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) 1998-2006 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 const SSL_METHOD *ssl23_get_server_method(int ver); 120int ssl23_get_client_hello(SSL *s); 121static const 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, 140 ssl23_get_server_method) 141 142int ssl23_accept(SSL *s) 143 { 144 BUF_MEM *buf; 145 unsigned long Time=(unsigned long)time(NULL); 146 void (*cb)(const SSL *ssl,int type,int val)=NULL; 147 int ret= -1; 148 int new_state,state; 149 150 RAND_add(&Time,sizeof(Time),0); 151 ERR_clear_error(); 152 clear_sys_error(); 153 154 if (s->info_callback != NULL) 155 cb=s->info_callback; 156 else if (s->ctx->info_callback != NULL) 157 cb=s->ctx->info_callback; 158 159 s->in_handshake++; 160 if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s); 161 162 for (;;) 163 { 164 state=s->state; 165 166 switch(s->state) 167 { 168 case SSL_ST_BEFORE: 169 case SSL_ST_ACCEPT: 170 case SSL_ST_BEFORE|SSL_ST_ACCEPT: 171 case SSL_ST_OK|SSL_ST_ACCEPT: 172 173 s->server=1; 174 if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1); 175 176 /* s->version=SSL3_VERSION; */ 177 s->type=SSL_ST_ACCEPT; 178 179 if (s->init_buf == NULL) 180 { 181 if ((buf=BUF_MEM_new()) == NULL) 182 { 183 ret= -1; 184 goto end; 185 } 186 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH)) 187 { 188 BUF_MEM_free(buf); 189 ret= -1; 190 goto end; 191 } 192 s->init_buf=buf; 193 } 194 195 ssl3_init_finished_mac(s); 196 197 s->state=SSL23_ST_SR_CLNT_HELLO_A; 198 s->ctx->stats.sess_accept++; 199 s->init_num=0; 200 break; 201 202 case SSL23_ST_SR_CLNT_HELLO_A: 203 case SSL23_ST_SR_CLNT_HELLO_B: 204 205 s->shutdown=0; 206 ret=ssl23_get_client_hello(s); 207 if (ret >= 0) cb=NULL; 208 goto end; 209 /* break; */ 210 211 default: 212 SSLerr(SSL_F_SSL23_ACCEPT,SSL_R_UNKNOWN_STATE); 213 ret= -1; 214 goto end; 215 /* break; */ 216 } 217 218 if ((cb != NULL) && (s->state != state)) 219 { 220 new_state=s->state; 221 s->state=state; 222 cb(s,SSL_CB_ACCEPT_LOOP,1); 223 s->state=new_state; 224 } 225 } 226end: 227 s->in_handshake--; 228 if (cb != NULL) 229 cb(s,SSL_CB_ACCEPT_EXIT,ret); 230 return(ret); 231 } 232 233 234int ssl23_get_client_hello(SSL *s) 235 { 236 char buf_space[11]; /* Request this many bytes in initial read. 237 * We can detect SSL 3.0/TLS 1.0 Client Hellos 238 * ('type == 3') correctly only when the following 239 * is in a single record, which is not guaranteed by 240 * the protocol specification: 241 * Byte Content 242 * 0 type \ 243 * 1/2 version > record header 244 * 3/4 length / 245 * 5 msg_type \ 246 * 6-8 length > Client Hello message 247 * 9/10 client_version / 248 */ 249 char *buf= &(buf_space[0]); 250 unsigned char *p,*d,*d_len,*dd; 251 unsigned int i; 252 unsigned int csl,sil,cl; 253 int n=0,j; 254 int type=0; 255 int v[2]; 256 257 if (s->state == SSL23_ST_SR_CLNT_HELLO_A) 258 { 259 /* read the initial header */ 260 v[0]=v[1]=0; 261 262 if (!ssl3_setup_buffers(s)) goto err; 263 264 n=ssl23_read_bytes(s, sizeof buf_space); 265 if (n != sizeof buf_space) return(n); /* n == -1 || n == 0 */ 266 267 p=s->packet; 268 269 memcpy(buf,p,n); 270 271 if ((p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO)) 272 { 273 /* 274 * SSLv2 header 275 */ 276 if ((p[3] == 0x00) && (p[4] == 0x02)) 277 { 278 v[0]=p[3]; v[1]=p[4]; 279 /* SSLv2 */ 280 if (!