ssl/s23_clnt.c

   1 /* ssl/s23_clnt.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
 119 static const SSL_METHOD *ssl23_get_client_method(int ver);
 120 static int ssl23_client_hello(SSL *s);
 121 static int ssl23_get_server_hello(SSL *s);
 122 static const SSL_METHOD *ssl23_get_client_method(int ver)
 123         {
 124 #ifndef OPENSSL_NO_SSL2
 125         if (ver == SSL2_VERSION)
 126                 return(SSLv2_client_method());
 127 #endif
 128 #ifndef OPENSSL_NO_SSL3
 129         if (ver == SSL3_VERSION)
 130                 return(SSLv3_client_method());
 131 #endif
 132         if (ver == TLS1_VERSION)
 133                 return(TLSv1_client_method());
 134         else
 135                 return(NULL);
 136         }
 137
 138 IMPLEMENT_ssl23_meth_func(SSLv23_client_method,
 139                         ssl_undefined_function,
 140                         ssl23_connect,
 141                         ssl23_get_client_method)
 142
 143 int ssl23_connect(SSL *s)
 144         {
 145         BUF_MEM *buf=NULL;
 146         unsigned long Time=(unsigned long)time(NULL);
 147         void (*cb)(const SSL *ssl,int type,int val)=NULL;
 148         int ret= -1;
 149         int new_state,state;
 150
 151         RAND_add(&Time,sizeof(Time),0);
 152         ERR_clear_error();
 153         clear_sys_error();
 154
 155         if (s->info_callback != NULL)
 156                 cb=s->info_callback;
 157         else if (s->ctx->info_callback != NULL)
 158                 cb=s->ctx->info_callback;
 159
 160         s->in_handshake++;
 161         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
 162
 163         for (;;)
 164                 {
 165                 state=s->state;
 166
 167                 switch(s->state)
 168                         {
 169                 case SSL_ST_BEFORE:
 170                 case SSL_ST_CONNECT:
 171                 case SSL_ST_BEFORE|SSL_ST_CONNECT:
 172                 case SSL_ST_OK|SSL_ST_CONNECT:
 173
 174                         if (s->session != NULL)
 175                                 {
 176                                 SSLerr(SSL_F_SSL23_CONNECT,SSL_R_SSL23_DOING_SESSION_ID_REUSE);
 177                                 ret= -1;
 178                                 goto end;
 179                                 }
 180                         s->server=0;
 181                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
 182
 183                         /* s->version=TLS1_VERSION; */
 184                         s->type=SSL_ST_CONNECT;
 185
 186                         if (s->init_buf == NULL)
 187                                 {
 188                                 if ((buf=BUF_MEM_new()) == NULL)
 189                                         {
 190                                         ret= -1;
 191                                         goto end;
 192                                         }
 193                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
 194                                         {
 195                                         ret= -1;
 196                                         goto end;
 197                                         }
 198                                 s->init_buf=buf;
 199                                 buf=NULL;
 200                                 }
 201
 202                         if (!ssl3_setup_buffers(s)) { ret= -1; goto end; }
 203
 204                         ssl3_init_finished_mac(s);
 205
 206                         s->state=SSL23_ST_CW_CLNT_HELLO_A;
 207                         s->ctx->stats.sess_connect++;
 208                         s->init_num=0;
 209                         break;
 210
 211                 case SSL23_ST_CW_CLNT_HELLO_A:
 212                 case SSL23_ST_CW_CLNT_HELLO_B:
 213
 214                         s->shutdown=0;
 215                         ret=ssl23_client_hello(s);
 216                         if (ret <= 0) goto end;
 217                         s->state=SSL23_ST_CR_SRVR_HELLO_A;
 218                         s->init_num=0;
 219
 220                         break;
 221
 222                 case SSL23_ST_CR_SRVR_HELLO_A:
 223                 case SSL23_ST_CR_SRVR_HELLO_B:
 224                         ret=ssl23_get_server_hello(s);
 225                         if (ret >= 0) cb=NULL;
 226                         goto end;
 227                         /* break; */
 228
 229                 default:
 230                         SSLerr(SSL_F_SSL23_CONNECT,SSL_R_UNKNOWN_STATE);
 231                         ret= -1;
 232                         goto end;
 233                         /* break; */
 234                         }
 235
 236                 if (s->debug) { (void)BIO_flush(s->wbio); }
 237
 238                 if ((cb != NULL) && (s->state != state))
 239                         {
 240                         new_state=s->state;
