s23_srvr.c revision 296465
1/* ssl/s23_srvr.c */ 2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay@cryptsoft.com). 7 * The implementation was written so as to conform with Netscapes SSL. 8 * 9 * This library is free for commercial and non-commercial use as long as 10 * the following conditions are aheared to. The following conditions 11 * apply to all code found in this distribution, be it the RC4, RSA, 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13 * included with this distribution is covered by the same copyright terms 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15 * 16 * Copyright remains Eric Young's, and as such any Copyright notices in 17 * the code are not to be removed. 18 * If this package is used in a product, Eric Young should be given attribution 19 * as the author of the parts of the library used. 20 * This can be in the form of a textual message at program startup or 21 * in documentation (online or textual) provided with the package. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 3. All advertising materials mentioning features or use of this software 32 * must display the following acknowledgement: 33 * "This product includes cryptographic software written by 34 * Eric Young (eay@cryptsoft.com)" 35 * The word 'cryptographic' can be left out if the rouines from the library 36 * being used are not cryptographic related :-). 37 * 4. If you include any Windows specific code (or a derivative thereof) from 38 * the apps directory (application code) you must include an acknowledgement: 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40 * 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 * SUCH DAMAGE. 52 * 53 * The licence and distribution terms for any publically available version or 54 * derivative of this code cannot be changed. i.e. this code cannot simply be 55 * copied and put under another distribution licence 56 * [including the GNU Public Licence.] 57 */ 58/* ==================================================================== 59 * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved. 60 * 61 * Redistribution and use in source and binary forms, with or without 62 * modification, are permitted provided that the following conditions 63 * are met: 64 * 65 * 1. Redistributions of source code must retain the above copyright 66 * notice, this list of conditions and the following disclaimer. 67 * 68 * 2. Redistributions in binary form must reproduce the above copyright 69 * notice, this list of conditions and the following disclaimer in 70 * the documentation and/or other materials provided with the 71 * distribution. 72 * 73 * 3. All advertising materials mentioning features or use of this 74 * software must display the following acknowledgment: 75 * "This product includes software developed by the OpenSSL Project 76 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 77 * 78 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 79 * endorse or promote products derived from this software without 80 * prior written permission. For written permission, please contact 81 * openssl-core@openssl.org. 82 * 83 * 5. Products derived from this software may not be called "OpenSSL" 84 * nor may "OpenSSL" appear in their names without prior written 85 * permission of the OpenSSL Project. 