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) 1998-2001 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_server_method(int ver);
 120 int ssl23_get_client_hello(SSL *s);
 121 static const SSL_METHOD *ssl23_get_server_method(int ver)
 122         {
 123 #ifndef OPENSSL_NO_SSL2
 124         if (ver == SSL2_VERSION)
 125                 return(SSLv2_server_method());
 126 #endif
 127         if (ver == SSL3_VERSION)
 128                 return(SSLv3_server_method());
 129         else if (ver == TLS1_VERSION)
 130                 return(TLSv1_server_method());
 131         else
 132                 return(NULL);
 133         }
 134
 135 IMPLEMENT_ssl23_meth_func(SSLv23_server_method,
 136                         ssl23_accept,
 137                         ssl_undefined_function,
 138                         ssl23_get_server_method)
 139
 140 int ssl23_accept(SSL *s)
 141         {
 142         BUF_MEM *buf;
 143         unsigned long Time=time(NULL);
 144         void (*cb)(const SSL *ssl,int type,int val)=NULL;
 145         int ret= -1;
 146         int new_state,state;
 147
 148         RAND_add(&Time,sizeof(Time),0);
 149         ERR_clear_error();
 150         clear_sys_error();
 151
 152         if (s->info_callback != NULL)
 153                 cb=s->info_callback;
 154         else if (s->ctx->info_callback != NULL)
 155                 cb=s->ctx->info_callback;
 156
 157         s->in_handshake++;
 158         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
 159
 160         for (;;)
 161                 {
 162                 state=s->state;
 163
 164                 switch(s->state)
 165                         {
 166                 case SSL_ST_BEFORE:
 167                 case SSL_ST_ACCEPT:
 168                 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
 169                 case SSL_ST_OK|SSL_ST_ACCEPT:
 170
 171                         s->server=1;
 172                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
 173
 174                         /* s->version=SSL3_VERSION; */
 175                         s->type=SSL_ST_ACCEPT;
 176
 177                         if (s->init_buf == NULL)
 178                                 {
 179                                 if ((buf=BUF_MEM_new()) == NULL)
 180                                         {
 181                                         ret= -1;
 182                                         goto end;
 183                                         }
 184                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
 185                                         {
 186                                         ret= -1;
 187                                         goto end;
 188                                         }
 189                                 s->init_buf=buf;
 190                                 }
 191
 192                         ssl3_init_finished_mac(s);
 193
 194                         s->state=SSL23_ST_SR_CLNT_HELLO_A;
 195                         s->ctx->stats.sess_accept++;
 196                         s->init_num=0;
 197                         break;
 198
 199                 case SSL23_ST_SR_CLNT_HELLO_A:
 200                 case SSL23_ST_SR_CLNT_HELLO_B:
 201
 202                         s->shutdown=0;
 203                         ret=ssl23_get_client_hello(s);
 204                         if (ret >= 0) cb=NULL;
 205                         goto end;
 206                         /* break; */
 207
 208                 default:
 209                         SSLerr(SSL_F_SSL23_ACCEPT,SSL_R_UNKNOWN_STATE);
 210                         ret= -1;
 211                         goto end;
 212                         /* break; */
 213                         }
 214
 215                 if ((cb != NULL) && (s->state != state))
 216                         {
 217                         new_state=s->state;
 218                         s->state=state;
 219                         cb(s,SSL_CB_ACCEPT_LOOP,1);
 220                         s->state=new_state;
 221                         }
 222                 }
 223 end:
 224         s->in_handshake--;
 225         if (cb != NULL)
 226                 cb(s,SSL_CB_ACCEPT_EXIT,ret);
 227         return(ret);
 228         }
 229
 230
 231 int ssl23_get_client_hello(SSL *s)
 232         {
 233         char buf_space[11]; /* Request this many bytes in initial read.
