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         if (ver == SSL3_VERSION)
 129                 return(SSLv3_client_method());
 130         else if (ver == TLS1_VERSION)
 131                 return(TLSv1_client_method());
 132         else
 133                 return(NULL);
 134         }
 135
 136 IMPLEMENT_ssl23_meth_func(SSLv23_client_method,
 137                         ssl_undefined_function,
 138                         ssl23_connect,
 139                         ssl23_get_client_method)
 140
 141 int ssl23_connect(SSL *s)
 142         {
 143         BUF_MEM *buf=NULL;
 144         unsigned long Time=(unsigned long)time(NULL);
 145         void (*cb)(const SSL *ssl,int type,int val)=NULL;
 146         int ret= -1;
 147         int new_state,state;
 148
 149         RAND_add(&Time,sizeof(Time),0);
 150         ERR_clear_error();
 151         clear_sys_error();
 152
 153         if (s->info_callback != NULL)
 154                 cb=s->info_callback;
 155         else if (s->ctx->info_callback != NULL)
 156                 cb=s->ctx->info_callback;
 157
 158         s->in_handshake++;
 159         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
 160
 161         for (;;)
 162                 {
 163                 state=s->state;
 164
 165                 switch(s->state)
 166                         {
 167                 case SSL_ST_BEFORE:
 168                 case SSL_ST_CONNECT:
 169                 case SSL_ST_BEFORE|SSL_ST_CONNECT:
 170                 case SSL_ST_OK|SSL_ST_CONNECT:
 171
 172                         if (s->session != NULL)
 173                                 {
 174                                 SSLerr(SSL_F_SSL23_CONNECT,SSL_R_SSL23_DOING_SESSION_ID_REUSE);
 175                                 ret= -1;
 176                                 goto end;
 177                                 }
 178                         s->server=0;
 179                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
 180
 181                         /* s->version=TLS1_VERSION; */
 182                         s->type=SSL_ST_CONNECT;
 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                                 buf=NULL;
 198                                 }
 199
 200                         if (!ssl3_setup_buffers(s)) { ret= -1; goto end; }
 201
 202                         ssl3_init_finished_mac(s);
 203
 204                         s->state=SSL23_ST_CW_CLNT_HELLO_A;
 205                         s->ctx->stats.sess_connect++;
 206                         s->init_num=0;
 207                         break;
 208
 209                 case SSL23_ST_CW_CLNT_HELLO_A:
 210                 case SSL23_ST_CW_CLNT_HELLO_B:
 211
 212                         s->shutdown=0;
 213                         ret=ssl23_client_hello(s);
 214                         if (ret <= 0) goto end;
 215                         s->state=SSL23_ST_CR_SRVR_HELLO_A;
 216                         s->init_num=0;
 217
 218                         break;
 219
 220                 case SSL23_ST_CR_SRVR_HELLO_A:
 221                 case SSL23_ST_CR_SRVR_HELLO_B:
 222                         ret=ssl23_get_server_hello(s);
 223                         if (ret >= 0) cb=NULL;
 224                         goto end;
 225                         /* break; */
 226
 227                 default:
 228                         SSLerr(SSL_F_SSL23_CONNECT,SSL_R_UNKNOWN_STATE);
 229                         ret= -1;
 230                         goto end;
 231                         /* break; */
 232                         }
 233
 234                 if (s->debug) { (void)BIO_flush(s->wbio); }
 235
 236                 if ((cb != NULL) && (s->state != state))
 237                         {
 238                         new_state=s->state;
 239                         s->state=state;
 240                         cb(s,SSL_CB_CONNECT_LOOP,1);
 241                         s->state=new_state;
 242                         }
 243                 }
 244 end:
 245         s->in_handshake--;
 246         if (buf != NULL)
 247                 BUF_MEM_free(buf);
 248         if (cb != NULL)
 249                 cb(s,SSL_CB_CONNECT_EXIT,ret);
 250         return(ret);
 251         }
 252
 253
 254 static int ssl23_client_hello(SSL *s)
 255         {
 256         unsigned char *buf;
 257         unsigned char *p,*d;
 258         int i,j,ch_len;
 259         unsigned long Time,l;
 260         int ssl2_compat;
 261         int version = 0, version_major, version_minor;
 262         SSL_COMP *comp;
 263         int ret;
 264
 265         ssl2_compat = (s->options & SSL_OP_NO_SSLv2) ? 0 : 1;
 266
 267         if (!(s->options & SSL_OP_NO_TLSv1))
 268                 {
 269                 version = TLS1_VERSION;
 270                 }
 271         else if (!(s->options & SSL_OP_NO_SSLv3))
 272                 {
 273                 version = SSL3_VERSION;
 274                 }
 275         else if (!(s->options & SSL_OP_NO_SSLv2))
 276                 {
 277                 version = SSL2_VERSION;
 278                 }
 279
 280         buf=(unsigned char *)s->init_buf->data;
