1 /* $OpenBSD: sshkey.h,v 1.74 2026/06/14 03:59:34 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/evp.h> 34 # ifdef OPENSSL_HAS_ECC 35 # include <openssl/ec.h> 36 # include <openssl/ecdsa.h> 37 # else /* OPENSSL_HAS_ECC */ 38 # define EC_KEY void 39 # define EC_GROUP void 40 # define EC_POINT void 41 # endif /* OPENSSL_HAS_ECC */ 42 #define SSH_OPENSSL_VERSION OpenSSL_version(OPENSSL_VERSION) 43 #else /* WITH_OPENSSL */ 44 # define BIGNUM void 45 # define RSA void 46 # define EC_KEY void 47 # define EC_GROUP void 48 # define EC_POINT void 49 # define EVP_PKEY void 50 #define SSH_OPENSSL_VERSION "without OpenSSL" 51 #endif /* WITH_OPENSSL */ 52 53 #define SSH_RSA_MINIMUM_MODULUS_SIZE 1024 54 #define SSH_KEY_MAX_SIGN_DATA_SIZE (1 << 20) 55 56 struct sshbuf; 57 58 /* Key types */ 59 enum sshkey_types { 60 KEY_RSA, 61 KEY_ECDSA, 62 KEY_ED25519, 63 KEY_RSA_CERT, 64 KEY_ECDSA_CERT, 65 KEY_ED25519_CERT, 66 KEY_ECDSA_SK, 67 KEY_ECDSA_SK_CERT, 68 KEY_ED25519_SK, 69 KEY_ED25519_SK_CERT, 70 KEY_MLDSA44_ED25519, 71 KEY_MLDSA44_ED25519_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 }; 91 92 /* Private key disk formats */ 93 enum sshkey_private_format { 94 SSHKEY_PRIVATE_OPENSSH = 0, 95 SSHKEY_PRIVATE_PEM = 1, 96 SSHKEY_PRIVATE_PKCS8 = 2, 97 }; 98 99 /* key is stored in external hardware */ 100 #define SSHKEY_FLAG_EXT 0x0001 101 102 #define SSHKEY_CERT_MAX_PRINCIPALS 256 103 /* XXX opacify? */ 104 struct sshkey_cert { 105 struct sshbuf *certblob; /* Kept around for use on wire */ 106 u_int type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */ 107 uint64_t serial; 108 char *key_id; 109 u_int nprincipals; 110 char **principals; 111 uint64_t valid_after, valid_before; 112 struct sshbuf *critical; 113 struct sshbuf *extensions; 114 struct sshkey *signature_key; 115 char *signature_type; 116 }; 117 118 /* XXX opacify? */ 119 struct sshkey { 120 int type; 121 int flags; 122 /* KEY_ECDSA and KEY_ECDSA_SK */ 123 int ecdsa_nid; /* NID of curve */ 124 /* libcrypto-backed keys */ 125 EVP_PKEY *pkey; 126 /* KEY_ED25519 and KEY_ED25519_SK */ 127 u_char *ed25519_sk; 128 u_char *ed25519_pk; 129 /* KEY_MLDSA44_ED25519 */ 130 u_char *mldsa_ed25519_sk; 131 u_char *mldsa_ed25519_pk; 132 /* KEY_ECDSA_SK and KEY_ED25519_SK */ 133 char *sk_application; 134 uint8_t sk_flags; 135 struct sshbuf *sk_key_handle; 136 struct sshbuf *sk_reserved; 137 /* Certificates */ 138 struct sshkey_cert *cert; 139 /* Private key shielding */ 140 u_char *shielded_private; 141 size_t shielded_len; 142 u_char *shield_prekey; 143 size_t shield_prekey_len; 144 }; 145 146 #define ED25519_SK_SZ crypto_sign_ed25519_SECRETKEYBYTES 147 #define ED25519_PK_SZ crypto_sign_ed25519_PUBLICKEYBYTES 148 149 /* Additional fields contained in signature */ 150 struct sshkey_sig_details { 151 uint32_t sk_counter; /* U2F signature counter */ 152 uint8_t sk_flags; /* U2F signature flags; see ssh-sk.h */ 153 }; 154 155 struct sshkey_impl_funcs { 156 u_int (*size)(const struct sshkey *); /* optional */ 157 int (*alloc)(struct sshkey *); /* optional */ 158 void (*cleanup)(struct sshkey *); /* optional */ 159 int (*equal)(const struct sshkey *, const struct sshkey *); 160 int (*serialize_public)(const struct sshkey *, struct sshbuf *, 161 enum sshkey_serialize_rep); 162 int (*deserialize_public)(const char *, struct sshbuf *, 163 struct sshkey *); 164 int (*serialize_private)(const struct sshkey *, struct sshbuf *, 165 enum sshkey_serialize_rep); 166 int (*deserialize_private)(const char *, struct sshbuf *, 167 struct sshkey *); 168 int (*generate)(struct sshkey *, int); /* optional */ 169 int (*copy_public)(const struct sshkey *, struct sshkey *); 170 int (*sign)(struct sshkey *, u_char **, size_t *, 171 const u_char *, size_t, const char *, 172 const char *, const char *, u_int); /* optional */ 173 int (*verify)(const struct