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 #include <stdio.h>
  60 #include <openssl/buffer.h>
  61 #include <openssl/rand.h>
  62 #include <openssl/objects.h>
  63 #include <openssl/evp.h>
  64 #include "ssl_locl.h"
  65
  66 static SSL_METHOD *ssl23_get_server_method(int ver);
  67 int ssl23_get_client_hello(SSL *s);
  68 static SSL_METHOD *ssl23_get_server_method(int ver)
  69         {
  70 #ifndef NO_SSL2
  71         if (ver == SSL2_VERSION)
  72                 return(SSLv2_server_method());
  73 #endif
  74         if (ver == SSL3_VERSION)
  75                 return(SSLv3_server_method());
  76         else if (ver == TLS1_VERSION)
  77                 return(TLSv1_server_method());
  78         else
  79                 return(NULL);
  80         }
  81
  82 SSL_METHOD *SSLv23_server_method(void)
  83         {
  84         static int init=1;
  85         static SSL_METHOD SSLv23_server_data;
  86
  87         if (init)
  88                 {
  89                 memcpy((char *)&SSLv23_server_data,
  90                         (char *)sslv23_base_method(),sizeof(SSL_METHOD));
  91                 SSLv23_server_data.ssl_accept=ssl23_accept;
  92                 SSLv23_server_data.get_ssl_method=ssl23_get_server_method;
  93                 init=0;
  94                 }
  95         return(&SSLv23_server_data);
  96         }
  97
  98 int ssl23_accept(SSL *s)
  99         {
 100         BUF_MEM *buf;
 101         unsigned long Time=time(NULL);
 102         void (*cb)()=NULL;
 103         int ret= -1;
 104         int new_state,state;
 105
 106         RAND_add(&Time,sizeof(Time),0);
 107         ERR_clear_error();
 108         clear_sys_error();
 109
 110         if (s->info_callback != NULL)
 111                 cb=s->info_callback;
 112         else if (s->ctx->info_callback != NULL)
 113                 cb=s->ctx->info_callback;
 114
 115         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
 116         s->in_handshake++;
 117
 118         for (;;)
 119                 {
 120                 state=s->state;
 121
 122                 switch(s->state)
 123                         {
 124                 case SSL_ST_BEFORE:
 125                 case SSL_ST_ACCEPT:
 126                 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
 127                 case SSL_ST_OK|SSL_ST_ACCEPT:
 128
 129                         s->server=1;
 130                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
 131
 132                         /* s->version=SSL3_VERSION; */
 133                         s->type=SSL_ST_ACCEPT;
 134
 135                         if (s->init_buf == NULL)
 136                                 {
 137                                 if ((buf=BUF_MEM_new()) == NULL)
 138                                         {
 139                                         ret= -1;
 140                                         goto end;
 141                                         }
 142                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
 143                                         {
 144                                         ret= -1;
 145                                         goto end;
 146                                         }
 147                                 s->init_buf=buf;
 148                                 }
 149
 150                         ssl3_init_finished_mac(s);
 151
 152                         s->state=SSL23_ST_SR_CLNT_HELLO_A;
 153                         s->ctx->stats.sess_accept++;
 154                         s->init_num=0;
 155                         break;
 156
 157                 case SSL23_ST_SR_CLNT_HELLO_A:
 158                 case SSL23_ST_SR_CLNT_HELLO_B:
 159
 160                         s->shutdown=0;
 161                         ret=ssl23_get_client_hello(s);
 162                         if (ret >= 0) cb=NULL;
 163                         goto end;
 164                         /* break; */
 165
 166                 default:
 167                         SSLerr(SSL_F_SSL23_ACCEPT,SSL_R_UNKNOWN_STATE);
 168                         ret= -1;
 169                         goto end;
 170                         /* break; */
 171                         }
 172
 173                 if ((cb != NULL) && (s->state != state))
 174                         {
 175                         new_state=s->state;
 176                         s->state=state;
 177                         cb(s,SSL_CB_ACCEPT_LOOP,1);
 178                         s->state=new_state;
 179                         }
 180                 }
 181 end:
 182         if (cb != NULL)
 183                 cb(s,SSL_CB_ACCEPT_EXIT,ret);
 184         s->in_handshake--;
 185         return(ret);
 186         }
 187
 188
 189 int ssl23_get_client_hello(SSL *s)
 190         {
 191         char buf_space[11]; /* Request this many bytes in initial read.