 241                         s->state=state;
 242                         cb(s,SSL_CB_CONNECT_LOOP,1);
 243                         s->state=new_state;
 244                         }
 245                 }
 246 end:
 247         s->in_handshake--;
 248         if (buf != NULL)
 249                 BUF_MEM_free(buf);
 250         if (cb != NULL)
 251                 cb(s,SSL_CB_CONNECT_EXIT,ret);
 252         return(ret);
 253         }
 254
 255 static int ssl23_no_ssl2_ciphers(SSL *s)
 256         {
 257         SSL_CIPHER *cipher;
 258         STACK_OF(SSL_CIPHER) *ciphers;
 259         int i;
 260         ciphers = SSL_get_ciphers(s);
 261         for (i = 0; i < sk_SSL_CIPHER_num(ciphers); i++)
 262                 {
 263                 cipher = sk_SSL_CIPHER_value(ciphers, i);
 264                 if (cipher->algorithm_ssl == SSL_SSLV2)
 265                         return 0;
 266                 }
 267         return 1;
 268         }
 269
 270 static int ssl23_client_hello(SSL *s)
 271         {
 272         unsigned char *buf;
 273         unsigned char *p,*d;
 274         int i,ch_len;
 275         unsigned long Time,l;
 276         int ssl2_compat;
 277         int version = 0, version_major, version_minor;
 278 #ifndef OPENSSL_NO_COMP
 279         int j;
 280         SSL_COMP *comp;
 281 #endif
 282         int ret;
 283
 284         ssl2_compat = (s->options & SSL_OP_NO_SSLv2) ? 0 : 1;
 285
 286         if (ssl2_compat && ssl23_no_ssl2_ciphers(s))
 287                 ssl2_compat = 0;
 288
 289         if (!(s->options & SSL_OP_NO_TLSv1))
 290                 {
 291                 version = TLS1_VERSION;
 292                 }
 293         else if (!(s->options & SSL_OP_NO_SSLv3))
 294                 {
 295                 version = SSL3_VERSION;
 296                 }
 297         else if (!(s->options & SSL_OP_NO_SSLv2))
 298                 {
 299                 version = SSL2_VERSION;
 300                 }
 301 #ifndef OPENSSL_NO_TLSEXT
 302         if (version != SSL2_VERSION)
 303                 {
 304                 /* have to disable SSL 2.0 compatibility if we need TLS extensions */
 305
 306                 if (s->tlsext_hostname != NULL)
 307                         ssl2_compat = 0;
 308                 if (s->tlsext_status_type != -1)
 309                         ssl2_compat = 0;
 310 #ifdef TLSEXT_TYPE_opaque_prf_input
 311                 if (s->ctx->tlsext_opaque_prf_input_callback != 0 || s->tlsext_opaque_prf_input != NULL)
 312                         ssl2_compat = 0;
 313 #endif
 314                 }
 315 #endif
 316
 317         buf=(unsigned char *)s->init_buf->data;
 318         if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
 319                 {
 320 #if 0
 321                 /* don't reuse session-id's */
 322                 if (!ssl_get_new_session(s,0))
 323                         {
 324                         return(-1);
 325                         }
 326 #endif
 327
 328                 p=s->s3->client_random;
 329                 Time=(unsigned long)time(NULL);         /* Time */
 330                 l2n(Time,p);
 331                 if (RAND_pseudo_bytes(p,SSL3_RANDOM_SIZE-4) <= 0)
 332                         return -1;
 333
 334                 if (version == TLS1_VERSION)
 335                         {
 336                         version_major = TLS1_VERSION_MAJOR;
 337                         version_minor = TLS1_VERSION_MINOR;
 338                         }
 339                 else if (version == SSL3_VERSION)
 340                         {
 341                         version_major = SSL3_VERSION_MAJOR;
 342                         version_minor = SSL3_VERSION_MINOR;
 343                         }
 344                 else if (version == SSL2_VERSION)
 345                         {
 346                         version_major = SSL2_VERSION_MAJOR;
 347                         version_minor = SSL2_VERSION_MINOR;
 348                         }
 349                 else
 350                         {
 351                         SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_PROTOCOLS_AVAILABLE);
 352                         return(-1);
 353                         }
 354
 355                 s->client_version = version;
 356
 357                 if (ssl2_compat)
 358                         {
 359                         /* create SSL 2.0 compatible Client Hello */
 360
 361                         /* two byte record header will be written last */
 362                         d = &(buf[2]);
 363                         p = d + 9; /* leave space for message type, version, individual length fields */
 364
 365                         *(d++) = SSL2_MT_CLIENT_HELLO;
 366                         *(d++) = version_major;
 367                         *(d++) = version_minor;
 368
 369                         /* Ciphers supported */