 234                              * We can detect SSL 3.0/TLS 1.0 Client Hellos
 235                              * ('type == 3') correctly only when the following
 236                              * is in a single record, which is not guaranteed by
 237                              * the protocol specification:
 238                              * Byte  Content
 239                              *  0     type            \
 240                              *  1/2   version          > record header
 241                              *  3/4   length          /
 242                              *  5     msg_type        \
 243                              *  6-8   length           > Client Hello message
 244                              *  9/10  client_version  /
 245                              */
 246         char *buf= &(buf_space[0]);
 247         unsigned char *p,*d,*d_len,*dd;
 248         unsigned int i;
 249         unsigned int csl,sil,cl;
 250         int n=0,j;
 251         int type=0;
 252         int v[2];
 253 #ifndef OPENSSL_NO_RSA
 254         int use_sslv2_strong=0;
 255 #endif
 256
 257         if (s->state == SSL23_ST_SR_CLNT_HELLO_A)
 258                 {
 259                 /* read the initial header */
 260                 v[0]=v[1]=0;
 261
 262                 if (!ssl3_setup_buffers(s)) goto err;
 263
 264                 n=ssl23_read_bytes(s, sizeof buf_space);
 265                 if (n != sizeof buf_space) return(n); /* n == -1 || n == 0 */
 266
 267                 p=s->packet;
 268
 269                 memcpy(buf,p,n);
 270
 271                 if ((p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO))
 272                         {
 273                         /*
 274                          * SSLv2 header
 275                          */
 276                         if ((p[3] == 0x00) && (p[4] == 0x02))
 277                                 {
 278                                 v[0]=p[3]; v[1]=p[4];
 279                                 /* SSLv2 */
 280                                 if (!(s->options & SSL_OP_NO_SSLv2))
 281                                         type=1;
 282                                 }
 283                         else if (p[3] == SSL3_VERSION_MAJOR)
 284                                 {
 285                                 v[0]=p[3]; v[1]=p[4];
 286                                 /* SSLv3/TLSv1 */
 287                                 if (p[4] >= TLS1_VERSION_MINOR)
 288                                         {
 289                                         if (!(s->options & SSL_OP_NO_TLSv1))
 290                                                 {
 291                                                 s->version=TLS1_VERSION;
 292                                                 /* type=2; */ /* done later to survive restarts */
 293                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
 294                                                 }
 295                                         else if (!(s->options & SSL_OP_NO_SSLv3))
 296                                                 {
 297                                                 s->version=SSL3_VERSION;
 298                                                 /* type=2; */
 299                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
 300                                                 }
 301                                         else if (!(s->options & SSL_OP_NO_SSLv2))
 302                                                 {
 303                                                 type=1;
 304                                                 }
 305                                         }
 306                                 else if (!(s->options & SSL_OP_NO_SSLv3))
 307                                         {
 308                                         s->version=SSL3_VERSION;
 309                                         /* type=2; */
 310                                         s->state=SSL23_ST_SR_CLNT_HELLO_B;
 311                                         }
 312                                 else if (!(s->options & SSL_OP_NO_SSLv2))
 313                                         type=1;
 314
 315                                 }
 316                         }
 317                 else if ((p[0] == SSL3_RT_HANDSHAKE) &&
 318                          (p[1] == SSL3_VERSION_MAJOR) &&
 319                          (p[5] == SSL3_MT_CLIENT_HELLO) &&
 320                          ((p[3] == 0 && p[4] < 5 /* silly record length? */)
 321                                 || (p[9] == p[1])))
 322                         {
 323                         /*
 324                          * SSLv3 or tls1 header
 325                          */
 326
 327                         v[0]=p[1]; /* major version (= SSL3_VERSION_MAJOR) */
 328                         /* We must look at client_version inside the Client Hello message
 329                          * to get the correct minor version.
 330                          * However if we have only a pathologically small fragment of the
 331                          * Client Hello message, this would be difficult, and we'd have
 332                          * to read more records to find out.
