sshkey.h revision 1.1.1.24 1 /* $OpenBSD: sshkey.h,v 1.65 2024/09/04 05:33:34 djm Exp $ */
2
3 /*
4 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26 #ifndef SSHKEY_H
27 #define SSHKEY_H
28
29 #include <sys/types.h>
30
31 #ifdef WITH_OPENSSL
32 #include <openssl/rsa.h>
33 #include <openssl/dsa.h>
34 #include <openssl/ec.h>
35 #include <openssl/ecdsa.h>
36 #include <openssl/evp.h>
37 #define SSH_OPENSSL_VERSION OpenSSL_version(OPENSSL_VERSION)
38 #else /* OPENSSL */
39 #define BIGNUM void
40 #define RSA void
41 #define DSA 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_DSA,
58 KEY_ECDSA,
59 KEY_ED25519,
60 KEY_RSA_CERT,
61 KEY_DSA_CERT,
62 KEY_ECDSA_CERT,
63 KEY_ED25519_CERT,
64 KEY_XMSS,
65 KEY_XMSS_CERT,
66 KEY_ECDSA_SK,
67 KEY_ECDSA_SK_CERT,
68 KEY_ED25519_SK,
69 KEY_ED25519_SK_CERT,
70 KEY_UNSPEC
71 };
72
73 /* Default fingerprint hash */
74 #define SSH_FP_HASH_DEFAULT SSH_DIGEST_SHA256
75
76 /* Fingerprint representation formats */
77 enum sshkey_fp_rep {
78 SSH_FP_DEFAULT = 0,
79 SSH_FP_HEX,
80 SSH_FP_BASE64,
81 SSH_FP_BUBBLEBABBLE,
82 SSH_FP_RANDOMART
83 };
84
85 /* Private key serialisation formats, used on the wire */
86 enum sshkey_serialize_rep {
87 SSHKEY_SERIALIZE_DEFAULT = 0,
88 SSHKEY_SERIALIZE_STATE = 1, /* only state is serialized */
89 SSHKEY_SERIALIZE_FULL = 2, /* include keys for saving to disk */
90 SSHKEY_SERIALIZE_SHIELD = 3, /* everything, for encrypting in ram */
91 SSHKEY_SERIALIZE_INFO = 254, /* minimal information */
92 };
93
94 /* Private key disk formats */
95 enum sshkey_private_format {
96 SSHKEY_PRIVATE_OPENSSH = 0,
97 SSHKEY_PRIVATE_PEM = 1,
98 SSHKEY_PRIVATE_PKCS8 = 2,
99 };
100
101 /* key is stored in external hardware */
102 #define SSHKEY_FLAG_EXT 0x0001
103
104 #define SSHKEY_CERT_MAX_PRINCIPALS 256
105 /* XXX opaquify? */
106 struct sshkey_cert {
107 struct sshbuf *certblob; /* Kept around for use on wire */
108 u_int type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */
109 u_int64_t serial;
110 char *key_id;
111 u_int nprincipals;
112 char **principals;
113 u_int64_t valid_after, valid_before;
114 struct sshbuf *critical;
115 struct sshbuf *extensions;
116 struct sshkey *signature_key;
117 char *signature_type;
118 };
119
120 /* XXX opaquify? */
121 struct sshkey {
122 int type;
123 int flags;
124 /* KEY_DSA */
125 DSA *dsa;
126 /* KEY_ECDSA and KEY_ECDSA_SK */
127 int ecdsa_nid; /* NID of curve */
128 /* libcrypto-backed keys */
129 EVP_PKEY *pkey;
130 /* KEY_ED25519 and KEY_ED25519_SK */
131 u_char *ed25519_sk;
132 u_char *ed25519_pk;
133 /* KEY_XMSS */
134 char *xmss_name;
135 char *xmss_filename; /* for state file updates */
136 void *xmss_state; /* depends on xmss_name, opaque */
137 u_char *xmss_sk;
138 u_char *xmss_pk;
139 /* KEY_ECDSA_SK and KEY_ED25519_SK */
140 char *sk_application;
141 uint8_t sk_flags;
142 struct sshbuf *sk_key_handle;
143 struct sshbuf *sk_reserved;
144 /* Certificates */
145 struct sshkey_cert *cert;
146 /* Private key shielding */
147 u_char *shielded_private;
148 size_t shielded_len;
149 u_char *shield_prekey;
150 size_t shield_prekey_len;
151 };
152
153 #define ED25519_SK_SZ crypto_sign_ed25519_SECRETKEYBYTES
154 #define ED25519_PK_SZ crypto_sign_ed25519_PUBLICKEYBYTES
155
156 /* Additional fields contained in signature */
157 struct sshkey_sig_details {
158 uint32_t sk_counter; /* U2F signature counter */
159 uint8_t sk_flags; /* U2F signature flags; see ssh-sk.h */
160 };
161
162 struct sshkey_impl_funcs {
163 u_int (*size)(const struct sshkey *); /* optional */
164 int (*alloc)(struct sshkey *); /* optional */
165 void (*cleanup)(struct sshkey *); /* optional */
166 int (*equal)(const struct sshkey *, const struct sshkey *);
167 int (*serialize_public)(const struct sshkey *, struct sshbuf *,
168 enum sshkey_serialize_rep);
169 int (*deserialize_public)(const char *, struct sshbuf *,
170 struct sshkey *);
171 int (*serialize_private)(const struct sshkey *, struct sshbuf *,
172 enum sshkey_serialize_rep);
173 int (*deserialize_private)(const char *, struct sshbuf *,
