sshkey.h revision 1.21 1 /* $NetBSD: sshkey.h,v 1.21 2024/09/24 21:32:19 christos Exp $ */
2 /* $OpenBSD: sshkey.h,v 1.65 2024/09/04 05:33:34 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/dsa.h>
36 #include <openssl/ec.h>
37 #include <openssl/ecdsa.h>
38 #include <openssl/evp.h>
39 #define SSH_OPENSSL_VERSION OpenSSL_version(OPENSSL_VERSION)
40 #else /* OPENSSL */
41 #define BIGNUM void
42 #define RSA void
43 #define DSA void
44 #define EC_KEY void
45 #define EC_GROUP void
46 #define EC_POINT void
47 #define EVP_PKEY void
48 #define SSH_OPENSSL_VERSION "without OpenSSL"
49 #endif /* WITH_OPENSSL */
50
51 #define SSH_RSA_MINIMUM_MODULUS_SIZE 1024
52 #define SSH_KEY_MAX_SIGN_DATA_SIZE (1 << 20)
53
54 struct sshbuf;
55
56 /* Key types */
57 enum sshkey_types {
58 KEY_RSA,
59 KEY_DSA,
60 KEY_ECDSA,
61 KEY_ED25519,
62 KEY_RSA_CERT,
63 KEY_DSA_CERT,
64 KEY_ECDSA_CERT,
65 KEY_ED25519_CERT,
66 KEY_XMSS,
67 KEY_XMSS_CERT,
68 KEY_ECDSA_SK,
69 KEY_ECDSA_SK_CERT,
70 KEY_ED25519_SK,
71 KEY_ED25519_SK_CERT,
72 KEY_UNSPEC
73 };
74
75 /* Default fingerprint hash */
76 #define SSH_FP_HASH_DEFAULT SSH_DIGEST_SHA256
77
78 /* Fingerprint representation formats */
79 enum sshkey_fp_rep {
80 SSH_FP_DEFAULT = 0,
81 SSH_FP_HEX,
82 SSH_FP_BASE64,
83 SSH_FP_BUBBLEBABBLE,
84 SSH_FP_RANDOMART
85 };
86
87 /* Private key serialisation formats, used on the wire */
88 enum sshkey_serialize_rep {
89 SSHKEY_SERIALIZE_DEFAULT = 0,
90 SSHKEY_SERIALIZE_STATE = 1, /* only state is serialized */
91 SSHKEY_SERIALIZE_FULL = 2, /* include keys for saving to disk */
92 SSHKEY_SERIALIZE_SHIELD = 3, /* everything, for encrypting in ram */
93 SSHKEY_SERIALIZE_INFO = 254, /* minimal information */
94 };
95
96 /* Private key disk formats */
97 enum sshkey_private_format {
98 SSHKEY_PRIVATE_OPENSSH = 0,
99 SSHKEY_PRIVATE_PEM = 1,
100 SSHKEY_PRIVATE_PKCS8 = 2,
101 };
102
103 /* key is stored in external hardware */
104 #define SSHKEY_FLAG_EXT 0x0001
105
106 #define SSHKEY_CERT_MAX_PRINCIPALS 256
107 /* XXX opaquify? */
108 struct sshkey_cert {
109 struct sshbuf *certblob; /* Kept around for use on wire */
110 u_int type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */
111 u_int64_t serial;
112 char *key_id;
113 u_int nprincipals;
114 char **principals;
115 u_int64_t valid_after, valid_before;
116 struct sshbuf *critical;
117 struct sshbuf *extensions;
118 struct sshkey *signature_key;
119 char *signature_type;
120 };
121
122 /* XXX opaquify? */
123 struct sshkey {
124 int type;
125 int flags;
126 /* KEY_DSA */
127 DSA *dsa;
128 /* KEY_ECDSA and KEY_ECDSA_SK */
129 int ecdsa_nid; /* NID of curve */
130 /* libcrypto-backed keys */
131 EVP_PKEY *pkey;
132 /* KEY_ED25519 and KEY_ED25519_SK */
133 u_char *ed25519_sk;
134 u_char *ed25519_pk;
135 /* KEY_XMSS */
136 char *xmss_name;
137 char *xmss_filename; /* for state file updates */
138 void *xmss_state; /* depends on xmss_name, opaque */
139 u_char *xmss_sk;
140 u_char *xmss_pk;
141 /* KEY_ECDSA_SK and KEY_ED25519_SK */
142 char *sk_application;
143 uint8_t sk_flags;
144 struct sshbuf *sk_key_handle;
145 struct sshbuf *sk_reserved;
146 /* Certificates */
147 struct sshkey_cert *cert;
148 /* Private key shielding */
149 u_char *shielded_private;
150 size_t shielded_len;
151 u_char *shield_prekey;
152 size_t shield_prekey_len;
153 };
154
155 #define ED25519_SK_SZ crypto_sign_ed25519_SECRETKEYBYTES
156 #define ED25519_PK_SZ crypto_sign_ed25519_PUBLICKEYBYTES
157
158 /* Additional fields contained in signature */
159 struct sshkey_sig_details {
160 uint32_t sk_counter; /* U2F signature counter */
161 uint8_t sk_flags; /* U2F signature flags; see ssh-sk.h */
162 };
163
164 struct sshkey_impl_funcs {
165 u_int (*size)(const struct sshkey *); /* optional */
166 int (*alloc)(struct sshkey *); /* optional */
167 void (*cleanup)(struct sshkey *); /* optional */
168 int (*equal)(const struct sshkey *, const struct sshkey *);
169 int (*serialize_public)(const struct sshkey *, struct sshbuf *,
170 enum sshkey_serialize_rep);
171 int (*deserialize_public)(const char *, struct sshbuf *,
172 struct sshkey *);
