1 /* $OpenBSD: sshkey.h,v 1.63 2024/05/17 06:42:04 jsg 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 #define SSH_OPENSSL_VERSION OpenSSL_version(OPENSSL_VERSION) 37 #else /* OPENSSL */ 38 #define BIGNUM void 39 #define RSA void 40 #define DSA void 41 #define EC_KEY void 42 #define EC_GROUP void 43 #define EC_POINT void 44 #define SSH_OPENSSL_VERSION "without OpenSSL" 45 #endif /* WITH_OPENSSL */ 46 47 #define SSH_RSA_MINIMUM_MODULUS_SIZE 1024 48 #define SSH_KEY_MAX_SIGN_DATA_SIZE (1 << 20) 49 50 struct sshbuf; 51 52 /* Key types */ 53 enum sshkey_types { 54 KEY_RSA, 55 KEY_DSA, 56 KEY_ECDSA, 57 KEY_ED25519, 58 KEY_RSA_CERT, 59 KEY_DSA_CERT, 60 KEY_ECDSA_CERT, 61 KEY_ED25519_CERT, 62 KEY_XMSS, 63 KEY_XMSS_CERT, 64 KEY_ECDSA_SK, 65 KEY_ECDSA_SK_CERT, 66 KEY_ED25519_SK, 67 KEY_ED25519_SK_CERT, 68 KEY_UNSPEC 69 }; 70 71 /* Default fingerprint hash */ 72 #define SSH_FP_HASH_DEFAULT SSH_DIGEST_SHA256 73 74 /* Fingerprint representation formats */ 75 enum sshkey_fp_rep { 76 SSH_FP_DEFAULT = 0, 77 SSH_FP_HEX, 78 SSH_FP_BASE64, 79 SSH_FP_BUBBLEBABBLE, 80 SSH_FP_RANDOMART 81 }; 82 83 /* Private key serialisation formats, used on the wire */ 84 enum sshkey_serialize_rep { 85 SSHKEY_SERIALIZE_DEFAULT = 0, 86 SSHKEY_SERIALIZE_STATE = 1, /* only state is serialized */ 87 SSHKEY_SERIALIZE_FULL = 2, /* include keys for saving to disk */ 88 SSHKEY_SERIALIZE_SHIELD = 3, /* everything, for encrypting in ram */ 89 SSHKEY_SERIALIZE_INFO = 254, /* minimal information */ 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 opaquify? */ 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 u_int64_t serial; 108 char *key_id; 109 u_int nprincipals; 110 char **principals; 111 u_int64_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 opaquify? */ 119 struct sshkey { 120 int type; 121 int flags; 122 /* KEY_RSA */ 123 RSA *rsa; 124 /* KEY_DSA */ 125 DSA *dsa; 126 /* KEY_ECDSA and KEY_ECDSA_SK */ 127 int ecdsa_nid; /* NID of curve */ 128 EC_KEY *ecdsa; 129 /* KEY_ED25519 and KEY_ED25519_SK */ 130 u_char *ed25519_sk; 131 u_char *ed25519_pk; 132 /* KEY_XMSS */ 133 char *xmss_name; 134 char *xmss_filename; /* for state file updates */ 135 void *xmss_state; /* depends on xmss_name, opaque */ 136 u_char *xmss_sk; 137 u_char *xmss_pk; 138 /* KEY_ECDSA_SK and KEY_ED25519_SK */ 139 char *sk_application; 140 uint8_t sk_flags; 141 struct sshbuf *sk_key_handle; 142 struct sshbuf *sk_reserved; 143 /* Certificates */ 144 struct sshkey_cert *cert; 145 /* Private key shielding */ 146 u_char *shielded_private; 147 size_t shielded_len; 148 u_char *shield_prekey; 149 size_t shield_prekey_len; 150 }; 151 152 #define ED25519_SK_SZ crypto_sign_ed25519_SECRETKEYBYTES 153 #define ED25519_PK_SZ crypto_sign_ed25519_PUBLICKEYBYTES 154 155 /* Additional fields contained in signature */ 156 struct sshkey_sig_details { 157 uint32_t sk_counter; /* U2F signature counter */ 158 uint8_t sk_flags; /* U2F signature flags; see ssh-sk.h */ 159 }; 160 161 struct sshkey_impl_funcs { 162 u_int (*size)(const struct sshkey *); /* optional */ 163 int (*alloc)(struct sshkey *); /* optional */ 164 void (*cleanup)(struct sshkey *); /* optional */ 165 int (*equal)(const struct sshkey *, const struct sshkey *); 166 int (*serialize_public)(const struct sshkey *, struct sshbuf *, 167 enum sshkey_serialize_rep); 168 int (*deserialize_public)(const char *, struct sshbuf *, 169 struct sshkey *); 170 int (*serialize_private)(const struct sshkey *, struct sshbuf *, 171 enum sshkey_serialize_rep); 172 int (*deserialize_private)(const char *, struct sshbuf *, 173 struct sshkey *); 174 int (*generate)(struct sshkey *, int); /* optional */ 175 int (*copy_public)(const struct sshkey *, struct sshkey *); 176 int (*sign)(struct sshkey *, u_char **, size_t *, 177 const u_char *, size_t, const char *, 178 const char *, const char *, u_int); /* optional */ 179 int (*verify)(const struct sshkey *, const u_char *, size_t, 180 const u_char *, size_t, const char *, u_int, 181 struct sshkey_sig_details **); 182 }; 183 184 struct sshkey_impl { 185 const char *name; 186 const char *shortname; 187 const char *sigalg; 188 int type; 189 int nid; 190 int cert; 191 int sigonly; 192 int keybits; 193 const struct sshkey_impl_funcs *funcs; 194 }; 195 196 struct sshkey *sshkey_new(int); 197 void sshkey_free(struct sshkey *); 198 int sshkey_equal_public(const struct sshkey *, 199 const struct sshkey *); 200 int sshkey_equal(const struct sshkey *, const struct sshkey *); 201 char *sshkey_fingerprint(const struct sshkey *, 202 int, enum sshkey_fp_rep); 203 int sshkey_fingerprint_raw(const struct sshkey *k, 204 int, u_char **retp, size_t *lenp); 205 const char *sshkey_type(const struct sshkey *); 206 const char *sshkey_cert_type(const struct sshkey *); 207 int sshkey_format_text(const struct sshkey *, struct sshbuf *); 208 int sshkey_write(const struct sshkey *, FILE *); 209 int sshkey_read(struct sshkey *, char **); 210 u_int sshkey_size(const struct sshkey *); 211 212 int sshkey_generate(int type, u_int bits, struct sshkey **keyp); 213 int sshkey_from_private(const struct sshkey *, struct sshkey **); 214 215 int sshkey_is_shielded(struct sshkey *); 216 int sshkey_shield_private(struct sshkey *); 217 int sshkey_unshield_private(struct sshkey *); 218 219 int sshkey_type_from_name(const char *); 220 int sshkey_is_cert(const struct sshkey *); 221 int sshkey_is_sk(const struct sshkey *); 222 int sshkey_type_is_cert(int); 223 int sshkey_type_plain(int); 224 225 /* Returns non-zero if key name match sigalgs pattern list. (handles RSA) */ 226 int sshkey_match_keyname_to_sigalgs(const char *, const char *); 227 228 int sshkey_to_certified(struct sshkey *); 229 int sshkey_drop_cert(struct sshkey *); 230 int sshkey_cert_copy(const struct sshkey *, struct sshkey *); 231 int sshkey_cert_check_authority(const struct sshkey *, int, int, int, 232 uint64_t, const char *, const char **); 233 int sshkey_cert_check_authority_now(const struct sshkey *, int, int, int, 234 const char *, const char **); 235 int sshkey_cert_check_host(const struct sshkey *, const char *, 236 int , const char *, const char **); 237 size_t sshkey_format_cert_validity(const struct sshkey_cert *, 238 char *, size_t) __attribute__((__bounded__(__string__, 2, 3))); 239 int sshkey_check_cert_sigtype(const struct sshkey *, const char *); 240 241 int sshkey_certify(struct sshkey *, struct sshkey *, 242 const char *, const char *, const char *); 243 /* Variant allowing use of a custom signature function (e.g. for ssh-agent) */ 244 typedef int sshkey_certify_signer(struct sshkey *, u_char **, size_t *, 245 const u_char *, size_t, const char *, const char *, const char *, 246 u_int, void *); 247 int sshkey_certify_custom(struct sshkey *, struct sshkey *, const char *, 248 const char *, const char *, sshkey_certify_signer *, void *); 249 250 int sshkey_ecdsa_nid_from_name(const char *); 251 int sshkey_curve_name_to_nid(const char *); 252 const char * sshkey_curve_nid_to_name(int); 253 u_int sshkey_curve_nid_to_bits(int); 254 int