174 struct sshkey *);
175 int (*generate)(struct sshkey *, int); /* optional */
176 int (*copy_public)(const struct sshkey *, struct sshkey *);
177 int (*sign)(struct sshkey *, u_char **, size_t *,
178 const u_char *, size_t, const char *,
179 const char *, const char *, u_int); /* optional */
180 int (*verify)(const struct sshkey *, const u_char *, size_t,
181 const u_char *, size_t, const char *, u_int,
182 struct sshkey_sig_details **);
183 };
184
185 struct sshkey_impl {
186 const char *name;
187 const char *shortname;
188 const char *sigalg;
189 int type;
190 int nid;
191 int cert;
192 int sigonly;
193 int keybits;
194 const struct sshkey_impl_funcs *funcs;
195 };
196
197 struct sshkey *sshkey_new(int);
198 void sshkey_free(struct sshkey *);
199 int sshkey_equal_public(const struct sshkey *,
200 const struct sshkey *);
201 int sshkey_equal(const struct sshkey *, const struct sshkey *);
202 char *sshkey_fingerprint(const struct sshkey *,
203 int, enum sshkey_fp_rep);
204 int sshkey_fingerprint_raw(const struct sshkey *k,
205 int, u_char **retp, size_t *lenp);
206 const char *sshkey_type(const struct sshkey *);
207 const char *sshkey_cert_type(const struct sshkey *);
208 int sshkey_format_text(const struct sshkey *, struct sshbuf *);
209 int sshkey_write(const struct sshkey *, FILE *);
210 int sshkey_read(struct sshkey *, char **);
211 u_int sshkey_size(const struct sshkey *);
212
213 int sshkey_generate(int type, u_int bits, struct sshkey **keyp);
214 int sshkey_from_private(const struct sshkey *, struct sshkey **);
215
216 int sshkey_is_shielded(struct sshkey *);
217 int sshkey_shield_private(struct sshkey *);
218 int sshkey_unshield_private(struct sshkey *);
219
220 int sshkey_type_from_name(const char *);
221 int sshkey_type_from_shortname(const char *);
222 int sshkey_is_cert(const struct sshkey *);
223 int sshkey_is_sk(const struct sshkey *);
224 int sshkey_type_is_cert(int);
225 int sshkey_type_plain(int);
226
227 /* Returns non-zero if key name match sigalgs pattern list. (handles RSA) */
228 int sshkey_match_keyname_to_sigalgs(const char *, const char *);
229
230 int sshkey_to_certified(struct sshkey *);
231 int sshkey_drop_cert(struct sshkey *);
232 int sshkey_cert_copy(const struct sshkey *, struct sshkey *);
233 int sshkey_cert_check_authority(const struct sshkey *, int, int, int,
234 uint64_t, const char *, const char **);
235 int sshkey_cert_check_authority_now(const struct sshkey *, int, int, int,
236 const char *, const char **);
237 int sshkey_cert_check_host(const struct sshkey *, const char *,
238 int , const char *, const char **);
239 size_t sshkey_format_cert_validity(const struct sshkey_cert *,
240 char *, size_t) __attribute__((__bounded__(__string__, 2, 3)));
241 int sshkey_check_cert_sigtype(const struct sshkey *, const char *);
242
243 int sshkey_certify(struct sshkey *, struct sshkey *,
244 const char *, const char *, const char *);
245 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */
246 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *,
247 const u_char *, size_t, const char *, const char *, const char *,
248 u_int, void *);
249 int sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *,
250 const char *, const char *, sshkey_certify_signer *, void *);
251
252 int sshkey_ecdsa_nid_from_name(const char *);
253 int sshkey_curve_name_to_nid(const char *);
254 const char * sshkey_curve_nid_to_name(int);
255 u_int sshkey_curve_nid_to_bits(int);
256 int sshkey_ecdsa_bits_to_nid(int);
257 int sshkey_ecdsa_key_to_nid(const EC_KEY *);
258 int sshkey_ecdsa_pkey_to_nid(EVP_PKEY *);
259 int sshkey_ec_nid_to_hash_alg(int nid);
260 int sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *);
261 int sshkey_ec_validate_private(const EC_KEY *);
262 const char *sshkey_ssh_name(const struct sshkey *);
263 const char *sshkey_ssh_name_plain(const struct sshkey *);
264 int sshkey_names_valid2(const char *, int, int);
265 char *sshkey_alg_list(int, int, int, char);
266