173 int (*serialize_private)(const struct sshkey *, struct sshbuf *,
174 enum sshkey_serialize_rep);
175 int (*deserialize_private)(const char *, struct sshbuf *,
176 struct sshkey *);
177 int (*generate)(struct sshkey *, int); /* optional */
178 int (*copy_public)(const struct sshkey *, struct sshkey *);
179 int (*sign)(struct sshkey *, u_char **, size_t *,
180 const u_char *, size_t, const char *,
181 const char *, const char *, u_int); /* optional */
182 int (*verify)(const struct sshkey *, const u_char *, size_t,
183 const u_char *, size_t, const char *, u_int,
184 struct sshkey_sig_details **);
185 };
186
187 struct sshkey_impl {
188 const char *name;
189 const char *shortname;
190 const char *sigalg;
191 int type;
192 int nid;
193 int cert;
194 int sigonly;
195 int keybits;
196 const struct sshkey_impl_funcs *funcs;
197 };
198
199 struct sshkey *sshkey_new(int);
200 void sshkey_free(struct sshkey *);
201 int sshkey_equal_public(const struct sshkey *,
202 const struct sshkey *);
203 int sshkey_equal(const struct sshkey *, const struct sshkey *);
204 char *sshkey_fingerprint(const struct sshkey *,
205 int, enum sshkey_fp_rep);
206 int sshkey_fingerprint_raw(const struct sshkey *k,
207 int, u_char **retp, size_t *lenp);
208 const char *sshkey_type(const struct sshkey *);
209 const char *sshkey_cert_type(const struct sshkey *);
210 int sshkey_format_text(const struct sshkey *, struct sshbuf *);
211 int sshkey_write(const struct sshkey *, FILE *);
212 int sshkey_read(struct sshkey *, char **);
213 u_int sshkey_size(const struct sshkey *);
214
215 int sshkey_generate(int type, u_int bits, struct sshkey **keyp);
216 int sshkey_from_private(const struct sshkey *, struct sshkey **);
217
218 int sshkey_is_shielded(struct sshkey *);
219 int sshkey_shield_private(struct sshkey *);
220 int sshkey_unshield_private(struct sshkey *);
221
222 int sshkey_type_from_name(const char *);
223 int sshkey_type_from_shortname(const char *);
224 int sshkey_is_cert(const struct sshkey *);
225 int sshkey_is_sk(const struct sshkey *);
226 int sshkey_type_is_cert(int);
227 int sshkey_type_plain(int);
228
229 /* Returns non-zero if key name match sigalgs pattern list. (handles RSA) */
230 int sshkey_match_keyname_to_sigalgs(const char *, const char *);
231
232 int sshkey_to_certified(struct sshkey *);
233 int sshkey_drop_cert(struct sshkey *);
234 int sshkey_cert_copy(const struct sshkey *, struct sshkey *);
235 int sshkey_cert_check_authority(const struct sshkey *, int, int, int,
236 uint64_t, const char *, const char **);
237 int sshkey_cert_check_authority_now(const struct sshkey *, int, int, int,
238 const char *, const char **);
239 int sshkey_cert_check_host(const struct sshkey *, const char *,
240 int , const char *, const char **);
241 size_t sshkey_format_cert_validity(const struct sshkey_cert *,
242 char *, size_t) __attribute__((__bounded__(__string__, 2, 3)));
243 int sshkey_check_cert_sigtype(const struct sshkey *, const char *);
244
245 int sshkey_certify(struct sshkey *, struct sshkey *,
246 const char *, const char *, const char *);
247 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */
248 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *,
249 const u_char *, size_t, const char *, const char *, const char *,
250 u_int, void *);
251 int sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *,
252 const char *, const char *, sshkey_certify_signer *, void *);
253
254 int sshkey_ecdsa_nid_from_name(const char *);
255 int sshkey_curve_name_to_nid(const char *);
256 const char * sshkey_curve_nid_to_name(int);
257 u_int sshkey_curve_nid_to_bits(int);
258 int sshkey_ecdsa_bits_to_nid(int);
259 int sshkey_ecdsa_key_to_nid(const EC_KEY *);
260 int sshkey_ecdsa_pkey_to_nid(EVP_PKEY *);
261 int sshkey_ec_nid_to_hash_alg(int nid);
262 int sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *);
263 int sshkey_ec_validate_private(const EC_KEY *);
264 const char *sshkey_ssh_name(const struct sshkey *);
265 const char *sshkey_ssh_name_plain(const struct sshkey *);
266 int sshkey_names_valid2(const char *, int, int);
