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 #ifdef OPENSSL_FIPS
 119 #include <openssl/fips.h>
 120 #endif
 121 
 122 static const SSL_METHOD *ssl23_get_server_method(int ver);
 123 int ssl23_get_client_hello(SSL *s);
 124 static const SSL_METHOD *ssl23_get_server_method(int ver)
 125         {
 126 #ifndef OPENSSL_NO_SSL2
 127         if (ver == SSL2_VERSION)
 128                 return(SSLv2_server_method());
 129 #endif
 130         if (ver == SSL3_VERSION)
 131                 return(SSLv3_server_method());
 132         else if (ver == TLS1_VERSION)
 133                 return(TLSv1_server_method());
 134         else if (ver == TLS1_1_VERSION)
 135                 return(TLSv1_1_server_method());
 136         else if (ver == TLS1_2_VERSION)
 137                 return(TLSv1_2_server_method());
 138         else
 139                 return(NULL);
 140         }
 141 
 142 IMPLEMENT_ssl23_meth_func(SSLv23_server_method,
 143                         ssl23_accept,
 144                         ssl_undefined_function,
 145                         ssl23_get_server_method)
 146 
 147 int ssl23_accept(SSL *s)
 148         {
 149         BUF_MEM *buf;
 150         unsigned long Time=(unsigned long)time(NULL);
 151         void (*cb)(const SSL *ssl,int type,int val)=NULL;
 152         int ret= -1;
 153         int new_state,state;
 154 
 155         RAND_add(&Time,sizeof(Time),0);
 156         ERR_clear_error();
 157         clear_sys_error();
 158 
 159         if (s->info_callback != NULL)
 160                 cb=s->info_callback;
 161         else if (s->ctx->info_callback != NULL)
 162                 cb=s->ctx->info_callback;
 163 
 164         s->in_handshake++;
 165         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
 166 
 167         for (;;)
 168                 {
 169                 state=s->state;
 170 
 171                 switch(s->state)
 172                         {
 173                 case SSL_ST_BEFORE:
 174                 case SSL_ST_ACCEPT:
 175                 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
 176                 case SSL_ST_OK|SSL_ST_ACCEPT:
 177 
 178                         s->server=1;
 179                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
 180 
 181                         /* s->version=SSL3_VERSION; */
 182                         s->type=SSL_ST_ACCEPT;
 183 
 184                         if (s->init_buf == NULL)
 185                                 {
 186                                 if ((buf=BUF_MEM_new()) == NULL)
 187                                         {
 188                                         ret= -1;
 189                                         goto end;
 190                                         }
 191                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
 192                                         {
 193                                         ret= -1;
 194                                         goto end;
 195                                         }
 196                                 s->init_buf=buf;
 197                                 }
 198 
 199                         ssl3_init_finished_mac(s);
 200 
 201                         s->state=SSL23_ST_SR_CLNT_HELLO_A;
 202                         s->ctx->stats.sess_accept++;
 203                         s->init_num=0;
 204                         break;
 205 
 206                 case SSL23_ST_SR_CLNT_HELLO_A:
 207                 case SSL23_ST_SR_CLNT_HELLO_B:
 208 
 209                         s->shutdown=0;
 210                         ret=ssl23_get_client_hello(s);
 211                         if (ret >= 0) cb=NULL;
 212                         goto end;
 213                         /* break; */
 214 
 215                 default:
 216                         SSLerr(SSL_F_SSL23_ACCEPT,SSL_R_UNKNOWN_STATE);
 217                         ret= -1;
 218                         goto end;
 219                         /* break; */
 220                         }
 221 
 222                 if ((cb != NULL) && (s->state != state))
 223                         {
 224                         new_state=s->state;
 225                         s->state=state;
 226                         cb(s,SSL_CB_ACCEPT_LOOP,1);
 227                         s->state=new_state;
 228                         }
 229                 }
 230 end:
 231         s->in_handshake--;
 232         if (cb != NULL)
 233                 cb(s,SSL_CB_ACCEPT_EXIT,ret);
 234         return(ret);
 235         }
 236 
 237 
 238 int ssl23_get_client_hello(SSL *s)
 239         {
 240         char buf_space[11]; /* Request this many bytes in initial read.
