ssl/s2_pkt.c

   1 /* ssl/s2_pkt.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 <errno.h>
  61 #define USE_SOCKETS
  62 #include "ssl_locl.h"
  63
  64 /* SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_PEER_ERROR_NO_CIPHER);
  65  * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_PEER_ERROR_NO_CERTIFICATE);
  66  * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_PEER_ERROR_CERTIFICATE);
  67  * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE);
  68  * SSLerr(SSL_F_GET_SERVER_HELLO,SSL_R_UNKNOWN_REMOTE_ERROR_TYPE);
  69  */
  70
  71 #ifndef NOPROTO
  72 static int read_n(SSL *s,unsigned int n,unsigned int max,unsigned int extend);
  73 static int do_ssl_write(SSL *s, const char *buf, unsigned int len);
  74 static int write_pending(SSL *s, const char *buf, unsigned int len);
  75 static int ssl_mt_error(int n);
  76 #else
  77 static int read_n();
  78 static int do_ssl_write();
  79 static int write_pending();
  80 static int ssl_mt_error();
  81 #endif
  82
  83 int ssl2_peek(SSL *s, char *buf, int len)
  84         {
  85         int ret;
  86
  87         ret=ssl2_read(s,buf,len);
  88         if (ret > 0)
  89                 {
  90                 s->s2->ract_data_length+=ret;
  91                 s->s2->ract_data-=ret;
  92                 }
  93         return(ret);
  94         }
  95
  96 /* SSL_read -
  97  * This routine will return 0 to len bytes, decrypted etc if required.
  98  */
  99 int ssl2_read(SSL *s, char *buf, int len)
 100         {
 101         int n;
 102         unsigned char mac[MAX_MAC_SIZE];
 103         unsigned char *p;
 104         int i;
 105         unsigned int mac_size=0;
 106
 107         if (SSL_in_init(s) && !s->in_handshake)
 108                 {
 109                 n=s->handshake_func(s);
 110                 if (n < 0) return(n);
 111                 if (n == 0)
 112                         {
 113                         SSLerr(SSL_F_SSL2_READ,SSL_R_SSL_HANDSHAKE_FAILURE);
 114                         return(-1);
 115                         }
 116                 }
 117
 118         clear_sys_error();
 119         s->rwstate=SSL_NOTHING;
 120         if (len <= 0) return(len);
 121
 122         if (s->s2->ract_data_length != 0) /* read from buffer */
 123                 {
 124                 if (len > s->s2->ract_data_length)
 125                         n=s->s2->ract_data_length;
 126                 else
 127                         n=len;
 128
 129                 memcpy(buf,s->s2->ract_data,(unsigned int)n);
 130                 s->s2->ract_data_length-=n;
 131                 s->s2->ract_data+=n;
 132                 if (s->s2->ract_data_length == 0)
 133                         s->rstate=SSL_ST_READ_HEADER;
 134                 return(n);
 135                 }
 136
 137         if (s->rstate == SSL_ST_READ_HEADER)
 138                 {
 139                 if (s->first_packet)
 140                         {
 141                         n=read_n(s,5,SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER+2,0);
 142                         if (n <= 0) return(n); /* error or non-blocking */
 143                         s->first_packet=0;
 144                         p=s->packet;
 145                         if (!((p[0] & 0x80) && (
 146                                 (p[2] == SSL2_MT_CLIENT_HELLO) ||
 147                                 (p[2] == SSL2_MT_SERVER_HELLO))))
 148                                 {
 149                                 SSLerr(SSL_F_SSL2_READ,SSL_R_NON_SSLV2_INITIAL_PACKET);
 150                                 return(-1);
 151                                 }
 152                         }
 153                 else
 154                         {
 155                         n=read_n(s,2,SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER+2,0);
 156                         if (n <= 0) return(n); /* error or non-blocking */
 157                         }
 158                 /* part read stuff */
 159
 160                 s->rstate=SSL_ST_READ_BODY;
 161                 p=s->packet;
 162                 /* Do header */
 163                 /*s->s2->padding=0;*/
 164                 s->s2->escape=0;
 165                 s->s2->rlength=(((unsigned int)p[0])<<8)|((unsigned int)p[1]);
 166                 if ((p[0] & TWO_BYTE_BIT))              /* Two byte header? */
 167                         {
 168                         s->s2->three_byte_header=0;
 169                         s->s2->rlength&=TWO_BYTE_MASK;
 170                         }
 171                 else
 172                         {
