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