1 /* 2 * Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #include <string.h> 11 #include "internal/nelem.h" 12 #include "internal/cryptlib.h" 13 #include "../ssl_locl.h" 14 #include "statem_locl.h" 15 #include "internal/cryptlib.h" 16 17 static int final_renegotiate(SSL *s, unsigned int context, int sent); 18 static int init_server_name(SSL *s, unsigned int context); 19 static int final_server_name(SSL *s, unsigned int context, int sent); 20 #ifndef OPENSSL_NO_EC 21 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent); 22 #endif 23 static int init_session_ticket(SSL *s, unsigned int context); 24 #ifndef OPENSSL_NO_OCSP 25 static int init_status_request(SSL *s, unsigned int context); 26 #endif 27 #ifndef OPENSSL_NO_NEXTPROTONEG 28 static int init_npn(SSL *s, unsigned int context); 29 #endif 30 static int init_alpn(SSL *s, unsigned int context); 31 static int final_alpn(SSL *s, unsigned int context, int sent); 32 static int init_sig_algs_cert(SSL *s, unsigned int context); 33 static int init_sig_algs(SSL *s, unsigned int context); 34 static int init_certificate_authorities(SSL *s, unsigned int context); 35 static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt, 36 unsigned int context, 37 X509 *x, 38 size_t chainidx); 39 static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt, 40 unsigned int context, X509 *x, 41 size_t chainidx); 42 #ifndef OPENSSL_NO_SRP 43 static int init_srp(SSL *s, unsigned int context); 44 #endif 45 static int init_etm(SSL *s, unsigned int context); 46 static int init_ems(SSL *s, unsigned int context); 47 static int final_ems(SSL *s, unsigned int context, int sent); 48 static int init_psk_kex_modes(SSL *s, unsigned int context); 49 #ifndef OPENSSL_NO_EC 50 static int final_key_share(SSL *s, unsigned int context, int sent); 51 #endif 52 #ifndef OPENSSL_NO_SRTP 53 static int init_srtp(SSL *s, unsigned int context); 54 #endif 55 static int final_sig_algs(SSL *s, unsigned int context, int sent); 56 static int final_early_data(SSL *s, unsigned int context, int sent); 57 static int final_maxfragmentlen(SSL *s, unsigned int context, int sent); 58 static int init_post_handshake_auth(SSL *s, unsigned int context); 59 60 /* Structure to define a built-in extension */ 61 typedef struct extensions_definition_st { 62 /* The defined type for the extension */ 63 unsigned int type; 64 /* 65 * The context that this extension applies to, e.g. what messages and 66 * protocol versions 67 */ 68 unsigned int context; 69 /* 70 * Initialise extension before parsing. Always called for relevant contexts 71 * even if extension not present 72 */ 73 int (*init)(SSL *s, unsigned int context); 74 /* Parse extension sent from client to server */ 75 int (*parse_ctos)(SSL *s, PACKET *pkt, unsigned int context, X509 *x, 76 size_t chainidx); 77 /* Parse extension send from server to client */ 78 int (*parse_stoc)(SSL *s, PACKET *pkt, unsigned int context, X509 *x, 79 size_t chainidx); 80 /* Construct extension sent from server to client */ 81 EXT_RETURN (*construct_stoc)(SSL *s, WPACKET *pkt, unsigned int context, 82 X509 *x, size_t chainidx); 83 /* Construct extension sent from client to server */ 84 EXT_RETURN (*construct_ctos)(SSL *s, WPACKET *pkt, unsigned int context, 85 X509 *x, size_t chainidx); 86 /* 87 * Finalise extension after parsing. Always called where an extensions was 88 * initialised even if the extension was not present. |sent| is set to 1 if 89 * the extension was seen, or 0 otherwise. 90 */ 91 int (*final)(SSL *s, unsigned int context, int sent); 92 } EXTENSION_DEFINITION; 93 94 /* 95 * Definitions of all built-in extensions. NOTE: Changes in the number or order 96 * of these extensions should be mirrored with equivalent changes to the 97 * indexes ( TLSEXT_IDX_* ) defined in ssl_locl.h. 98 * Each extension has an initialiser, a client and 99 * server side parser and a finaliser. The initialiser is called (if the 100 * extension is relevant to the given context) even if we did not see the 101 * extension in the message that we received. The parser functions are only 102 * called if we see the extension in the message. The finalisers are always 103 * called if the initialiser was called. 104 * There are also server and client side constructor functions which are always 105 * called during message construction if the extension is relevant for the 106 * given context. 107 * The initialisation, parsing, finalisation and construction functions are 108 * always called in the order defined in this list. Some extensions may depend 109 * on others having been processed first, so the order of this list is 110 * significant. 111 * The extension context is defined by a series of flags which specify which 112 * messages the extension is relevant to. These flags also specify whether the 113 * extension is relevant to a particular protocol or protocol version. 114 * 115 * TODO(TLS1.3): Make sure we have a test to check the consistency of these 116 * 117 * NOTE: WebSphere Application Server 7+ cannot handle empty extensions at 118 * the end, keep these extensions before signature_algorithm. 119 */ 120 #define INVALID_EXTENSION { 0x10000, 0, NULL, NULL, NULL, NULL, NULL, NULL } 121 static const EXTENSION_DEFINITION ext_defs[] = { 122 { 123 TLSEXT_TYPE_renegotiate, 124 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO 125 | SSL_EXT_SSL3_ALLOWED | SSL_EXT_TLS1_2_AND_BELOW_ONLY, 126 NULL, tls_parse_ctos_renegotiate, tls_parse_stoc_renegotiate, 127 tls_construct_stoc_renegotiate, tls_construct_ctos_renegotiate, 128 final_renegotiate 129 }, 130 { 131 TLSEXT_TYPE_server_name, 132 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO 133 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS, 134 init_server_name, 135 tls_parse_ctos_server_name, tls_parse_stoc_server_name, 136 tls_construct_stoc_server_name, tls_construct_ctos_server_name, 137 final_server_name 138 }, 139 { 140 TLSEXT_TYPE_max_fragment_length, 141 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO 142 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS, 143 NULL, tls_parse_ctos_maxfragmentlen, tls_parse_stoc_maxfragmentlen, 144 tls_construct_stoc_maxfragmentlen, tls_construct_ctos_maxfragmentlen, 145 final_maxfragmentlen 146 }, 147 #ifndef OPENSSL_NO_SRP 148 { 149 TLSEXT_TYPE_srp, 150 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_AND_BELOW_ONLY, 151 init_srp, tls_parse_ctos_srp, NULL, NULL, tls_construct_ctos_srp, NULL 152 }, 153 #else 154 INVALID_EXTENSION, 155 #endif 156 #ifndef OPENSSL_NO_EC 157 { 158 TLSEXT_TYPE_ec_point_formats, 159 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO 160 | SSL_EXT_TLS1_2_AND_BELOW_ONLY, 161 NULL, tls_parse_ctos_ec_pt_formats, tls_parse_stoc_ec_pt_formats, 162 tls_construct_stoc_ec_pt_formats, tls_construct_ctos_ec_pt_formats, 163 final_ec_pt_formats 164 }, 165 { 166 /* 167 * "supported_groups" is spread across several specifications. 168 * It was originally specified as "elliptic_curves" in RFC 4492, 169 * and broadened to include named FFDH groups by RFC 7919. 