1 /* $OpenBSD: sshkey.h,v 1.66 2025/04/02 04:28:03 tb 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 #ifdef WITH_DSA 34 #include <openssl/dsa.h> 35 #endif 36 #include <openssl/evp.h> 37 # ifdef OPENSSL_HAS_ECC 38 # include <openssl/ec.h> 39 # include <openssl/ecdsa.h> 40 # else /* OPENSSL_HAS_ECC */ 41 # define EC_KEY void 42 # define EC_GROUP void 43 # define EC_POINT void 44 # endif /* OPENSSL_HAS_ECC */ 45 #define SSH_OPENSSL_VERSION OpenSSL_version(OPENSSL_VERSION) 46 #else /* WITH_OPENSSL */ 47 # define BIGNUM void 48 # define RSA void 49 # define DSA void 50 # define EC_KEY void 51 # define EC_GROUP void 52 # define EC_POINT void 53 # define EVP_PKEY void 54 #define SSH_OPENSSL_VERSION "without OpenSSL" 55 #endif /* WITH_OPENSSL */ 56 57 #define SSH_RSA_MINIMUM_MODULUS_SIZE 1024 58 #define SSH_KEY_MAX_SIGN_DATA_SIZE (1 << 20) 59 60 struct sshbuf; 61 62 /* Key types */ 63 enum sshkey_types { 64 KEY_RSA, 65 KEY_DSA, 66 KEY_ECDSA, 67 KEY_ED25519, 68 KEY_RSA_CERT, 69 KEY_DSA_CERT, 70 KEY_ECDSA_CERT, 71 KEY_ED25519_CERT, 72 KEY_XMSS, 73 KEY_XMSS_CERT, 74 KEY_ECDSA_SK, 75 KEY_ECDSA_SK_CERT, 76 KEY_ED25519_SK, 77 KEY_ED25519_SK_CERT, 78 KEY_UNSPEC 79 }; 80 81 /* Default fingerprint hash */ 82 #define SSH_FP_HASH_DEFAULT SSH_DIGEST_SHA256 83 84 /* Fingerprint representation formats */ 85 enum sshkey_fp_rep { 86 SSH_FP_DEFAULT = 0, 87 SSH_FP_HEX, 88 SSH_FP_BASE64, 89 SSH_FP_BUBBLEBABBLE, 90 SSH_FP_RANDOMART 91 }; 92 93 /* Private key serialisation formats, used on the wire */ 94 enum sshkey_serialize_rep { 95 SSHKEY_SERIALIZE_DEFAULT = 0, 96 SSHKEY_SERIALIZE_STATE = 1, /* only state is serialized */ 97 SSHKEY_SERIALIZE_FULL = 2, /* include keys for saving to disk */ 98 SSHKEY_SERIALIZE_SHIELD = 3, /* everything, for encrypting in ram */ 99 SSHKEY_SERIALIZE_INFO = 254, /* minimal information */ 100 }; 101 102 /* Private key disk formats */ 103 enum sshkey_private_format { 104 SSHKEY_PRIVATE_OPENSSH = 0, 105 SSHKEY_PRIVATE_PEM = 1, 106 SSHKEY_PRIVATE_PKCS8 = 2, 107 }; 108 109 /* key is stored in external hardware */ 110 #define SSHKEY_FLAG_EXT 0x0001 111 112 #define SSHKEY_CERT_MAX_PRINCIPALS 256 113 /* XXX opaquify? */ 114 struct sshkey_cert { 115 struct sshbuf *certblob; /* Kept around for use on wire */ 116 u_int type; /* SSH2_CERT_TYPE_USER or SSH2_CERT_TYPE_HOST */ 117 u_int64_t serial; 118 char *key_id; 119 u_int nprincipals; 120 char **principals; 121 u_int64_t valid_after, valid_before; 122 struct sshbuf *critical; 123 struct sshbuf *extensions; 124 struct sshkey *signature_key; 125 char *signature_type; 126 }; 127 128 /* XXX opaquify? */ 129 struct sshkey { 130 int type; 131 int flags; 132 /* KEY_DSA */ 133 DSA *dsa; 134 /* KEY_ECDSA and KEY_ECDSA_SK */ 135 int ecdsa_nid; /* NID of curve */ 136 /* libcrypto-backed keys */ 137 EVP_PKEY *pkey; 138 /* KEY_ED25519 and KEY_ED25519_SK */ 139 u_char *ed25519_sk; 140 u_char *ed25519_pk; 141 /* KEY_XMSS */ 142 char *xmss_name; 143 char *xmss_filename; /* for state file updates */ 144 void *xmss_state; /* depends on xmss_name, opaque */ 145 u_char *xmss_sk; 146 u_char *xmss_pk; 147 /* KEY_ECDSA_SK and KEY_ED25519_SK */ 148 char *sk_application; 149 uint8_t sk_flags; 150 struct sshbuf *sk_key_handle; 151 struct sshbuf *sk_reserved; 152 /* Certificates */ 153 struct sshkey_cert *cert; 154 /* Private key shielding */ 155 u_char *shielded_private; 156 size_t shielded_len; 157 u_char *shield_prekey; 158 size_t shield_prekey_len; 159 }; 160 161 #define ED25519_SK_SZ crypto_sign_ed25519_SECRETKEYBYTES 162 #define ED25519_PK_SZ crypto_sign_ed25519_PUBLICKEYBYTES 163 164 /* Additional fields contained in signature */ 165 struct sshkey_sig_details { 166 uint32_t sk_counter; /* U2F signature counter */ 167 uint8_t sk_flags; /* U2F signature flags; see ssh-sk.h */ 168 }; 169 170 struct sshkey_impl_funcs { 171 u_int (*size)(const struct sshkey *); /* optional */ 172 int (*alloc)(struct sshkey *); /* optional */ 173 void (*cleanup)(struct sshkey *); /* optional */ 174 int (*equal)(const struct sshkey *, const struct sshkey *); 175 int (*serialize_public)(const struct sshkey *, struct sshbuf *, 176 enum sshkey_serialize_rep); 177 int (*deserialize_public)(const char *, struct sshbuf *, 178 struct sshkey *); 179 int (*serialize_private)(const struct sshkey *, struct sshbuf *, 180 enum sshkey_serialize_rep); 181 int (*deserialize_private)(const char *, struct sshbuf *, 182 struct sshkey *); 183 int (*generate)(struct sshkey *, int); /* optional */ 184 int (*copy_public)(const struct sshkey *, struct sshkey *); 185 int (*sign)(struct sshkey *, u_char **, size_t *, 186 const u_char *, size_t, const char *, 187 const char *, const char *, u_int); /* optional */ 188 int (*verify)(const struct sshkey *, const u_char *, size_t, 189 const u_char *, size_t, const char *, u_int, 190 struct sshkey_sig_details **); 191 }; 192 193 struct sshkey_impl { 194 const char *name; 195 const char *shortname; 196 const char *sigalg; 197 int type; 198 int nid; 199 int cert; 200 int sigonly; 201 int keybits; 202 const struct sshkey_impl_funcs *funcs; 203 }; 204 205 struct sshkey *sshkey_new(int); 206 void sshkey_free(struct sshkey *); 207 int sshkey_equal_public(const struct sshkey *, 208 const struct sshkey *); 209 int sshkey_equal(const struct sshkey *, const struct sshkey *); 210 char *sshkey_fingerprint(const struct sshkey *, 211 int, enum sshkey_fp_rep); 212 int sshkey_fingerprint_raw(const struct sshkey *k, 213 int, u_char **retp, size_t *lenp); 214 const char *sshkey_type(const struct sshkey *); 215 const char *sshkey_cert_type(const struct sshkey *); 216 int sshkey_format_text(const struct sshkey *, struct sshbuf *); 217 int sshkey_write(const struct sshkey *, FILE *); 218 int sshkey_read(struct sshkey *, char **); 219 u_int sshkey_size(const struct sshkey *); 220 221 int sshkey_generate(int type, u_int bits, struct sshkey **keyp); 222 int sshkey_from_private(const struct sshkey *, struct sshkey **); 223 224 int sshkey_is_shielded(struct sshkey *); 225 int sshkey_shield_private(struct sshkey *); 226 int sshkey_unshield_private(struct sshkey *); 227 228 int sshkey_type_from_name(const char *); 229 int sshkey_type_from_shortname(const char *); 230 int sshkey_is_cert(const struct sshkey *); 231 int sshkey_is_sk(const