 333                          * No known SSL 3.0 client fragments ClientHello like this,
 334                          * so we simply assume TLS 1.0 to avoid protocol version downgrade
 335                          * attacks. */
 336                         if (p[3] == 0 && p[4] < 6)
 337                                 {
 338 #if 0
 339                                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_SMALL);
 340                                 goto err;
 341 #else
 342                                 v[1] = TLS1_VERSION_MINOR;
 343 #endif
 344                                 }
 345                         else
 346                                 v[1]=p[10]; /* minor version according to client_version */
 347                         if (v[1] >= TLS1_VERSION_MINOR)
 348                                 {
 349                                 if (!(s->options & SSL_OP_NO_TLSv1))
 350                                         {
 351                                         s->version=TLS1_VERSION;
 352                                         type=3;
 353                                         }
 354                                 else if (!(s->options & SSL_OP_NO_SSLv3))
 355                                         {
 356                                         s->version=SSL3_VERSION;
 357                                         type=3;
 358                                         }
 359                                 }
 360                         else
 361                                 {
 362                                 /* client requests SSL 3.0 */
 363                                 if (!(s->options & SSL_OP_NO_SSLv3))
 364                                         {
 365                                         s->version=SSL3_VERSION;
 366                                         type=3;
 367                                         }
 368                                 else if (!(s->options & SSL_OP_NO_TLSv1))
 369                                         {
 370                                         /* we won't be able to use TLS of course,
 371                                          * but this will send an appropriate alert */
 372                                         s->version=TLS1_VERSION;
 373                                         type=3;
 374                                         }
 375                                 }
 376                         }
 377                 else if ((strncmp("GET ", (char *)p,4) == 0) ||
 378                          (strncmp("POST ",(char *)p,5) == 0) ||
 379                          (strncmp("HEAD ",(char *)p,5) == 0) ||
 380                          (strncmp("PUT ", (char *)p,4) == 0))
 381                         {
 382                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTP_REQUEST);
 383                         goto err;
 384                         }
 385                 else if (strncmp("CONNECT",(char *)p,7) == 0)
 386                         {
 387                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTPS_PROXY_REQUEST);
 388                         goto err;
 389                         }
 390                 }
 391
 392         if (s->state == SSL23_ST_SR_CLNT_HELLO_B)
 393                 {
 394                 /* we have SSLv3/TLSv1 in an SSLv2 header
 395                  * (other cases skip this state) */
 396
 397                 type=2;
 398                 p=s->packet;
 399                 v[0] = p[3]; /* == SSL3_VERSION_MAJOR */
 400                 v[1] = p[4];
 401
 402                 n=((p[0]&0x7f)<<8)|p[1];
 403                 if (n > (1024*4))
 404                         {
 405                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_LARGE);
 406                         goto err;
 407                         }
 408
 409                 j=ssl23_read_bytes(s,n+2);
 410                 if (j <= 0) return(j);
 411
 412                 ssl3_finish_mac(s, s->packet+2, s->packet_length-2);
 413                 if (s->msg_callback)
 414                         s->msg_callback(0, SSL2_VERSION, 0, s->packet+2, s->packet_length-2, s, s->msg_callback_arg); /* CLIENT-HELLO */
 415
 416                 p=s->packet;
 417                 p+=5;
 418                 n2s(p,csl);
 419                 n2s(p,sil);
 420                 n2s(p,cl);
 421                 d=(unsigned char *)s->init_buf->data;
 422                 if ((csl+sil+cl+11) != s->packet_length)
 423                         {
 424                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_LENGTH_MISMATCH);
 425                         goto err;
 426                         }
 427
 428                 /* record header: msg_type ... */
 429                 *(d++) = SSL3_MT_CLIENT_HELLO;
 430                 /* ... and length (actual value will be written later) */
 431                 d_len = d;
 432                 d += 3;
 433
 434                 /* client_version */
 435                 *(d++) = SSL3_VERSION_MAJOR; /* == v[0] */
 436                 *(d++) = v[1];
 437
 438                 /* lets populate the random area */
 439                 /* get the challenge_length */
 440                 i=(cl > SSL3_RANDOM_SIZE)?SSL3_RANDOM_SIZE:cl;
 441                 memset(d,0,SSL3_RANDOM_SIZE);
 442                 memcpy(&(d[SSL3_RANDOM_SIZE-i]),&(p[csl+sil]),i);