sshkey_ecdsa_bits_to_nid(int); 255 int sshkey_ecdsa_key_to_nid(EC_KEY *); 256 int sshkey_ec_nid_to_hash_alg(int nid); 257 int sshkey_ec_validate_public(const EC_GROUP *, const EC_POINT *); 258 int sshkey_ec_validate_private(const EC_KEY *); 259 const char *sshkey_ssh_name(const struct sshkey *); 260 const char *sshkey_ssh_name_plain(const struct sshkey *); 261 int sshkey_names_valid2(const char *, int, int); 262 char *sshkey_alg_list(int, int, int, char); 263 264 int sshkey_from_blob(const u_char *, size_t, struct sshkey **); 265 int sshkey_fromb(struct sshbuf *, struct sshkey **); 266 int sshkey_froms(struct sshbuf *, struct sshkey **); 267 int sshkey_to_blob(const struct sshkey *, u_char **, size_t *); 268 int sshkey_to_base64(const struct sshkey *, char **); 269 int sshkey_putb(const struct sshkey *, struct sshbuf *); 270 int sshkey_puts(const struct sshkey *, struct sshbuf *); 271 int sshkey_puts_opts(const struct sshkey *, struct sshbuf *, 272 enum sshkey_serialize_rep); 273 int sshkey_plain_to_blob(const struct sshkey *, u_char **, size_t *); 274 int sshkey_putb_plain(const struct sshkey *, struct sshbuf *); 275 276 int sshkey_sign(struct sshkey *, u_char **, size_t *, 277 const u_char *, size_t, const char *, const char *, const char *, u_int); 278 int sshkey_verify(const struct sshkey *, const u_char *, size_t, 279 const u_char *, size_t, const char *, u_int, struct sshkey_sig_details **); 280 int sshkey_check_sigtype(const u_char *, size_t, const char *); 281 const char *sshkey_sigalg_by_name(const char *); 282 int sshkey_get_sigtype(const u_char *, size_t, char **); 283 284 /* for debug */ 285 void sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *); 286 void sshkey_dump_ec_key(const EC_KEY *); 287 288 /* private key parsing and serialisation */ 289 int sshkey_private_serialize(struct sshkey *key, struct sshbuf *buf); 290 int sshkey_private_serialize_opt(struct sshkey *key, struct sshbuf *buf, 291 enum sshkey_serialize_rep); 292 int sshkey_private_deserialize(struct sshbuf *buf, struct sshkey **keyp); 293 294 /* private key file format parsing and serialisation */ 295 int sshkey_private_to_fileblob(struct sshkey *key, struct sshbuf *blob, 296 const char *passphrase, const char *comment, 297 int format, const char *openssh_format_cipher, int openssh_format_rounds); 298 int sshkey_parse_private_fileblob(struct sshbuf *buffer, 299 const char *passphrase, struct sshkey **keyp, char **commentp); 300 int sshkey_parse_private_fileblob_type(struct sshbuf *blob, int type, 301 const char *passphrase, struct sshkey **keyp, char **commentp); 302 int sshkey_parse_pubkey_from_private_fileblob_type(struct sshbuf *blob, 303 int type, struct sshkey **pubkeyp); 304 305 int sshkey_check_rsa_length(const struct sshkey *, int); 306 /* XXX should be internal, but used by ssh-keygen */ 307 int ssh_rsa_complete_crt_parameters(struct sshkey *, const BIGNUM *); 308 309 /* stateful keys (e.g. XMSS) */ 310 int sshkey_set_filename(struct sshkey *, const char *); 311 int sshkey_enable_maxsign(struct sshkey *, u_int32_t); 312 u_int32_t sshkey_signatures_left(const struct sshkey *); 313 int sshkey_private_serialize_maxsign(struct sshkey *key, 314 struct sshbuf *buf, u_int32_t maxsign, int); 315 316 void sshkey_sig_details_free(struct sshkey_sig_details *); 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 #ifndef WITH_OPENSSL 333 #undef RSA 334 #undef DSA 335 #undef EC_KEY 336 #undef EC_GROUP 337 #undef EC_POINT 338 #endif /* WITH_OPENSSL */ 339 340 #endif /* SSHKEY_H */ 341