 192                              * We can detect SSL 3.0/TLS 1.0 Client Hellos
 193                              * ('type == 3') correctly only when the following
 194                              * is in a single record, which is not guaranteed by
 195                              * the protocol specification:
 196                              * Byte  Content
 197                              *  0     type            \
 198                              *  1/2   version          > record header
 199                              *  3/4   length          /
 200                              *  5     msg_type        \
 201                              *  6-8   length           > Client Hello message
 202                              *  9/10  client_version  /
 203                              */
 204         char *buf= &(buf_space[0]);
 205         unsigned char *p,*d,*dd;
 206         unsigned int i;
 207         unsigned int csl,sil,cl;
 208         int n=0,j;
 209         int type=0;
 210         int v[2];
 211 #ifndef NO_RSA
 212         int use_sslv2_strong=0;
 213 #endif
 214
 215         if (s->state == SSL23_ST_SR_CLNT_HELLO_A)
 216                 {
 217                 /* read the initial header */
 218                 v[0]=v[1]=0;
 219
 220                 if (!ssl3_setup_buffers(s)) goto err;
 221
 222                 n=ssl23_read_bytes(s, sizeof buf_space);
 223                 if (n != sizeof buf_space) return(n); /* n == -1 || n == 0 */
 224
 225                 p=s->packet;
 226
 227                 memcpy(buf,p,n);
 228
 229                 if ((p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO))
 230                         {
 231                         /*
 232                          * SSLv2 header
 233                          */
 234                         if ((p[3] == 0x00) && (p[4] == 0x02))
 235                                 {
 236                                 v[0]=p[3]; v[1]=p[4];
 237                                 /* SSLv2 */
 238                                 if (!(s->options & SSL_OP_NO_SSLv2))
 239                                         type=1;
 240                                 }
 241                         else if (p[3] == SSL3_VERSION_MAJOR)
 242                                 {
 243                                 v[0]=p[3]; v[1]=p[4];
 244                                 /* SSLv3/TLSv1 */
 245                                 if (p[4] >= TLS1_VERSION_MINOR)
 246                                         {
 247                                         if (!(s->options & SSL_OP_NO_TLSv1))
 248                                                 {
 249                                                 s->version=TLS1_VERSION;
 250                                                 /* type=2; */ /* done later to survive restarts */
 251                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
 252                                                 }
 253                                         else if (!(s->options & SSL_OP_NO_SSLv3))
 254                                                 {
 255                                                 s->version=SSL3_VERSION;
 256                                                 /* type=2; */
 257                                                 s->state=SSL23_ST_SR_CLNT_HELLO_B;
 258                                                 }
 259                                         else if (!(s->options & SSL_OP_NO_SSLv2))
 260                                                 {
 261                                                 type=1;
 262                                                 }
 263                                         }
 264                                 else if (!(s->options & SSL_OP_NO_SSLv3))
 265                                         {
 266                                         s->version=SSL3_VERSION;
 267                                         /* type=2; */
 268                                         s->state=SSL23_ST_SR_CLNT_HELLO_B;
 269                                         }
 270                                 else if (!(s->options & SSL_OP_NO_SSLv2))
 271                                         type=1;
 272
 273                                 if (s->options & SSL_OP_NON_EXPORT_FIRST)
 274                                         /* Not only utterly confusing, but broken
 275                                          * ('fractured programming'?) -- the details
 276                                          * of this block nearly make it work
 277                                          * as intended in this environment, but on one
 278                                          * of the fine points (w.r.t. restarts) it fails.