(s->options & SSL_OP_NO_SSLv2)) 281 type=1; 282 } 283 else if (p[3] == SSL3_VERSION_MAJOR) 284 { 285 v[0]=p[3]; v[1]=p[4]; 286 /* SSLv3/TLSv1 */ 287 if (p[4] >= TLS1_VERSION_MINOR) 288 { 289 if (!(s->options & SSL_OP_NO_TLSv1)) 290 { 291 s->version=TLS1_VERSION; 292 /* type=2; */ /* done later to survive restarts */ 293 s->state=SSL23_ST_SR_CLNT_HELLO_B; 294 } 295 else if (!(s->options & SSL_OP_NO_SSLv3)) 296 { 297 s->version=SSL3_VERSION; 298 /* type=2; */ 299 s->state=SSL23_ST_SR_CLNT_HELLO_B; 300 } 301 else if (!(s->options & SSL_OP_NO_SSLv2)) 302 { 303 type=1; 304 } 305 } 306 else if (!(s->options & SSL_OP_NO_SSLv3)) 307 { 308 s->version=SSL3_VERSION; 309 /* type=2; */ 310 s->state=SSL23_ST_SR_CLNT_HELLO_B; 311 } 312 else if (!(s->options & SSL_OP_NO_SSLv2)) 313 type=1; 314 315 } 316 } 317 else if ((p[0] == SSL3_RT_HANDSHAKE) && 318 (p[1] == SSL3_VERSION_MAJOR) && 319 (p[5] == SSL3_MT_CLIENT_HELLO) && 320 ((p[3] == 0 && p[4] < 5 /* silly record length? */) 321 || (p[9] >= p[1]))) 322 { 323 /* 324 * SSLv3 or tls1 header 325 */ 326 327 v[0]=p[1]; /* major version (= SSL3_VERSION_MAJOR) */ 328 /* We must look at client_version inside the Client Hello message 329 * to get the correct minor version. 330 * However if we have only a pathologically small fragment of the 331 * Client Hello message, this would be difficult, and we'd have 332 * to read more records to find out. 333 * No known SSL 3.0 client fragments ClientHello like this, 334 * so we simply reject such connections to avoid 335 * protocol version downgrade attacks. */ 336 if (p[3] == 0 && p[4] < 6) 337 { 338 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_SMALL); 339 goto err; 340 } 341 /* if major version number > 3 set minor to a value 342 * which will use the highest version 3 we support. 343 * If TLS 2.0 ever appears we will need to revise 344 * this.... 345 */ 346 if (p[9] > SSL3_VERSION_MAJOR) 347 v[1]=0xff; 348 else 349 v[1]=p[10]; /* minor version according to client_version */ 350 if (v[1] >= TLS1_VERSION_MINOR) 351 { 352 if (!(s->options & SSL_OP_NO_TLSv1)) 353 { 354 s->version=TLS1_VERSION; 355 type=3; 356 } 357 else if (!(s->options & SSL_OP_NO_SSLv3)) 358 { 359 s->version=SSL3_VERSION; 360 type=3; 361 } 362 } 363 else 364 { 365 /* client requests SSL 3.0 */ 366 if (!(s->options & SSL_OP_NO_SSLv3)) 367 { 368 s->version=SSL3_VERSION; 369 type=3; 370 } 371 else if (!