ssl/s23_srvr.c

   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 #ifndef OPENSSL_NO_SSL3
 131     if (ver == SSL3_VERSION)
 132         return (SSLv3_server_method());
 133 #endif
 134     if (ver == TLS1_VERSION)
 135         return (TLSv1_server_method());
 136     else if (ver == TLS1_1_VERSION)
 137         return (TLSv1_1_server_method());
 138     else if (ver == TLS1_2_VERSION)
 139         return (TLSv1_2_server_method());
 140     else
 141         return (NULL);
 142 }
 143
 144 IMPLEMENT_ssl23_meth_func(SSLv23_server_method,
 145                           ssl23_accept,
 146                           ssl_undefined_function, ssl23_get_server_method)
 147
 148 int ssl23_accept(SSL *s)
 149 {
 150     BUF_MEM *buf;
 151     unsigned long Time = (unsigned long)time(NULL);
 152     void (*cb) (const SSL *ssl, int type, int val) = NULL;
 153     int ret = -1;
 154     int new_state, state;
 155
 156     RAND_add(&Time, sizeof(Time), 0);
 157     ERR_clear_error();
 158     clear_sys_error();
 159
 160     if (s->info_callback != NULL)
 161         cb = s->info_callback;
 162     else if (s->ctx->info_callback != NULL)
 163         cb = s->ctx->info_callback;
 164
 165     s->in_handshake++;
 166     if (!SSL_in_init(s) || SSL_in_before(s))
 167         SSL_clear(s);
 168
 169     for (;;) {
 170         state = s->state;
 171
 172         switch (s->state) {
 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)
 180                 cb(s, SSL_CB_HANDSHAKE_START, 1);
 181
 182             /* s->version=SSL3_VERSION; */
 183             s->type = SSL_ST_ACCEPT;
 184
 185             if (s->init_buf == NULL) {
 186                 if ((buf = BUF_MEM_new()) == NULL) {
 187                     ret = -1;
 188                     goto end;
 189                 }
 190                 if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
 191                     BUF_MEM_free(buf);
 192                     ret = -1;
 193                     goto end;
 194                 }
 195                 s->init_buf = buf;
 196             }
 197
 198             if (!ssl3_init_finished_mac(s)) {
 199                 ret = -1;
 200                 goto end;
 201             }
 202
 203             s->state = SSL23_ST_SR_CLNT_HELLO_A;
 204             s->ctx->stats.sess_accept++;
 205             s->init_num = 0;
 206             break;
 207
 208         case SSL23_ST_SR_CLNT_HELLO_A:
 209         case SSL23_ST_SR_CLNT_HELLO_B:
 210
 211             s->shutdown = 0;
 212             ret = ssl23_get_client_hello(s);
 213             if (ret >= 0)
 214                 cb = NULL;
 215             goto end;
 216             /* break; */
 217
 218         default:
 219             SSLerr(SSL_F_SSL23_ACCEPT, SSL_R_UNKNOWN_STATE);
 220             ret = -1;
 221             goto end;
 222             /* break; */
 223         }
 224
 225         if ((cb != NULL) && (s->state != state)) {
 226             new_state = s->state;
 227             s->state = state;
 228             cb(s, SSL_CB_ACCEPT_LOOP, 1);
 229             s->state = new_state;
 230         }
 231     }
 232  end:
 233     s->in_handshake--;
 234     if (cb != NULL)
 235         cb(s, SSL_CB_ACCEPT_EXIT, ret);
 236     return (ret);
 237 }
 238
 239 int ssl23_get_client_hello(SSL *s)
 240 {
 241     /*-
 242      * Request this many bytes in initial read.