 370                         i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),p,0);
 371                         if (i == 0)
 372                                 {
 373                                 /* no ciphers */
 374                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
 375                                 return -1;
 376                                 }
 377                         s2n(i,d);
 378                         p+=i;
 379
 380                         /* put in the session-id length (zero since there is no reuse) */
 381 #if 0
 382                         s->session->session_id_length=0;
 383 #endif
 384                         s2n(0,d);
 385
 386                         if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
 387                                 ch_len=SSL2_CHALLENGE_LENGTH;
 388                         else
 389                                 ch_len=SSL2_MAX_CHALLENGE_LENGTH;
 390
 391                         /* write out sslv2 challenge */
 392                         /* Note that ch_len must be <= SSL3_RANDOM_SIZE (32),
 393                            because it is one of SSL2_MAX_CHALLENGE_LENGTH (32)
 394                            or SSL2_MAX_CHALLENGE_LENGTH (16), but leave the
 395                            check in for futurproofing */
 396                         if (SSL3_RANDOM_SIZE < ch_len)
 397                                 i=SSL3_RANDOM_SIZE;
 398                         else
 399                                 i=ch_len;
 400                         s2n(i,d);
 401                         memset(&(s->s3->client_random[0]),0,SSL3_RANDOM_SIZE);
 402                         if (RAND_pseudo_bytes(&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i) <= 0)
 403                                 return -1;
 404
 405                         memcpy(p,&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i);
 406                         p+=i;
 407
 408                         i= p- &(buf[2]);
 409                         buf[0]=((i>>8)&0xff)|0x80;
 410                         buf[1]=(i&0xff);
 411
 412                         /* number of bytes to write */
 413                         s->init_num=i+2;
 414                         s->init_off=0;
 415
 416                         ssl3_finish_mac(s,&(buf[2]),i);
 417                         }
 418                 else
 419                         {
 420                         /* create Client Hello in SSL 3.0/TLS 1.0 format */
 421
 422                         /* do the record header (5 bytes) and handshake message header (4 bytes) last */
 423                         d = p = &(buf[9]);
 424
 425                         *(p++) = version_major;
 426                         *(p++) = version_minor;
 427
 428                         /* Random stuff */
 429                         memcpy(p, s->s3->client_random, SSL3_RANDOM_SIZE);
 430                         p += SSL3_RANDOM_SIZE;
 431
 432                         /* Session ID (zero since there is no reuse) */
 433                         *(p++) = 0;
 434
 435                         /* Ciphers supported (using SSL 3.0/TLS 1.0 format) */
 436                         i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),&(p[2]),ssl3_put_cipher_by_char);
 437                         if (i == 0)
 438                                 {
 439                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
 440                                 return -1;
 441                                 }
 442                         s2n(i,p);
 443                         p+=i;
 444
 445                         /* COMPRESSION */
 446 #ifdef OPENSSL_NO_COMP
 447                         *(p++)=1;
 448 #else
 449                         if ((s->options & SSL_OP_NO_COMPRESSION)
 450                                                 || !s->ctx->comp_methods)
 451                                 j=0;
 452                         else
 453                                 j=sk_SSL_COMP_num(s->ctx->comp_methods);
 454                         *(p++)=1+j;
 455                         for (i=0; i<j; i++)
 456                                 {
 457                                 comp=sk_SSL_COMP_value(s->ctx->comp_methods,i);
 458                                 *(p++)=comp->id;
 459                                 }
 460 #endif
 461                         *(p++)=0; /* Add the NULL method */
 462
 463 #ifndef OPENSSL_NO_TLSEXT
 464                         /* TLS extensions*/
 465                         if (ssl_prepare_clienthello_tlsext(s) <= 0)
 466                                 {
 467                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_CLIENTHELLO_TLSEXT);
 468                                 return -1;
 469                                 }
 470                         if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
