1 /* $OpenBSD: sshkey.h,v 1.64 2024/08/15 00:51:51 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_is_cert(const struct sshkey *); 222 int sshkey_is_sk(const struct sshkey *); 223 int sshkey_type_is_cert(int); 224 int sshkey_type_plain(int); 225 226 /* Returns non-zero if key name match sigalgs pattern list. (handles RSA) */ 227 int sshkey_match_keyname_to_sigalgs(const char *, const char *); 228 229 int sshkey_to_certified(struct sshkey *); 230 int sshkey_drop_cert(struct sshkey *); 231 int sshkey_cert_copy(const struct sshkey *, struct sshkey *); 232 int sshkey_cert_check_authority(const struct sshkey *, int, int, int, 233 uint64_t, const char *, const char **); 234 int sshkey_cert_check_authority_now(const struct sshkey *, int, int, int, 235 const char *, const char **); 236 int sshkey_cert_check_host(const struct sshkey *, const char *, 237 int , const char *, const char **); 238 size_t sshkey_format_cert_validity(const struct sshkey_cert *, 239 char *, size_t) __attribute__((__bounded__(__string__, 2, 3))); 240 int sshkey_check_cert_sigtype(const struct sshkey *, const char *); 241 242 int sshkey_certify(struct sshkey *, struct sshkey *, 243 const char *, const char *, const char *); 244 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */ 245 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *, 246 const u_char *, size_t, const char *, const char *, const char *, 247 u_int, void *); 248 int sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *, 249 const char *, const char *, sshkey_certify_signer *, void *); 250 251 int sshkey_ecdsa_nid_from_name(const char *); 252 int sshkey_curve_name_to_nid(const char *); 253 const char * sshkey_curve_nid_to_name(int); 254 u_int sshkey_curve_nid_to_bits(int); 255 int sshkey_ecdsa_bits_to_nid(int); 256 int sshkey_ecdsa_key_to_nid(const EC_KEY *); 257 int sshkey_ecdsa_pkey_to_nid(EVP_PKEY *); 258 int sshkey_ec_nid_to_hash_alg(int nid); 259 int sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *); 260 int sshkey_ec_validate_private(const EC_KEY *); 261 const char *sshkey_ssh_name(const struct sshkey *); 262 const char *sshkey_ssh_name_plain(const struct sshkey *); 263 int sshkey_names_valid2(const char *, int, int); 264 char *sshkey_alg_list(int, int, int, char); 265 266 int sshkey_from_blob(const u_char *, size_t, struct sshkey **); 267 int sshkey_fromb(struct sshbuf *, struct sshkey **); 268 int sshkey_froms(struct sshbuf *, struct sshkey **); 269 int sshkey_to_blob(const struct sshkey *, u_char **, size_t *); 270 int sshkey_to_base64(const struct sshkey *, char **); 271 int sshkey_putb(const struct sshkey *, struct sshbuf *); 272 int sshkey_puts(const struct sshkey *, struct sshbuf *); 273 int sshkey_puts_opts(const struct sshkey *, struct sshbuf *, 274 enum sshkey_serialize_rep); 275 int sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *); 276 int sshkey_putb_plain(const struct sshkey *, struct sshbuf *); 277 278 int sshkey_sign(struct sshkey *, u_char **, size_t *, 279 const u_char *, size_t, const char *, const char *, const char *, u_int); 280 int sshkey_verify(const struct sshkey *, const u_char *, size_t, 281 const u_char *, size_t, const char *, u_int, struct sshkey_sig_details **); 282 int sshkey_check_sigtype(const u_char *, size_t, const char *); 283 const char *sshkey_sigalg_by_name(const char *); 284 int sshkey_get_sigtype(const u_char *, size_t, char **); 285 286 /* Signing and verification backend for libcrypto-backed keys */ 287 int sshkey_pkey_digest_sign(EVP_PKEY*, int, u_char **, 288 size_t *, const u_char *, size_t); 289 int sshkey_pkey_digest_verify(EVP_PKEY *, int, const u_char *, 290 size_t, u_char *, size_t); 291 292 /* for debug */ 293 void sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *); 294 void sshkey_dump_ec_key(const EC_KEY *); 295 296 /* private key parsing and serialisation */ 297 int sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf); 298 int sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf, 299 enum sshkey_serialize_rep); 300 int sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **keyp); 301 302 /* private key file format parsing and serialisation */ 303 int sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob, 304 const char *passphrase, const char *comment, 305 int format, const char *openssh_format_cipher, int openssh_format_rounds); 306 int sshkey_parse_private_fileblob(struct sshbuf *buffer, 307 const char *passphrase, struct sshkey **keyp, char **commentp); 308 int sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type, 309 const char *passphrase, struct sshkey **keyp, char **commentp); 310 int sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob, 311 int type, struct sshkey **pubkeyp); 312 313 int sshkey_check_rsa_length(const struct sshkey *, int); 314 /* XXX should be internal, but used by ssh-keygen */ 315 int ssh_rsa_complete_crt_parameters(const BIGNUM *, const BIGNUM *, 316 const BIGNUM *, const BIGNUM *, BIGNUM **, BIGNUM **); 317 318 /* stateful keys (e.g. XMSS) */ 319 int sshkey_set_filename(struct sshkey *, const char *); 320 int sshkey_enable_maxsign(struct sshkey *, u_int32_t); 321 u_int32_t sshkey_signatures_left(const struct sshkey *); 322 int sshkey_private_serialize_maxsign(struct sshkey *key, 323 struct sshbuf *buf, u_int32_t maxsign, int); 324 325 void sshkey_sig_details_free(struct sshkey_sig_details *); 326 327 #ifdef WITH_OPENSSL 328 int sshkey_ecdsa_fixup_group(EVP_PKEY *k); /* ssh-ecdsa.c */ 329 #endif 330 331 #ifdef SSHKEY_INTERNAL 332 int sshkey_sk_fields_equal(const struct sshkey *a, const struct sshkey *b); 333 void sshkey_sk_cleanup(struct sshkey *k); 334 int sshkey_serialize_sk(const struct sshkey *key, struct sshbuf *b); 335 int sshkey_copy_public_sk(const struct sshkey *from, struct sshkey *to); 336 int sshkey_deserialize_sk(struct sshbuf *b, struct sshkey *key); 337 int sshkey_serialize_private_sk(const struct sshkey *key, 338 struct sshbuf *buf); 339 int sshkey_private_deserialize_sk(struct sshbuf *buf, struct sshkey *k); 340 #ifdef WITH_OPENSSL 341 int check_rsa_length(const RSA *rsa); /* XXX remove */ 342 #endif 343 #endif 344 345 #ifndef WITH_OPENSSL 346 #undef RSA 347 #undef DSA 348 #undef EC_KEY 349 #undef EC_GROUP 350 #undef EC_POINT 351 #undef EVP_PKEY 352 #endif /* WITH_OPENSSL */ 353 354 #endif /* SSHKEY_H */ 355