 243      * We can detect SSL 3.0/TLS 1.0 Client Hellos
 244      * ('type == 3') correctly only when the following
 245      * is in a single record, which is not guaranteed by
 246      * the protocol specification:
 247      * Byte  Content
 248      *  0     type            \
 249      *  1/2   version          > record header
 250      *  3/4   length          /
 251      *  5     msg_type        \
 252      *  6-8   length           > Client Hello message
 253      *  9/10  client_version  /
 254      */
 255     char buf_space[11];
 256     char *buf = &(buf_space[0]);
 257     unsigned char *p, *d, *d_len, *dd;
 258     unsigned int i;
 259     unsigned int csl, sil, cl;
 260     int n = 0, j;
 261     int type = 0;
 262     int v[2];
 263
 264     if (s->state == SSL23_ST_SR_CLNT_HELLO_A) {
 265         /* read the initial header */
 266         v[0] = v[1] = 0;
 267
 268         if (!ssl3_setup_buffers(s))
 269             goto err;
 270
 271         n = ssl23_read_bytes(s, sizeof(buf_space));
 272         if (n != sizeof(buf_space))
 273             return (n);         /* n == -1 || n == 0 */
 274
 275         p = s->packet;
 276
 277         memcpy(buf, p, n);
 278
 279         if ((p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO)) {
 280             /*
 281              * SSLv2 header
 282              */
 283             if ((p[3] == 0x00) && (p[4] == 0x02)) {
 284                 v[0] = p[3];
 285                 v[1] = p[4];
 286                 /* SSLv2 */
 287                 if (!(s->options & SSL_OP_NO_SSLv2))
 288                     type = 1;
 289             } else if (p[3] == SSL3_VERSION_MAJOR) {
 290                 v[0] = p[3];
 291                 v[1] = p[4];
 292                 /* SSLv3/TLSv1 */
 293                 if (p[4] >= TLS1_VERSION_MINOR) {
 294                     if (p[4] >= TLS1_2_VERSION_MINOR &&
 295                         !(s->options & SSL_OP_NO_TLSv1_2)) {
 296                         s->version = TLS1_2_VERSION;
 297                         s->state = SSL23_ST_SR_CLNT_HELLO_B;
 298                     } else if (p[4] >= TLS1_1_VERSION_MINOR &&
 299                                !(s->options & SSL_OP_NO_TLSv1_1)) {
 300                         s->version = TLS1_1_VERSION;
 301                         /*
 302                          * type=2;
 303                          *//*
 304                          * done later to survive restarts
 305                          */
 306                         s->state = SSL23_ST_SR_CLNT_HELLO_B;
 307                     } else if (!(s->options & SSL_OP_NO_TLSv1)) {
 308                         s->version = TLS1_VERSION;
 309                         /*
 310                          * type=2;
 311                          *//*
 312                          * done later to survive restarts
 313                          */
 314                         s->state = SSL23_ST_SR_CLNT_HELLO_B;
 315                     } else if (!(s->options & SSL_OP_NO_SSLv3)) {
 316                         s->version = SSL3_VERSION;
 317                         /* type=2; */
 318                         s->state = SSL23_ST_SR_CLNT_HELLO_B;
 319                     } else if (!(s->options & SSL_OP_NO_SSLv2)) {
 320                         type = 1;
 321                     }
 322                 } else if (!(s->options & SSL_OP_NO_SSLv3)) {
 323                     s->version = SSL3_VERSION;
 324                     /* type=2; */
 325                     s->state = SSL23_ST_SR_CLNT_HELLO_B;
 326                 } else if (!(s->options & SSL_OP_NO_SSLv2))
 327                     type = 1;
 328
 329             }
 330         }
 331         /* p[4] < 5 ... silly record length? */
 332         else if ((p[0] == SSL3_RT_HANDSHAKE) &&
 333                  (p[1] == SSL3_VERSION_MAJOR) &&
 334                  (p[5] == SSL3_MT_CLIENT_HELLO) && ((p[3] == 0 && p[4] < 5)
 335                                                     || (p[9] >= p[1]))) {
 336             /*
 337              * SSLv3 or tls1 header
 338              */
 339
 340             v[0] = p[1];        /* major version (= SSL3_VERSION_MAJOR) */
 341             /*
 342              * We must look at client_version inside the Client Hello message
 343              * to get the correct minor version. However if we have only a
 344              * pathologically small fragment of the Client Hello message, this
 345              * would be difficult, and we'd have to read more records to find
 346              * out. No known SSL 3.0 client fragments ClientHello like this,
 347              * so we simply reject such connections to avoid protocol version
 348              * downgrade attacks.
