1 /* $OpenBSD: sshkey.h,v 1.73 2026/03/03 09:57:26 dtucker 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_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 }; 89 90 /* Private key disk formats */ 91 enum sshkey_private_format { 92 SSHKEY_PRIVATE_OPENSSH = 0, 93 SSHKEY_PRIVATE_PEM = 1, 94 SSHKEY_PRIVATE_PKCS8 = 2, 95 }; 96 97 /* key is stored in external hardware */ 98 #define SSHKEY_FLAG_EXT 0x0001 99 100 #define SSHKEY_CERT_MAX_PRINCIPALS 256 101 /* XXX opacify? */ 102 struct sshkey_cert { 103 struct sshbuf *certblob; /* Kept around for use on wire */ 104 u_int type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */ 105 uint64_t serial; 106 char *key_id; 107 u_int nprincipals; 108 char **principals; 109 uint64_t valid_after, valid_before; 110 struct sshbuf *critical; 111 struct sshbuf *extensions; 112 struct sshkey *signature_key; 113 char *signature_type; 114 }; 115 116 /* XXX opacify? */ 117 struct sshkey { 118 int type; 119 int flags; 120 /* KEY_ECDSA and KEY_ECDSA_SK */ 121 int ecdsa_nid; /* NID of curve */ 122 /* libcrypto-backed keys */ 123 EVP_PKEY *pkey; 124 /* KEY_ED25519 and KEY_ED25519_SK */ 125 u_char *ed25519_sk; 126 u_char *ed25519_pk; 127 /* KEY_ECDSA_SK and KEY_ED25519_SK */ 128 char *sk_application; 129 uint8_t sk_flags; 130 struct sshbuf *sk_key_handle; 131 struct sshbuf *sk_reserved; 132 /* Certificates */ 133 struct sshkey_cert *cert; 134 /* Private key shielding */ 135 u_char *shielded_private; 136 size_t shielded_len; 137 u_char *shield_prekey; 138 size_t shield_prekey_len; 139 }; 140 141 #define ED25519_SK_SZ crypto_sign_ed25519_SECRETKEYBYTES 142 #define ED25519_PK_SZ crypto_sign_ed25519_PUBLICKEYBYTES 143 144 /* Additional fields contained in signature */ 145 struct sshkey_sig_details { 146 uint32_t sk_counter; /* U2F signature counter */ 147 uint8_t sk_flags; /* U2F signature flags; see ssh-sk.h */ 148 }; 149 150 struct sshkey_impl_funcs { 151 u_int (*size)(const struct sshkey *); /* optional */ 152 int (*alloc)(struct sshkey *); /* optional */ 153 void (*cleanup)(struct sshkey *); /* optional */ 154 int (*equal)(const struct sshkey *, const struct sshkey *); 155 int (*serialize_public)(const struct sshkey *, struct sshbuf *, 156 enum sshkey_serialize_rep); 157 int (*deserialize_public)(const char *, struct sshbuf *, 158 struct sshkey *); 159 int (*serialize_private)(const struct sshkey *, struct sshbuf *, 160 enum sshkey_serialize_rep); 161 int (*deserialize_private)(const char *, struct sshbuf *, 162 struct sshkey *); 163 int (*generate)(struct sshkey *, int); /* optional */ 164 int (*copy_public)(const struct sshkey *, struct sshkey *); 165 int (*sign)(struct sshkey *, u_char **, size_t *, 166 const u_char *, size_t, const char *, 167 const char *, const char *, u_int); /* optional */ 168 int (*verify)(const struct sshkey *, const u_char *, size_t, 169 const u_char *, size_t, const char *, u_int, 170 struct sshkey_sig_details **); 171 }; 172 173 struct sshkey_impl { 174 const char *name; 175 const char *shortname; 176 const char *sigalg; 177 int type; 178 int nid; 179 int cert; 180 int sigonly; 181 int keybits; 182 const struct sshkey_impl_funcs *funcs; 183 }; 184 185 struct sshkey *sshkey_new(int); 186 void sshkey_free(struct sshkey *); 187 int sshkey_equal_public(const struct sshkey *, 188 const struct sshkey *); 189 int sshkey_equal(const struct sshkey *, const struct sshkey *); 190 char *sshkey_fingerprint(const struct sshkey *, 191 int, enum sshkey_fp_rep); 192 int sshkey_fingerprint_raw(const