 241                              * We can detect SSL 3.0/TLS 1.0 Client Hellos
 242                              * ('type == 3') correctly only when the following
 243                              * is in a single record, which is not guaranteed by
 244                              * the protocol specification:
 245                              * Byte  Content
 246                              *  0     type            \
 247                              *  1/2   version          > record header
 248                              *  3/4   length          /
 249                              *  5     msg_type        \
 250                              *  6-8   length           > Client Hello message
 251                              *  9/10  client_version  /
 252                              */
 253         char *buf= &(buf_space[0]);
 254         unsigned char *p,*d,*d_len,*dd;
 255         unsigned int i;
 256         unsigned int csl,sil,cl;
 257         int n=0,j;
 258         int type=0;
 259         int v[2];
 260 
 261         if (s->state ==      SSL23_ST_SR_CLNT_HELLO_A)
 262                 {
 263                 /* read the initial header */
 264                 v[0]=v[1]=0;
 265 
 266                 if (!ssl3_setup_buffers(s)) goto err;
 267 
 268                 n=ssl23_read_bytes(s, sizeof buf_space);
 269                 if (n != sizeof buf_space) return(n); /* n == -1 || n == 0 */
 270 
 271                 p=s->packet;
 272 
 273                 memcpy(buf,p,n);
 274 
 275                 if ((p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO))
 276                         {
 277                         /*
 278                          * SSLv2 header
 279                          */
 280                         if ((p[3] == 0x00) && (p[4] == 0x02))
 281                                 {
 282                                 v[0]=p[3]; v[1]=p[4];
 283                                 /* SSLv2 */
 284                                 if (!(s->options & SSL_OP_NO_SSLv2))
 285                                         type=1;
 286                                 }
 287                         else if (p[3] == SSL3_VERSION_MAJOR)
 288                                 {
 289                                 v[0]=p[3]; v[1]=p[4];
 290                                 /* SSLv3/TLSv1 */
 291                                 if (p[4] >= TLS1_VERSION_MINOR)
 292                                         {
 293                                         if (p[4] >= TLS1_2_VERSION_MINOR &&
 294                                            !(s->options & SSL_OP_NO_TLSv1_2))
 295                                                 {
 296                                                 s->version=TLS1_2_VERSION;
 297                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
 298                                                 }
 299                                         else if (p[4] >= TLS1_1_VERSION_MINOR &&
 300                                            !(s->options & SSL_OP_NO_TLSv1_1))
 301                                                 {
 302                                                 s->version=TLS1_1_VERSION;
 303                                                 /* type=2; */ /* done later to survive restarts */
 304                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
 305                                                 }
 306                                         else if (!(s->options & SSL_OP_NO_TLSv1))
 307                                                 {
 308                                                 s->version=TLS1_VERSION;
 309                                                 /* type=2; */ /* done later to survive restarts */
 310                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
 311                                                 }
 312                                         else if (!(s->options & SSL_OP_NO_SSLv3))
 313                                                 {
 314                                                 s->version=SSL3_VERSION;
 315                                                 /* type=2; */
 316                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
 317                                                 }
 318                                         else if (!(s->options & SSL_OP_NO_SSLv2))
 319                                                 {
 320                                                 type=1;
 321                                                 }
 322                                         }
 323                                 else if (!(s->options & SSL_OP_NO_SSLv3))
 324                                         {
 325                                         s->version=SSL3_VERSION;
 326                                         /* type=2; */
 327                                         s->state=SSL23_ST_SR_CLNT_HELLO_B;
 328                                         }
 329                                 else if (!(s->options & SSL_OP_NO_SSLv2))
 330                                         type=1;
 331 
 332                                 }
 333                         }
 334                 else if ((p[0] == SSL3_RT_HANDSHAKE) &&
 335                          (p[1] == SSL3_VERSION_MAJOR) &&
 336                          (p[5] == SSL3_MT_CLIENT_HELLO) &&
 337                          ((p[3] == 0 && p[4] < 5 /* silly record length? */)
 338                                 || (p[9] >= p[1])))
 339                         {
 340                         /*
 341                          * SSLv3 or tls1 header
 342                          */
 343 
 344                         v[0]=p[1]; /* major version (= SSL3_VERSION_MAJOR) */
 345                         /* We must look at client_version inside the Client Hello message
 346                          * to get the correct minor version.
