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