170 * Both RFCs 4492 and 7919 do not include a provision for the server 171 * to indicate to the client the complete list of groups supported 172 * by the server, with the server instead just indicating the 173 * selected group for this connection in the ServerKeyExchange 174 * message. TLS 1.3 adds a scheme for the server to indicate 175 * to the client its list of supported groups in the 176 * EncryptedExtensions message, but none of the relevant 177 * specifications permit sending supported_groups in the ServerHello. 178 * Nonetheless (possibly due to the close proximity to the 179 * "ec_point_formats" extension, which is allowed in the ServerHello), 180 * there are several servers that send this extension in the 181 * ServerHello anyway. Up to and including the 1.1.0 release, 182 * we did not check for the presence of nonpermitted extensions, 183 * so to avoid a regression, we must permit this extension in the 184 * TLS 1.2 ServerHello as well. 185 * 186 * Note that there is no tls_parse_stoc_supported_groups function, 187 * so we do not perform any additional parsing, validation, or 188 * processing on the server's group list -- this is just a minimal 189 * change to preserve compatibility with these misbehaving servers. 190 */ 191 TLSEXT_TYPE_supported_groups, 192 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS 193 | SSL_EXT_TLS1_2_SERVER_HELLO, 194 NULL, tls_parse_ctos_supported_groups, NULL, 195 tls_construct_stoc_supported_groups, 196 tls_construct_ctos_supported_groups, NULL 197 }, 198 #else 199 INVALID_EXTENSION, 200 INVALID_EXTENSION, 201 #endif 202 { 203 TLSEXT_TYPE_session_ticket, 204 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO 205 | SSL_EXT_TLS1_2_AND_BELOW_ONLY, 206 init_session_ticket, tls_parse_ctos_session_ticket, 207 tls_parse_stoc_session_ticket, tls_construct_stoc_session_ticket, 208 tls_construct_ctos_session_ticket, NULL 209 }, 210 #ifndef OPENSSL_NO_OCSP 211 { 212 TLSEXT_TYPE_status_request, 213 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO 214 | SSL_EXT_TLS1_3_CERTIFICATE | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST, 215 init_status_request, tls_parse_ctos_status_request, 216 tls_parse_stoc_status_request, tls_construct_stoc_status_request, 217 tls_construct_ctos_status_request, NULL 218 }, 219 #else 220 INVALID_EXTENSION, 221 #endif 222 #ifndef OPENSSL_NO_NEXTPROTONEG 223 { 224 TLSEXT_TYPE_next_proto_neg, 225 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO 226 | SSL_EXT_TLS1_2_AND_BELOW_ONLY, 227 init_npn, tls_parse_ctos_npn, tls_parse_stoc_npn, 228 tls_construct_stoc_next_proto_neg, tls_construct_ctos_npn, NULL 229 }, 230 #else 231 INVALID_EXTENSION, 232 #endif 233 { 234 /* 235 * Must appear in this list after server_name so that finalisation 236 * happens after server_name callbacks 237 */ 238 TLSEXT_TYPE_application_layer_protocol_negotiation, 239 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO 240 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS, 241 init_alpn, tls_parse_ctos_alpn, tls_parse_stoc_alpn, 242 tls_construct_stoc_alpn, tls_construct_ctos_alpn, final_alpn 243 }, 244 #ifndef OPENSSL_NO_SRTP 245 { 246 TLSEXT_TYPE_use_srtp, 247 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO 248 | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS | SSL_EXT_DTLS_ONLY, 249 init_srtp, tls_parse_ctos_use_srtp, tls_parse_stoc_use_srtp, 250 tls_construct_stoc_use_srtp, tls_construct_ctos_use_srtp, NULL 251 }, 252 #else 253 INVALID_EXTENSION, 254 #endif 255 { 256 TLSEXT_TYPE_encrypt_then_mac, 257 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO 258 | SSL_EXT_TLS1_2_AND_BELOW_ONLY, 259 init_etm, tls_parse_ctos_etm, tls_parse_stoc_etm, 260 tls_construct_stoc_etm, tls_construct_ctos_etm, NULL 261 }, 262 #ifndef OPENSSL_NO_CT 263 { 264 TLSEXT_TYPE_signed_certificate_timestamp, 265 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO 266 | SSL_EXT_TLS1_3_CERTIFICATE | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST, 267 NULL, 268 /* 269 * No server side support for this, but can be provided by a custom 270 * extension. This is an exception to the rule that custom extensions 271 * cannot override built in ones. 272 */ 273 NULL, tls_parse_stoc_sct, NULL, tls_construct_ctos_sct, NULL 274 }, 275 #else 276 INVALID_EXTENSION, 277 #endif 278 { 279 TLSEXT_TYPE_extended_master_secret, 280 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO 281 | SSL_EXT_TLS1_2_AND_BELOW_ONLY, 282 init_ems, tls_parse_ctos_ems, tls_parse_stoc_ems, 283 tls_construct_stoc_ems, tls_construct_ctos_ems, final_ems 284 }, 285 { 286 TLSEXT_TYPE_signature_algorithms_cert, 287 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST, 288 init_sig_algs_cert, tls_parse_ctos_sig_algs_cert, 289 tls_parse_ctos_sig_algs_cert, 290 /* We do not generate signature_algorithms_cert at present. */ 291 NULL, NULL, NULL 292 }, 293 { 294 TLSEXT_TYPE_post_handshake_auth, 295 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ONLY, 296 init_post_handshake_auth, 297 tls_parse_ctos_post_handshake_auth, NULL, 298 NULL, tls_construct_ctos_post_handshake_auth, 299 NULL, 300 }, 301 { 302 TLSEXT_TYPE_signature_algorithms, 303 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST, 304 init_sig_algs, tls_parse_ctos_sig_algs, 305 tls_parse_ctos_sig_algs, tls_construct_ctos_sig_algs, 306 tls_construct_ctos_sig_algs, final_sig_algs 307 }, 308 { 309 TLSEXT_TYPE_supported_versions, 310 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO 311 | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST | SSL_EXT_TLS_IMPLEMENTATION_ONLY, 312 NULL, 313 /* Processed inline as part of version selection */ 314 NULL, tls_parse_stoc_supported_versions, 315 tls_construct_stoc_supported_versions, 316 tls_construct_ctos_supported_versions, NULL 317 }, 318 { 319 TLSEXT_TYPE_psk_kex_modes, 320 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS_IMPLEMENTATION_ONLY 321 | SSL_EXT_TLS1_3_ONLY, 322 init_psk_kex_modes, tls_parse_ctos_psk_kex_modes, NULL, NULL, 323 tls_construct_ctos_psk_kex_modes, NULL 324 }, 325 #ifndef OPENSSL_NO_EC 326 { 327 /* 328 * Must be in this list after supported_groups. We need that to have 329 * been parsed before we do this one. 330 */ 331 TLSEXT_TYPE_key_share, 332 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO 333 | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST | SSL_EXT_TLS_IMPLEMENTATION_ONLY 334 | SSL_EXT_TLS1_3_ONLY, 335 NULL, tls_parse_ctos_key_share, tls_parse_stoc_key_share, 336 tls_construct_stoc_key_share, tls_construct_ctos_key_share, 337 final_key_share 338 }, 339 #endif 340 { 341 /* Must be after key_share */ 342 TLSEXT_TYPE_cookie, 343 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST 344 | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY, 345 NULL, tls_parse_ctos_cookie, tls_parse_stoc_cookie, 346 tls_construct_stoc_cookie, tls_construct_ctos_cookie, NULL 347 }, 348 { 349 /* 350 * Special unsolicited ServerHello extension only