sshkey *, const u_char *, size_t, 174 const u_char *, size_t, const char *, u_int, 175 struct sshkey_sig_details **); 176 }; 177 178 struct sshkey_impl { 179 const char *name; 180 const char *shortname; 181 const char *sigalg; 182 int type; 183 int nid; 184 int cert; 185 int sigonly; 186 int keybits; 187 const struct sshkey_impl_funcs *funcs; 188 }; 189 190 struct sshkey *sshkey_new(int); 191 void sshkey_free(struct sshkey *); 192 int sshkey_equal_public(const struct sshkey *, 193 const struct sshkey *); 194 int sshkey_equal(const struct sshkey *, const struct sshkey *); 195 char *sshkey_fingerprint(const struct sshkey *, 196 int, enum sshkey_fp_rep); 197 int sshkey_fingerprint_raw(const struct sshkey *k, 198 int, u_char **retp, size_t *lenp); 199 const char *sshkey_type(const struct sshkey *); 200 const char *sshkey_cert_type(const struct sshkey *); 201 int sshkey_format_text(const struct sshkey *, struct sshbuf *); 202 int sshkey_write(const struct sshkey *, FILE *); 203 int sshkey_read(struct sshkey *, char **); 204 u_int sshkey_size(const struct sshkey *); 205 206 int sshkey_generate(int type, u_int bits, struct sshkey **keyp); 207 int sshkey_from_private(const struct sshkey *, struct sshkey **); 208 209 int sshkey_is_shielded(struct sshkey *); 210 int sshkey_shield_private(struct sshkey *); 211 int sshkey_unshield_private(struct sshkey *); 212 213 int sshkey_type_from_name(const char *); 214 int sshkey_type_from_shortname(const char *); 215 int sshkey_is_cert(const struct sshkey *); 216 int sshkey_is_sk(const struct sshkey *); 217 int sshkey_type_is_cert(int); 218 int sshkey_type_plain(int); 219 220 /* Returns non-zero if key name match sigalgs pattern list. (handles RSA) */ 221 int sshkey_match_keyname_to_sigalgs(const char *, const char *); 222 223 int sshkey_to_certified(struct sshkey *); 224 int sshkey_drop_cert(struct sshkey *); 225 int sshkey_cert_copy(const struct sshkey *, struct sshkey *); 226 int sshkey_cert_check_authority(const struct sshkey *, int, int, 227 uint64_t, const char *, const char **); 228 int sshkey_cert_check_authority_now(const struct sshkey *, int, int, 229 const char *, const char **); 230 int sshkey_cert_check_host(const struct sshkey *, const char *, 231 const char *, const char **); 232 size_t sshkey_format_cert_validity(const struct sshkey_cert *, 233 char *, size_t) __attribute__((__bounded__(__string__, 2, 3))); 234 int sshkey_check_cert_sigtype(const struct sshkey *, const char *); 235 236 int sshkey_certify(struct sshkey *, struct sshkey *, 237 const char *, const char *, const char *); 238 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */ 239 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *, 240 const u_char *, size_t, const char *, const char *, const char *, 241 u_int, void *); 242 int sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *, 243 const char *, const char *, sshkey_certify_signer *, void *); 244 245 int sshkey_ecdsa_nid_from_name(const char *); 246 int sshkey_curve_name_to_nid(const char *); 247 const char * sshkey_curve_nid_to_name(int); 248 u_int sshkey_curve_nid_to_bits(int); 249 int sshkey_ecdsa_bits_to_nid(int); 250 int sshkey_ecdsa_key_to_nid(const EC_KEY *); 251 int sshkey_ecdsa_pkey_to_nid(EVP_PKEY *); 252 int sshkey_ec_nid_to_hash_alg(int nid); 253 int sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *); 254 int sshkey_ec_validate_private(const EC_KEY *); 255 const char *sshkey_ssh_name(const struct sshkey *); 256 const char *sshkey_ssh_name_plain(const struct sshkey *); 257 int sshkey_names_valid2(const char *, int, int); 258 char *sshkey_alg_list(int, int, int, char); 259 260 int sshkey_from_blob(const u_char *, size_t, struct sshkey **); 261 int sshkey_fromb(struct sshbuf *, struct sshkey **); 262 int sshkey_froms(struct sshbuf *, struct sshkey **); 263 int sshkey_to_blob(const struct