86 * 87 * 6. Redistributions of any form whatsoever must retain the following 88 * acknowledgment: 89 * "This product includes software developed by the OpenSSL Project 90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 91 * 92 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 93 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 94 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 95 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 96 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 97 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 98 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 99 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 101 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 102 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 103 * OF THE POSSIBILITY OF SUCH DAMAGE. 104 * ==================================================================== 105 * 106 * This product includes cryptographic software written by Eric Young 107 * (eay@cryptsoft.com). This product includes software written by Tim 108 * Hudson (tjh@cryptsoft.com). 109 * 110 */ 111 112#include <stdio.h> 113#include "ssl_locl.h" 114#include <openssl/buffer.h> 115#include <openssl/rand.h> 116#include <openssl/objects.h> 117#include <openssl/evp.h> 118 119static SSL_METHOD *ssl23_get_server_method(int ver); 120int ssl23_get_client_hello(SSL *s); 121static SSL_METHOD *ssl23_get_server_method(int ver) 122{ 123#ifndef OPENSSL_NO_SSL2 124 if (ver == SSL2_VERSION) 125 return (SSLv2_server_method()); 126#endif 127#ifndef OPENSSL_NO_SSL3 128 if (ver == SSL3_VERSION) 129 return (SSLv3_server_method()); 130#endif 131 if (ver == TLS1_VERSION) 132 return (TLSv1_server_method()); 133 else 134 return (NULL); 135} 136 137IMPLEMENT_ssl23_meth_func(SSLv23_server_method, 138 ssl23_accept, 139 ssl_undefined_function, ssl23_get_server_method) 140 141int ssl23_accept(SSL *s) 142{ 143 BUF_MEM *buf; 144 unsigned long Time = (unsigned long)time(NULL); 145 void (*cb) (const SSL *ssl, int type, int val) = NULL; 146 int ret = -1; 147 int new_state, state; 148 149 RAND_add(&Time, sizeof(Time), 0); 150 ERR_clear_error(); 151 clear_sys_error(); 152 153 if (s->info_callback != NULL) 154 cb = s->info_callback; 155 else if (s->ctx->info_callback != NULL) 156 cb = s->ctx->info_callback; 157 158 s->in_handshake++; 159 if (!SSL_in_init(s) || SSL_in_before(s)) 160 SSL_clear(s); 161 162 for (;;) { 163 state = s->state; 164 165 switch (s->state) { 166 case SSL_ST_BEFORE: 167 case SSL_ST_ACCEPT: 168 case SSL_ST_BEFORE | SSL_ST_ACCEPT: 169 case SSL_ST_OK | SSL_ST_ACCEPT: 170 171 s->server = 1; 172 if (cb != NULL) 173 cb(s, SSL_CB_HANDSHAKE_START, 1); 174 175 /* s->version=SSL3_VERSION; */ 176 s->type = SSL_ST_ACCEPT; 177 178 if (s->init_buf == NULL) { 179 if ((buf = BUF_MEM_new()) == NULL) { 180 ret = -1; 181 goto end; 182 } 183 if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) { 184 ret = -1; 185 goto end; 186 } 187 s->init_buf = buf; 188 } 189 190 ssl3_init_finished_mac(s); 191 192 s->state = SSL23_ST_SR_CLNT_HELLO_A; 193 s->ctx->stats.sess_accept++; 194 s->init_num = 0; 195 break; 196 197 case SSL23_ST_SR_CLNT_HELLO_A: 198 case SSL23_ST_SR_CLNT_HELLO_B: 199 200 s->shutdown = 0; 201 ret = ssl23_get_client_hello(s); 202 if (ret >= 0) 203 cb = NULL; 204 goto end; 205 /* break; */ 206 207 default: 208 SSLerr(SSL_F_SSL23_ACCEPT, SSL_R_UNKNOWN_STATE); 209 ret = -1; 210 goto end; 211 /* break; */ 212 } 213 214 if ((cb != NULL) && (s->state != state)) { 215 new_state = s->state; 