 347                          * However if we have only a pathologically small fragment of the
 348                          * Client Hello message, this would be difficult, and we'd have
 349                          * to read more records to find out.
 350                          * No known SSL 3.0 client fragments ClientHello like this,
 351                          * so we simply reject such connections to avoid
 352                          * protocol version downgrade attacks. */
 353                         if (p[3] == 0 && p[4] < 6)
 354                                 {
 355                                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_SMALL);
 356                                 goto err;
 357                                 }
 358                         /* if major version number > 3 set minor to a value
 359                          * which will use the highest version 3 we support.
 360                          * If TLS 2.0 ever appears we will need to revise
 361                          * this....
 362                          */
 363                         if (p[9] > SSL3_VERSION_MAJOR)
 364                                 v[1]=0xff;
 365                         else
 366                                 v[1]=p[10]; /* minor version according to client_version */
 367                         if (v[1] >= TLS1_VERSION_MINOR)
 368                                 {
 369                                 if (v[1] >= TLS1_2_VERSION_MINOR &&
 370                                         !(s->options & SSL_OP_NO_TLSv1_2))
 371                                         {
 372                                         s->version=TLS1_2_VERSION;
 373                                         type=3;
 374                                         }
 375                                 else if (v[1] >= TLS1_1_VERSION_MINOR &&
 376                                         !(s->options & SSL_OP_NO_TLSv1_1))
 377                                         {
 378                                         s->version=TLS1_1_VERSION;
 379                                         type=3;
 380                                         }
 381                                 else if (!(s->options & SSL_OP_NO_TLSv1))
 382                                         {
 383                                         s->version=TLS1_VERSION;
 384                                         type=3;
 385                                         }
 386                                 else if (!(s->options & SSL_OP_NO_SSLv3))
 387                                         {
 388                                         s->version=SSL3_VERSION;
 389                                         type=3;
 390                                         }
 391                                 }
 392                         else
 393                                 {
 394                                 /* client requests SSL 3.0 */
 395                                 if (!(s->options & SSL_OP_NO_SSLv3))
 396                                         {
 397                                         s->version=SSL3_VERSION;
 398                                         type=3;
 399                                         }
 400                                 else if (!(s->options & SSL_OP_NO_TLSv1))
 401                                         {
 402                                         /* we won't be able to use TLS of course,
 403                                          * but this will send an appropriate alert */
 404                                         s->version=TLS1_VERSION;
 405                                         type=3;
 406                                         }
 407                                 }
 408                         }
 409                 else if ((strncmp("GET ", (char *)p,4) == 0) ||
 410                          (strncmp("POST ",(char *)p,5) == 0) ||
 411                          (strncmp("HEAD ",(char *)p,5) == 0) ||
 412                          (strncmp("PUT ", (char *)p,4) == 0))
 413                         {
 414                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTP_REQUEST);
 415                         goto err;
 416                         }
 417                 else if (strncmp("CONNECT",(char *)p,7) == 0)
 418                         {
 419                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTPS_PROXY_REQUEST);
 420                         goto err;
 421                         }
 422                 }
 423 
 424 #ifdef OPENSSL_FIPS
 425         if (FIPS_mode() && (s->version < TLS1_VERSION))
 426                 {
 427                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,
 428                                         SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
 429                 goto err;
 430                 }
 431 #endif
 432 
 433         if (s->state == SSL23_ST_SR_CLNT_HELLO_B)
 434                 {
 435                 /* we have SSLv3/TLSv1 in an SSLv2 header
 436                  * (other cases skip this state) */
 437 
 438                 type=2;
 439                 p=s->packet;
 440                 v[0] = p[3]; /* == SSL3_VERSION_MAJOR */
 441                 v[1] = p[4];
 442 
 443                 /* An SSLv3/TLSv1 backwards-compatible CLIENT-HELLO in an SSLv2
 444                  * header is sent directly on the wire, not wrapped as a TLS
 445                  * record. It's format is:
 446                  * Byte  Content
 447                  * 0-1   msg_length
 448                  * 2     msg_type
 449                  * 3-4   version
 450                  * 5-6   cipher_spec_length
 451                  * 7-8   session_id_length
 452                  * 9-10  challenge_length
 453                  * ...   ...