struct sshkey *); 232 int sshkey_type_is_cert(int); 233 int sshkey_type_plain(int); 234 235 /* Returns non-zero if key name match sigalgs pattern list. (handles RSA) */ 236 int sshkey_match_keyname_to_sigalgs(const char *, const char *); 237 238 int sshkey_to_certified(struct sshkey *); 239 int sshkey_drop_cert(struct sshkey *); 240 int sshkey_cert_copy(const struct sshkey *, struct sshkey *); 241 int sshkey_cert_check_authority(const struct sshkey *, int, int, int, 242 uint64_t, const char *, const char **); 243 int sshkey_cert_check_authority_now(const struct sshkey *, int, int, int, 244 const char *, const char **); 245 int sshkey_cert_check_host(const struct sshkey *, const char *, 246 int , const char *, const char **); 247 size_t sshkey_format_cert_validity(const struct sshkey_cert *, 248 char *, size_t) __attribute__((__bounded__(__string__, 2, 3))); 249 int sshkey_check_cert_sigtype(const struct sshkey *, const char *); 250 251 int sshkey_certify(struct sshkey *, struct sshkey *, 252 const char *, const char *, const char *); 253 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */ 254 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *, 255 const u_char *, size_t, const char *, const char *, const char *, 256 u_int, void *); 257 int sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *, 258 const char *, const char *, sshkey_certify_signer *, void *); 259 260 int sshkey_ecdsa_nid_from_name(const char *); 261 int sshkey_curve_name_to_nid(const char *); 262 const char * sshkey_curve_nid_to_name(int); 263 u_int sshkey_curve_nid_to_bits(int); 264 int sshkey_ecdsa_bits_to_nid(int); 265 int sshkey_ecdsa_key_to_nid(const EC_KEY *); 266 int sshkey_ecdsa_pkey_to_nid(EVP_PKEY *); 267 int sshkey_ec_nid_to_hash_alg(int nid); 268 int sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *); 269 int sshkey_ec_validate_private(const EC_KEY *); 270 const char *sshkey_ssh_name(const struct sshkey *); 271 const char *sshkey_ssh_name_plain(const struct sshkey *); 272 int sshkey_names_valid2(const char *, int, int); 273 char *sshkey_alg_list(int, int, int, char); 274 275 int sshkey_from_blob(const u_char *, size_t, struct sshkey **); 276 int sshkey_fromb(struct sshbuf *, struct sshkey **); 277 int sshkey_froms(struct sshbuf *, struct sshkey **); 278 int sshkey_to_blob(const struct sshkey *, u_char **, size_t *); 279 int sshkey_to_base64(const struct sshkey *, char **); 280 int sshkey_putb(const struct sshkey *, struct sshbuf *); 281 int sshkey_puts(const struct sshkey *, struct sshbuf *); 282 int sshkey_puts_opts(const struct sshkey *, struct sshbuf *, 283 enum sshkey_serialize_rep); 284 int sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *); 285 int sshkey_putb_plain(const struct sshkey *, struct sshbuf *); 286 287 int sshkey_sign(struct sshkey *, u_char **, size_t *, 288 const u_char *, size_t, const char *, const char *, const char *, u_int); 289 int sshkey_verify(const struct sshkey *, const u_char *, size_t, 290 const u_char *, size_t, const char *, u_int, struct sshkey_sig_details **); 291 int sshkey_check_sigtype(const u_char *, size_t, const char *); 