 281         if (s->state == SSL23_ST_CW_CLNT_HELLO_A)
 282                 {
 283 #if 0
 284                 /* don't reuse session-id's */
 285                 if (!ssl_get_new_session(s,0))
 286                         {
 287                         return(-1);
 288                         }
 289 #endif
 290
 291                 p=s->s3->client_random;
 292                 Time=(unsigned long)time(NULL);         /* Time */
 293                 l2n(Time,p);
 294                 if (RAND_pseudo_bytes(p,SSL3_RANDOM_SIZE-4) <= 0)
 295                         return -1;
 296
 297                 if (version == TLS1_VERSION)
 298                         {
 299                         version_major = TLS1_VERSION_MAJOR;
 300                         version_minor = TLS1_VERSION_MINOR;
 301                         }
 302                 else if (version == SSL3_VERSION)
 303                         {
 304                         version_major = SSL3_VERSION_MAJOR;
 305                         version_minor = SSL3_VERSION_MINOR;
 306                         }
 307                 else if (version == SSL2_VERSION)
 308                         {
 309                         version_major = SSL2_VERSION_MAJOR;
 310                         version_minor = SSL2_VERSION_MINOR;
 311                         }
 312                 else
 313                         {
 314                         SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_PROTOCOLS_AVAILABLE);
 315                         return(-1);
 316                         }
 317
 318                 s->client_version = version;
 319
 320                 if (ssl2_compat)
 321                         {
 322                         /* create SSL 2.0 compatible Client Hello */
 323
 324                         /* two byte record header will be written last */
 325                         d = &(buf[2]);
 326                         p = d + 9; /* leave space for message type, version, individual length fields */
 327
 328                         *(d++) = SSL2_MT_CLIENT_HELLO;
 329                         *(d++) = version_major;
 330                         *(d++) = version_minor;
 331
 332                         /* Ciphers supported */
 333                         i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),p,0);
 334                         if (i == 0)
 335                                 {
 336                                 /* no ciphers */
 337                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
 338                                 return -1;
 339                                 }
 340                         s2n(i,d);
 341                         p+=i;
 342
 343                         /* put in the session-id length (zero since there is no reuse) */
 344 #if 0
 345                         s->session->session_id_length=0;
 346 #endif
 347                         s2n(0,d);
 348
 349                         if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
 350                                 ch_len=SSL2_CHALLENGE_LENGTH;
 351                         else
 352                                 ch_len=SSL2_MAX_CHALLENGE_LENGTH;
 353
 354                         /* write out sslv2 challenge */
 355                         if (SSL3_RANDOM_SIZE < ch_len)
 356                                 i=SSL3_RANDOM_SIZE;
 357                         else
 358                                 i=ch_len;
 359                         s2n(i,d);
 360                         memset(&(s->s3->client_random[0]),0,SSL3_RANDOM_SIZE);
 361                         if (RAND_pseudo_bytes(&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i) <= 0)
 362                                 return -1;
 363
 364                         memcpy(p,&(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i);
 365                         p+=i;
 366
 367                         i= p- &(buf[2]);
 368                         buf[0]=((i>>8)&0xff)|0x80;
 369                         buf[1]=(i&0xff);
 370
 371                         /* number of bytes to write */
 372                         s->init_num=i+2;
 373                         s->init_off=0;
 374
 375                         ssl3_finish_mac(s,&(buf[2]),i);
 376                         }
 377                 else
 378                         {
 379                         /* create Client Hello in SSL 3.0/TLS 1.0 format */
 380
 381                         /* do the record header (5 bytes) and handshake message header (4 bytes) last */
 382                         d = p = &(buf[9]);
 383
 384                         *(p++) = version_major;
 385                         *(p++) = version_minor;
 386
 387                         /* Random stuff */
 388                         memcpy(p, s->s3->client_random, SSL3_RANDOM_SIZE);
 389                         p += SSL3_RANDOM_SIZE;
 390
 391                         /* Session ID (zero since there is no reuse) */
 392                         *(p++) = 0;
 393
 394                         /* Ciphers supported (using SSL 3.0/TLS 1.0 format) */
 395                         i=ssl_cipher_list_to_bytes(s,SSL_get_ciphers(s),&(p[2]),ssl3_put_cipher_by_char);