 454                  */
 455                 n=((p[0]&0x7f)<<8)|p[1];
 456                 if (n > (1024*4))
 457                         {
 458                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_LARGE);
 459                         goto err;
 460                         }
 461                 if (n < 9)
 462                         {
 463                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_LENGTH_MISMATCH);
 464                         goto err;
 465                         }
 466 
 467                 j=ssl23_read_bytes(s,n+2);
 468                 /* We previously read 11 bytes, so if j > 0, we must have
 469                  * j == n+2 == s->packet_length. We have at least 11 valid
 470                  * packet bytes. */
 471                 if (j <= 0) return(j);
 472 
 473                 ssl3_finish_mac(s, s->packet+2, s->packet_length-2);
 474                 if (s->msg_callback)
 475                         s->msg_callback(0, SSL2_VERSION, 0, s->packet+2, s->packet_length-2, s, s->msg_callback_arg); /* CLIENT-HELLO */
 476 
 477                 p=s->packet;
 478                 p+=5;
 479                 n2s(p,csl);
 480                 n2s(p,sil);
 481                 n2s(p,cl);
 482                 d=(unsigned char *)s->init_buf->data;
 483                 if ((csl+sil+cl+11) != s->packet_length) /* We can't have TLS extensions in SSL 2.0 format
 484                                                           * Client Hello, can we? Error condition should be
 485                                                           * '>' otherweise */
 486                         {
 487                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_LENGTH_MISMATCH);
 488                         goto err;
 489                         }
 490 
 491                 /* record header: msg_type ... */
 492                 *(d++) = SSL3_MT_CLIENT_HELLO;
 493                 /* ... and length (actual value will be written later) */
 494                 d_len = d;
 495                 d += 3;
 496 
 497                 /* client_version */
 498                 *(d++) = SSL3_VERSION_MAJOR; /* == v[0] */
 499                 *(d++) = v[1];
 500 
 501                 /* lets populate the random area */
 502                 /* get the challenge_length */
 503                 i=(cl > SSL3_RANDOM_SIZE)?SSL3_RANDOM_SIZE:cl;
 504                 memset(d,0,SSL3_RANDOM_SIZE);
 505                 memcpy(&(d[SSL3_RANDOM_SIZE-i]),&(p[csl+sil]),i);
 506                 d+=SSL3_RANDOM_SIZE;
 507 
 508                 /* no session-id reuse */
 509                 *(d++)=0;
 510 
 511                 /* ciphers */
 512                 j=0;
 513                 dd=d;
 514                 d+=2;
 515                 for (i=0; i<csl; i+=3)
 516                         {
 517                         if (p[i] != 0) continue;
 518                         *(d++)=p[i+1];
 519                         *(d++)=p[i+2];
 520                         j+=2;
 521                         }
 522                 s2n(j,dd);
 523 
 524                 /* COMPRESSION */
 525                 *(d++)=1;
 526                 *(d++)=0;
 527 
 528 #if 0
 529                 /* copy any remaining data with may be extensions */
 530                 p = p+csl+sil+cl;
 531                 while (p <  s->packet+s->packet_length)
 532                         {
 533                         *(d++)=*(p++);
 534                         }
 535 #endif
 536 
 537                 i = (d-(unsigned char *)s->init_buf->data) - 4;
 538                 l2n3((long)i, d_len);
 539 
 540                 /* get the data reused from the init_buf */
 541                 s->s3->tmp.reuse_message=1;
 542                 s->s3->tmp.message_type=SSL3_MT_CLIENT_HELLO;
 543                 s->s3->tmp.message_size=i;
 544                 }
 545 
 546         /* imaginary new state (for program structure): */
 547         /* s->state = SSL23_SR_CLNT_HELLO_C */
 548 
 549         if (type == 1)
 550                 {
 551 #ifdef OPENSSL_NO_SSL2
 552                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
 553                 goto err;
 554 #else
