1 /* $OpenBSD: ssl_asn1.c,v 1.65 2022/06/07 17:53:42 tb 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_locl.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 /* XXX - require cipher to be non-NULL or always/only use cipher_id. */ 74 cid = (uint16_t)(s->cipher_id & SSL3_CK_VALUE_MASK); 75 if (s->cipher != NULL) 76 cid = ssl3_cipher_get_value(s->cipher); 77 if (!CBB_add_asn1(&session, &cipher_suite, CBS_ASN1_OCTETSTRING)) 78 goto err; 79 if (!CBB_add_u16(&cipher_suite, cid)) 80 goto err; 81 82 /* Session ID - zero length for a ticket. */ 83 if (!CBB_add_asn1(&session, &session_id, CBS_ASN1_OCTETSTRING)) 84 goto err; 85 if (!CBB_add_bytes(&session_id, s->session_id, 86 ticket_encoding ? 0 : s->session_id_length)) 87 goto err; 88 89 /* Master key. */ 90 if (!CBB_add_asn1(&session, &master_key, CBS_ASN1_OCTETSTRING)) 91 goto err; 92 if (!CBB_add_bytes(&master_key, s->master_key, s->master_key_length)) 93 goto err; 94 95 /* Time [1]. */ 96 if (s->time != 0) { 97 if (s->time < 0) 98 goto err; 99 if (!CBB_add_asn1(&session, &time, SSLASN1_TIME_TAG)) 100 goto err; 101 if (!CBB_add_asn1_uint64(&time, s->time)) 102 goto err; 103 } 104 105 /* Timeout [2]. */ 106 if (s->timeout != 0) { 107 if (s->timeout < 0) 108 goto err; 109 if (!CBB_add_asn1(&session, &timeout, SSLASN1_TIMEOUT_TAG)) 110 goto err; 111 if (!CBB_add_asn1_uint64(&timeout, s->timeout)) 112 goto err; 113 } 114 115 /* Peer certificate [3]. */ 116 if (s->peer_cert != NULL) { 117 if ((len = i2d_X509(s->peer_cert, &peer_cert_bytes)) <= 0) 118 goto err; 119 if (!CBB_add_asn1(&session, &peer_cert, SSLASN1_PEER_CERT_TAG)) 120 goto err; 121 if (!CBB_add_bytes(&peer_cert, peer_cert_bytes, len)) 122 goto err; 123 } 124 125 /* Session ID context [4]. */ 126 /* XXX - Actually handle this as optional? */ 127 if (!CBB_add_asn1(&session, &sidctx, SSLASN1_SESSION_ID_CTX_TAG)) 128 goto err; 129 if (!CBB_add_asn1(&sidctx, &value, CBS_ASN1_OCTETSTRING)) 130 goto err; 131 if (!CBB_add_bytes(&value, s->sid_ctx, s->sid_ctx_length)) 132 goto err; 133 134 /* Verify result [5]. */ 135 if (s->verify_result != X509_V_OK) { 136 if (s->verify_result < 0) 137 goto err; 138 if (!CBB_add_asn1(&session, &verify_result, 139 SSLASN1_VERIFY_RESULT_TAG)) 140 goto err; 141 if (!CBB_add_asn1_uint64(&verify_result, s->verify_result)) 142 goto err; 143 } 144 145 /* Hostname [6]. */ 146 if (s->tlsext_hostname != NULL) { 147 if (!CBB_add_asn1(&session, &hostname, SSLASN1_HOSTNAME_TAG)) 148 goto err; 149 if (!CBB_add_asn1(&hostname, &value, CBS_ASN1_OCTETSTRING)) 150 goto err; 151 if (!CBB_add_bytes(&value, (const uint8_t *)s->tlsext_hostname, 152 strlen(s->tlsext_hostname))) 153 goto err; 154 } 155 156 /* PSK identity hint [7]. */ 157 /* PSK identity [8]. */ 158 159 /* Ticket lifetime hint [9]. */ 160 if (s->tlsext_tick_lifetime_hint > 0) { 161 if (!CBB_add_asn1(&session, &lifetime, SSLASN1_LIFETIME_TAG)) 162 goto err; 163 if (!CBB_add_asn1_uint64(&lifetime, 164 s->tlsext_tick_lifetime_hint)) 165 goto err; 166 } 167 168 /* Ticket [10]. */ 169 if (s->tlsext_tick != NULL) { 