 396                         if (i == 0)
 397                                 {
 398                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,SSL_R_NO_CIPHERS_AVAILABLE);
 399                                 return -1;
 400                                 }
 401                         s2n(i,p);
 402                         p+=i;
 403
 404                         /* COMPRESSION */
 405 #ifdef OPENSSL_NO_COMP
 406                         *(p++)=1;
 407 #else
 408                         if ((s->options & SSL_OP_NO_COMPRESSION)
 409                                                 || !s->ctx->comp_methods)
 410                                 j=0;
 411                         else
 412                                 j=sk_SSL_COMP_num(s->ctx->comp_methods);
 413                         *(p++)=1+j;
 414                         for (i=0; i<j; i++)
 415                                 {
 416                                 comp=sk_SSL_COMP_value(s->ctx->comp_methods,i);
 417                                 *(p++)=comp->id;
 418                                 }
 419 #endif
 420                         *(p++)=0; /* Add the NULL method */
 421
 422 #ifndef OPENSSL_NO_TLSEXT
 423                         if ((p = ssl_add_clienthello_tlsext(s, p, buf+SSL3_RT_MAX_PLAIN_LENGTH)) == NULL)
 424                                 {
 425                                 SSLerr(SSL_F_SSL3_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
 426                                 return -1;
 427                                 }
 428 #endif
 429
 430                         l = p-d;
 431
 432                         /* fill in 4-byte handshake header */
 433                         d=&(buf[5]);
 434                         *(d++)=SSL3_MT_CLIENT_HELLO;
 435                         l2n3(l,d);
 436
 437                         l += 4;
 438
 439                         if (l > SSL3_RT_MAX_PLAIN_LENGTH)
 440                                 {
 441                                 SSLerr(SSL_F_SSL23_CLIENT_HELLO,ERR_R_INTERNAL_ERROR);
 442                                 return -1;
 443                                 }
 444
 445                         /* fill in 5-byte record header */
 446                         d=buf;
 447                         *(d++) = SSL3_RT_HANDSHAKE;
 448                         *(d++) = version_major;
 449                         *(d++) = version_minor; /* arguably we should send the *lowest* suported version here
 450                                                  * (indicating, e.g., TLS 1.0 in "SSL 3.0 format") */
 451                         s2n((int)l,d);
 452
 453                         /* number of bytes to write */
 454                         s->init_num=p-buf;
 455                         s->init_off=0;
 456
 457                         ssl3_finish_mac(s,&(buf[5]), s->init_num - 5);
 458                         }
 459
 460                 s->state=SSL23_ST_CW_CLNT_HELLO_B;
 461                 s->init_off=0;
 462                 }
 463
 464         /* SSL3_ST_CW_CLNT_HELLO_B */
 465         ret = ssl23_write_bytes(s);
 466
 467         if ((ret >= 2) && s->msg_callback)
 468                 {
 469                 /* Client Hello has been sent; tell msg_callback */
 470
 471                 if (ssl2_compat)
 472                         s->msg_callback(1, SSL2_VERSION, 0, s->init_buf->data+2, ret-2, s, s->msg_callback_arg);
 473                 else
 474                         s->msg_callback(1, version, SSL3_RT_HANDSHAKE, s->init_buf->data+5, ret-5, s, s->msg_callback_arg);
 475                 }
 476
 477         return ret;
 478         }
 479
 480 static int ssl23_get_server_hello(SSL *s)
 481         {
 482         char buf[8];
 483         unsigned char *p;
 484         int i;
 485         int n;
 486
 487         n=ssl23_read_bytes(s,7);
 488
 489         if (n != 7) return(n);
 490         p=s->packet;
 491
 492         memcpy(buf,p,n);
 493
 494         if ((p[0] & 0x80) && (p[2] == SSL2_MT_SERVER_HELLO) &&
 495                 (p[5] == 0x00) && (p[6] == 0x02))
 496                 {
 497 #ifdef OPENSSL_NO_SSL2
 498                 SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
 499                 goto err;
 500 #else
 501                 /* we are talking sslv2 */
 502                 /* we need to clean up the SSLv3 setup and put in the
 503                  * sslv2 stuff. */
 504                 int ch_len;
 505
 506                 if (s->options & SSL_OP_NO_SSLv2)
 507                         {
 508                         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
 509                         goto err;
 510                         }
 511                 if (s->s2 == NULL)
 512                         {
 513                         if (!ssl2_new(s))
 514                                 goto err;
 515                         }
 516                 else
 517                         ssl2_clear(s);
 518
 519                 if (s->options & SSL_OP_NETSCAPE_CHALLENGE_BUG)
 520                         ch_len=SSL2_CHALLENGE_LENGTH;
 521                 else
 522                         ch_len=SSL2_MAX_CHALLENGE_LENGTH;