 279                                          * The obvious fix would be even more devastating
 280                                          * to program structure; if you want the functionality,
 281                                          * throw this away and implement it in a way
 282                                          * that makes sense */
 283                                         {
 284 #if 0
 285                                         STACK_OF(SSL_CIPHER) *sk;
 286                                         SSL_CIPHER *c;
 287                                         int ne2,ne3;
 288
 289                                         j=((p[0]&0x7f)<<8)|p[1];
 290                                         if (j > (1024*4))
 291                                                 {
 292                                                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_LARGE);
 293                                                 goto err;
 294                                                 }
 295
 296                                         n=ssl23_read_bytes(s,j+2);
 297                                         if (n <= 0) return(n);
 298                                         p=s->packet;
 299
 300                                         if ((buf=OPENSSL_malloc(n)) == NULL)
 301                                                 {
 302                                                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,ERR_R_MALLOC_FAILURE);
 303                                                 goto err;
 304                                                 }
 305                                         memcpy(buf,p,n);
 306
 307                                         p+=5;
 308                                         n2s(p,csl);
 309                                         p+=4;
 310
 311                                         sk=ssl_bytes_to_cipher_list(
 312                                                 s,p,csl,NULL);
 313                                         if (sk != NULL)
 314                                                 {
 315                                                 ne2=ne3=0;
 316                                                 for (j=0; j<sk_SSL_CIPHER_num(sk); j++)
 317                                                         {
 318                                                         c=sk_SSL_CIPHER_value(sk,j);
 319                                                         if (!SSL_C_IS_EXPORT(c))
 320                                                                 {
 321                                                                 if ((c->id>>24L) == 2L)
 322                                                                         ne2=1;
 323                                                                 else
 324                                                                         ne3=1;
 325                                                                 }
 326                                                         }
 327                                                 if (ne2 && !ne3)
 328                                                         {
 329                                                         type=1;
 330                                                         use_sslv2_strong=1;
 331                                                         goto next_bit;
 332                                                         }
 333                                                 }
 334 #else
 335                                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNSUPPORTED_OPTION);
 336                                         goto err;
 337 #endif
 338                                         }
 339                                 }
 340                         }
 341                 else if ((p[0] == SSL3_RT_HANDSHAKE) &&
 342                          (p[1] == SSL3_VERSION_MAJOR) &&
 343                          (p[5] == SSL3_MT_CLIENT_HELLO) &&
 344                          ((p[3] == 0 && p[4] < 5 /* silly record length? */)
 345                                 || (p[9] == p[1])))
 346                         {
 347                         /*
 348                          * SSLv3 or tls1 header
 349                          */
 350
 351                         v[0]=p[1]; /* major version (= SSL3_VERSION_MAJOR) */
 352                         /* We must look at client_version inside the Client Hello message
 353                          * to get the correct minor version.
 354                          * However if we have only a pathologically small fragment of the
 355                          * Client Hello message, this would be difficult, we'd have
 356                          * to read at least one additional record to find out.
 357                          * This doesn't usually happen in real life, so we just complain
 358                          * for now.