used when 351 * SSL_OP_CRYPTOPRO_TLSEXT_BUG is set 352 */ 353 TLSEXT_TYPE_cryptopro_bug, 354 SSL_EXT_TLS1_2_SERVER_HELLO | SSL_EXT_TLS1_2_AND_BELOW_ONLY, 355 NULL, NULL, NULL, tls_construct_stoc_cryptopro_bug, NULL, NULL 356 }, 357 { 358 TLSEXT_TYPE_early_data, 359 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS 360 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET | SSL_EXT_TLS1_3_ONLY, 361 NULL, tls_parse_ctos_early_data, tls_parse_stoc_early_data, 362 tls_construct_stoc_early_data, tls_construct_ctos_early_data, 363 final_early_data 364 }, 365 { 366 TLSEXT_TYPE_certificate_authorities, 367 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST 368 | SSL_EXT_TLS1_3_ONLY, 369 init_certificate_authorities, 370 tls_parse_certificate_authorities, tls_parse_certificate_authorities, 371 tls_construct_certificate_authorities, 372 tls_construct_certificate_authorities, NULL, 373 }, 374 { 375 /* Must be immediately before pre_shared_key */ 376 TLSEXT_TYPE_padding, 377 SSL_EXT_CLIENT_HELLO, 378 NULL, 379 /* We send this, but don't read it */ 380 NULL, NULL, NULL, tls_construct_ctos_padding, NULL 381 }, 382 { 383 /* Required by the TLSv1.3 spec to always be the last extension */ 384 TLSEXT_TYPE_psk, 385 SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_SERVER_HELLO 386 | SSL_EXT_TLS_IMPLEMENTATION_ONLY | SSL_EXT_TLS1_3_ONLY, 387 NULL, tls_parse_ctos_psk, tls_parse_stoc_psk, tls_construct_stoc_psk, 388 tls_construct_ctos_psk, NULL 389 } 390 }; 391 392 /* Check whether an extension's context matches the current context */ 393 static int validate_context(SSL *s, unsigned int extctx, unsigned int thisctx) 394 { 395 /* Check we're allowed to use this extension in this context */ 396 if ((thisctx & extctx) == 0) 397 return 0; 398 399 if (SSL_IS_DTLS(s)) { 400 if ((extctx & SSL_EXT_TLS_ONLY) != 0) 401 return 0; 402 } else if ((extctx & SSL_EXT_DTLS_ONLY) != 0) { 403 return 0; 404 } 405 406 return 1; 407 } 408 409 int tls_validate_all_contexts(SSL *s, unsigned int thisctx, RAW_EXTENSION *exts) 410 { 411 size_t i, num_exts, builtin_num = OSSL_NELEM(ext_defs), offset; 412 RAW_EXTENSION *thisext; 413 unsigned int context; 414 ENDPOINT role = ENDPOINT_BOTH; 415 416 if ((thisctx & SSL_EXT_CLIENT_HELLO) != 0) 417 role = ENDPOINT_SERVER; 418 else if ((thisctx & SSL_EXT_TLS1_2_SERVER_HELLO) != 0) 419 role = ENDPOINT_CLIENT; 420 421 /* Calculate the number of extensions in the extensions list */ 422 num_exts = builtin_num + s->cert->custext.meths_count; 423 424 for (thisext = exts, i = 0; i < num_exts; i++, thisext++) { 425 if (!thisext->present) 426 continue; 427 428 if (i < builtin_num) { 429 context = ext_defs[i].context; 430 } else { 431 custom_ext_method *meth = NULL; 432 433 meth = custom_ext_find(&s->cert->custext, role, thisext->type, 434 &offset); 435 if (!ossl_assert(meth != NULL)) 436 return 0; 437 context = meth->context; 438 } 439 440 if (!validate_context(s, context, thisctx)) 441 return 0; 442 } 443 444 return 1; 445 } 446 447 /* 448 * Verify whether we are allowed to use the extension |type| in the current 449 * |context|. Returns 1 to indicate the extension is allowed or unknown or 0 to 450 * indicate the extension is not allowed. If returning 1 then |*found| is set to 451 * the definition for the extension we found. 452 */ 453 static int verify_extension(SSL *s, unsigned int context, unsigned int type, 454 custom_ext_methods *meths, RAW_EXTENSION *rawexlist, 455 RAW_EXTENSION **found) 456 { 457 size_t i; 458 size_t builtin_num = OSSL_NELEM(ext_defs); 459 const EXTENSION_DEFINITION *thisext; 460 461 for (i = 0, thisext = ext_defs; i < builtin_num; i++, thisext++) { 462 if (type == thisext->type) { 463 if (!validate_context(s, thisext->context, context)) 464 return 0; 465 466 *found = &rawexlist[i]; 467 return 1; 468 } 469 } 470 471 /* Check the custom extensions */ 472 if (meths != NULL) { 473 size_t offset = 0; 474 ENDPOINT role = ENDPOINT_BOTH; 475 custom_ext_method *meth = NULL; 476 477 if ((context & SSL_EXT_CLIENT_HELLO) != 0) 478 role = ENDPOINT_SERVER; 479 else if ((context & SSL_EXT_TLS1_2_SERVER_HELLO) != 0) 480 role = ENDPOINT_CLIENT; 481 482 meth = custom_ext_find(meths, role, type, &offset); 483 if (meth != NULL) { 484 if (!validate_context(s, meth->context, context)) 485 return 0; 486 *found = &rawexlist[offset + builtin_num]; 487 return 1; 488 } 489 } 490 491 /* Unknown extension. We allow it */ 492 *found = NULL; 493 return 1; 494 } 495 496 /* 497 * Check whether the context defined for an extension |extctx| means whether 498 * the extension is relevant for the current context |thisctx| or not. Returns 499 * 1 if the extension is relevant for this context, and 0 otherwise 500 */ 501 int extension_is_relevant(SSL *s, unsigned int extctx, unsigned int thisctx) 502 { 503 int is_tls13; 504 505 /* 506 * For HRR we haven't selected the version yet but we know it will be 507 * TLSv1.3 508 */ 509 if ((thisctx & SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0) 510 is_tls13 = 1; 511 else 512 is_tls13 = SSL_IS_TLS13(s); 513 514 if ((SSL_IS_DTLS(s) 515 && (extctx & SSL_EXT_TLS_IMPLEMENTATION_ONLY) != 0) 516 || (s->version == SSL3_VERSION 517 && (extctx & SSL_EXT_SSL3_ALLOWED) == 0) 518 /* 519 * Note that SSL_IS_TLS13() means "TLS 1.3 has been negotiated", 520 * which is never true when generating the ClientHello. 521 * However, version negotiation *has* occurred by the time the 522 * ClientHello extensions are being parsed. 523 * Be careful to allow TLS 1.3-only extensions when generating 524 * the ClientHello. 525 */ 526 || (is_tls13 && (extctx & SSL_EXT_TLS1_2_AND_BELOW_ONLY) != 0) 527 || (!is_tls13 && (extctx & SSL_EXT_TLS1_3_ONLY) != 0 528 && (thisctx & SSL_EXT_CLIENT_HELLO) == 0) 529 || (s->server && !is_tls13 && (extctx & SSL_EXT_TLS1_3_ONLY) != 0) 530 || (s->hit && (extctx & SSL_EXT_IGNORE_ON_RESUMPTION) != 0)) 531 return 0; 532 return 1; 533 } 534 535 /* 536 * Gather a list of all the extensions from the data in |packet]. |context| 537 * tells us which message this extension is for. The raw extension data is 538 * stored in |*res| on success. We don't actually process the content of the 539 * extensions yet, except to check their types. This function also runs the 540 * initialiser functions for all known extensions if |init| is nonzero (whether 541 * we have collected them or not). If successful the caller is responsible for 542 * freeing the contents of |*res|. 543 * 544 * Per http://tools.ietf.org/html/rfc5246#section-7.4.1.4, there may not be 545 * more than one extension of the same type in a ClientHello or ServerHello. 546 * This function returns 1 if all extensions are unique and we have parsed their 547 * types, and 0 if the extensions contain duplicates, could not be successfully 548 * found, or an internal error occurred. We only check duplicates for 549 * extensions that we know about. We ignore others. 