struct sshkey *k, 193 int, u_char **retp, size_t *lenp); 194 const char *sshkey_type(const struct sshkey *); 195 const char *sshkey_cert_type(const struct sshkey *); 196 int sshkey_format_text(const struct sshkey *, struct sshbuf *); 197 int sshkey_write(const struct sshkey *, FILE *); 198 int sshkey_read(struct sshkey *, char **); 199 u_int sshkey_size(const struct sshkey *); 200 201 int sshkey_generate(int type, u_int bits, struct sshkey **keyp); 202 int sshkey_from_private(const struct sshkey *, struct sshkey **); 203 204 int sshkey_is_shielded(struct sshkey *); 205 int sshkey_shield_private(struct sshkey *); 206 int sshkey_unshield_private(struct sshkey *); 207 208 int sshkey_type_from_name(const char *); 209 int sshkey_type_from_shortname(const char *); 210 int sshkey_is_cert(const struct sshkey *); 211 int sshkey_is_sk(const struct sshkey *); 212 int sshkey_type_is_cert(int); 213 int sshkey_type_plain(int); 214 215 /* Returns non-zero if key name match sigalgs pattern list. (handles RSA) */ 216 int sshkey_match_keyname_to_sigalgs(const char *, const char *); 217 218 int sshkey_to_certified(struct sshkey *); 219 int sshkey_drop_cert(struct sshkey *); 220 int sshkey_cert_copy(const struct sshkey *, struct sshkey *); 221 int sshkey_cert_check_authority(const struct sshkey *, int, int, 222 uint64_t, const char *, const char **); 223 int sshkey_cert_check_authority_now(const struct sshkey *, int, int, 224 const char *, const char **); 225 int sshkey_cert_check_host(const struct sshkey *, const char *, 226 const char *, const char **); 227 size_t sshkey_format_cert_validity(const struct sshkey_cert *, 228 char *, size_t) __attribute__((__bounded__(__string__, 2, 3))); 229 int sshkey_check_cert_sigtype(const struct sshkey *, const char *); 230 231 int sshkey_certify(struct sshkey *, struct sshkey *, 232 const char *, const char *, const char *); 233 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */ 234 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *, 235 const u_char *, size_t, const char *, const char *, const char *, 236 u_int, void *); 237 int sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *, 238 const char *, const char *, sshkey_certify_signer *, void *); 239 240 int sshkey_ecdsa_nid_from_name(const char *); 241 int sshkey_curve_name_to_nid(const char *); 242 const char * sshkey_curve_nid_to_name(int); 243 u_int sshkey_curve_nid_to_bits(int); 244 int sshkey_ecdsa_bits_to_nid(int); 245 int sshkey_ecdsa_key_to_nid(const EC_KEY *); 246 int sshkey_ecdsa_pkey_to_nid(EVP_PKEY *); 247 int sshkey_ec_nid_to_hash_alg(int nid); 248 int sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *); 249 int sshkey_ec_validate_private(const EC_KEY *); 250 const char *sshkey_ssh_name(const struct sshkey *); 251 const char *sshkey_ssh_name_plain(const struct sshkey *); 252 int sshkey_names_valid2(const char *, int, int); 253 char *sshkey_alg_list(int, int, int, char); 254 255 int sshkey_from_blob(const u_char *, size_t, struct sshkey **); 256 int sshkey_fromb(struct sshbuf *, struct sshkey **); 257 int sshkey_froms(struct sshbuf *, struct sshkey **); 258 int sshkey_to_blob(const struct sshkey *, u_char **, size_t *); 259 int sshkey_to_base64(const struct sshkey *, char **); 260 int sshkey_putb(const struct sshkey *, struct sshbuf *); 261 int sshkey_puts(const struct sshkey *, struct sshbuf *); 262 int sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *); 263 int sshkey_putb_plain(const struct sshkey *, struct sshbuf *); 264 int sshkey_puts_plain(const struct sshkey *, struct sshbuf *); 265 266 int sshkey_sign(struct sshkey *, u_char **, size_t *, 267 const u_char *, size_t, const char *, const char *, const char *, u_int); 268 int sshkey_verify(const struct sshkey *, const u_char *, size_t, 269 const u_char *, size_t, const char *, u_int, struct sshkey_sig_details **); 270 int sshkey_check_sigtype(const u_char *, size_t, const char *); 271 const char *sshkey_sigalg_by_name(const char *); 272 int sshkey_get_sigtype(const u_char *, size_t, char **); 273 274 /* Signing and verification backend for libcrypto-backed keys */ 275 int sshkey_pkey_digest_sign(EVP_PKEY*, int, u_char **, 276 size_t *, const u_char *, size_t); 277 int sshkey_pkey_digest_verify(EVP_PKEY *, int, const u_char *, 278 size_t, u_char *, size_t); 279 280 /* for debug */ 281 void sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *); 282 void sshkey_dump_ec_key(const EC_KEY *); 283 284 /* private key parsing and serialisation */ 285 int sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf); 286 int sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **keyp); 287 288 /* private key file format parsing and serialisation */ 289 int sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob, 290 const char *passphrase, const char *comment, 291 int format, const char *openssh_format_cipher, int openssh_format_rounds); 292 int sshkey_parse_private_fileblob(struct sshbuf *buffer, 293 const char *passphrase, struct sshkey **keyp, char **commentp); 294 int sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type, 295 const char *passphrase, struct sshkey **keyp, char **commentp); 296 int sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob, 297 int type, struct sshkey **pubkeyp); 298 299 int sshkey_check_rsa_length(const struct sshkey *, int); 300 int ssh_rsa_hash_id_from_keyname(const char *); 301 const char *ssh_rsa_hash_alg_ident(int); 302 int ssh_rsa_encode_store_sig(int, const u_char *, size_t, 303 u_char **, size_t *); 304 int ssh_ecdsa_encode_store_sig(const struct sshkey *, 305 const BIGNUM *, const BIGNUM *, u_char **, size_t *); 306 int ssh_ed25519_encode_store_sig(const u_char *, size_t, 307 u_char **, size_t *); 308 /* XXX should be internal, but used by ssh-keygen */ 309 int ssh_rsa_complete_crt_parameters(const BIGNUM *, const BIGNUM *, 310 const BIGNUM *, const BIGNUM *, BIGNUM **, BIGNUM **); 311 312 void sshkey_sig_details_free(struct sshkey_sig_details *); 313 314 #ifdef WITH_OPENSSL 315 int sshkey_ecdsa_fixup_group(EVP_PKEY *k); /* ssh-ecdsa.c */ 316 #endif 317 318 #ifdef SSHKEY_INTERNAL 319 int sshkey_sk_fields_equal(const struct sshkey *a, const struct sshkey *b); 320 void sshkey_sk_cleanup(struct sshkey *k); 321 int sshkey_serialize_sk(const struct sshkey *key, struct sshbuf *b); 322 int sshkey_copy_public_sk(const struct sshkey *from, struct sshkey *to); 323 int sshkey_deserialize_sk(struct sshbuf *b, struct sshkey *key); 324 int sshkey_serialize_private_sk(const struct sshkey *key, 325 struct sshbuf *buf); 326 int sshkey_private_deserialize_sk(struct sshbuf *buf, struct sshkey *k); 327 #ifdef WITH_OPENSSL 328 int check_rsa_length(const RSA *rsa); /* XXX remove */ 329 #endif 330 #endif 331 332 #if !defined(WITH_OPENSSL) 333 # undef RSA 334 # undef EC_KEY 335 # undef EC_GROUP 336 # undef EC_POINT 337 # undef EVP_PKEY 338 #elif !defined(OPENSSL_HAS_ECC) 339 # undef EC_KEY 340 # undef EC_GROUP 341 # undef EC_POINT 342 #endif 343 344 #endif /* SSHKEY_H */ 345