 349              */
 350             if (p[3] == 0 && p[4] < 6) {
 351                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_RECORD_TOO_SMALL);
 352                 goto err;
 353             }
 354             /*
 355              * if major version number > 3 set minor to a value which will
 356              * use the highest version 3 we support. If TLS 2.0 ever appears
 357              * we will need to revise this....
 358              */
 359             if (p[9] > SSL3_VERSION_MAJOR)
 360                 v[1] = 0xff;
 361             else
 362                 v[1] = p[10];   /* minor version according to client_version */
 363             if (v[1] >= TLS1_VERSION_MINOR) {
 364                 if (v[1] >= TLS1_2_VERSION_MINOR &&
 365                     !(s->options & SSL_OP_NO_TLSv1_2)) {
 366                     s->version = TLS1_2_VERSION;
 367                     type = 3;
 368                 } else if (v[1] >= TLS1_1_VERSION_MINOR &&
 369                            !(s->options & SSL_OP_NO_TLSv1_1)) {
 370                     s->version = TLS1_1_VERSION;
 371                     type = 3;
 372                 } else if (!(s->options & SSL_OP_NO_TLSv1)) {
 373                     s->version = TLS1_VERSION;
 374                     type = 3;
 375                 } else if (!(s->options & SSL_OP_NO_SSLv3)) {
 376                     s->version = SSL3_VERSION;
 377                     type = 3;
 378                 }
 379             } else {
 380                 /* client requests SSL 3.0 */
 381                 if (!(s->options & SSL_OP_NO_SSLv3)) {
 382                     s->version = SSL3_VERSION;
 383                     type = 3;
 384                 } else if (!(s->options & SSL_OP_NO_TLSv1)) {
 385                     /*
 386                      * we won't be able to use TLS of course, but this will
 387                      * send an appropriate alert
 388                      */
 389                     s->version = TLS1_VERSION;
 390                     type = 3;
 391                 }
 392             }
 393         } else if ((strncmp("GET ", (char *)p, 4) == 0) ||
 394                    (strncmp("POST ", (char *)p, 5) == 0) ||
 395                    (strncmp("HEAD ", (char *)p, 5) == 0) ||
 396                    (strncmp("PUT ", (char *)p, 4) == 0)) {
 397             SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_HTTP_REQUEST);
 398             goto err;
 399         } else if (strncmp("CONNECT", (char *)p, 7) == 0) {
 400             SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_HTTPS_PROXY_REQUEST);
 401             goto err;
 402         }
 403     }
 404
 405     /* ensure that TLS_MAX_VERSION is up-to-date */
 406     OPENSSL_assert(s->version <= TLS_MAX_VERSION);
 407
 408     if (s->version < TLS1_2_VERSION && tls1_suiteb(s)) {
 409         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,
 410                SSL_R_ONLY_TLS_1_2_ALLOWED_IN_SUITEB_MODE);
 411         goto err;
 412     }
 413 #ifdef OPENSSL_FIPS
 414     if (FIPS_mode() && (s->version < TLS1_VERSION)) {
 415         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,
 416                SSL_R_ONLY_TLS_ALLOWED_IN_FIPS_MODE);
 417         goto err;
 418     }
 419 #endif
 420
 421     if (s->state == SSL23_ST_SR_CLNT_HELLO_B) {
 422         /*
 423          * we have SSLv3/TLSv1 in an SSLv2 header (other cases skip this
 424          * state)
 425          */
 426
 427         type = 2;
 428         p = s->packet;
 429         v[0] = p[3];            /* == SSL3_VERSION_MAJOR */
 430         v[1] = p[4];
 431
 432         /*-
 433          * An SSLv3/TLSv1 backwards-compatible CLIENT-HELLO in an SSLv2
 434          * header is sent directly on the wire, not wrapped as a TLS
 435          * record. It's format is:
 436          * Byte  Content
 437          * 0-1   msg_length
 438          * 2     msg_type
 439          * 3-4   version
 440          * 5-6   cipher_spec_length
 441          * 7-8   session_id_length
 442          * 9-10  challenge_length
 443          * ...   ...