 471                                 {
 472                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
 473                                 return -1;
 474                                 }
 475 #endif
 476
 477                         l = p-d;
 478
 479                         /* fill in 4-byte handshake header */
 480                         d=&(buf[5]);
 481                         *(d++)=SSL3_MT_CLIENT_HELLO;
 482                         l2n3(l,d);
 483
 484                         l += 4;
 485
 486                         if (l > SSL3_RT_MAX_PLAIN_LENGTH)
 487                                 {
 488                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
 489                                 return -1;
 490                                 }
 491
 492                         /* fill in 5-byte record header */
 493                         d=buf;
 494                         *(d++) = SSL3_RT_HANDSHAKE;
 495                         *(d++) = version_major;
 496                         *(d++) = version_minor; /* arguably we should send the *lowest* suported version here
 497                                                  * (indicating, e.g., TLS 1.0 in "SSL 3.0 format") */
 498                         s2n((int)l,d);
 499
 500                         /* number of bytes to write */
 501                         s->init_num=p-buf;
 502                         s->init_off=0;
 503
 504                         ssl3_finish_mac(s,&(buf[5]), s->init_num - 5);
 505                         }
 506
 507                 s->state=SSL23_ST_CW_CLNT_HELLO_B;
 508                 s->init_off=0;
 509                 }
 510
 511         /* SSL3_ST_CW_CLNT_HELLO_B */
 512         ret = ssl23_write_bytes(s);
 513
 514         if ((ret >= 2) && s->msg_callback)
 515                 {
 516                 /* Client Hello has been sent; tell msg_callback */
 517
 518                 if (ssl2_compat)
 519                         s->msg_callback(1, SSL2_VERSION, 0, s->init_buf->data+2, ret-2, s, s->msg_callback_arg);
 520                 else
 521                         s->msg_callback(1, version, SSL3_RT_HANDSHAKE, s->init_buf->data+5, ret-5, s, s->msg_callback_arg);
 522                 }
 523
 524         return ret;
 525         }
 526
 527 static int ssl23_get_server_hello(SSL *s)
 528         {
 529         char buf[8];
 530         unsigned char *p;
 531         int i;
 532         int n;
 533
 534         n=ssl23_read_bytes(s,7);
 535
 536         if (n != 7) return(n);
 537         p=s->packet;
 538
 539         memcpy(buf,p,n);
 540
 541         if ((p[0] & 0x80) && (p[2] == SSL2_MT_SERVER_HELLO) &&
 542                 (p[5] == 0x00) && (p[6] == 0x02))
 543                 {
 544 #ifdef OPENSSL_NO_SSL2
 545                 SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
 546                 goto err;
 547 #else
 548                 /* we are talking sslv2 */
 549                 /* we need to clean up the SSLv3 setup and put in the
 550                  * sslv2 stuff. */
 551                 int ch_len;
 552
 553                 if (s->options & SSL_OP_NO_SSLv2)
 554                         {
 555                         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
 556                         goto err;
 557                         }
 558                 if (s->s2 == NULL)
 559                         {
 560                         if (!ssl2_new(s))
 561                                 goto err;
 562                         }
 563                 else
 564                         ssl2_clear(s);
 565
 566                 if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
 567                         ch_len=SSL2_CHALLENGE_LENGTH;
 568                 else
 569                         ch_len=SSL2_MAX_CHALLENGE_LENGTH;
 570
 571                 /* write out sslv2 challenge */
 572                 /* Note that ch_len must be <= SSL3_RANDOM_SIZE (32), because
 573                    it is one of SSL2_MAX_CHALLENGE_LENGTH (32) or
 574                    SSL2_MAX_CHALLENGE_LENGTH (16), but leave the check in for
 575                    futurproofing */
 576                 i=(SSL3_RANDOM_SIZE < ch_len)
 577                         ?SSL3_RANDOM_SIZE:ch_len;
 578                 s->s2->challenge_length=i;
 579                 memcpy(s->s2->challenge,
 580                         &(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i);
 581
 582                 if (s->s3 != NULL) ssl3_free(s);
 583
 584                 if (!BUF_MEM_grow_clean(s->init_buf,
 585                         SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER))
 586                         {
 587                         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,ERR_R_BUF_LIB);
 588                         goto err;
 589                         }
 590