 173                         s->s2->three_byte_header=1;
 174                         s->s2->rlength&=THREE_BYTE_MASK;
 175
 176                         /* security >s2->escape */
 177                         s->s2->escape=((p[0] & SEC_ESC_BIT))?1:0;
 178                         }
 179                 }
 180
 181         if (s->rstate == SSL_ST_READ_BODY)
 182                 {
 183                 n=s->s2->rlength+2+s->s2->three_byte_header;
 184                 if (n > (int)s->packet_length)
 185                         {
 186                         n-=s->packet_length;
 187                         i=read_n(s,(unsigned int)n,(unsigned int)n,1);
 188                         if (i <= 0) return(i); /* ERROR */
 189                         }
 190
 191                 p= &(s->packet[2]);
 192                 s->rstate=SSL_ST_READ_HEADER;
 193                 if (s->s2->three_byte_header)
 194                         s->s2->padding= *(p++);
 195                 else    s->s2->padding=0;
 196
 197                 /* Data portion */
 198                 if (s->s2->clear_text)
 199                         {
 200                         s->s2->mac_data=p;
 201                         s->s2->ract_data=p;
 202                         s->s2->pad_data=NULL;
 203                         }
 204                 else
 205                         {
 206                         mac_size=EVP_MD_size(s->read_hash);
 207                         s->s2->mac_data=p;
 208                         s->s2->ract_data= &p[mac_size];
 209                         s->s2->pad_data= &p[mac_size+
 210                                 s->s2->rlength-s->s2->padding];
 211                         }
 212
 213                 s->s2->ract_data_length=s->s2->rlength;
 214                 /* added a check for length > max_size in case
 215                  * encryption was not turned on yet due to an error */
 216                 if ((!s->s2->clear_text) &&
 217                         (s->s2->rlength >= mac_size))
 218                         {
 219                         ssl2_enc(s,0);
 220                         s->s2->ract_data_length-=mac_size;
 221                         ssl2_mac(s,mac,0);
 222                         s->s2->ract_data_length-=s->s2->padding;
 223                         if (    (memcmp(mac,s->s2->mac_data,
 224                                 (unsigned int)mac_size) != 0) ||
 225                                 (s->s2->rlength%EVP_CIPHER_CTX_block_size(s->enc_read_ctx) != 0))
 226                                 {
 227                                 SSLerr(SSL_F_SSL2_READ,SSL_R_BAD_MAC_DECODE);
 228                                 return(-1);
 229                                 }
 230                         }
 231                 INC32(s->s2->read_sequence); /* expect next number */
 232                 /* s->s2->ract_data is now available for processing */
 233
 234                 /* If a 0 byte packet was sent, return 0, otherwise
 235                  * we play havoc with people using select with
 236                  * blocking sockets.  Let them handle a packet at a time,
 237                  * they should really be using non-blocking sockets. */
 238                 if (s->s2->ract_data_length == 0)
 239                         return(0);
 240                 return(ssl2_read(s,buf,len));
 241                 }
 242         else
 243                 {
 244                 SSLerr(SSL_F_SSL2_READ,SSL_R_BAD_STATE);
 245                         return(-1);
 246                 }
 247         }
 248
 249 static int read_n(SSL *s, unsigned int n, unsigned int max,
 250              unsigned int extend)
 251         {
 252         int i,off,newb;
 253
 254         /* if there is stuff still in the buffer from a previous read,
 255          * and there is more than we want, take some. */
 256         if (s->s2->rbuf_left >= (int)n)
 257                 {
 258                 if (extend)
 259                         s->packet_length+=n;
 260                 else
 261                         {
 262                         s->packet= &(s->s2->rbuf[s->s2->rbuf_offs]);
 263                         s->packet_length=n;
 264                         }
 265                 s->s2->rbuf_left-=n;
 266                 s->s2->rbuf_offs+=n;
 267                 return(n);
 268                 }
 269
 270         if (!s->read_ahead) max=n;
 271         if (max > (unsigned int)(SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER+2))
 272                 max=SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER+2;
 273
 274
 275         /* Else we want more than we have.