(s->options & SSL_OP_NO_TLSv1)) 372 { 373 /* we won't be able to use TLS of course, 374 * but this will send an appropriate alert */ 375 s->version=TLS1_VERSION; 376 type=3; 377 } 378 } 379 } 380 else if ((strncmp("GET ", (char *)p,4) == 0) || 381 (strncmp("POST ",(char *)p,5) == 0) || 382 (strncmp("HEAD ",(char *)p,5) == 0) || 383 (strncmp("PUT ", (char *)p,4) == 0)) 384 { 385 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTP_REQUEST); 386 goto err; 387 } 388 else if (strncmp("CONNECT",(char *)p,7) == 0) 389 { 390 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTPS_PROXY_REQUEST); 391 goto err; 392 } 393 } 394 395 /* ensure that TLS_MAX_VERSION is up-to-date */ 396 OPENSSL_assert(s->version <= TLS_MAX_VERSION); 397 398 if (s->state == SSL23_ST_SR_CLNT_HELLO_B) 399 { 400 /* we have SSLv3/TLSv1 in an SSLv2 header 401 * (other cases skip this state) */ 402 403 type=2; 404 p=s->packet; 405 v[0] = p[3]; /* == SSL3_VERSION_MAJOR */ 406 v[1] = p[4]; 407 408 /* An SSLv3/TLSv1 backwards-compatible CLIENT-HELLO in an SSLv2 409 * header is sent directly on the wire, not wrapped as a TLS 410 * record. It's format is: 411 * Byte Content 412 * 0-1 msg_length 413 * 2 msg_type 414 * 3-4 version 415 * 5-6 cipher_spec_length 416 * 7-8 session_id_length 417 * 9-10 challenge_length 418 * ... ... 419 */ 420 n=((p[0]&0x7f)<<8)|p[1]; 421 if (n > (1024*4)) 422 { 423 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_LARGE); 424 goto err; 425 } 426 if (n < 9) 427 { 428 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_LENGTH_MISMATCH); 429 goto err; 430 } 431 432 j=ssl23_read_bytes(s,n+2); 433 /* We previously read 11 bytes, so if j > 0, we must have 434 * j == n+2 == s->packet_length. We have at least 11 valid 435 * packet bytes. */ 436 if (j <= 0) return(j); 437 438 ssl3_finish_mac(s, s->packet+2, s->packet_length-2); 439 if (s->msg_callback) 440 s->msg_callback(0, SSL2_VERSION, 0, s->packet+2, s->packet_length-2, s, s->msg_callback_arg); /* CLIENT-HELLO */ 441 442 p=s->packet; 443 p+=5; 444 n2s(p,csl); 445 n2s(p,sil); 446 n2s(p,cl); 447 d=(unsigned char *)s->init_buf->data; 448 if ((csl+sil+cl+11) != s->packet_length) /* We can't have TLS extensions in SSL 2.0 format 449 * Client Hello, can we? Error condition should be 450 * '>' otherweise */ 451 { 452 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_LENGTH_MISMATCH); 453 goto err; 454 } 455 456 /* record header: msg_type ... */ 457 *(d++) = SSL3_MT_CLIENT_HELLO; 458 /* ... and length (actual value will be written later) */ 459 d_len = d; 460 d += 3; 461 462 /* client_version */ 463 *(d++) = SSL3_VERSION_MAJOR; /* == v[0] */ 464 *(d++) = v[1]; 465 466 /* lets populate the random area */ 467 /* get the challenge_length */ 468 i=(cl > SSL3_RANDOM_SIZE)?SSL3_RANDOM_SIZE:cl; 469 memset(d,0,SSL3_RANDOM_SIZE); 470 memcpy(&(d[SSL3_RANDOM_SIZE-i]),&(p[csl+sil]),i); 471 d+=SSL3_RANDOM_SIZE; 472 473 /* no session-id reuse */ 474 *(d++)=0; 475 476 /* ciphers */ 477 j=0; 478 dd=d; 479 d+=2; 480 for (i=0; i<csl; i+=3) 481 { 482 if (p[i] != 0) continue; 483 *(d++)=p[i+1]; 484 *(d++)=p[i+2]; 485 j+=2; 486 } 487 s2n(j,dd); 488 489 /* COMPRESSION */ 490 *(d++)=1; 491 *(d++)=0; 492 493#if 0 494 /* copy any remaining data with may be extensions */ 495 p = p+csl+sil+cl; 496 while (p < s->packet+s->packet_length) 497 { 498 *(d++)=*(p++); 