267 int sshkey_from_blob(const u_char *, size_t, struct sshkey **);
268 int sshkey_fromb(struct sshbuf *, struct sshkey **);
269 int sshkey_froms(struct sshbuf *, struct sshkey **);
270 int sshkey_to_blob(const struct sshkey *, u_char **, size_t *);
271 int sshkey_to_base64(const struct sshkey *, char **);
272 int sshkey_putb(const struct sshkey *, struct sshbuf *);
273 int sshkey_puts(const struct sshkey *, struct sshbuf *);
274 int sshkey_puts_opts(const struct sshkey *, struct sshbuf *,
275 enum sshkey_serialize_rep);
276 int sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *);
277 int sshkey_putb_plain(const struct sshkey *, struct sshbuf *);
278
279 int sshkey_sign(struct sshkey *, u_char **, size_t *,
280 const u_char *, size_t, const char *, const char *, const char *, u_int);
281 int sshkey_verify(const struct sshkey *, const u_char *, size_t,
282 const u_char *, size_t, const char *, u_int, struct sshkey_sig_details **);
283 int sshkey_check_sigtype(const u_char *, size_t, const char *);
284 const char *sshkey_sigalg_by_name(const char *);
285 int sshkey_get_sigtype(const u_char *, size_t, char **);
286
287 /* Signing and verification backend for libcrypto-backed keys */
288 int sshkey_pkey_digest_sign(EVP_PKEY*, int, u_char **,
289 size_t *, const u_char *, size_t);
290 int sshkey_pkey_digest_verify(EVP_PKEY *, int, const u_char *,
291 size_t, u_char *, size_t);
292
293 /* for debug */
294 void sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);
295 void sshkey_dump_ec_key(const EC_KEY *);
296
297 /* private key parsing and serialisation */
298 int sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf);
299 int sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf,
300 enum sshkey_serialize_rep);
301 int sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **keyp);
302
303 /* private key file format parsing and serialisation */
304 int sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob,
305 const char *passphrase, const char *comment,
306 int format, const char *openssh_format_cipher, int openssh_format_rounds);
307 int sshkey_parse_private_fileblob(struct sshbuf *buffer,
308 const char *passphrase, struct sshkey **keyp, char **commentp);
309 int sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type,
310 const char *passphrase, struct sshkey **keyp, char **commentp);
311 int sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob,
312 int type, struct sshkey **pubkeyp);
313
314 int sshkey_check_rsa_length(const struct sshkey *, int);
315 /* XXX should be internal, but used by ssh-keygen */
316 int ssh_rsa_complete_crt_parameters(const BIGNUM *, const BIGNUM *,
317 const BIGNUM *, const BIGNUM *, BIGNUM **, BIGNUM **);
318
319 /* stateful keys (e.g. XMSS) */
320 int sshkey_set_filename(struct sshkey *, const char *);
321 int sshkey_enable_maxsign(struct sshkey *, u_int32_t);
322 u_int32_t sshkey_signatures_left(const struct sshkey *);
323 int sshkey_private_serialize_maxsign(struct sshkey *key,
324 struct sshbuf *buf, u_int32_t maxsign, int);
325
326 void sshkey_sig_details_free(struct sshkey_sig_details *);
327
328 #ifdef WITH_OPENSSL
329 int sshkey_ecdsa_fixup_group(EVP_PKEY *k); /* ssh-ecdsa.c */
330 #endif
331
332 #ifdef SSHKEY_INTERNAL
333 int sshkey_sk_fields_equal(const struct sshkey *a, const struct sshkey *b);
334 void sshkey_sk_cleanup(struct sshkey *k);
335 int sshkey_serialize_sk(const struct sshkey *key, struct sshbuf *b);
336 int sshkey_copy_public_sk(const struct sshkey *from, struct sshkey *to);
337 int sshkey_deserialize_sk(struct sshbuf *b, struct sshkey *key);
338 int sshkey_serialize_private_sk(const struct sshkey *key,
339 struct sshbuf *buf);
340 int sshkey_private_deserialize_sk(struct sshbuf *buf, struct sshkey *k);
341 #ifdef WITH_OPENSSL
342 int check_rsa_length(const RSA *rsa); /* XXX remove */
343 #endif
344 #endif
345
346 #ifndef WITH_OPENSSL
347 #undef RSA
348 #undef DSA
349 #undef EC_KEY
350 #undef EC_GROUP
351 #undef EC_POINT
352 #undef EVP_PKEY
353 #endif /* WITH_OPENSSL */
354
355 #endif /* SSHKEY_H */
356