216 s->state = state; 217 cb(s, SSL_CB_ACCEPT_LOOP, 1); 218 s->state = new_state; 219 } 220 } 221 end: 222 s->in_handshake--; 223 if (cb != NULL) 224 cb(s, SSL_CB_ACCEPT_EXIT, ret); 225 return (ret); 226} 227 228int ssl23_get_client_hello(SSL *s) 229{ 230 /*- 231 * Request this many bytes in initial read. 232 * We can detect SSL 3.0/TLS 1.0 Client Hellos 233 * ('type == 3') correctly only when the following 234 * is in a single record, which is not guaranteed by 235 * the protocol specification: 236 * Byte Content 237 * 0 type \ 238 * 1/2 version > record header 239 * 3/4 length / 240 * 5 msg_type \ 241 * 6-8 length > Client Hello message 242 * 9/10 client_version / 243 */ 244 char buf_space[11]; 245 char *buf = &(buf_space[0]); 246 unsigned char *p, *d, *d_len, *dd; 247 unsigned int i; 248 unsigned int csl, sil, cl; 249 int n = 0, j; 250 int type = 0; 251 int v[2]; 252 253 if (s->state == SSL23_ST_SR_CLNT_HELLO_A) { 254 /* read the initial header */ 255 v[0] = v[1] = 0; 256 257 if (!ssl3_setup_buffers(s)) 258 goto err; 259 260 n = ssl23_read_bytes(s, sizeof buf_space); 261 if (n != sizeof buf_space) 262 return (n); /* n == -1 || n == 0 */ 263 264 p = s->packet; 265 266 memcpy(buf, p, n); 267 268 if ((p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO)) { 269 /* 270 * SSLv2 header 271 */ 272 if ((p[3] == 0x00) && (p[4] == 0x02)) { 273 v[0] = p[3]; 274 v[1] = p[4]; 275 /* SSLv2 */ 276 if (!(s->options & SSL_OP_NO_SSLv2)) 277 type = 1; 278 } else if (p[3] == SSL3_VERSION_MAJOR) { 279 v[0] = p[3]; 280 v[1] = p[4]; 281 /* SSLv3/TLSv1 */ 282 if (p[4] >= TLS1_VERSION_MINOR) { 283 if (!(s->options & SSL_OP_NO_TLSv1)) { 284 s->version = TLS1_VERSION; 285 /* 286 * type=2; 287 *//* 288 * done later to survive restarts 289 */ 290 s->state = SSL23_ST_SR_CLNT_HELLO_B; 291 } else if (!(s->options & SSL_OP_NO_SSLv3)) { 292 s->version = SSL3_VERSION; 293 /* type=2; */ 294 s->state = SSL23_ST_SR_CLNT_HELLO_B; 295 } else if (!(s->options & SSL_OP_NO_SSLv2)) { 296 type = 1; 297 } 298 } else if (!(s->options & SSL_OP_NO_SSLv3)) { 299 s->version = SSL3_VERSION; 300 /* type=2; */ 301 s->state = SSL23_ST_SR_CLNT_HELLO_B; 302 } else if (!(s->options & SSL_OP_NO_SSLv2)) 303 type = 1; 304 305 } 306 } 307 /* p[4] < 5 ... silly record length? */ 308 else if ((p[0] == SSL3_RT_HANDSHAKE) && 309 (p[1] == SSL3_VERSION_MAJOR) && 310 (p[5] == SSL3_MT_CLIENT_HELLO) && ((p[3] == 0 && p[4] < 5) 311 || (p[9] >= p[1]))) { 312 /* 313 * SSLv3 or tls1 header 314 */ 315 316 v[0] = p[1]; /* major version (= SSL3_VERSION_MAJOR) */ 317 /* 318 * We must look at client_version inside the Client Hello message 319 * to get the correct minor version. However if we have only a 320 * pathologically small fragment of the Client Hello message, this 321 * would be difficult, and we'd have to read more records to find 322 * out. No known SSL 3.0 client fragments ClientHello like this, 323 * so we simply reject such connections to avoid protocol version 324 * downgrade attacks. 325 */ 326 if (p[3] == 0 && p[4] < 6) { 327 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_RECORD_TOO_SMALL); 328 goto err; 329 } 330 /* 331 * if major version number > 3 set minor to a value which will 332 * use the highest version 3 we support. If TLS 2.0 ever appears 333 * we will need to revise this.... 334 */ 335 if (p[9] > SSL3_VERSION_MAJOR) 336 v[1] = 0xff; 337 else 338 v[1] = p[10]; /* minor version according to client_version */ 339 if (v[1] >= TLS1_VERSION_MINOR) { 340 if (!