 276          * First, if there is some left or we want to extend */
 277         off=0;
 278         if ((s->s2->rbuf_left != 0) || ((s->packet_length != 0) && extend))
 279                 {
 280                 newb=s->s2->rbuf_left;
 281                 if (extend)
 282                         {
 283                         off=s->packet_length;
 284                         if (s->packet != s->s2->rbuf)
 285                                 memcpy(s->s2->rbuf,s->packet,
 286                                         (unsigned int)newb+off);
 287                         }
 288                 else if (s->s2->rbuf_offs != 0)
 289                         {
 290                         memcpy(s->s2->rbuf,&(s->s2->rbuf[s->s2->rbuf_offs]),
 291                                 (unsigned int)newb);
 292                         s->s2->rbuf_offs=0;
 293                         }
 294                 s->s2->rbuf_left=0;
 295                 }
 296         else
 297                 newb=0;
 298
 299         /* off is the offset to start writing too.
 300          * r->s2->rbuf_offs is the 'unread data', now 0.
 301          * newb is the number of new bytes so far
 302          */
 303         s->packet=s->s2->rbuf;
 304         while (newb < (int)n)
 305                 {
 306                 clear_sys_error();
 307                 if (s->rbio != NULL)
 308                         {
 309                         s->rwstate=SSL_READING;
 310                         i=BIO_read(s->rbio,(char *)&(s->s2->rbuf[off+newb]),
 311                                 max-newb);
 312                         }
 313                 else
 314                         {
 315                         SSLerr(SSL_F_READ_N,SSL_R_READ_BIO_NOT_SET);
 316                         i= -1;
 317                         }
 318 #ifdef PKT_DEBUG
 319                 if (s->debug & 0x01) sleep(1);
 320 #endif
 321                 if (i <= 0)
 322                         {
 323                         s->s2->rbuf_left+=newb;
 324                         return(i);
 325                         }
 326                 newb+=i;
 327                 }
 328
 329         /* record unread data */
 330         if (newb > (int)n)
 331                 {
 332                 s->s2->rbuf_offs=n+off;
 333                 s->s2->rbuf_left=newb-n;
 334                 }
 335         else
 336                 {
 337                 s->s2->rbuf_offs=0;
 338                 s->s2->rbuf_left=0;
 339                 }
 340         if (extend)
 341                 s->packet_length+=n;
 342         else
 343                 s->packet_length=n;
 344         s->rwstate=SSL_NOTHING;
 345         return(n);
 346         }
 347
 348 int ssl2_write(SSL *s, const char *buf, int len)
 349         {
 350         unsigned int n,tot;
 351         int i;
 352
 353         if (SSL_in_init(s) && !s->in_handshake)
 354                 {
 355                 i=s->handshake_func(s);
 356                 if (i < 0) return(i);
 357                 if (i == 0)
 358                         {
 359                         SSLerr(SSL_F_SSL2_WRITE,SSL_R_SSL_HANDSHAKE_FAILURE);
 360                         return(-1);
 361                         }
 362                 }
 363
 364         if (s->error)
 365                 {
 366                 ssl2_write_error(s);
 367                 if (s->error)
 368                         return(-1);
 369                 }
 370
 371         clear_sys_error();
 372         s->rwstate=SSL_NOTHING;
 373         if (len <= 0) return(len);
 374
 375         tot=s->s2->wnum;
 376         s->s2->wnum=0;
 377
 378         n=(len-tot);
 379         for (;;)
 380                 {
 381                 i=do_ssl_write(s,&(buf[tot]),n);
 382                 if (i <= 0)
 383                         {
 384                         s->s2->wnum=tot;
 385                         return(i);
 386                         }
 387                 if (i == (int)n) return(tot+i);
 388
 389                 n-=i;
 390                 tot+=i;
 391                 }
 392         }
 393
 394 static int write_pending(SSL *s, const char *buf, unsigned int len)
 395         {
 396         int i;
 397
 398         /* s->s2->wpend_len != 0 MUST be true. */
 399