550 */ 551 int tls_collect_extensions(SSL *s, PACKET *packet, unsigned int context, 552 RAW_EXTENSION **res, size_t *len, int init) 553 { 554 PACKET extensions = *packet; 555 size_t i = 0; 556 size_t num_exts; 557 custom_ext_methods *exts = &s->cert->custext; 558 RAW_EXTENSION *raw_extensions = NULL; 559 const EXTENSION_DEFINITION *thisexd; 560 561 *res = NULL; 562 563 /* 564 * Initialise server side custom extensions. Client side is done during 565 * construction of extensions for the ClientHello. 566 */ 567 if ((context & SSL_EXT_CLIENT_HELLO) != 0) 568 custom_ext_init(&s->cert->custext); 569 570 num_exts = OSSL_NELEM(ext_defs) + (exts != NULL ? exts->meths_count : 0); 571 raw_extensions = OPENSSL_zalloc(num_exts * sizeof(*raw_extensions)); 572 if (raw_extensions == NULL) { 573 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_COLLECT_EXTENSIONS, 574 ERR_R_MALLOC_FAILURE); 575 return 0; 576 } 577 578 i = 0; 579 while (PACKET_remaining(&extensions) > 0) { 580 unsigned int type, idx; 581 PACKET extension; 582 RAW_EXTENSION *thisex; 583 584 if (!PACKET_get_net_2(&extensions, &type) || 585 !PACKET_get_length_prefixed_2(&extensions, &extension)) { 586 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_COLLECT_EXTENSIONS, 587 SSL_R_BAD_EXTENSION); 588 goto err; 589 } 590 /* 591 * Verify this extension is allowed. We only check duplicates for 592 * extensions that we recognise. We also have a special case for the 593 * PSK extension, which must be the last one in the ClientHello. 594 */ 595 if (!verify_extension(s, context, type, exts, raw_extensions, &thisex) 596 || (thisex != NULL && thisex->present == 1) 597 || (type == TLSEXT_TYPE_psk 598 && (context & SSL_EXT_CLIENT_HELLO) != 0 599 && PACKET_remaining(&extensions) != 0)) { 600 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_COLLECT_EXTENSIONS, 601 SSL_R_BAD_EXTENSION); 602 goto err; 603 } 604 idx = thisex - raw_extensions; 605 /*- 606 * Check that we requested this extension (if appropriate). Requests can 607 * be sent in the ClientHello and CertificateRequest. Unsolicited 608 * extensions can be sent in the NewSessionTicket. We only do this for 609 * the built-in extensions. Custom extensions have a different but 610 * similar check elsewhere. 611 * Special cases: 612 * - The HRR cookie extension is unsolicited 613 * - The renegotiate extension is unsolicited (the client signals 614 * support via an SCSV) 615 * - The signed_certificate_timestamp extension can be provided by a 616 * custom extension or by the built-in version. We let the extension 617 * itself handle unsolicited response checks. 618 */ 619 if (idx < OSSL_NELEM(ext_defs) 620 && (context & (SSL_EXT_CLIENT_HELLO 621 | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST 622 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET)) == 0 623 && type != TLSEXT_TYPE_cookie 624 && type != TLSEXT_TYPE_renegotiate 625 && type != TLSEXT_TYPE_signed_certificate_timestamp 626 && (s->ext.extflags[idx] & SSL_EXT_FLAG_SENT) == 0) { 627 SSLfatal(s, SSL_AD_UNSUPPORTED_EXTENSION, 628 SSL_F_TLS_COLLECT_EXTENSIONS, SSL_R_UNSOLICITED_EXTENSION); 629 goto err; 630 } 631 if (thisex != NULL) { 632 thisex->data = extension; 633 thisex->present = 1; 634 thisex->type = type; 635 thisex->received_order = i++; 636 if (s->ext.debug_cb) 637 s->ext.debug_cb(s, !s->server, thisex->type, 638 PACKET_data(&thisex->data), 639 PACKET_remaining(&thisex->data), 640 s->ext.debug_arg); 641 } 642 } 643 644 if (init) { 645 /* 646 * Initialise all known extensions relevant to this context, 647 * whether we have found them or not 648 */ 649 for (thisexd = ext_defs, i = 0; i < OSSL_NELEM(ext_defs); 650 i++, thisexd++) { 651 if (thisexd->init != NULL && (thisexd->context & context) != 0 652 && extension_is_relevant(s, thisexd->context, context) 653 && !thisexd->init(s, context)) { 654 /* SSLfatal() already called */ 655 goto err; 656 } 657 } 658 } 659 660 *res = raw_extensions; 661 if (len != NULL) 662 *len = num_exts; 663 return 1; 664 665 err: 666 OPENSSL_free(raw_extensions); 667 return 0; 668 } 669 670 /* 671 * Runs the parser for a given extension with index |idx|. |exts| contains the 672 * list of all parsed extensions previously collected by 673 * tls_collect_extensions(). The parser is only run if it is applicable for the 674 * given |context| and the parser has not already been run. If this is for a 675 * Certificate message, then we also provide the parser with the relevant 676 * Certificate |x| and its position in the |chainidx| with 0 being the first 677 * Certificate. Returns 1 on success or 0 on failure. If an extension is not 678 * present this counted as success. 679 */ 680 int tls_parse_extension(SSL *s, TLSEXT_INDEX idx, int context, 681 RAW_EXTENSION *exts, X509 *x, size_t chainidx) 682 { 683 RAW_EXTENSION *currext = &exts[idx]; 684 int (*parser)(SSL *s, PACKET *pkt, unsigned int context, X509 *x, 685 size_t chainidx) = NULL; 686 687 /* Skip if the extension is not present */ 688 if (!currext->present) 689 return 1; 690 691 /* Skip if we've already parsed this extension */ 692 if (currext->parsed) 693 return 1; 694 695 currext->parsed = 1; 696 697 if (idx < OSSL_NELEM(ext_defs)) { 698 /* We are handling a built-in extension */ 699 const EXTENSION_DEFINITION *extdef = &ext_defs[idx]; 700 701 /* Check if extension is defined for our protocol. If not, skip */ 702 if (!extension_is_relevant(s, extdef->context, context)) 703 return 1; 704 705 parser = s->server ? extdef->parse_ctos : extdef->parse_stoc; 706 707 if (parser != NULL) 708 return parser(s, &currext->data, context, x, chainidx); 709 710 /* 711 * If the parser is NULL we fall through to the custom extension 712 * processing 713 */ 714 } 715 716 /* Parse custom extensions */ 717 return custom_ext_parse(s, context, currext->type, 718 PACKET_data(&currext->data), 719 PACKET_remaining(&currext->data), 720 x, chainidx); 721 } 722 723 /* 724 * Parse all remaining extensions that have not yet been parsed. Also calls the 725 * finalisation for all extensions at the end if |fin| is nonzero, whether we 726 * collected them or not. Returns 1 for success or 0 for failure. If we are 727 * working on a Certificate message then we also pass the Certificate |x| and 728 * its position in the |chainidx|, with 0 being the first certificate. 