sshkey *, u_char **, size_t *); 264 int sshkey_to_base64(const struct sshkey *, char **); 265 int sshkey_putb(const struct sshkey *, struct sshbuf *); 266 int sshkey_puts(const struct sshkey *, struct sshbuf *); 267 int sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *); 268 int sshkey_putb_plain(const struct sshkey *, struct sshbuf *); 269 int sshkey_puts_plain(const struct sshkey *, struct sshbuf *); 270 271 int sshkey_sign(struct sshkey *, u_char **, size_t *, 272 const u_char *, size_t, const char *, const char *, const char *, u_int); 273 int sshkey_verify(const struct sshkey *, const u_char *, size_t, 274 const u_char *, size_t, const char *, u_int, struct sshkey_sig_details **); 275 int sshkey_check_sigtype(const u_char *, size_t, const char *); 276 const char *sshkey_sigalg_by_name(const char *); 277 int sshkey_get_sigtype(const u_char *, size_t, char **); 278 279 /* Signing and verification backend for libcrypto-backed keys */ 280 int sshkey_pkey_digest_sign(EVP_PKEY*, int, u_char **, 281 size_t *, const u_char *, size_t); 282 int sshkey_pkey_digest_verify(EVP_PKEY *, int, const u_char *, 283 size_t, u_char *, size_t); 284 285 /* for debug */ 286 void sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *); 287 void sshkey_dump_ec_key(const EC_KEY *); 288 289 /* private key parsing and serialisation */ 290 int sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf); 291 int sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **keyp); 292 293 /* private key file format parsing and serialisation */ 294 int sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob, 295 const char *passphrase, const char *comment, 296 int format, const char *openssh_format_cipher, int openssh_format_rounds); 297 int sshkey_parse_private_fileblob(struct sshbuf *buffer, 298 const char *passphrase, struct sshkey **keyp, char **commentp); 299 int sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type, 300 const char *passphrase, struct sshkey **keyp, char **commentp); 301 int sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob, 302 int type, struct sshkey **pubkeyp); 303 304 int sshkey_check_rsa_length(const struct sshkey *, int); 305 int ssh_rsa_hash_id_from_keyname(const char *); 306 const char *ssh_rsa_hash_alg_ident(int); 307 int ssh_rsa_encode_store_sig(int, const u_char *, size_t, 308 u_char **, size_t *); 309 int ssh_ecdsa_encode_store_sig(const struct sshkey *, 310 const BIGNUM *, const BIGNUM *, u_char **, size_t *); 311 int ssh_ed25519_encode_store_sig(const u_char *, size_t, 312 u_char **, size_t *); 313 /* XXX should be internal, but used by ssh-keygen */ 314 int ssh_rsa_complete_crt_parameters(const BIGNUM *, const BIGNUM *, 315 const BIGNUM *, const BIGNUM *, BIGNUM **, BIGNUM **); 316 317 void sshkey_sig_details_free(struct sshkey_sig_details *); 318 319 #ifdef WITH_OPENSSL 320 int sshkey_ecdsa_fixup_group(EVP_PKEY *k); /* ssh-ecdsa.c */ 321 #endif 322 323 #ifdef SSHKEY_INTERNAL 324 int sshkey_sk_fields_equal(const struct sshkey *a, const struct sshkey *b); 325 void sshkey_sk_cleanup(struct sshkey *k); 326 int sshkey_serialize_sk(const struct sshkey *key, struct sshbuf *b); 327 int sshkey_copy_public_sk(const struct sshkey *from, struct sshkey *to); 328 int sshkey_deserialize_sk(struct sshbuf *b, struct sshkey *key); 329 int sshkey_serialize_private_sk(const struct sshkey *key, 330 struct sshbuf *buf); 331 int sshkey_private_deserialize_sk(struct sshbuf *buf, struct sshkey *k); 332 #ifdef WITH_OPENSSL 333 int check_rsa_length(const RSA *rsa); /* XXX remove */ 334 #endif 335 #endif 336 337 #if !defined(WITH_OPENSSL) 338 # undef RSA 339 # undef EC_KEY 340 # undef EC_GROUP 341 # undef EC_POINT 342 # undef EVP_PKEY 343 #elif !defined(OPENSSL_HAS_ECC) 344 # undef EC_KEY 345 # undef EC_GROUP 346 # undef EC_POINT 347 #endif 348 349 #endif /* SSHKEY_H */ 350