 359                          */
 360                         if (p[3] == 0 && p[4] < 6)
 361                                 {
 362                                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_SMALL);
 363                                 goto err;
 364                                 }
 365                         v[1]=p[10]; /* minor version according to client_version */
 366                         if (v[1] >= TLS1_VERSION_MINOR)
 367                                 {
 368                                 if (!(s->options & SSL_OP_NO_TLSv1))
 369                                         {
 370                                         s->version=TLS1_VERSION;
 371                                         type=3;
 372                                         }
 373                                 else if (!(s->options & SSL_OP_NO_SSLv3))
 374                                         {
 375                                         s->version=SSL3_VERSION;
 376                                         type=3;
 377                                         }
 378                                 }
 379                         else if (!(s->options & SSL_OP_NO_SSLv3))
 380                                 {
 381                                 s->version=SSL3_VERSION;
 382                                 type=3;
 383                                 }
 384                         }
 385                 else if ((strncmp("GET ", (char *)p,4) == 0) ||
 386                          (strncmp("POST ",(char *)p,5) == 0) ||
 387                          (strncmp("HEAD ",(char *)p,5) == 0) ||
 388                          (strncmp("PUT ", (char *)p,4) == 0))
 389                         {
 390                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTP_REQUEST);
 391                         goto err;
 392                         }
 393                 else if (strncmp("CONNECT",(char *)p,7) == 0)
 394                         {
 395                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_HTTPS_PROXY_REQUEST);
 396                         goto err;
 397                         }
 398                 }
 399
 400         if (s->state == SSL23_ST_SR_CLNT_HELLO_B)
 401                 {
 402                 /* we have SSLv3/TLSv1 in an SSLv2 header
 403                  * (other cases skip this state) */
 404
 405                 type=2;
 406                 p=s->packet;
 407                 v[0] = p[3]; /* == SSL3_VERSION_MAJOR */
 408                 v[1] = p[4];
 409
 410                 n=((p[0]&0x7f)<<8)|p[1];
 411                 if (n > (1024*4))
 412                         {
 413                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_TOO_LARGE);
 414                         goto err;
 415                         }
 416
 417                 j=ssl23_read_bytes(s,n+2);
 418                 if (j <= 0) return(j);
 419
 420                 ssl3_finish_mac(s,&(s->packet[2]),s->packet_length-2);
 421
 422                 p=s->packet;
 423                 p+=5;
 424                 n2s(p,csl);
 425                 n2s(p,sil);
 426                 n2s(p,cl);
 427                 d=(unsigned char *)s->init_buf->data;
 428                 if ((csl+sil+cl+11) != s->packet_length)
 429                         {
 430                         SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_RECORD_LENGTH_MISMATCH);
 431                         goto err;
 432                         }
 433
 434                 *(d++) = SSL3_VERSION_MAJOR; /* == v[0] */
 435                 *(d++) = v[1];
 436
 437                 /* lets populate the random area */
 438                 /* get the challenge_length */
 439                 i=(cl > SSL3_RANDOM_SIZE)?SSL3_RANDOM_SIZE:cl;
 440                 memset(d,0,SSL3_RANDOM_SIZE);
 441                 memcpy(&(d[SSL3_RANDOM_SIZE-i]),&(p[csl+sil]),i);
 442                 d+=SSL3_RANDOM_SIZE;
 443
 444                 /* no session-id reuse */
 445                 *(d++)=0;
 446
 447                 /* ciphers */
 448                 j=0;
 449                 dd=d;
 450                 d+=2;
 451                 for (i=0; i<csl; i+=3)
 452                         {
 453                         if (p[i] != 0) continue;
 454                         *(d++)=p[i+1];
 455                         *(d++)=p[i+2];
 456                         j+=2;
 457                         }
 458                 s2n(j,dd);
 459
 460                 /* COMPRESSION */
 461                 *(d++)=1;
 462                 *(d++)=0;
 463