729 */ 730 int tls_parse_all_extensions(SSL *s, int context, RAW_EXTENSION *exts, X509 *x, 731 size_t chainidx, int fin) 732 { 733 size_t i, numexts = OSSL_NELEM(ext_defs); 734 const EXTENSION_DEFINITION *thisexd; 735 736 /* Calculate the number of extensions in the extensions list */ 737 numexts += s->cert->custext.meths_count; 738 739 /* Parse each extension in turn */ 740 for (i = 0; i < numexts; i++) { 741 if (!tls_parse_extension(s, i, context, exts, x, chainidx)) { 742 /* SSLfatal() already called */ 743 return 0; 744 } 745 } 746 747 if (fin) { 748 /* 749 * Finalise all known extensions relevant to this context, 750 * whether we have found them or not 751 */ 752 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); 753 i++, thisexd++) { 754 if (thisexd->final != NULL && (thisexd->context & context) != 0 755 && !thisexd->final(s, context, exts[i].present)) { 756 /* SSLfatal() already called */ 757 return 0; 758 } 759 } 760 } 761 762 return 1; 763 } 764 765 int should_add_extension(SSL *s, unsigned int extctx, unsigned int thisctx, 766 int max_version) 767 { 768 /* Skip if not relevant for our context */ 769 if ((extctx & thisctx) == 0) 770 return 0; 771 772 /* Check if this extension is defined for our protocol. If not, skip */ 773 if (!extension_is_relevant(s, extctx, thisctx) 774 || ((extctx & SSL_EXT_TLS1_3_ONLY) != 0 775 && (thisctx & SSL_EXT_CLIENT_HELLO) != 0 776 && (SSL_IS_DTLS(s) || max_version < TLS1_3_VERSION))) 777 return 0; 778 779 return 1; 780 } 781 782 /* 783 * Construct all the extensions relevant to the current |context| and write 784 * them to |pkt|. If this is an extension for a Certificate in a Certificate 785 * message, then |x| will be set to the Certificate we are handling, and 786 * |chainidx| will indicate the position in the chainidx we are processing (with 787 * 0 being the first in the chain). Returns 1 on success or 0 on failure. On a 788 * failure construction stops at the first extension to fail to construct. 789 */ 790 int tls_construct_extensions(SSL *s, WPACKET *pkt, unsigned int context, 791 X509 *x, size_t chainidx) 792 { 793 size_t i; 794 int min_version, max_version = 0, reason; 795 const EXTENSION_DEFINITION *thisexd; 796 797 if (!WPACKET_start_sub_packet_u16(pkt) 798 /* 799 * If extensions are of zero length then we don't even add the 800 * extensions length bytes to a ClientHello/ServerHello 801 * (for non-TLSv1.3). 802 */ 803 || ((context & 804 (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0 805 && !WPACKET_set_flags(pkt, 806 WPACKET_FLAGS_ABANDON_ON_ZERO_LENGTH))) { 807 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_EXTENSIONS, 808 ERR_R_INTERNAL_ERROR); 809 return 0; 810 } 811 812 if ((context & SSL_EXT_CLIENT_HELLO) != 0) { 813 reason = ssl_get_min_max_version(s, &min_version, &max_version, NULL); 814 if (reason != 0) { 815 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_EXTENSIONS, 816 reason); 817 return 0; 818 } 819 } 820 821 /* Add custom extensions first */ 822 if ((context & SSL_EXT_CLIENT_HELLO) != 0) { 823 /* On the server side with initialise during ClientHello parsing */ 824 custom_ext_init(&s->cert->custext); 825 } 826 if (!custom_ext_add(s, context, pkt, x, chainidx, max_version)) { 827 /* SSLfatal() already called */ 828 return 0; 829 } 830 831 for (i = 0, thisexd = ext_defs; i < OSSL_NELEM(ext_defs); i++, thisexd++) { 832 EXT_RETURN (*construct)(SSL *s, WPACKET *pkt, unsigned int context, 833 X509 *x, size_t chainidx); 834 EXT_RETURN ret; 835 836 /* Skip if not relevant for our context */ 837 if (!should_add_extension(s, thisexd->context, context, max_version)) 838 continue; 839 840 construct = s->server ? thisexd->construct_stoc 841 : thisexd->construct_ctos; 842 843 if (construct == NULL) 844 continue; 845 846 ret = construct(s, pkt, context, x, chainidx); 847 if (ret == EXT_RETURN_FAIL) { 848 /* SSLfatal() already called */ 849 return 0; 850 } 851 if (ret == EXT_RETURN_SENT 852 && (context & (SSL_EXT_CLIENT_HELLO 853 | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST 854 | SSL_EXT_TLS1_3_NEW_SESSION_TICKET)) != 0) 855 s->ext.extflags[i] |= SSL_EXT_FLAG_SENT; 856 } 857 858 if (!WPACKET_close(pkt)) { 859 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_EXTENSIONS, 860 ERR_R_INTERNAL_ERROR); 861 return 0; 862 } 863 864 return 1; 865 } 866 867 /* 868 * Built in extension finalisation and initialisation functions. All initialise 869 * or finalise the associated extension type for the given |context|. For 870 * finalisers |sent| is set to 1 if we saw the extension during parsing, and 0 871 * otherwise. These functions return 1 on success or 0 on failure. 872 */ 873 874 static int final_renegotiate(SSL *s, unsigned int context, int sent) 875 { 876 if (!s->server) { 877 /* 878 * Check if we can connect to a server that doesn't support safe 879 * renegotiation 880 */ 881 if (!(s->options & SSL_OP_LEGACY_SERVER_CONNECT) 882 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION) 883 && !sent) { 884 SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_FINAL_RENEGOTIATE, 885 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED); 886 return 0; 887 } 888 889 return 1; 890 } 891 892 /* Need RI if renegotiating */ 893 if (s->renegotiate 894 && !(s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION) 895 && !sent) { 896 SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_FINAL_RENEGOTIATE, 897 SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED); 898 return 0; 899 } 900 901 902 return 1; 903 } 904 905 static int init_server_name(SSL *s, unsigned int context) 906 { 907 if (s->server) { 908 s->servername_done = 0; 909 910 OPENSSL_free(s->ext.hostname); 911 s->ext.hostname = NULL; 912 } 913 914 return 1; 915 } 916 917 static int final_server_name(SSL *s, unsigned int context, int sent) 918 { 919 int ret = SSL_TLSEXT_ERR_NOACK; 920 int altmp = SSL_AD_UNRECOGNIZED_NAME; 921 int was_ticket = (SSL_get_options(s) & SSL_OP_NO_TICKET) == 0; 922 923 if (!ossl_assert(s->ctx != NULL) || !ossl_assert(s->session_ctx != NULL)) { 924 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME, 925 ERR_R_INTERNAL_ERROR); 926 return 0; 927 } 928 929 if (s->ctx->ext.servername_cb != NULL) 930 ret = s->ctx->ext.servername_cb(s, &altmp, 931 s->ctx->ext.servername_arg); 932 else if (s->session_ctx->ext.servername_cb != NULL) 933 ret = s->session_ctx->ext.servername_cb(s, &altmp, 934 s->session_ctx->ext.servername_arg); 935 936 /* 937 * For servers, propagate the SNI hostname from the temporary 938 * storage in the SSL to the persistent SSL_SESSION, now that we 939 * know we accepted it. 940 * Clients make this copy when parsing the server's response to 941 * the extension, which is when they find out that the negotiation 942 * was successful. 943 */ 944 if (s->server) { 945 /* TODO(OpenSSL1.2) revisit !sent case */ 946 if (sent && ret == SSL_TLSEXT_ERR_OK && (!s->hit || SSL_IS_TLS13(s))) { 947 /* Only store the hostname in the session if we accepted it. */ 948 OPENSSL_free(s->session->ext.hostname); 949 s->session->ext.hostname = OPENSSL_strdup(s->ext.hostname); 950 if (s->session->ext.hostname == NULL && s->ext.hostname != NULL) { 951 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME, 952 ERR_R_INTERNAL_ERROR); 953 } 954 } 955 } 956 957 /* 958 * If we switched contexts (whether here or in the client_hello callback), 959 * move the sess_accept increment from the session_ctx to the new 960 * context, to avoid the confusing situation of having sess_accept_good 961 * exceed sess_accept (zero) for the new context. 962 */ 963 if (SSL_IS_FIRST_HANDSHAKE(s) && s->ctx != s->session_ctx) { 964 tsan_counter(&s->ctx->stats.sess_accept); 965 tsan_decr(&s->session_ctx->stats.sess_accept); 966 } 967 968 /* 969 * If we're expecting to send a ticket, and tickets were previously enabled, 970 * and now tickets are disabled, then turn off expected ticket. 