1 /* $OpenBSD: ssl_asn1.c,v 1.68 2024/07/20 04:04:23 jsing Exp $ */ 2 /* 3 * Copyright (c) 2016 Joel Sing <jsing@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 #include <limits.h> 19 20 #include <openssl/ssl.h> 21 #include <openssl/x509.h> 22 23 #include "bytestring.h" 24 #include "ssl_local.h" 25 26 #define SSLASN1_TAG (CBS_ASN1_CONSTRUCTED | CBS_ASN1_CONTEXT_SPECIFIC) 27 #define SSLASN1_TIME_TAG (SSLASN1_TAG | 1) 28 #define SSLASN1_TIMEOUT_TAG (SSLASN1_TAG | 2) 29 #define SSLASN1_PEER_CERT_TAG (SSLASN1_TAG | 3) 30 #define SSLASN1_SESSION_ID_CTX_TAG (SSLASN1_TAG | 4) 31 #define SSLASN1_VERIFY_RESULT_TAG (SSLASN1_TAG | 5) 32 #define SSLASN1_HOSTNAME_TAG (SSLASN1_TAG | 6) 33 #define SSLASN1_LIFETIME_TAG (SSLASN1_TAG | 9) 34 #define SSLASN1_TICKET_TAG (SSLASN1_TAG | 10) 35 36 static uint64_t 37 time_max(void) 38 { 39 if (sizeof(time_t) == sizeof(int32_t)) 40 return INT32_MAX; 41 if (sizeof(time_t) == sizeof(int64_t)) 42 return INT64_MAX; 43 return 0; 44 } 45 46 static int 47 SSL_SESSION_encode(SSL_SESSION *s, unsigned char **out, size_t *out_len, 48 int ticket_encoding) 49 { 50 CBB cbb, session, cipher_suite, session_id, master_key, time, timeout; 51 CBB peer_cert, sidctx, verify_result, hostname, lifetime, ticket, value; 52 unsigned char *peer_cert_bytes = NULL; 53 int len, rv = 0; 54 uint16_t cid; 55 56 if (!CBB_init(&cbb, 0)) 57 goto err; 58 59 if (!CBB_add_asn1(&cbb, &session, CBS_ASN1_SEQUENCE)) 60 goto err; 61 62 /* Session ASN1 version. */ 63 if (!CBB_add_asn1_uint64(&session, SSL_SESSION_ASN1_VERSION)) 64 goto err; 65 66 /* TLS/SSL protocol version. */ 67 if (s->ssl_version < 0) 68 goto err; 69 if (!CBB_add_asn1_uint64(&session, s->ssl_version)) 70 goto err; 71 72 /* Cipher suite ID. */ 73 cid = (uint16_t)(s->cipher_id & SSL3_CK_VALUE_MASK); 74 if (!CBB_add_asn1(&session, &cipher_suite, CBS_ASN1_OCTETSTRING)) 75 goto err; 76 if (!CBB_add_u16(&cipher_suite, cid)) 77 goto err; 78 79 /* Session ID - zero length for a ticket. */ 80 if (!CBB_add_asn1(&session, &session_id, CBS_ASN1_OCTETSTRING)) 81 goto err; 82 if (!CBB_add_bytes(&session_id, s->session_id, 83 ticket_encoding ? 0 : s->session_id_length)) 84 goto err; 85 86 /* Master key. */ 87 if (!CBB_add_asn1(&session, &master_key, CBS_ASN1_OCTETSTRING)) 88 goto err; 89 if (!CBB_add_bytes(&master_key, s->master_key, s->master_key_length)) 90 goto err; 91 92 /* Time [1]. */ 93 if (s->time != 0) { 94 if (s->time < 0) 95 goto err; 96 if (!CBB_add_asn1(&session, &time, SSLASN1_TIME_TAG)) 97 goto err; 98 if (!CBB_add_asn1_uint64(&time, s->time)) 99 goto err; 100 } 101 102 /* Timeout [2]. */ 103 if (s->timeout != 0) { 104 if (s->timeout < 0) 105 goto err; 106 if (!CBB_add_asn1(&session, &timeout, SSLASN1_TIMEOUT_TAG)) 107 goto err; 108 if (!CBB_add_asn1_uint64(&timeout, s->timeout)) 109 goto err; 110 } 111 112 /* Peer certificate [3]. */ 113 if (s->peer_cert != NULL) { 114 if ((len = i2d_X509(s->peer_cert, &peer_cert_bytes)) <= 0) 115 goto err; 116 if (!CBB_add_asn1(&session, &peer_cert, SSLASN1_PEER_CERT_TAG)) 117 goto err; 118 if (!CBB_add_bytes(&peer_cert, peer_cert_bytes, len)) 119 goto err; 120 } 121 122 /* Session ID context [4]. */ 123 /* XXX - Actually handle this as optional? */ 124 if (!CBB_add_asn1(&session, &sidctx, SSLASN1_SESSION_ID_CTX_TAG)) 125 goto err; 126 if (!CBB_add_asn1(&sidctx, &value, CBS_ASN1_OCTETSTRING)) 127 goto err; 128 if (!CBB_add_bytes(&value, s->sid_ctx, s->sid_ctx_length)) 129 goto err; 130 131 /* Verify result [5]. */ 132 if (s->verify_result != X509_V_OK) { 133 if (s->verify_result < 0) 134 goto err; 135 if (!CBB_add_asn1(&session, &verify_result, 136 SSLASN1_VERIFY_RESULT_TAG)) 137 goto err; 138 if (!CBB_add_asn1_uint64(&verify_result, s->verify_result)) 139 goto err; 140 } 141 142 /* Hostname [6]. */ 143 if (s->tlsext_hostname != NULL) { 144 if (!CBB_add_asn1(&session, &hostname, SSLASN1_HOSTNAME_TAG)) 145 goto err; 146 if (!CBB_add_asn1(&hostname, &value, CBS_ASN1_OCTETSTRING)) 147 goto err; 148 if (!CBB_add_bytes(&value, (const uint8_t *)s->tlsext_hostname, 149 strlen(s->tlsext_hostname))) 150 goto err; 151 } 152 153 /* PSK identity hint [7]. */ 154 /* PSK identity [8]. */ 155 156 /* Ticket lifetime hint [9]. */ 157 if (s->tlsext_tick_lifetime_hint > 0) { 158 if (!CBB_add_asn1(&session, &lifetime, SSLASN1_LIFETIME_TAG)) 159 goto err; 160 if (!CBB_add_asn1_uint64(&lifetime, 161 s->tlsext_tick_lifetime_hint)) 162 goto err; 163 } 164 165 /* Ticket [10]. */ 166 if (s->tlsext_tick != NULL) { 167 if (!CBB_add_asn1(&session, &ticket, SSLASN1_TICKET_TAG)) 168 goto err; 169 if (!CBB_add_asn1(&ticket, &value, CBS_ASN1_OCTETSTRING)) 170 goto err; 171 if (!CBB_add_bytes(&value, s->tlsext_tick, s->tlsext_ticklen)) 172 goto err; 173 } 174 175 /* Compression method [11]. */ 176 /* SRP username [12]. */ 177 178 if (!CBB_finish(&cbb, out, out_len)) 179 goto err; 180 181 rv = 1; 182 183 err: 184 CBB_cleanup(&cbb); 185 free(peer_cert_bytes); 186 187 return rv; 188 } 189 190 int 191 SSL_SESSION_ticket(SSL_SESSION *ss, unsigned char **out, size_t *out_len) 192 { 193 if (ss == NULL) 194 return 0; 195 196 if (ss->cipher_id == 0) 197 return 0; 198 199 return SSL_SESSION_encode(ss, out, out_len, 1); 200 } 201 202 int 203 i2d_SSL_SESSION(SSL_SESSION *ss, unsigned char **pp) 204 { 205 unsigned char *data = NULL; 206 size_t data_len = 0; 207 int rv = -1; 208 209 if (ss == NULL) 210 return 0; 211 212 if (ss->cipher_id == 0) 213 return 0; 214 215 if (!SSL_SESSION_encode(ss, &data, &data_len, 0)) 216 goto err; 217 218 if (data_len > INT_MAX) 219 goto err; 220 221 if (pp != NULL) { 222 if (*pp == NULL) { 223 *pp = data; 224 data = NULL; 225 } else { 226 memcpy(*pp, data, data_len); 227 *pp += data_len; 228 } 229 } 230 231 rv = (int)data_len; 232 233 err: 234 freezero(data, data_len); 235 236 return rv; 237 } 238 LSSL_ALIAS(i2d_SSL_SESSION); 239 240 SSL_SESSION * 241 d2i_SSL_SESSION(SSL_SESSION **a, const unsigned char **pp, long length) 242 { 243 CBS cbs, session, cipher_suite, session_id, master_key, peer_cert; 244 CBS hostname, ticket; 245 uint64_t version, tls_version, stime, timeout, verify_result, lifetime; 246 const unsigned char *peer_cert_bytes; 247 uint16_t cipher_value; 248 SSL_SESSION *s = NULL; 249 size_t data_len; 250 int present; 251 252 if (a != NULL) 253 s = *a; 254 255 if (s == NULL) { 256 if ((s = SSL_SESSION_new()) == NULL) { 257 SSLerrorx(ERR_R_MALLOC_FAILURE); 258 return (NULL); 259 } 260 } 261 262 CBS_init(&cbs, *pp, length); 263 264 if (!CBS_get_asn1(&cbs, &session, CBS_ASN1_SEQUENCE)) 265 goto err; 266 267 /* Session ASN1 version. */ 268 if (!CBS_get_asn1_uint64(&session, &version)) 269 goto err; 270 if (version != SSL_SESSION_ASN1_VERSION) 271 goto err; 272 273 /* TLS/SSL Protocol Version. */ 274 if (!CBS_get_asn1_uint64(&session, &tls_version)) 275 goto err; 276 if (tls_version > INT_MAX) 277 goto err; 278 s->ssl_version = (int)tls_version; 279 280 /* Cipher suite. */ 281 if (!CBS_get_asn1(&session, &cipher_suite, CBS_ASN1_OCTETSTRING)) 282 goto err; 283 if (!CBS_get_u16(&cipher_suite, &cipher_value)) 