292 const char *sshkey_sigalg_by_name(const char *); 293 int sshkey_get_sigtype(const u_char *, size_t, char **); 294 295 /* Signing and verification backend for libcrypto-backed keys */ 296 int sshkey_pkey_digest_sign(EVP_PKEY*, int, u_char **, 297 size_t *, const u_char *, size_t); 298 int sshkey_pkey_digest_verify(EVP_PKEY *, int, const u_char *, 299 size_t, u_char *, size_t); 300 301 /* for debug */ 302 void sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *); 303 void sshkey_dump_ec_key(const EC_KEY *); 304 305 /* private key parsing and serialisation */ 306 int sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf); 307 int sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf, 308 enum sshkey_serialize_rep); 309 int sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **keyp); 310 311 /* private key file format parsing and serialisation */ 312 int sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob, 313 const char *passphrase, const char *comment, 314 int format, const char *openssh_format_cipher, int openssh_format_rounds); 315 int sshkey_parse_private_fileblob(struct sshbuf *buffer, 316 const char *passphrase, struct sshkey **keyp, char **commentp); 317 int sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type, 318 const char *passphrase, struct sshkey **keyp, char **commentp); 319 int sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob, 320 int type, struct sshkey **pubkeyp); 321 322 int sshkey_check_rsa_length(const struct sshkey *, int); 323 /* XXX should be internal, but used by ssh-keygen */ 324 int ssh_rsa_complete_crt_parameters(const BIGNUM *, const BIGNUM *, 325 const BIGNUM *, const BIGNUM *, BIGNUM **, BIGNUM **); 326 327 /* stateful keys (e.g. XMSS) */ 328 int sshkey_set_filename(struct sshkey *, const char *); 329 int sshkey_enable_maxsign(struct sshkey *, u_int32_t); 330 u_int32_t sshkey_signatures_left(const struct sshkey *); 331 int sshkey_private_serialize_maxsign(struct sshkey *key, 332 struct sshbuf *buf, u_int32_t maxsign, int); 333 334 void sshkey_sig_details_free(struct sshkey_sig_details *); 335 336 #ifdef WITH_OPENSSL 337 int sshkey_ecdsa_fixup_group(EVP_PKEY *k); /* ssh-ecdsa.c */ 338 #endif 339 340 #ifdef SSHKEY_INTERNAL 341 int sshkey_sk_fields_equal(const struct sshkey *a, const struct sshkey *b); 342 void sshkey_sk_cleanup(struct sshkey *k); 343 int sshkey_serialize_sk(const struct sshkey *key, struct sshbuf *b); 344 int sshkey_copy_public_sk(const struct sshkey *from, struct sshkey *to); 345 int sshkey_deserialize_sk(struct sshbuf *b, struct sshkey *key); 346 int sshkey_serialize_private_sk(const struct sshkey *key, 347 struct sshbuf *buf); 348 int sshkey_private_deserialize_sk(struct sshbuf *buf, struct sshkey *k); 349 #ifdef WITH_OPENSSL 350 int check_rsa_length(const RSA *rsa); /* XXX remove */ 351 #endif 352 #endif 353 354 #if !defined(WITH_OPENSSL) 355 # undef RSA 356 # undef DSA 357 # undef EC_KEY 358 # undef EC_GROUP 359 # undef EC_POINT 360 # undef EVP_PKEY 361 #elif !defined(OPENSSL_HAS_ECC) 362 # undef EC_KEY 363 # undef EC_GROUP 364 # undef EC_POINT 365 #endif 366 367 #endif /* SSHKEY_H */ 368