(s->options & SSL_OP_NO_TLSv1)) { 341 s->version = TLS1_VERSION; 342 type = 3; 343 } else if (!(s->options & SSL_OP_NO_SSLv3)) { 344 s->version = SSL3_VERSION; 345 type = 3; 346 } 347 } else { 348 /* client requests SSL 3.0 */ 349 if (!(s->options & SSL_OP_NO_SSLv3)) { 350 s->version = SSL3_VERSION; 351 type = 3; 352 } else if (!(s->options & SSL_OP_NO_TLSv1)) { 353 /* 354 * we won't be able to use TLS of course, but this will 355 * send an appropriate alert 356 */ 357 s->version = TLS1_VERSION; 358 type = 3; 359 } 360 } 361 } else if ((strncmp("GET ", (char *)p, 4) == 0) || 362 (strncmp("POST ", (char *)p, 5) == 0) || 363 (strncmp("HEAD ", (char *)p, 5) == 0) || 364 (strncmp("PUT ", (char *)p, 4) == 0)) { 365 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_HTTP_REQUEST); 366 goto err; 367 } else if (strncmp("CONNECT", (char *)p, 7) == 0) { 368 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_HTTPS_PROXY_REQUEST); 369 goto err; 370 } 371 } 372#ifdef OPENSSL_FIPS 373 if (FIPS_mode() && (s->version < TLS1_VERSION)) { 374 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, 375 SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE); 376 goto err; 377 } 378#endif 379 380 /* ensure that TLS_MAX_VERSION is up-to-date */ 381 OPENSSL_assert(s->version <= TLS_MAX_VERSION); 382 383 if (s->state == SSL23_ST_SR_CLNT_HELLO_B) { 384 /* 385 * we have SSLv3/TLSv1 in an SSLv2 header (other cases skip this 386 * state) 387 */ 388 389 type = 2; 390 p = s->packet; 391 v[0] = p[3]; /* == SSL3_VERSION_MAJOR */ 392 v[1] = p[4]; 393 394 /*- 395 * An SSLv3/TLSv1 backwards-compatible CLIENT-HELLO in an SSLv2 396 * header is sent directly on the wire, not wrapped as a TLS 397 * record. It's format is: 398 * Byte Content 399 * 0-1 msg_length 400 * 2 msg_type 401 * 3-4 version 402 * 5-6 cipher_spec_length 403 * 7-8 session_id_length 404 * 9-10 challenge_length 405 * ... ... 406 */ 407 n = ((p[0] & 0x7f) << 8) | p[1]; 408 if (n > (1024 * 4)) { 409 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_RECORD_TOO_LARGE); 410 goto err; 411 } 412 if (n < 9) { 413 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, 414 SSL_R_RECORD_LENGTH_MISMATCH); 415 goto err; 416 } 417 418 j = ssl23_read_bytes(s, n + 2); 419 /* 420 * We previously read 11 bytes, so if j > 0, we must have j == n+2 == 421 * s->packet_length. We have at least 11 valid packet bytes. 422 */ 423 if (j <= 0) 424 return (j); 425 426 ssl3_finish_mac(s, s->packet + 2, s->packet_length - 2); 427 428 /* CLIENT-HELLO */ 429 if (s->msg_callback) 430 s->msg_callback(0, SSL2_VERSION, 0, s->packet + 2, 431 s->packet_length - 2, s, s->msg_callback_arg); 432 433 p = s->packet; 434 p += 5; 435 n2s(p, csl); 436 n2s(p, sil); 437 n2s(p, cl); 438 d = (unsigned char *)s->init_buf->data; 439 if ((csl + sil + cl + 11) != s->packet_length) { 440 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, 441 SSL_R_RECORD_LENGTH_MISMATCH); 442 goto err; 443 } 444 445 /* record header: msg_type ... */ 446 *(d++) = SSL3_MT_CLIENT_HELLO; 447 /* ... and length (actual value will be written later) */ 448 d_len = d; 449 d += 3; 450 451 /* client_version */ 452 *(d++) = SSL3_VERSION_MAJOR; /* == v[0] */ 453 *(d++) = v[1]; 454 455 /* lets populate the random area */ 456 /* get the challenge_length */ 457 i = (cl > SSL3_RANDOM_SIZE) ? SSL3_RANDOM_SIZE : cl; 458 