254 int sshkey_to_blob(const struct sshkey *, u_char **, size_t *);
255 int sshkey_to_base64(const struct sshkey *, char **);
256 int sshkey_putb(const struct sshkey *, struct sshbuf *);
257 int sshkey_puts(const struct sshkey *, struct sshbuf *);
258 int sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *);
259 int sshkey_putb_plain(const struct sshkey *, struct sshbuf *);
260 int sshkey_puts_plain(const struct sshkey *, struct sshbuf *);
261
262 int sshkey_sign(struct sshkey *, u_char **, size_t *,
263 const u_char *, size_t, const char *, const char *, const char *, u_int);
264 int sshkey_verify(const struct sshkey *, const u_char *, size_t,
265 const u_char *, size_t, const char *, u_int, struct sshkey_sig_details **);
266 int sshkey_check_sigtype(const u_char *, size_t, const char *);
267 const char *sshkey_sigalg_by_name(const char *);
268 int sshkey_get_sigtype(const u_char *, size_t, char **);
269
270 /* Signing and verification backend for libcrypto-backed keys */
271 int sshkey_pkey_digest_sign(EVP_PKEY*, int, u_char **,
272 size_t *, const u_char *, size_t);
273 int sshkey_pkey_digest_verify(EVP_PKEY *, int, const u_char *,
274 size_t, u_char *, size_t);
275
276 /* for debug */
277 void sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);
278 void sshkey_dump_ec_key(const EC_KEY *);
279
280 /* private key parsing and serialisation */
281 int sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf);
282 int sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **keyp);
283
284 /* private key file format parsing and serialisation */
285 int sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
286 const char *passphrase, const char *comment,
287 int format, const char *openssh_format_cipher, int openssh_format_rounds);
288 int sshkey_parse_private_fileblob(struct sshbuf *buffer,
289 const char *passphrase, struct sshkey **keyp, char **commentp);
290 int sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
291 const char *passphrase, struct sshkey **keyp, char **commentp);
292 int sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob,
293 int type, struct sshkey **pubkeyp);
294
295 int sshkey_check_rsa_length(const struct sshkey *, int);
296 /* XXX should be internal, but used by ssh-keygen */
297 int ssh_rsa_complete_crt_parameters(const BIGNUM *, const BIGNUM *,
298 const BIGNUM *, const BIGNUM *, BIGNUM **, BIGNUM **);
299
300 void sshkey_sig_details_free(struct sshkey_sig_details *);
301
302 #ifdef WITH_OPENSSL
303 int sshkey_ecdsa_fixup_group(EVP_PKEY *k); /* ssh-ecdsa.c */
304 #endif
305
306 #ifdef SSHKEY_INTERNAL
307 int sshkey_sk_fields_equal(const struct sshkey *a, const struct sshkey *b);
308 void sshkey_sk_cleanup(struct sshkey *k);
309 int sshkey_serialize_sk(const struct sshkey *key, struct sshbuf *b);
310 int sshkey_copy_public_sk(const struct sshkey *from, struct sshkey *to);
311 int sshkey_deserialize_sk(struct sshbuf *b, struct sshkey *key);
312 int sshkey_serialize_private_sk(const struct sshkey *key,
313 struct sshbuf *buf);
314 int sshkey_private_deserialize_sk(struct sshbuf *buf, struct sshkey *k);
315 #ifdef WITH_OPENSSL
316 int check_rsa_length(const RSA *rsa); /* XXX remove */
317 int ssh_rsa_hash_id_from_keyname(const char *);
318 const char *ssh_rsa_hash_alg_ident(int);
319 int ssh_rsa_encode_store_sig(int, const u_char *, size_t,
320 u_char **, size_t *);
321 int ssh_ecdsa_encode_store_sig(const struct sshkey *,
322 const BIGNUM *, const BIGNUM *, u_char **, size_t *);
323 #endif
324 int ssh_ed25519_encode_store_sig(const u_char *, size_t,
325 u_char **, size_t *);
326 #endif
327
328 #ifndef WITH_OPENSSL
329 #undef RSA
330 #undef EC_KEY
331 #undef EC_GROUP
332 #undef EC_POINT
333 #undef EVP_PKEY
334 #endif /* WITH_OPENSSL */
335
336 #endif /* SSHKEY_H */
337