 400         /* check that they have given us the same buffer to
 401          * write */
 402         if ((s->s2->wpend_tot > (int)len) || (s->s2->wpend_buf != buf))
 403                 {
 404                 SSLerr(SSL_F_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
 405                 return(-1);
 406                 }
 407
 408         for (;;)
 409                 {
 410                 clear_sys_error();
 411                 if (s->wbio != NULL)
 412                         {
 413                         s->rwstate=SSL_WRITING;
 414                         i=BIO_write(s->wbio,
 415                                 (char *)&(s->s2->write_ptr[s->s2->wpend_off]),
 416                                 (unsigned int)s->s2->wpend_len);
 417                         }
 418                 else
 419                         {
 420                         SSLerr(SSL_F_WRITE_PENDING,SSL_R_WRITE_BIO_NOT_SET);
 421                         i= -1;
 422                         }
 423 #ifdef PKT_DEBUG
 424                 if (s->debug & 0x01) sleep(1);
 425 #endif
 426                 if (i == s->s2->wpend_len)
 427                         {
 428                         s->s2->wpend_len=0;
 429                         s->rwstate=SSL_NOTHING;
 430                         return(s->s2->wpend_ret);
 431                         }
 432                 else if (i <= 0)
 433                         return(i);
 434                 s->s2->wpend_off+=i;
 435                 s->s2->wpend_len-=i;
 436                 }
 437         }
 438
 439 static int do_ssl_write(SSL *s, const char *buf, unsigned int len)
 440         {
 441         unsigned int j,k,olen,p,mac_size,bs;
 442         register unsigned char *pp;
 443
 444         olen=len;
 445
 446         /* first check if there is data from an encryption waiting to
 447          * be sent - it must be sent because the other end is waiting.
 448          * This will happen with non-blocking IO.  We print it and then
 449          * return.
 450          */
 451         if (s->s2->wpend_len != 0) return(write_pending(s,buf,len));
 452
 453         /* set mac_size to mac size */
 454         if (s->s2->clear_text)
 455                 mac_size=0;
 456         else
 457                 mac_size=EVP_MD_size(s->write_hash);
 458
 459         /* lets set the pad p */
 460         if (s->s2->clear_text)
 461                 {
 462                 if (len > SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER)
 463                         len=SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER;
 464                 p=0;
 465                 s->s2->three_byte_header=0;
 466                 /* len=len; */
 467                 }
 468         else
 469                 {
 470                 bs=EVP_CIPHER_CTX_block_size(s->enc_read_ctx);
 471                 j=len+mac_size;
 472                 if ((j > SSL2_MAX_RECORD_LENGTH_3_BYTE_HEADER) &&
 473                         (!s->s2->escape))
 474                         {
 475                         if (j > SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER)
 476                                 j=SSL2_MAX_RECORD_LENGTH_2_BYTE_HEADER;
 477                         /* set k to the max number of bytes with 2
 478                          * byte header */
 479                         k=j-(j%bs);
 480                         /* how many data bytes? */
 481                         len=k-mac_size;
 482                         s->s2->three_byte_header=0;
 483                         p=0;
 484                         }
 485                 else if ((bs <= 1) && (!s->s2->escape))
 486                         {
 487                         /* len=len; */
 488                         s->s2->three_byte_header=0;
 489                         p=0;
 490                         }
 491                 else /* 3 byte header */
 492                         {
 493                         /*len=len; */
 494                         p=(j%bs);
 495                         p=(p == 0)?0:(bs-p);
 496                         if (s->s2->escape)
 497                                 s->s2->three_byte_header=1;
 498                         else
 499                                 s->s2->three_byte_header=(p == 0)?0:1;
 500                         }
 501                 }