 444          */
 445         n = ((p[0] & 0x7f) << 8) | p[1];
 446         if (n > (1024 * 4)) {
 447             SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_RECORD_TOO_LARGE);
 448             goto err;
 449         }
 450         if (n < 9) {
 451             SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,
 452                    SSL_R_RECORD_LENGTH_MISMATCH);
 453             goto err;
 454         }
 455
 456         j = ssl23_read_bytes(s, n + 2);
 457         /*
 458          * We previously read 11 bytes, so if j > 0, we must have j == n+2 ==
 459          * s->packet_length. We have at least 11 valid packet bytes.
 460          */
 461         if (j <= 0)
 462             return (j);
 463
 464         ssl3_finish_mac(s, s->packet + 2, s->packet_length - 2);
 465
 466         /* CLIENT-HELLO */
 467         if (s->msg_callback)
 468             s->msg_callback(0, SSL2_VERSION, 0, s->packet + 2,
 469                             s->packet_length - 2, s, s->msg_callback_arg);
 470
 471         p = s->packet;
 472         p += 5;
 473         n2s(p, csl);
 474         n2s(p, sil);
 475         n2s(p, cl);
 476         d = (unsigned char *)s->init_buf->data;
 477         if ((csl + sil + cl + 11) != s->packet_length) { /* We can't have TLS
 478                                                           * extensions in SSL
 479                                                           * 2.0 format *
 480                                                           * Client Hello, can
 481                                                           * we? Error
 482                                                           * condition should
 483                                                           * be * '>'
 484                                                           * otherweise */
 485             SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,
 486                    SSL_R_RECORD_LENGTH_MISMATCH);
 487             goto err;
 488         }
 489
 490         /* record header: msg_type ... */
 491         *(d++) = SSL3_MT_CLIENT_HELLO;
 492         /* ... and length (actual value will be written later) */
 493         d_len = d;
 494         d += 3;
 495
 496         /* client_version */
 497         *(d++) = SSL3_VERSION_MAJOR; /* == v[0] */
 498         *(d++) = v[1];
 499
 500         /* lets populate the random area */
 501         /* get the challenge_length */
 502         i = (cl > SSL3_RANDOM_SIZE) ? SSL3_RANDOM_SIZE : cl;
 503         memset(d, 0, SSL3_RANDOM_SIZE);
 504         memcpy(&(d[SSL3_RANDOM_SIZE - i]), &(p[csl + sil]), i);
 505         d += SSL3_RANDOM_SIZE;
 506
 507         /* no session-id reuse */
 508         *(d++) = 0;
 509
 510         /* ciphers */
 511         j = 0;
 512         dd = d;
 513         d += 2;
 514         for (i = 0; i < csl; i += 3) {
 515             if (p[i] != 0)
 516                 continue;
 517             *(d++) = p[i + 1];
 518             *(d++) = p[i + 2];
 519             j += 2;
 520         }
 521         s2n(j, dd);
 522
 523         /* COMPRESSION */
 524         *(d++) = 1;
 525         *(d++) = 0;
 526
 527 #if 0
 528         /* copy any remaining data with may be extensions */
 529         p = p + csl + sil + cl;
 530         while (p < s->packet + s->packet_length) {
 531             *(d++) = *(p++);
 532         }
 533 #endif
 534
 535         i = (d - (unsigned char *)s->init_buf->data) - 4;
 536         l2n3((long)i, d_len);
 537
 538         /* get the data reused from the init_buf */
 539         s->s3->tmp.reuse_message = 1;
 540         s->s3->tmp.message_type = SSL3_MT_CLIENT_HELLO;
 541         s->s3->tmp.message_size = i;
 542     }
 543
 544     /* imaginary new state (for program structure): */
 545     /* s->state = SSL23_SR_CLNT_HELLO_C */
 546
 547     if (type == 1) {
 548 #ifdef OPENSSL_NO_SSL2
 549         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNSUPPORTED_PROTOCOL);
 550         goto err;
 551 #else
 552         /* we are talking sslv2 */
 553         /*
 554          * we need to clean up the SSLv3/TLSv1 setup and put in the sslv2
 555          * stuff.