 523
 524                 /* write out sslv2 challenge */
 525                 i=(SSL3_RANDOM_SIZE < ch_len)
 526                         ?SSL3_RANDOM_SIZE:ch_len;
 527                 s->s2->challenge_length=i;
 528                 memcpy(s->s2->challenge,
 529                         &(s->s3->client_random[SSL3_RANDOM_SIZE-i]),i);
 530
 531                 if (s->s3 != NULL) ssl3_free(s);
 532
 533                 if (!BUF_MEM_grow_clean(s->init_buf,
 534                         SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER))
 535                         {
 536                         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,ERR_R_BUF_LIB);
 537                         goto err;
 538                         }
 539
 540                 s->state=SSL2_ST_GET_SERVER_HELLO_A;
 541                 if (!(s->client_version == SSL2_VERSION))
 542                         /* use special padding (SSL 3.0 draft/RFC 2246, App. E.2) */
 543                         s->s2->ssl2_rollback=1;
 544
 545                 /* setup the 5 bytes we have read so we get them from
 546                  * the sslv2 buffer */
 547                 s->rstate=SSL_ST_READ_HEADER;
 548                 s->packet_length=n;
 549                 s->packet= &(s->s2->rbuf[0]);
 550                 memcpy(s->packet,buf,n);
 551                 s->s2->rbuf_left=n;
 552                 s->s2->rbuf_offs=0;
 553
 554                 /* we have already written one */
 555                 s->s2->write_sequence=1;
 556
 557                 s->method=SSLv2_client_method();
 558                 s->handshake_func=s->method->ssl_connect;
 559 #endif
 560                 }
 561         else if ((p[0] == SSL3_RT_HANDSHAKE) &&
 562                  (p[1] == SSL3_VERSION_MAJOR) &&
 563                  ((p[2] == SSL3_VERSION_MINOR) ||
 564                   (p[2] == TLS1_VERSION_MINOR)) &&
 565                  (p[5] == SSL3_MT_SERVER_HELLO))
 566                 {
 567                 /* we have sslv3 or tls1 */
 568
 569                 if (!ssl_init_wbio_buffer(s,1)) goto err;
 570
 571                 /* we are in this state */
 572                 s->state=SSL3_ST_CR_SRVR_HELLO_A;
 573
 574                 /* put the 5 bytes we have read into the input buffer
 575                  * for SSLv3 */
 576                 s->rstate=SSL_ST_READ_HEADER;
 577                 s->packet_length=n;
 578                 s->packet= &(s->s3->rbuf.buf[0]);
 579                 memcpy(s->packet,buf,n);
 580                 s->s3->rbuf.left=n;
 581                 s->s3->rbuf.offset=0;
 582
 583                 if ((p[2] == SSL3_VERSION_MINOR) &&
 584                         !(s->options & SSL_OP_NO_SSLv3))
 585                         {
 586                         s->version=SSL3_VERSION;
 587                         s->method=SSLv3_client_method();
 588                         }
 589                 else if ((p[2] == TLS1_VERSION_MINOR) &&
 590                         !(s->options & SSL_OP_NO_TLSv1))
 591                         {
 592                         s->version=TLS1_VERSION;
 593                         s->method=TLSv1_client_method();
 594                         }
 595                 else
 596                         {
 597                         SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
 598                         goto err;
 599                         }
 600
 601                 s->handshake_func=s->method->ssl_connect;
 602                 }
 603         else if ((p[0] == SSL3_RT_ALERT) &&
 604                  (p[1] == SSL3_VERSION_MAJOR) &&
 605                  ((p[2] == SSL3_VERSION_MINOR) ||
 606                   (p[2] == TLS1_VERSION_MINOR)) &&
 607                  (p[3] == 0) &&
 608                  (p[4] == 2))
 609                 {
 610                 void (*cb)(const SSL *ssl,int type,int val)=NULL;
 611                 int j;
 612
 613                 /* An alert */
 614                 if (s->info_callback != NULL)
 615                         cb=s->info_callback;
 616                 else if (s->ctx->info_callback != NULL)
 617                         cb=s->ctx->info_callback;
 618
 619                 i=p[5];
 620                 if (cb != NULL)
 621                         {
 622                         j=(i<<8)|p[6];
 623                         cb(s,SSL_CB_READ_ALERT,j);
 624                         }
 625
 626                 s->rwstate=SSL_NOTHING;
 627                 SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_AD_REASON_OFFSET+p[6]);
 628                 goto err;
 629                 }
 630         else
 631                 {
 632                 SSLerr(SSL_F_SSL23_GET_SERVER_HELLO,SSL_R_UNKNOWN_PROTOCOL);
 633                 goto err;
 634                 }
 635         s->init_num=0;
 636
 637         /* Since, if we are sending a ssl23 client hello, we are not
 638          * reusing a session-id */
 639         if (!ssl_get_new_session(s,0))
 640                 goto err;
 641
 642         s->first_packet=1;
 643         return(SSL_connect(s));
 644 err:
 645         return(-1);
 646         }
 647