memset(d, 0, SSL3_RANDOM_SIZE); 459 memcpy(&(d[SSL3_RANDOM_SIZE - i]), &(p[csl + sil]), i); 460 d += SSL3_RANDOM_SIZE; 461 462 /* no session-id reuse */ 463 *(d++) = 0; 464 465 /* ciphers */ 466 j = 0; 467 dd = d; 468 d += 2; 469 for (i = 0; i < csl; i += 3) { 470 if (p[i] != 0) 471 continue; 472 *(d++) = p[i + 1]; 473 *(d++) = p[i + 2]; 474 j += 2; 475 } 476 s2n(j, dd); 477 478 /* COMPRESSION */ 479 *(d++) = 1; 480 *(d++) = 0; 481 482 i = (d - (unsigned char *)s->init_buf->data) - 4; 483 l2n3((long)i, d_len); 484 485 /* get the data reused from the init_buf */ 486 s->s3->tmp.reuse_message = 1; 487 s->s3->tmp.message_type = SSL3_MT_CLIENT_HELLO; 488 s->s3->tmp.message_size = i; 489 } 490 491 /* imaginary new state (for program structure): */ 492 /* s->state = SSL23_SR_CLNT_HELLO_C */ 493 494 if (type == 1) { 495#ifdef OPENSSL_NO_SSL2 496 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNSUPPORTED_PROTOCOL); 497 goto err; 498#else 499 /* we are talking sslv2 */ 500 /* 501 * we need to clean up the SSLv3/TLSv1 setup and put in the sslv2 502 * stuff. 503 */ 504 505 if (s->s2 == NULL) { 506 if (!ssl2_new(s)) 507 goto err; 508 } else 509 ssl2_clear(s); 510 511 if (s->s3 != NULL) 512 ssl3_free(s); 513 514 if (!BUF_MEM_grow_clean(s->init_buf, 515 SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)) { 516 goto err; 517 } 518 519 s->state = SSL2_ST_GET_CLIENT_HELLO_A; 520 if (s->options & SSL_OP_NO_TLSv1 && s->options & SSL_OP_NO_SSLv3) 521 s->s2->ssl2_rollback = 0; 522 else 523 /* 524 * reject SSL 2.0 session if client supports SSL 3.0 or TLS 1.0 525 * (SSL 3.0 draft/RFC 2246, App. E.2) 526 */ 527 s->s2->ssl2_rollback = 1; 528 529 /* 530 * setup the n bytes we have read so we get them from the sslv2 531 * buffer 532 */ 533 s->rstate = SSL_ST_READ_HEADER; 534 s->packet_length = n; 535 s->packet = &(s->s2->rbuf[0]); 536 memcpy(s->packet, buf, n); 537 s->s2->rbuf_left = n; 538 s->s2->rbuf_offs = 0; 539 540 s->method = SSLv2_server_method(); 541 s->handshake_func = s->method->ssl_accept; 542#endif 543 } 544 545 if ((type == 2) || (type == 3)) { 546 /* 547 * we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style) 548 */ 549 SSL_METHOD *new_method; 550 new_method = ssl23_get_server_method(s->version); 551 if (new_method == NULL) { 552 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNSUPPORTED_PROTOCOL); 553 goto err; 554 } 555 s->method = new_method; 556 557 if (!ssl_init_wbio_buffer(s, 1)) 558 goto err; 559 560 /* we are in this state */ 561 s->state = SSL3_ST_SR_CLNT_HELLO_A; 562 563 if (type == 3) { 564 /* 565 * put the 'n' bytes we have read into the input buffer for SSLv3 566 */ 567 s->rstate = SSL_ST_READ_HEADER; 568 s->packet_length = n; 569 s->packet = &(s->s3->rbuf.buf[0]); 570 memcpy(s->packet, buf, n); 571 s->s3->rbuf.left = n; 572 s->s3->rbuf.offset = 0; 573 } else { 574 s->packet_length = 0; 575 s->s3->rbuf.left = 0; 576 s->s3->rbuf.offset = 0; 577 } 578#if 0 /* ssl3_get_client_hello does this */ 579 s->client_version = (v[0] << 8) | v[1]; 580#endif 581 s->handshake_func = s->method->ssl_accept; 582 } 583 584 if ((type < 1) || (type > 3)) { 585 /* bad, very bad */ 586 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL); 587 goto err; 588 } 589 s->init_num = 0; 590 591 if (buf != buf_space) 592 OPENSSL_free(buf); 593 return (SSL_accept(s)); 594 err: 595 if (buf != buf_space) 596 OPENSSL_free(buf); 597 return (-1); 598} 599