499 } 500#endif 501 502 i = (d-(unsigned char *)s->init_buf->data) - 4; 503 l2n3((long)i, d_len); 504 505 /* get the data reused from the init_buf */ 506 s->s3->tmp.reuse_message=1; 507 s->s3->tmp.message_type=SSL3_MT_CLIENT_HELLO; 508 s->s3->tmp.message_size=i; 509 } 510 511 /* imaginary new state (for program structure): */ 512 /* s->state = SSL23_SR_CLNT_HELLO_C */ 513 514 if (type == 1) 515 { 516#ifdef OPENSSL_NO_SSL2 517 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNSUPPORTED_PROTOCOL); 518 goto err; 519#else 520 /* we are talking sslv2 */ 521 /* we need to clean up the SSLv3/TLSv1 setup and put in the 522 * sslv2 stuff. */ 523 524 if (s->s2 == NULL) 525 { 526 if (!ssl2_new(s)) 527 goto err; 528 } 529 else 530 ssl2_clear(s); 531 532 if (s->s3 != NULL) ssl3_free(s); 533 534 if (!BUF_MEM_grow_clean(s->init_buf, 535 SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)) 536 { 537 goto err; 538 } 539 540 s->state=SSL2_ST_GET_CLIENT_HELLO_A; 541 if (s->options & SSL_OP_NO_TLSv1 && s->options & SSL_OP_NO_SSLv3) 542 s->s2->ssl2_rollback=0; 543 else 544 /* reject SSL 2.0 session if client supports SSL 3.0 or TLS 1.0 545 * (SSL 3.0 draft/RFC 2246, App. E.2) */ 546 s->s2->ssl2_rollback=1; 547 548 /* setup the n bytes we have read so we get them from 549 * the sslv2 buffer */ 550 s->rstate=SSL_ST_READ_HEADER; 551 s->packet_length=n; 552 s->packet= &(s->s2->rbuf[0]); 553 memcpy(s->packet,buf,n); 554 s->s2->rbuf_left=n; 555 s->s2->rbuf_offs=0; 556 557 s->method=SSLv2_server_method(); 558 s->handshake_func=s->method->ssl_accept; 559#endif 560 } 561 562 if ((type == 2) || (type == 3)) 563 { 564 /* we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style) */ 565 const SSL_METHOD *new_method; 566 new_method = ssl23_get_server_method(s->version); 567 if (new_method == NULL) 568 { 569 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNSUPPORTED_PROTOCOL); 570 goto err; 571 } 572 s->method = new_method; 573 574 if (!ssl_init_wbio_buffer(s,1)) goto err; 575 576 /* we are in this state */ 577 s->state=SSL3_ST_SR_CLNT_HELLO_A; 578 579 if (type == 3) 580 { 581 /* put the 'n' bytes we have read into the input buffer 582 * for SSLv3 */ 583 s->rstate=SSL_ST_READ_HEADER; 584 s->packet_length=n; 585 if (s->s3->rbuf.buf == NULL) 586 if (!ssl3_setup_read_buffer(s)) 587 goto err; 588 589 s->packet= &(s->s3->rbuf.buf[0]); 590 memcpy(s->packet,buf,n); 591 s->s3->rbuf.left=n; 592 s->s3->rbuf.offset=0; 593 } 594 else 595 { 596 s->packet_length=0; 597 s->s3->rbuf.left=0; 598 s->s3->rbuf.offset=0; 599 } 600#if 0 /* ssl3_get_client_hello does this */ 601 s->client_version=(v[0]<<8)|v[1]; 602#endif 603 s->handshake_func=s->method->ssl_accept; 604 } 605 606 if ((type < 1) || (type > 3)) 607 { 608 /* bad, very bad */ 609 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNKNOWN_PROTOCOL); 610 goto err; 611 } 612 s->init_num=0; 613 614 if (buf != buf_space) OPENSSL_free(buf); 615 return(SSL_accept(s)); 616err: 617 if (buf != buf_space) OPENSSL_free(buf); 618 return(-1); 619 } 620