267 char *sshkey_alg_list(int, int, int, char);
268
269 int sshkey_from_blob(const u_char *, size_t, struct sshkey **);
270 int sshkey_fromb(struct sshbuf *, struct sshkey **);
271 int sshkey_froms(struct sshbuf *, struct sshkey **);
272 int sshkey_to_blob(const struct sshkey *, u_char **, size_t *);
273 int sshkey_to_base64(const struct sshkey *, char **);
274 int sshkey_putb(const struct sshkey *, struct sshbuf *);
275 int sshkey_puts(const struct sshkey *, struct sshbuf *);
276 int sshkey_puts_opts(const struct sshkey *, struct sshbuf *,
277 enum sshkey_serialize_rep);
278 int sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *);
279 int sshkey_putb_plain(const struct sshkey *, struct sshbuf *);
280
281 int sshkey_sign(struct sshkey *, u_char **, size_t *,
282 const u_char *, size_t, const char *, const char *, const char *, u_int);
283 int sshkey_verify(const struct sshkey *, const u_char *, size_t,
284 const u_char *, size_t, const char *, u_int, struct sshkey_sig_details **);
285 int sshkey_check_sigtype(const u_char *, size_t, const char *);
286 const char *sshkey_sigalg_by_name(const char *);
287 int sshkey_get_sigtype(const u_char *, size_t, char **);
288
289 /* Signing and verification backend for libcrypto-backed keys */
290 int sshkey_pkey_digest_sign(EVP_PKEY*, int, u_char **,
291 size_t *, const u_char *, size_t);
292 int sshkey_pkey_digest_verify(EVP_PKEY *, int, const u_char *,
293 size_t, u_char *, size_t);
294
295 /* for debug */
296 void sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);
297 void sshkey_dump_ec_key(const EC_KEY *);
298
299 /* private key parsing and serialisation */
300 int sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf);
301 int sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf,
302 enum sshkey_serialize_rep);
303 int sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **keyp);
304
305 /* private key file format parsing and serialisation */
306 int sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
307 const char *passphrase, const char *comment,
308 int format, const char *openssh_format_cipher, int openssh_format_rounds);
309 int sshkey_parse_private_fileblob(struct sshbuf *buffer,
310 const char *passphrase, struct sshkey **keyp, char **commentp);
311 int sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
312 const char *passphrase, struct sshkey **keyp, char **commentp);
313 int sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob,
314 int type, struct sshkey **pubkeyp);
315
316 int sshkey_check_rsa_length(const struct sshkey *, int);
317 /* XXX should be internal, but used by ssh-keygen */
318 int ssh_rsa_complete_crt_parameters(const BIGNUM *, const BIGNUM *,
319 const BIGNUM *, const BIGNUM *, BIGNUM **, BIGNUM **);
320
321 /* stateful keys (e.g. XMSS) */
322 int sshkey_set_filename(struct sshkey *, const char *);
323 int sshkey_enable_maxsign(struct sshkey *, u_int32_t);
324 u_int32_t sshkey_signatures_left(const struct sshkey *);
325 int sshkey_private_serialize_maxsign(struct sshkey *key,
326 struct sshbuf *buf, u_int32_t maxsign, int);
327
328 void sshkey_sig_details_free(struct sshkey_sig_details *);
329
330 #ifdef WITH_OPENSSL
331 int sshkey_ecdsa_fixup_group(EVP_PKEY *k); /* ssh-ecdsa.c */
332 #endif
333
334 #ifdef SSHKEY_INTERNAL
335 int sshkey_sk_fields_equal(const struct sshkey *a, const struct sshkey *b);
336 void sshkey_sk_cleanup(struct sshkey *k);
337 int sshkey_serialize_sk(const struct sshkey *key, struct sshbuf *b);
338 int sshkey_copy_public_sk(const struct sshkey *from, struct sshkey *to);
339 int sshkey_deserialize_sk(struct sshbuf *b, struct sshkey *key);
340 int sshkey_serialize_private_sk(const struct sshkey *key,
341 struct sshbuf *buf);
342 int sshkey_private_deserialize_sk(struct sshbuf *buf, struct sshkey *k);
343 #ifdef WITH_OPENSSL
344 int check_rsa_length(const RSA *rsa); /* XXX remove */
345 #endif
346 #endif
347
348 #ifndef WITH_OPENSSL
349 #undef RSA
350 #undef DSA
351 #undef EC_KEY
352 #undef EC_GROUP
353 #undef EC_POINT
354 #undef EVP_PKEY
355 #endif /* WITH_OPENSSL */
356
357 #endif /* SSHKEY_H */
358