 591                 s->state=SSL2_ST_GET_SERVER_HELLO_A;
 592                 if (!(s->client_version == SSL2_VERSION))
 593                         /* use special padding (SSL 3.0 draft/RFC 2246, App. E.2) */
 594                         s->s2->ssl2_rollback=1;
 595
 596                 /* setup the 7 bytes we have read so we get them from
 597                  * the sslv2 buffer */
 598                 s->rstate=SSL_ST_READ_HEADER;
 599                 s->packet_length=n;
 600                 s->packet= &(s->s2->rbuf[0]);
 601                 memcpy(s->packet,buf,n);
 602                 s->s2->rbuf_left=n;
 603                 s->s2->rbuf_offs=0;
 604
 605                 /* we have already written one */
 606                 s->s2->write_sequence=1;
 607
 608                 s->method=SSLv2_client_method();
 609                 s->handshake_func=s->method->ssl_connect;
 610 #endif
 611                 }
 612         else if (p[1] == SSL3_VERSION_MAJOR &&
 613                  (p[2] == SSL3_VERSION_MINOR || p[2] == TLS1_VERSION_MINOR) &&
 614                  ((p[0] == SSL3_RT_HANDSHAKE && p[5] == SSL3_MT_SERVER_HELLO) ||
 615                   (p[0] == SSL3_RT_ALERT && p[3] == 0 && p[4] == 2)))
 616                 {
 617                 /* we have sslv3 or tls1 (server hello or alert) */
 618
 619 #ifndef OPENSSL_NO_SSL3
 620                 if ((p[2] == SSL3_VERSION_MINOR) &&
 621                         !(s->options & SSL_OP_NO_SSLv3))
 622                         {
 623                         s->version=SSL3_VERSION;
 624                         s->method=SSLv3_client_method();
 625                         }
 626                 else
 627 #endif
 628                 if ((p[2] == TLS1_VERSION_MINOR) &&
 629                         !(s->options & SSL_OP_NO_TLSv1))
 630                         {
 631                         s->version=TLS1_VERSION;
 632                         s->method=TLSv1_client_method();
 633                         }
 634                 else
 635                         {
 636                         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
 637                         goto err;
 638                         }
 639
 640                 /* ensure that TLS_MAX_VERSION is up-to-date */
 641                 OPENSSL_assert(s->version <= TLS_MAX_VERSION);
 642
 643                 if (p[0] == SSL3_RT_ALERT && p[5] != SSL3_AL_WARNING)
 644                         {
 645                         /* fatal alert */
 646
 647                         void (*cb)(const SSL *ssl,int type,int val)=NULL;
 648                         int j;
 649
 650                         if (s->info_callback != NULL)
 651                                 cb=s->info_callback;
 652                         else if (s->ctx->info_callback != NULL)
 653                                 cb=s->ctx->info_callback;
 654
 655                         i=p[5];
 656                         if (cb != NULL)
 657                                 {
 658                                 j=(i<<8)|p[6];
 659                                 cb(s,SSL_CB_READ_ALERT,j);
 660                                 }
 661
 662                         if (s->msg_callback)
 663                                 s->msg_callback(0, s->version, SSL3_RT_ALERT, p+5, 2, s, s->msg_callback_arg);
 664
 665                         s->rwstate=SSL_NOTHING;
 666                         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_AD_REASON_OFFSET+p[6]);
 667                         goto err;
 668                         }
 669
 670                 if (!ssl_init_wbio_buffer(s,1)) goto err;
 671
 672                 /* we are in this state */
 673                 s->state=SSL3_ST_CR_SRVR_HELLO_A;
 674
 675                 /* put the 7 bytes we have read into the input buffer
 676                  * for SSLv3 */
 677                 s->rstate=SSL_ST_READ_HEADER;
 678                 s->packet_length=n;
 679                 if (s->s3->rbuf.buf == NULL)
 680                         if (!ssl3_setup_read_buffer(s))
 681                                 goto err;
 682                 s->packet= &(s->s3->rbuf.buf[0]);
 683                 memcpy(s->packet,buf,n);
 684                 s->s3->rbuf.left=n;
 685                 s->s3->rbuf.offset=0;
 686
 687                 s->handshake_func=s->method->ssl_connect;
 688                 }
 689         else
 690                 {
 691                 SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNKNOWN_PROTOCOL);
 692                 goto err;
 693                 }
 694         s->init_num=0;
 695
 696         /* Since, if we are sending a ssl23 client hello, we are not
 697          * reusing a session-id */
 698         if (!ssl_get_new_session(s,0))
 699                 goto err;
 700
 701         return(SSL_connect(s));
 702 err:
 703         return(-1);
 704         }