971 * Also, if this is not a resumption, create a new session ID 972 */ 973 if (ret == SSL_TLSEXT_ERR_OK && s->ext.ticket_expected 974 && was_ticket && (SSL_get_options(s) & SSL_OP_NO_TICKET) != 0) { 975 s->ext.ticket_expected = 0; 976 if (!s->hit) { 977 SSL_SESSION* ss = SSL_get_session(s); 978 979 if (ss != NULL) { 980 OPENSSL_free(ss->ext.tick); 981 ss->ext.tick = NULL; 982 ss->ext.ticklen = 0; 983 ss->ext.tick_lifetime_hint = 0; 984 ss->ext.tick_age_add = 0; 985 ss->ext.tick_identity = 0; 986 if (!ssl_generate_session_id(s, ss)) { 987 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME, 988 ERR_R_INTERNAL_ERROR); 989 return 0; 990 } 991 } else { 992 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_SERVER_NAME, 993 ERR_R_INTERNAL_ERROR); 994 return 0; 995 } 996 } 997 } 998 999 switch (ret) { 1000 case SSL_TLSEXT_ERR_ALERT_FATAL: 1001 SSLfatal(s, altmp, SSL_F_FINAL_SERVER_NAME, SSL_R_CALLBACK_FAILED); 1002 return 0; 1003 1004 case SSL_TLSEXT_ERR_ALERT_WARNING: 1005 /* TLSv1.3 doesn't have warning alerts so we suppress this */ 1006 if (!SSL_IS_TLS13(s)) 1007 ssl3_send_alert(s, SSL3_AL_WARNING, altmp); 1008 return 1; 1009 1010 case SSL_TLSEXT_ERR_NOACK: 1011 s->servername_done = 0; 1012 return 1; 1013 1014 default: 1015 return 1; 1016 } 1017 } 1018 1019 #ifndef OPENSSL_NO_EC 1020 static int final_ec_pt_formats(SSL *s, unsigned int context, int sent) 1021 { 1022 unsigned long alg_k, alg_a; 1023 1024 if (s->server) 1025 return 1; 1026 1027 alg_k = s->s3->tmp.new_cipher->algorithm_mkey; 1028 alg_a = s->s3->tmp.new_cipher->algorithm_auth; 1029 1030 /* 1031 * If we are client and using an elliptic curve cryptography cipher 1032 * suite, then if server returns an EC point formats lists extension it 1033 * must contain uncompressed. 1034 */ 1035 if (s->ext.ecpointformats != NULL 1036 && s->ext.ecpointformats_len > 0 1037 && s->session->ext.ecpointformats != NULL 1038 && s->session->ext.ecpointformats_len > 0 1039 && ((alg_k & SSL_kECDHE) || (alg_a & SSL_aECDSA))) { 1040 /* we are using an ECC cipher */ 1041 size_t i; 1042 unsigned char *list = s->session->ext.ecpointformats; 1043 1044 for (i = 0; i < s->session->ext.ecpointformats_len; i++) { 1045 if (*list++ == TLSEXT_ECPOINTFORMAT_uncompressed) 1046 break; 1047 } 1048 if (i == s->session->ext.ecpointformats_len) { 1049 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_FINAL_EC_PT_FORMATS, 1050 SSL_R_TLS_INVALID_ECPOINTFORMAT_LIST); 1051 return 0; 1052 } 1053 } 1054 1055 return 1; 1056 } 1057 #endif 1058 1059 static int init_session_ticket(SSL *s, unsigned int context) 1060 { 1061 if (!s->server) 1062 s->ext.ticket_expected = 0; 1063 1064 return 1; 1065 } 1066 1067 #ifndef OPENSSL_NO_OCSP 1068 static int init_status_request(SSL *s, unsigned int context) 1069 { 1070 if (s->server) { 1071 s->ext.status_type = TLSEXT_STATUSTYPE_nothing; 1072 } else { 1073 /* 1074 * Ensure we get sensible values passed to tlsext_status_cb in the event 1075 * that we don't receive a status message 1076 */ 1077 OPENSSL_free(s->ext.ocsp.resp); 1078 s->ext.ocsp.resp = NULL; 1079 s->ext.ocsp.resp_len = 0; 1080 } 1081 1082 return 1; 1083 } 1084 #endif 1085 1086 #ifndef OPENSSL_NO_NEXTPROTONEG 1087 static int init_npn(SSL *s, unsigned int context) 1088 { 1089 s->s3->npn_seen = 0; 1090 1091 return 1; 1092 } 1093 #endif 1094 1095 static int init_alpn(SSL *s, unsigned int context) 1096 { 1097 OPENSSL_free(s->s3->alpn_selected); 1098 s->s3->alpn_selected = NULL; 1099 s->s3->alpn_selected_len = 0; 1100 if (s->server) { 1101 OPENSSL_free(s->s3->alpn_proposed); 1102 s->s3->alpn_proposed = NULL; 1103 s->s3->alpn_proposed_len = 0; 1104 } 1105 return 1; 1106 } 1107 1108 static int final_alpn(SSL *s, unsigned int context, int sent) 1109 { 1110 if (!s->server && !sent && s->session->ext.alpn_selected != NULL) 1111 s->ext.early_data_ok = 0; 1112 1113 if (!s->server || !SSL_IS_TLS13(s)) 1114 return 1; 1115 1116 /* 1117 * Call alpn_select callback if needed. Has to be done after SNI and 1118 * cipher negotiation (HTTP/2 restricts permitted ciphers). In TLSv1.3 1119 * we also have to do this before we decide whether to accept early_data. 1120 * In TLSv1.3 we've already negotiated our cipher so we do this call now. 1121 * For < TLSv1.3 we defer it until after cipher negotiation. 1122 * 1123 * On failure SSLfatal() already called. 1124 */ 1125 return tls_handle_alpn(s); 1126 } 1127 1128 static int init_sig_algs(SSL *s, unsigned int context) 1129 { 1130 /* Clear any signature algorithms extension received */ 1131 OPENSSL_free(s->s3->tmp.peer_sigalgs); 1132 s->s3->tmp.peer_sigalgs = NULL; 1133 1134 return 1; 1135 } 1136 1137 static int init_sig_algs_cert(SSL *s, unsigned int context) 1138 { 1139 /* Clear any signature algorithms extension received */ 1140 OPENSSL_free(s->s3->tmp.peer_cert_sigalgs); 1141 s->s3->tmp.peer_cert_sigalgs = NULL; 1142 1143 return 1; 1144 } 1145 1146 #ifndef OPENSSL_NO_SRP 1147 static int init_srp(SSL *s, unsigned int context) 1148 { 1149 OPENSSL_free(s->srp_ctx.login); 1150 s->srp_ctx.login = NULL; 1151 1152 return 1; 1153 } 1154 #endif 1155 1156 static int init_etm(SSL *s, unsigned int context) 1157 { 1158 s->ext.use_etm = 0; 1159 1160 return 1; 1161 } 1162 1163 static int init_ems(SSL *s, unsigned int context) 1164 { 1165 if (!s->server) 1166 s->s3->flags &= ~TLS1_FLAGS_RECEIVED_EXTMS; 1167 1168 return 1; 1169 } 1170 1171 static int final_ems(SSL *s, unsigned int context, int sent) 1172 { 1173 if (!s->server && s->hit) { 1174 /* 1175 * Check extended master secret extension is consistent with 1176 * original session. 1177 */ 1178 if (!(s->s3->flags & TLS1_FLAGS_RECEIVED_EXTMS) != 1179 !(s->session->flags & SSL_SESS_FLAG_EXTMS)) { 1180 SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_FINAL_EMS, 1181 SSL_R_INCONSISTENT_EXTMS); 1182 return 0; 1183 } 1184 } 1185 1186 return 1; 1187 } 1188 1189 static int init_certificate_authorities(SSL *s, unsigned int context) 1190 { 1191 sk_X509_NAME_pop_free(s->s3->tmp.peer_ca_names, X509_NAME_free); 1192 s->s3->tmp.peer_ca_names = NULL; 1193 return 1; 1194 } 1195 1196 static EXT_RETURN tls_construct_certificate_authorities(SSL *s, WPACKET *pkt, 1197 unsigned int context, 1198 X509 *x, 1199 size_t chainidx) 1200 { 1201 const STACK_OF(X509_NAME) *ca_sk = get_ca_names(s); 1202 1203 if (ca_sk == NULL || sk_X509_NAME_num(ca_sk) == 0) 1204 return EXT_RETURN_NOT_SENT; 1205 1206 if (!WPACKET_put_bytes_u16(pkt, TLSEXT_TYPE_certificate_authorities) 1207 || !WPACKET_start_sub_packet_u16(pkt)) { 1208 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 1209 SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES, 1210 ERR_R_INTERNAL_ERROR); 1211 return EXT_RETURN_FAIL; 1212 } 1213 1214 if (!construct_ca_names(s, ca_sk, pkt)) { 1215 /* SSLfatal() already called */ 1216 return EXT_RETURN_FAIL; 1217 } 1218 1219 if (!WPACKET_close(pkt)) { 1220 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 1221 