 464                 i=(d-(unsigned char *)s->init_buf->data);
 465
 466                 /* get the data reused from the init_buf */
 467                 s->s3->tmp.reuse_message=1;
 468                 s->s3->tmp.message_type=SSL3_MT_CLIENT_HELLO;
 469                 s->s3->tmp.message_size=i;
 470                 }
 471
 472         /* imaginary new state (for program structure): */
 473         /* s->state = SSL23_SR_CLNT_HELLO_C */
 474
 475         if (type == 1)
 476                 {
 477 #ifdef NO_SSL2
 478                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNSUPPORTED_PROTOCOL);
 479                 goto err;
 480 #else
 481                 /* we are talking sslv2 */
 482                 /* we need to clean up the SSLv3/TLSv1 setup and put in the
 483                  * sslv2 stuff. */
 484
 485                 if (s->s2 == NULL)
 486                         {
 487                         if (!ssl2_new(s))
 488                                 goto err;
 489                         }
 490                 else
 491                         ssl2_clear(s);
 492
 493                 if (s->s3 != NULL) ssl3_free(s);
 494
 495                 if (!BUF_MEM_grow(s->init_buf,
 496                         SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER))
 497                         {
 498                         goto err;
 499                         }
 500
 501                 s->state=SSL2_ST_GET_CLIENT_HELLO_A;
 502                 if ((s->options & SSL_OP_MSIE_SSLV2_RSA_PADDING) ||
 503                         use_sslv2_strong ||
 504                         (s->options & SSL_OP_NO_TLSv1 && s->options & SSL_OP_NO_SSLv3))
 505                         s->s2->ssl2_rollback=0;
 506                 else
 507                         /* reject SSL 2.0 session if client supports SSL 3.0 or TLS 1.0
 508                          * (SSL 3.0 draft/RFC 2246, App. E.2) */
 509                         s->s2->ssl2_rollback=1;
 510
 511                 /* setup the n bytes we have read so we get them from
 512                  * the sslv2 buffer */
 513                 s->rstate=SSL_ST_READ_HEADER;
 514                 s->packet_length=n;
 515                 s->packet= &(s->s2->rbuf[0]);
 516                 memcpy(s->packet,buf,n);
 517                 s->s2->rbuf_left=n;
 518                 s->s2->rbuf_offs=0;
 519
 520                 s->method=SSLv2_server_method();
 521                 s->handshake_func=s->method->ssl_accept;
 522 #endif
 523                 }
 524
 525         if ((type == 2) || (type == 3))
 526                 {
 527                 /* we have SSLv3/TLSv1 (type 2: SSL2 style, type 3: SSL3/TLS style) */
 528
 529                 if (!ssl_init_wbio_buffer(s,1)) goto err;
 530
 531                 /* we are in this state */
 532                 s->state=SSL3_ST_SR_CLNT_HELLO_A;
 533
 534                 if (type == 3)
 535                         {
 536                         /* put the 'n' bytes we have read into the input buffer
 537                          * for SSLv3 */
 538                         s->rstate=SSL_ST_READ_HEADER;
 539                         s->packet_length=n;
 540                         s->packet= &(s->s3->rbuf.buf[0]);
 541                         memcpy(s->packet,buf,n);
 542                         s->s3->rbuf.left=n;
 543                         s->s3->rbuf.offset=0;
 544                         }
 545                 else
 546                         {
 547                         s->packet_length=0;
 548                         s->s3->rbuf.left=0;
 549                         s->s3->rbuf.offset=0;
 550                         }
 551
 552                 if (s->version == TLS1_VERSION)
 553                         s->method = TLSv1_server_method();
 554                 else
 555                         s->method = SSLv3_server_method();
 556 #if 0 /* ssl3_get_client_hello does this */
 557                 s->client_version=(v[0]<<8)|v[1];
 558 #endif
 559                 s->handshake_func=s->method->ssl_accept;
 560                 }
 561
 562         if ((type < 1) || (type > 3))
 563                 {
 564                 /* bad, very bad */
 565                 SSLerr(SSL_F_SSL23_GET_CLIENT_HELLO,SSL_R_UNKNOWN_PROTOCOL);
 566                 goto err;
 567                 }
 568         s->init_num=0;
 569
 570         if (buf != buf_space) OPENSSL_free(buf);
 571         s->first_packet=1;
 572         return(SSL_accept(s));
 573 err:
 574         if (buf != buf_space) OPENSSL_free(buf);
 575         return(-1);
 576         }