 443                 d+=SSL3_RANDOM_SIZE;
 444
 445                 /* no session-id reuse */
 446                 *(d++)=0;
 447
 448                 /* ciphers */
 449                 j=0;
 450                 dd=d;
 451                 d+=2;
 452                 for (i=0; i<csl; i+=3)
 453                         {
 454                         if (p[i] != 0) continue;
 455                         *(d++)=p[i+1];
 456                         *(d++)=p[i+2];
 457                         j+=2;
 458                         }
 459                 s2n(j,dd);
 460
 461                 /* COMPRESSION */
 462                 *(d++)=1;
 463                 *(d++)=0;
 464
 465                 i = (d-(unsigned char *)s->init_buf->data) - 4;
 466                 l2n3((long)i, d_len);
 467
 468                 /* get the data reused from the init_buf */
 469                 s->s3->tmp.reuse_message=1;
 470                 s->s3->tmp.message_type=SSL3_MT_CLIENT_HELLO;
 471                 s->s3->tmp.message_size=i;
 472                 }
 473
 474         /* imaginary new state (for program structure): */
 475         /* s->state = SSL23_SR_CLNT_HELLO_C */
 476
 477         if (type == 1)
 478                 {
 479 #ifdef OPENSSL_NO_SSL2
 480                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
 481                 goto err;
 482 #else
 483                 /* we are talking sslv2 */
 484                 /* we need to clean up the SSLv3/TLSv1 setup and put in the
 485                  * sslv2 stuff. */
 486
 487                 if (s->s2 == NULL)
 488                         {
 489                         if (!ssl2_new(s))
 490                                 goto err;
 491                         }
 492                 else
 493                         ssl2_clear(s);
 494
 495                 if (s->s3 != NULL) ssl3_free(s);
 496
 497                 if (!BUF_MEM_grow_clean(s->init_buf,
 498                         SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER))
 499                         {
 500                         goto err;
 501                         }
 502
 503                 s->state=SSL2_ST_GET_CLIENT_HELLO_A;
 504                 if ((s->options & SSL_OP_MSIE_SSLV2_RSA_PADDING) ||
 505                         use_sslv2_strong ||
 506                         (s->options & SSL_OP_NO_TLSv1 && s->options & SSL_OP_NO_SSLv3))
 507                         s->s2->ssl2_rollback=0;
 508                 else
 509                         /* reject SSL 2.0 session if client supports SSL 3.0 or TLS 1.0
 510                          * (SSL 3.0 draft/RFC 2246, App. E.2) */
 511                         s->s2->ssl2_rollback=1;
 512
 513                 /* setup the n bytes we have read so we get them from
 514                  * the sslv2 buffer */
 515                 s->rstate=SSL_ST_READ_HEADER;
 516                 s->packet_length=n;
 517                 s->packet= &(s->s2->rbuf[0]);
 518                 memcpy(s->packet,buf,n);
 519                 s->s2->rbuf_left=n;
 520                 s->s2->rbuf_offs=0;
 521
 522                 s->method=SSLv2_server_method();
 523                 s->handshake_func=s->method->ssl_accept;
 524 #endif
 525                 }
 526
 527         if ((type == 2) || (type == 3))
 528                 {
 529                 /* we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style) */
 530
 531                 if (!ssl_init_wbio_buffer(s,1)) goto err;
 532
 533                 /* we are in this state */
 534                 s->state=SSL3_ST_SR_CLNT_HELLO_A;
 535
 536                 if (type == 3)
 537                         {
 538                         /* put the 'n' bytes we have read into the input buffer
 539                          * for SSLv3 */
 540                         s->rstate=SSL_ST_READ_HEADER;
 541                         s->packet_length=n;
 542                         s->packet= &(s->s3->rbuf.buf[0]);
 543                         memcpy(s->packet,buf,n);
 544                         s->s3->rbuf.left=n;
 545                         s->s3->rbuf.offset=0;
 546                         }
 547                 else
 548                         {
 549                         s->packet_length=0;
 550                         s->s3->rbuf.left=0;
 551                         s->s3->rbuf.offset=0;
 552                         }
 553
 554                 if (s->version == TLS1_VERSION)
 555                         s->method = TLSv1_server_method();
 556                 else
 557                         s->method = SSLv3_server_method();
 558 #if 0 /* ssl3_get_client_hello does this */
 559                 s->client_version=(v[0]<<8)|v[1];
 560 #endif
 561                 s->handshake_func=s->method->ssl_accept;
 562                 }
 563
 564         if ((type < 1) || (type > 3))
 565                 {
 566                 /* bad, very bad */
 567                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNKNOWN_PROTOCOL);
 568                 goto err;
 569                 }
 570         s->init_num=0;
 571
 572         if (buf != buf_space) OPENSSL_free(buf);
 573         s->first_packet=1;
 574         return(SSL_accept(s));
 575 err:
 576         if (buf != buf_space) OPENSSL_free(buf);
 577         return(-1);
 578         }