170 if (!CBB_add_asn1(&session, &ticket, SSLASN1_TICKET_TAG)) 171 goto err; 172 if (!CBB_add_asn1(&ticket, &value, CBS_ASN1_OCTETSTRING)) 173 goto err; 174 if (!CBB_add_bytes(&value, s->tlsext_tick, s->tlsext_ticklen)) 175 goto err; 176 } 177 178 /* Compression method [11]. */ 179 /* SRP username [12]. */ 180 181 if (!CBB_finish(&cbb, out, out_len)) 182 goto err; 183 184 rv = 1; 185 186 err: 187 CBB_cleanup(&cbb); 188 free(peer_cert_bytes); 189 190 return rv; 191 } 192 193 int 194 SSL_SESSION_ticket(SSL_SESSION *ss, unsigned char **out, size_t *out_len) 195 { 196 if (ss == NULL) 197 return 0; 198 199 if (ss->cipher == NULL && ss->cipher_id == 0) 200 return 0; 201 202 return SSL_SESSION_encode(ss, out, out_len, 1); 203 } 204 205 int 206 i2d_SSL_SESSION(SSL_SESSION *ss, unsigned char **pp) 207 { 208 unsigned char *data = NULL; 209 size_t data_len = 0; 210 int rv = -1; 211 212 if (ss == NULL) 213 return 0; 214 215 if (ss->cipher == NULL && ss->cipher_id == 0) 216 return 0; 217 218 if (!SSL_SESSION_encode(ss, &data, &data_len, 0)) 219 goto err; 220 221 if (data_len > INT_MAX) 222 goto err; 223 224 if (pp != NULL) { 225 if (*pp == NULL) { 226 *pp = data; 227 data = NULL; 228 } else { 229 memcpy(*pp, data, data_len); 230 *pp += data_len; 231 } 232 } 233 234 rv = (int)data_len; 235 236 err: 237 freezero(data, data_len); 238 239 return rv; 240 } 241 242 SSL_SESSION * 243 d2i_SSL_SESSION(SSL_SESSION **a, const unsigned char **pp, long length) 244 { 245 CBS cbs, session, cipher_suite, session_id, master_key, peer_cert; 246 CBS hostname, ticket; 247 uint64_t version, tls_version, stime, timeout, verify_result, lifetime; 248 const unsigned char *peer_cert_bytes; 249 uint16_t cipher_value; 250 SSL_SESSION *s = NULL; 251 size_t data_len; 252 int present; 253 254 if (a != NULL) 255 s = *a; 256 257 if (s == NULL) { 258 if ((s = SSL_SESSION_new()) == NULL) { 259 SSLerrorx(ERR_R_MALLOC_FAILURE); 260 return (NULL); 261 } 262 } 263 264 CBS_init(&cbs, *pp, length); 265 266 if (!CBS_get_asn1(&cbs, &session, CBS_ASN1_SEQUENCE)) 267 goto err; 268 269 /* Session ASN1 version. */ 270 if (!CBS_get_asn1_uint64(&session, &version)) 271 goto err; 272 if (version != SSL_SESSION_ASN1_VERSION) 273 goto err; 274 275 /* TLS/SSL Protocol Version. */ 276 if (!CBS_get_asn1_uint64(&session, &tls_version)) 277 goto err; 278 if (tls_version > INT_MAX) 279 goto err; 280 s->ssl_version = (int)tls_version; 281 282 /* Cipher suite. */ 283 if (!CBS_get_asn1(&session, &cipher_suite, CBS_ASN1_OCTETSTRING)) 284 goto err; 285 if (!CBS_get_u16(&cipher_suite, &cipher_value)) 286 goto err; 287 if (CBS_len(&cipher_suite) != 0) 288 goto err; 289 290 /* XXX - populate cipher instead? */ 291 s->cipher = NULL; 292 s->cipher_id = SSL3_CK_ID | cipher_value; 293 294 /* Session ID. */ 295 if (!CBS_get_asn1(&session, &session_id, CBS_ASN1_OCTETSTRING)) 296 goto err; 297 if (!CBS_write_bytes(&session_id, s->session_id, sizeof(s->session_id), 298 &s->session_id_length)) 299 goto err; 300 301 /* Master key. */ 302 if (!CBS_get_asn1(&session, &master_key, CBS_ASN1_OCTETSTRING)) 