284 goto err; 285 if (CBS_len(&cipher_suite) != 0) 286 goto err; 287 s->cipher_id = SSL3_CK_ID | cipher_value; 288 289 /* Session ID. */ 290 if (!CBS_get_asn1(&session, &session_id, CBS_ASN1_OCTETSTRING)) 291 goto err; 292 if (!CBS_write_bytes(&session_id, s->session_id, sizeof(s->session_id), 293 &s->session_id_length)) 294 goto err; 295 296 /* Master key. */ 297 if (!CBS_get_asn1(&session, &master_key, CBS_ASN1_OCTETSTRING)) 298 goto err; 299 if (!CBS_write_bytes(&master_key, s->master_key, sizeof(s->master_key), 300 &s->master_key_length)) 301 goto err; 302 303 /* Time [1]. */ 304 s->time = time(NULL); 305 if (!CBS_get_optional_asn1_uint64(&session, &stime, SSLASN1_TIME_TAG, 306 0)) 307 goto err; 308 if (stime > time_max()) 309 goto err; 310 if (stime != 0) 311 s->time = (time_t)stime; 312 313 /* Timeout [2]. */ 314 s->timeout = 3; 315 if (!CBS_get_optional_asn1_uint64(&session, &timeout, 316 SSLASN1_TIMEOUT_TAG, 0)) 317 goto err; 318 if (timeout > LONG_MAX) 319 goto err; 320 if (timeout != 0) 321 s->timeout = (long)timeout; 322 323 /* Peer certificate [3]. */ 324 X509_free(s->peer_cert); 325 s->peer_cert = NULL; 326 if (!CBS_get_optional_asn1(&session, &peer_cert, &present, 327 SSLASN1_PEER_CERT_TAG)) 328 goto err; 329 if (present) { 330 data_len = CBS_len(&peer_cert); 331 if (data_len > LONG_MAX) 332 goto err; 333 peer_cert_bytes = CBS_data(&peer_cert); 334 if (d2i_X509(&s->peer_cert, &peer_cert_bytes, 335 (long)data_len) == NULL) 336 goto err; 337 } 338 339 /* Session ID context [4]. */ 340 s->sid_ctx_length = 0; 341 if (!CBS_get_optional_asn1_octet_string(&session, &session_id, &present, 342 SSLASN1_SESSION_ID_CTX_TAG)) 343 goto err; 344 if (present) { 345 if (!CBS_write_bytes(&session_id, (uint8_t *)&s->sid_ctx, 346 sizeof(s->sid_ctx), &s->sid_ctx_length)) 347 goto err; 348 } 349 350 /* Verify result [5]. */ 351 s->verify_result = X509_V_OK; 352 if (!CBS_get_optional_asn1_uint64(&session, &verify_result, 353 SSLASN1_VERIFY_RESULT_TAG, X509_V_OK)) 354 goto err; 355 if (verify_result > LONG_MAX) 356 goto err; 357 s->verify_result = (long)verify_result; 358 359 /* Hostname [6]. */ 360 free(s->tlsext_hostname); 361 s->tlsext_hostname = NULL; 362 if (!CBS_get_optional_asn1_octet_string(&session, &hostname, &present, 363 SSLASN1_HOSTNAME_TAG)) 364 goto err; 365 if (present) { 366 if (CBS_contains_zero_byte(&hostname)) 367 goto err; 368 if (!CBS_strdup(&hostname, &s->tlsext_hostname)) 369 goto err; 370 } 371 372 /* PSK identity hint [7]. */ 373 /* PSK identity [8]. */ 374 375 /* Ticket lifetime [9]. */ 376 s->tlsext_tick_lifetime_hint = 0; 377 if (!CBS_get_optional_asn1_uint64(&session, &lifetime, 378 SSLASN1_LIFETIME_TAG, 0)) 379 goto err; 380 if (lifetime > UINT32_MAX) 381 goto err; 382 if (lifetime > 0) 383 s->tlsext_tick_lifetime_hint = (uint32_t)lifetime; 384 385 /* Ticket [10]. */ 386 free(s->tlsext_tick); 387 s->tlsext_tick = NULL; 388 if (!CBS_get_optional_asn1_octet_string(&session, &ticket, &present, 389 SSLASN1_TICKET_TAG)) 390 goto err; 391 if (present) { 392 if (!CBS_stow(&ticket, &s->tlsext_tick, &s->tlsext_ticklen)) 393 goto err; 394 } 395 396 /* Compression method [11]. */ 397 /* SRP username [12]. */ 398 399 *pp = CBS_data(&cbs); 400 401 if (a != NULL) 402 *a = s; 403 404 return (s); 405 406 err: 407 ERR_asprintf_error_data("offset=%d", (int)(CBS_data(&cbs) - *pp)); 408 409 if (s != NULL && (a == NULL || *a != s)) 410 SSL_SESSION_free(s); 411 412 return (NULL); 413 } 414 LSSL_ALIAS(d2i_SSL_SESSION); 415