 555                 /* we are talking sslv2 */
 556                 /* we need to clean up the SSLv3/TLSv1 setup and put in the
 557                  * sslv2 stuff. */
 558 
 559                 if (s->s2 == NULL)
 560                         {
 561                         if (!ssl2_new(s))
 562                                 goto err;
 563                         }
 564                 else
 565                         ssl2_clear(s);
 566 
 567                 if (s->s3 != NULL) ssl3_free(s);
 568 
 569                 if (!BUF_MEM_grow_clean(s->init_buf,
 570                         SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER))
 571                         {
 572                         goto err;
 573                         }
 574 
 575                 s->state=SSL2_ST_GET_CLIENT_HELLO_A;
 576                 if (s->options & SSL_OP_NO_TLSv1 && s->options & SSL_OP_NO_SSLv3)
 577                         s->s2->ssl2_rollback=0;
 578                 else
 579                         /* reject SSL 2.0 session if client supports SSL 3.0 or TLS 1.0
 580                          * (SSL 3.0 draft/RFC 2246, App. E.2) */
 581                         s->s2->ssl2_rollback=1;
 582 
 583                 /* setup the n bytes we have read so we get them from
 584                  * the sslv2 buffer */
 585                 s->rstate=SSL_ST_READ_HEADER;
 586                 s->packet_length=n;
 587                 s->packet= &(s->s2->rbuf[0]);
 588                 memcpy(s->packet,buf,n);
 589                 s->s2->rbuf_left=n;
 590                 s->s2->rbuf_offs=0;
 591 
 592                 s->method=SSLv2_server_method();
 593                 s->handshake_func=s->method->ssl_accept;
 594 #endif
 595                 }
 596 
 597         if ((type == 2) || (type == 3))
 598                 {
 599                 /* we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style) */
 600 
 601                 if (!ssl_init_wbio_buffer(s,1)) goto err;
 602 
 603                 /* we are in this state */
 604                 s->state=SSL3_ST_SR_CLNT_HELLO_A;
 605 
 606                 if (type == 3)
 607                         {
 608                         /* put the 'n' bytes we have read into the input buffer
 609                          * for SSLv3 */
 610                         s->rstate=SSL_ST_READ_HEADER;
 611                         s->packet_length=n;
 612                         if (s->s3->rbuf.buf == NULL)
 613                                 if (!ssl3_setup_read_buffer(s))
 614                                         goto err;
 615 
 616                         s->packet= &(s->s3->rbuf.buf[0]);
 617                         memcpy(s->packet,buf,n);
 618                         s->s3->rbuf.left=n;
 619                         s->s3->rbuf.offset=0;
 620                         }
 621                 else
 622                         {
 623                         s->packet_length=0;
 624                         s->s3->rbuf.left=0;
 625                         s->s3->rbuf.offset=0;
 626                         }
 627                 if (s->version == TLS1_2_VERSION)
 628                         s->method = TLSv1_2_server_method();
 629                 else if (s->version == TLS1_1_VERSION)
 630                         s->method = TLSv1_1_server_method();
 631                 else if (s->version == TLS1_VERSION)
 632                         s->method = TLSv1_server_method();
 633                 else
 634                         s->method = SSLv3_server_method();
 635 #if 0 /* ssl3_get_client_hello does this */
 636                 s->client_version=(v[0]<<8)|v[1];
 637 #endif
 638                 s->handshake_func=s->method->ssl_accept;
 639                 }
 640 
 641         if ((type < 1) || (type > 3))
 642                 {
 643                 /* bad, very bad */
 644                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNKNOWN_PROTOCOL);
 645                 goto err;
 646                 }
 647         s->init_num=0;
 648 
 649         if (buf != buf_space) OPENSSL_free(buf);
 650         return(SSL_accept(s));
 651 err:
 652         if (buf != buf_space) OPENSSL_free(buf);
 653         return(-1);
 654         }