303 goto err; 304 if (!CBS_write_bytes(&master_key, s->master_key, sizeof(s->master_key), 305 &s->master_key_length)) 306 goto err; 307 308 /* Time [1]. */ 309 s->time = time(NULL); 310 if (!CBS_get_optional_asn1_uint64(&session, &stime, SSLASN1_TIME_TAG, 311 0)) 312 goto err; 313 if (stime > time_max()) 314 goto err; 315 if (stime != 0) 316 s->time = (time_t)stime; 317 318 /* Timeout [2]. */ 319 s->timeout = 3; 320 if (!CBS_get_optional_asn1_uint64(&session, &timeout, 321 SSLASN1_TIMEOUT_TAG, 0)) 322 goto err; 323 if (timeout > LONG_MAX) 324 goto err; 325 if (timeout != 0) 326 s->timeout = (long)timeout; 327 328 /* Peer certificate [3]. */ 329 X509_free(s->peer_cert); 330 s->peer_cert = NULL; 331 if (!CBS_get_optional_asn1(&session, &peer_cert, &present, 332 SSLASN1_PEER_CERT_TAG)) 333 goto err; 334 if (present) { 335 data_len = CBS_len(&peer_cert); 336 if (data_len > LONG_MAX) 337 goto err; 338 peer_cert_bytes = CBS_data(&peer_cert); 339 if (d2i_X509(&s->peer_cert, &peer_cert_bytes, 340 (long)data_len) == NULL) 341 goto err; 342 } 343 344 /* Session ID context [4]. */ 345 s->sid_ctx_length = 0; 346 if (!CBS_get_optional_asn1_octet_string(&session, &session_id, &present, 347 SSLASN1_SESSION_ID_CTX_TAG)) 348 goto err; 349 if (present) { 350 if (!CBS_write_bytes(&session_id, (uint8_t *)&s->sid_ctx, 351 sizeof(s->sid_ctx), &s->sid_ctx_length)) 352 goto err; 353 } 354 355 /* Verify result [5]. */ 356 s->verify_result = X509_V_OK; 357 if (!CBS_get_optional_asn1_uint64(&session, &verify_result, 358 SSLASN1_VERIFY_RESULT_TAG, X509_V_OK)) 359 goto err; 360 if (verify_result > LONG_MAX) 361 goto err; 362 s->verify_result = (long)verify_result; 363 364 /* Hostname [6]. */ 365 free(s->tlsext_hostname); 366 s->tlsext_hostname = NULL; 367 if (!CBS_get_optional_asn1_octet_string(&session, &hostname, &present, 368 SSLASN1_HOSTNAME_TAG)) 369 goto err; 370 if (present) { 371 if (CBS_contains_zero_byte(&hostname)) 372 goto err; 373 if (!CBS_strdup(&hostname, &s->tlsext_hostname)) 374 goto err; 375 } 376 377 /* PSK identity hint [7]. */ 378 /* PSK identity [8]. */ 379 380 /* Ticket lifetime [9]. */ 381 s->tlsext_tick_lifetime_hint = 0; 382 if (!CBS_get_optional_asn1_uint64(&session, &lifetime, 383 SSLASN1_LIFETIME_TAG, 0)) 384 goto err; 385 if (lifetime > UINT32_MAX) 386 goto err; 387 if (lifetime > 0) 388 s->tlsext_tick_lifetime_hint = (uint32_t)lifetime; 389 390 /* Ticket [10]. */ 391 free(s->tlsext_tick); 392 s->tlsext_tick = NULL; 393 if (!CBS_get_optional_asn1_octet_string(&session, &ticket, &present, 394 SSLASN1_TICKET_TAG)) 395 goto err; 396 if (present) { 397 if (!CBS_stow(&ticket, &s->tlsext_tick, &s->tlsext_ticklen)) 398 goto err; 399 } 400 401 /* Compression method [11]. */ 402 /* SRP username [12]. */ 403 404 *pp = CBS_data(&cbs); 405 406 if (a != NULL) 407 *a = s; 408 409 return (s); 410 411 err: 412 ERR_asprintf_error_data("offset=%d", (int)(CBS_data(&cbs) - *pp)); 413 414 if (s != NULL && (a == NULL || *a != s)) 415 SSL_SESSION_free(s); 416 417 return (NULL); 418 } 419