 556          */
 557
 558         if (s->s2 == NULL) {
 559             if (!ssl2_new(s))
 560                 goto err;
 561         } else
 562             ssl2_clear(s);
 563
 564         if (s->s3 != NULL)
 565             ssl3_free(s);
 566
 567         if (!BUF_MEM_grow_clean(s->init_buf,
 568                                 SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER)) {
 569             goto err;
 570         }
 571
 572         s->state = SSL2_ST_GET_CLIENT_HELLO_A;
 573         if (s->options & SSL_OP_NO_TLSv1 && s->options & SSL_OP_NO_SSLv3)
 574             s->s2->ssl2_rollback = 0;
 575         else
 576             /*
 577              * reject SSL 2.0 session if client supports SSL 3.0 or TLS 1.0
 578              * (SSL 3.0 draft/RFC 2246, App. E.2)
 579              */
 580             s->s2->ssl2_rollback = 1;
 581
 582         /*
 583          * setup the n bytes we have read so we get them from the sslv2
 584          * buffer
 585          */
 586         s->rstate = SSL_ST_READ_HEADER;
 587         s->packet_length = n;
 588         s->packet = &(s->s2->rbuf[0]);
 589         memcpy(s->packet, buf, n);
 590         s->s2->rbuf_left = n;
 591         s->s2->rbuf_offs = 0;
 592
 593         s->method = SSLv2_server_method();
 594         s->handshake_func = s->method->ssl_accept;
 595 #endif
 596     }
 597
 598     if ((type == 2) || (type == 3)) {
 599         /*
 600          * we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style)
 601          */
 602         const SSL_METHOD *new_method;
 603         new_method = ssl23_get_server_method(s->version);
 604         if (new_method == NULL) {
 605             SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNSUPPORTED_PROTOCOL);
 606             goto err;
 607         }
 608         s->method = new_method;
 609
 610         if (!ssl_init_wbio_buffer(s, 1))
 611             goto err;
 612
 613         /* we are in this state */
 614         s->state = SSL3_ST_SR_CLNT_HELLO_A;
 615
 616         if (type == 3) {
 617             /*
 618              * put the 'n' bytes we have read into the input buffer for SSLv3
 619              */
 620             s->rstate = SSL_ST_READ_HEADER;
 621             s->packet_length = n;
 622             if (s->s3->rbuf.buf == NULL)
 623                 if (!ssl3_setup_read_buffer(s))
 624                     goto err;
 625
 626             s->packet = &(s->s3->rbuf.buf[0]);
 627             memcpy(s->packet, buf, n);
 628             s->s3->rbuf.left = n;
 629             s->s3->rbuf.offset = 0;
 630         } else {
 631             s->packet_length = 0;
 632             s->s3->rbuf.left = 0;
 633             s->s3->rbuf.offset = 0;
 634         }
 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         /* bad, very bad */
 643         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO, SSL_R_UNKNOWN_PROTOCOL);
 644         goto err;
 645     }
 646     s->init_num = 0;
 647
 648     if (buf != buf_space)
 649         OPENSSL_free(buf);
 650     return (SSL_accept(s));
 651  err:
 652     if (buf != buf_space)
 653         OPENSSL_free(buf);
 654     return (-1);
 655 }