SSL_F_TLS_CONSTRUCT_CERTIFICATE_AUTHORITIES, 1222 ERR_R_INTERNAL_ERROR); 1223 return EXT_RETURN_FAIL; 1224 } 1225 1226 return EXT_RETURN_SENT; 1227 } 1228 1229 static int tls_parse_certificate_authorities(SSL *s, PACKET *pkt, 1230 unsigned int context, X509 *x, 1231 size_t chainidx) 1232 { 1233 if (!parse_ca_names(s, pkt)) 1234 return 0; 1235 if (PACKET_remaining(pkt) != 0) { 1236 SSLfatal(s, SSL_AD_DECODE_ERROR, 1237 SSL_F_TLS_PARSE_CERTIFICATE_AUTHORITIES, SSL_R_BAD_EXTENSION); 1238 return 0; 1239 } 1240 return 1; 1241 } 1242 1243 #ifndef OPENSSL_NO_SRTP 1244 static int init_srtp(SSL *s, unsigned int context) 1245 { 1246 if (s->server) 1247 s->srtp_profile = NULL; 1248 1249 return 1; 1250 } 1251 #endif 1252 1253 static int final_sig_algs(SSL *s, unsigned int context, int sent) 1254 { 1255 if (!sent && SSL_IS_TLS13(s) && !s->hit) { 1256 SSLfatal(s, TLS13_AD_MISSING_EXTENSION, SSL_F_FINAL_SIG_ALGS, 1257 SSL_R_MISSING_SIGALGS_EXTENSION); 1258 return 0; 1259 } 1260 1261 return 1; 1262 } 1263 1264 #ifndef OPENSSL_NO_EC 1265 static int final_key_share(SSL *s, unsigned int context, int sent) 1266 { 1267 if (!SSL_IS_TLS13(s)) 1268 return 1; 1269 1270 /* Nothing to do for key_share in an HRR */ 1271 if ((context & SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST) != 0) 1272 return 1; 1273 1274 /* 1275 * If 1276 * we are a client 1277 * AND 1278 * we have no key_share 1279 * AND 1280 * (we are not resuming 1281 * OR the kex_mode doesn't allow non key_share resumes) 1282 * THEN 1283 * fail; 1284 */ 1285 if (!s->server 1286 && !sent 1287 && (!s->hit 1288 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0)) { 1289 /* Nothing left we can do - just fail */ 1290 SSLfatal(s, SSL_AD_MISSING_EXTENSION, SSL_F_FINAL_KEY_SHARE, 1291 SSL_R_NO_SUITABLE_KEY_SHARE); 1292 return 0; 1293 } 1294 /* 1295 * IF 1296 * we are a server 1297 * THEN 1298 * IF 1299 * we have a suitable key_share 1300 * THEN 1301 * IF 1302 * we are stateless AND we have no cookie 1303 * THEN 1304 * send a HelloRetryRequest 1305 * ELSE 1306 * IF 1307 * we didn't already send a HelloRetryRequest 1308 * AND 1309 * the client sent a key_share extension 1310 * AND 1311 * (we are not resuming 1312 * OR the kex_mode allows key_share resumes) 1313 * AND 1314 * a shared group exists 1315 * THEN 1316 * send a HelloRetryRequest 1317 * ELSE IF 1318 * we are not resuming 1319 * OR 1320 * the kex_mode doesn't allow non key_share resumes 1321 * THEN 1322 * fail 1323 * ELSE IF 1324 * we are stateless AND we have no cookie 1325 * THEN 1326 * send a HelloRetryRequest 1327 */ 1328 if (s->server) { 1329 if (s->s3->peer_tmp != NULL) { 1330 /* We have a suitable key_share */ 1331 if ((s->s3->flags & TLS1_FLAGS_STATELESS) != 0 1332 && !s->ext.cookieok) { 1333 if (!ossl_assert(s->hello_retry_request == SSL_HRR_NONE)) { 1334 /* 1335 * If we are stateless then we wouldn't know about any 1336 * previously sent HRR - so how can this be anything other 1337 * than 0? 1338 */ 1339 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_KEY_SHARE, 1340 ERR_R_INTERNAL_ERROR); 1341 return 0; 1342 } 1343 s->hello_retry_request = SSL_HRR_PENDING; 1344 return 1; 1345 } 1346 } else { 1347 /* No suitable key_share */ 1348 if (s->hello_retry_request == SSL_HRR_NONE && sent 1349 && (!s->hit 1350 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE_DHE) 1351 != 0)) { 1352 const uint16_t *pgroups, *clntgroups; 1353 size_t num_groups, clnt_num_groups, i; 1354 unsigned int group_id = 0; 1355 1356 /* Check if a shared group exists */ 1357 1358 /* Get the clients list of supported groups. */ 1359 tls1_get_peer_groups(s, &clntgroups, &clnt_num_groups); 1360 tls1_get_supported_groups(s, &pgroups, &num_groups); 1361 1362 /* 1363 * Find the first group we allow that is also in client's list 1364 */ 1365 for (i = 0; i < num_groups; i++) { 1366 group_id = pgroups[i]; 1367 1368 if (check_in_list(s, group_id, clntgroups, clnt_num_groups, 1369 1)) 1370 break; 1371 } 1372 1373 if (i < num_groups) { 1374 /* A shared group exists so send a HelloRetryRequest */ 1375 s->s3->group_id = group_id; 1376 s->hello_retry_request = SSL_HRR_PENDING; 1377 return 1; 1378 } 1379 } 1380 if (!s->hit 1381 || (s->ext.psk_kex_mode & TLSEXT_KEX_MODE_FLAG_KE) == 0) { 1382 /* Nothing left we can do - just fail */ 1383 SSLfatal(s, sent ? SSL_AD_HANDSHAKE_FAILURE 1384 : SSL_AD_MISSING_EXTENSION, 1385 SSL_F_FINAL_KEY_SHARE, SSL_R_NO_SUITABLE_KEY_SHARE); 1386 return 0; 1387 } 1388 1389 if ((s->s3->flags & TLS1_FLAGS_STATELESS) != 0 1390 && !s->ext.cookieok) { 1391 if (!ossl_assert(s->hello_retry_request == SSL_HRR_NONE)) { 1392 /* 1393 * If we are stateless then we wouldn't know about any 1394 * previously sent HRR - so how can this be anything other 1395 * than 0? 1396 */ 1397 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_KEY_SHARE, 1398 ERR_R_INTERNAL_ERROR); 1399 return 0; 1400 } 1401 s->hello_retry_request = SSL_HRR_PENDING; 1402 return 1; 1403 } 1404 } 1405 1406 /* 1407 * We have a key_share so don't send any more HelloRetryRequest 1408 * messages 1409 */ 1410 if (s->hello_retry_request == SSL_HRR_PENDING) 1411 s->hello_retry_request = SSL_HRR_COMPLETE; 1412 } else { 1413 /* 1414 * For a client side resumption with no key_share we need to generate 1415 * the handshake secret (otherwise this is done during key_share 1416 * processing). 1417 */ 1418 if (!sent && !tls13_generate_handshake_secret(s, NULL, 0)) { 1419 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_FINAL_KEY_SHARE, 1420 ERR_R_INTERNAL_ERROR); 1421 return 0; 1422 } 1423 } 1424 1425 return 1; 1426 } 1427 #endif 1428 1429 static int init_psk_kex_modes(SSL *s, unsigned int context) 1430 { 1431 s->ext.psk_kex_mode = TLSEXT_KEX_MODE_FLAG_NONE; 1432 return 1; 1433 } 1434 1435 int tls_psk_do_binder(SSL *s, const EVP_MD *md, const unsigned char *msgstart, 1436 size_t binderoffset, const unsigned char *binderin, 1437 unsigned char *binderout, SSL_SESSION *sess, int sign, 1438 int external) 1439 { 1440 EVP_PKEY *mackey = NULL; 1441 EVP_MD_CTX *mctx = NULL; 1442 unsigned char hash[EVP_MAX_MD_SIZE], binderkey[EVP_MAX_MD_SIZE]; 1443 unsigned char finishedkey[EVP_MAX_MD_SIZE], tmpbinder[EVP_MAX_MD_SIZE]; 1444 unsigned char *early_secret; 1445 static const unsigned char resumption_label[] = "res binder"; 1446 static const unsigned char external_label[] = "ext binder"; 1447 const unsigned char *label; 1448 size_t bindersize, labelsize, hashsize; 1449 int hashsizei = EVP_MD_size(md); 1450 int ret = -1; 1451 int usepskfored = 0; 1452 1453 /* Ensure cast to size_t is safe */ 1454 if (!ossl_assert(hashsizei >= 0)) { 1455 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, 1456 ERR_R_INTERNAL_ERROR); 1457 goto err; 1458 } 1459 hashsize = (size_t)hashsizei; 1460 1461 if (external 1462 && s->early_data_state == SSL_EARLY_DATA_CONNECTING 1463 && s->session->ext.max_early_data == 0 1464 && sess->ext.max_early_data > 0) 1465 usepskfored = 1; 1466 1467 if (external) { 1468 label = external_label; 1469 labelsize = sizeof(external_label) - 1; 1470 } else { 1471 label = resumption_label; 1472 labelsize = sizeof(resumption_label) - 1; 1473 } 1474 1475 /* 1476 * Generate the early_secret. On the server side we've selected a PSK to 1477 * resume with (internal or external) so we always do this. On the client 1478 * side we do this for a non-external (i.e. resumption) PSK or external PSK 1479 * that will be used for early_data so that it is in place for sending early 1480 * data. For client side external PSK not being used for early_data we 1481 * generate it but store it away for later use. 1482 */ 1483 if (s->server || !external || usepskfored) 1484 early_secret = (unsigned char *)s->early_secret; 1485 else 1486 early_secret = (unsigned char *)sess->early_secret; 1487 1488 if (!tls13_generate_secret(s, md, NULL, sess->master_key, 1489 sess->master_key_length, early_secret)) { 1490 /* SSLfatal() already called */ 1491 goto err; 1492 } 1493 1494 /* 1495 * Create the handshake hash for the binder key...the messages so far are 1496 * empty! 