 502         /* mac_size is the number of MAC bytes
 503          * len is the number of data bytes we are going to send
 504          * p is the number of padding bytes
 505          * if p == 0, it is a 2 byte header */
 506
 507         s->s2->wlength=len;
 508         s->s2->padding=p;
 509         s->s2->mac_data= &(s->s2->wbuf[3]);
 510         s->s2->wact_data= &(s->s2->wbuf[3+mac_size]);
 511         /* we copy the data into s->s2->wbuf */
 512         memcpy(s->s2->wact_data,buf,len);
 513 #ifdef PURIFY
 514         if (p)
 515                 memset(&(s->s2->wact_data[len]),0,p);
 516 #endif
 517
 518         if (!s->s2->clear_text)
 519                 {
 520                 s->s2->wact_data_length=len+p;
 521                 ssl2_mac(s,s->s2->mac_data,1);
 522                 s->s2->wlength+=p+mac_size;
 523                 ssl2_enc(s,1);
 524                 }
 525
 526         /* package up the header */
 527         s->s2->wpend_len=s->s2->wlength;
 528         if (s->s2->three_byte_header) /* 3 byte header */
 529                 {
 530                 pp=s->s2->mac_data;
 531                 pp-=3;
 532                 pp[0]=(s->s2->wlength>>8)&(THREE_BYTE_MASK>>8);
 533                 if (s->s2->escape) pp[0]|=SEC_ESC_BIT;
 534                 pp[1]=s->s2->wlength&0xff;
 535                 pp[2]=s->s2->padding;
 536                 s->s2->wpend_len+=3;
 537                 }
 538         else
 539                 {
 540                 pp=s->s2->mac_data;
 541                 pp-=2;
 542                 pp[0]=((s->s2->wlength>>8)&(TWO_BYTE_MASK>>8))|TWO_BYTE_BIT;
 543                 pp[1]=s->s2->wlength&0xff;
 544                 s->s2->wpend_len+=2;
 545                 }
 546         s->s2->write_ptr=pp;
 547
 548         INC32(s->s2->write_sequence); /* expect next number */
 549
 550         /* lets try to actually write the data */
 551         s->s2->wpend_tot=olen;
 552         s->s2->wpend_buf=buf;
 553
 554         s->s2->wpend_ret=len;
 555
 556         s->s2->wpend_off=0;
 557         return(write_pending(s,buf,olen));
 558         }
 559
 560 int ssl2_part_read(SSL *s, unsigned long f, int i)
 561         {
 562         unsigned char *p;
 563         int j;
 564
 565         /* check for error */
 566         if ((s->init_num == 0) && (i >= 3))
 567                 {
 568                 p=(unsigned char *)s->init_buf->data;
 569                 if (p[0] == SSL2_MT_ERROR)
 570                         {
 571                         j=(p[1]<<8)|p[2];
 572                         SSLerr((int)f,ssl_mt_error(j));
 573                         }
 574                 }
 575
 576         if (i < 0)
 577                 {
 578                 /* ssl2_return_error(s); */
 579                 /* for non-blocking io,
 580                  * this is not fatal */
 581                 return(i);
 582                 }
 583         else
 584                 {
 585                 s->init_num+=i;
 586                 return(0);
 587                 }
 588         }
 589
 590 int ssl2_do_write(SSL *s)
 591         {
 592         int ret;
 593
 594         ret=ssl2_write(s,(char *)&(s->init_buf->data[s->init_off]),
 595                 s->init_num);
 596         if (ret == s->init_num)
 597                 return(1);
 598         if (ret < 0)
 599                 return(-1);
 600         s->init_off+=ret;
 601         s->init_num-=ret;
 602         return(0);
 603         }
 604
 605 static int ssl_mt_error(int n)
 606         {
 607         int ret;
 608
 609         switch (n)
 610                 {
 611         case SSL2_PE_NO_CIPHER:
 612                 ret=SSL_R_PEER_ERROR_NO_CIPHER;
 613                 break;
 614         case SSL2_PE_NO_CERTIFICATE:
 615                 ret=SSL_R_PEER_ERROR_NO_CERTIFICATE;
 616                 break;
 617         case SSL2_PE_BAD_CERTIFICATE:
 618                 ret=SSL_R_PEER_ERROR_CERTIFICATE;
 619                 break;
 620         case SSL2_PE_UNSUPPORTED_CERTIFICATE_TYPE:
 621                 ret=SSL_R_PEER_ERROR_UNSUPPORTED_CERTIFICATE_TYPE;
 622                 break;
 623         default:
 624                 ret=SSL_R_UNKNOWN_REMOTE_ERROR_TYPE;
 625                 break;
 626                 }
 627         return(ret);
 628         }