1497 */ 1498 mctx = EVP_MD_CTX_new(); 1499 if (mctx == NULL 1500 || EVP_DigestInit_ex(mctx, md, NULL) <= 0 1501 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { 1502 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, 1503 ERR_R_INTERNAL_ERROR); 1504 goto err; 1505 } 1506 1507 /* Generate the binder key */ 1508 if (!tls13_hkdf_expand(s, md, early_secret, label, labelsize, hash, 1509 hashsize, binderkey, hashsize)) { 1510 /* SSLfatal() already called */ 1511 goto err; 1512 } 1513 1514 /* Generate the finished key */ 1515 if (!tls13_derive_finishedkey(s, md, binderkey, finishedkey, hashsize)) { 1516 /* SSLfatal() already called */ 1517 goto err; 1518 } 1519 1520 if (EVP_DigestInit_ex(mctx, md, NULL) <= 0) { 1521 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, 1522 ERR_R_INTERNAL_ERROR); 1523 goto err; 1524 } 1525 1526 /* 1527 * Get a hash of the ClientHello up to the start of the binders. If we are 1528 * following a HelloRetryRequest then this includes the hash of the first 1529 * ClientHello and the HelloRetryRequest itself. 1530 */ 1531 if (s->hello_retry_request == SSL_HRR_PENDING) { 1532 size_t hdatalen; 1533 long hdatalen_l; 1534 void *hdata; 1535 1536 hdatalen = hdatalen_l = 1537 BIO_get_mem_data(s->s3->handshake_buffer, &hdata); 1538 if (hdatalen_l <= 0) { 1539 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, 1540 SSL_R_BAD_HANDSHAKE_LENGTH); 1541 goto err; 1542 } 1543 1544 /* 1545 * For servers the handshake buffer data will include the second 1546 * ClientHello - which we don't want - so we need to take that bit off. 1547 */ 1548 if (s->server) { 1549 PACKET hashprefix, msg; 1550 1551 /* Find how many bytes are left after the first two messages */ 1552 if (!PACKET_buf_init(&hashprefix, hdata, hdatalen) 1553 || !PACKET_forward(&hashprefix, 1) 1554 || !PACKET_get_length_prefixed_3(&hashprefix, &msg) 1555 || !PACKET_forward(&hashprefix, 1) 1556 || !PACKET_get_length_prefixed_3(&hashprefix, &msg)) { 1557 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, 1558 ERR_R_INTERNAL_ERROR); 1559 goto err; 1560 } 1561 hdatalen -= PACKET_remaining(&hashprefix); 1562 } 1563 1564 if (EVP_DigestUpdate(mctx, hdata, hdatalen) <= 0) { 1565 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, 1566 ERR_R_INTERNAL_ERROR); 1567 goto err; 1568 } 1569 } 1570 1571 if (EVP_DigestUpdate(mctx, msgstart, binderoffset) <= 0 1572 || EVP_DigestFinal_ex(mctx, hash, NULL) <= 0) { 1573 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, 1574 ERR_R_INTERNAL_ERROR); 1575 goto err; 1576 } 1577 1578 mackey = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, NULL, finishedkey, 1579 hashsize); 1580 if (mackey == NULL) { 1581 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, 1582 ERR_R_INTERNAL_ERROR); 1583 goto err; 1584 } 1585 1586 if (!sign) 1587 binderout = tmpbinder; 1588 1589 bindersize = hashsize; 1590 if (EVP_DigestSignInit(mctx, NULL, md, NULL, mackey) <= 0 1591 || EVP_DigestSignUpdate(mctx, hash, hashsize) <= 0 1592 || EVP_DigestSignFinal(mctx, binderout, &bindersize) <= 0 1593 || bindersize != hashsize) { 1594 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PSK_DO_BINDER, 1595 ERR_R_INTERNAL_ERROR); 1596 goto err; 1597 } 1598 1599 if (sign) { 1600 ret = 1; 1601 } else { 1602 /* HMAC keys can't do EVP_DigestVerify* - use CRYPTO_memcmp instead */ 1603 ret = (CRYPTO_memcmp(binderin, binderout, hashsize) == 0); 1604 if (!ret) 1605 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PSK_DO_BINDER, 1606 SSL_R_BINDER_DOES_NOT_VERIFY); 1607 } 1608 1609 err: 1610 OPENSSL_cleanse(binderkey, sizeof(binderkey)); 1611 OPENSSL_cleanse(finishedkey, sizeof(finishedkey)); 1612 EVP_PKEY_free(mackey); 1613 EVP_MD_CTX_free(mctx); 1614 1615 return ret; 1616 } 1617 1618 static int final_early_data(SSL *s, unsigned int context, int sent) 1619 { 1620 if (!sent) 1621 return 1; 1622 1623 if (!s->server) { 1624 if (context == SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS 1625 && sent 1626 && !s->ext.early_data_ok) { 1627 /* 1628 * If we get here then the server accepted our early_data but we 1629 * later realised that it shouldn't have done (e.g. inconsistent 1630 * ALPN) 1631 */ 1632 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_FINAL_EARLY_DATA, 1633 SSL_R_BAD_EARLY_DATA); 1634 return 0; 1635 } 1636 1637 return 1; 1638 } 1639 1640 if (s->max_early_data == 0 1641 || !s->hit 1642 || s->session->ext.tick_identity != 0 1643 || s->early_data_state != SSL_EARLY_DATA_ACCEPTING 1644 || !s->ext.early_data_ok 1645 || s->hello_retry_request != SSL_HRR_NONE 1646 || (s->ctx->allow_early_data_cb != NULL 1647 && !s->ctx->allow_early_data_cb(s, 1648 s->ctx->allow_early_data_cb_data))) { 1649 s->ext.early_data = SSL_EARLY_DATA_REJECTED; 1650 } else { 1651 s->ext.early_data = SSL_EARLY_DATA_ACCEPTED; 1652 1653 if (!tls13_change_cipher_state(s, 1654 SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_SERVER_READ)) { 1655 /* SSLfatal() already called */ 1656 return 0; 1657 } 1658 } 1659 1660 return 1; 1661 } 1662 1663 static int final_maxfragmentlen(SSL *s, unsigned int context, int sent) 1664 { 1665 /* 1666 * Session resumption on server-side with MFL extension active 1667 * BUT MFL extension packet was not resent (i.e. sent == 0) 1668 */ 1669 if (s->server && s->hit && USE_MAX_FRAGMENT_LENGTH_EXT(s->session) 1670 && !sent ) { 1671 SSLfatal(s, SSL_AD_MISSING_EXTENSION, SSL_F_FINAL_MAXFRAGMENTLEN, 1672 SSL_R_BAD_EXTENSION); 1673 return 0; 1674 } 1675 1676 /* Current SSL buffer is lower than requested MFL */ 1677 if (s->session && USE_MAX_FRAGMENT_LENGTH_EXT(s->session) 1678 && s->max_send_fragment < GET_MAX_FRAGMENT_LENGTH(s->session)) 1679 /* trigger a larger buffer reallocation */ 1680 if (!ssl3_setup_buffers(s)) { 1681 /* SSLfatal() already called */ 1682 return 0; 1683 } 1684 1685 return 1; 1686 } 1687 1688 static int init_post_handshake_auth(SSL *s, unsigned int context) 1689 { 1690 s->post_handshake_auth = SSL_PHA_NONE; 1691 1692 return 1; 1693 } 1694