ssl/s3_pkt.c

   1 /* ssl/s3_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 <openssl/evp.h>
  63 #include <openssl/buffer.h>
  64 #include "ssl_locl.h"
  65
  66 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
  67                          unsigned int len);
  68 static int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
  69                               unsigned int len);
  70 static int ssl3_get_record(SSL *s);
  71 static int do_compress(SSL *ssl);
  72 static int do_uncompress(SSL *ssl);
  73 static int do_change_cipher_spec(SSL *ssl);
  74 static int ssl3_read_n(SSL *s, int n, int max, int extend)
  75         {
  76         int i,off,newb;
  77
  78         /* if there is stuff still in the buffer from a previous read,
  79          * and there is more than we want, take some. */
  80         if (s->s3->rbuf.left >= (int)n)
  81                 {
  82                 if (extend)
  83                         s->packet_length+=n;
  84                 else
  85                         {
  86                         s->packet= &(s->s3->rbuf.buf[s->s3->rbuf.offset]);
  87                         s->packet_length=n;
  88                         }
  89                 s->s3->rbuf.left-=n;
  90                 s->s3->rbuf.offset+=n;
  91                 return(n);
  92                 }
  93
  94         /* else we need to read more data */
  95         if (!s->read_ahead) max=n;
  96         if (max > SSL3_RT_MAX_PACKET_SIZE)
  97                 max=SSL3_RT_MAX_PACKET_SIZE;
  98
  99         /* First check if there is some left or we want to extend */
 100         off=0;
 101         if (    (s->s3->rbuf.left != 0) ||
 102                 ((s->packet_length != 0) && extend))
 103                 {
 104                 newb=s->s3->rbuf.left;
 105                 if (extend)
 106                         {
 107                         /* Copy bytes back to the front of the buffer
 108                          * Take the bytes already pointed to by 'packet'
 109                          * and take the extra ones on the end. */
 110                         off=s->packet_length;
 111                         if (s->packet != s->s3->rbuf.buf)
 112                                 memcpy(s->s3->rbuf.buf,s->packet,newb+off);
 113                         }
 114                 else if (s->s3->rbuf.offset != 0)
 115                         { /* so the data is not at the start of the buffer */
 116                         memcpy(s->s3->rbuf.buf,
 117                                 &(s->s3->rbuf.buf[s->s3->rbuf.offset]),newb);
 118                         s->s3->rbuf.offset=0;
 119                         }
 120
 121                 s->s3->rbuf.left=0;
 122                 }
 123         else
 124                 newb=0;
 125
 126         /* So we now have 'newb' bytes at the front of
 127          * s->s3->rbuf.buf and need to read some more in on the end
 128          * We start reading into the buffer at 's->s3->rbuf.offset'
 129          */
 130         s->packet=s->s3->rbuf.buf;
 131
 132         while (newb < n)
 133                 {
 134                 clear_sys_error();
 135                 if (s->rbio != NULL)
 136                         {
 137                         s->rwstate=SSL_READING;
 138                         i=BIO_read(s->rbio,
 139                                 (char *)&(s->s3->rbuf.buf[off+newb]),
 140                                 max-newb);
 141                         }
 142                 else
 143                         {
 144                         SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
 145                         i= -1;
 146                         }
 147
 148                 if (i <= 0)
 149                         {
 150                         s->s3->rbuf.left+=newb;
 151                         return(i);
 152                         }
 153                 newb+=i;
 154                 }
 155
 156         /* record used data read */
 157         if (newb > n)
 158                 {
 159                 s->s3->rbuf.offset=n+off;
 160                 s->s3->rbuf.left=newb-n;
 161                 }
 162         else
 163                 {
 164                 s->s3->rbuf.offset=0;
 165                 s->s3->rbuf.left=0;
 166                 }
 167
 168         if (extend)
 169                 s->packet_length+=n;
 170         else
 171                 s->packet_length+=n;
 172         return(n);
 173         }
 174
 175 /* Call this to get a new input record.
 176  * It will return <= 0 if more data is needed, normally due to an error
 177  * or non-blocking IO.
 178  * When it finishes, one packet has been decoded and can be found in
 179  * ssl->s3->rrec.type   - is the type of record
 180  * ssl->s3->rrec.data,  - data
 181  * ssl->s3->rrec.length, - number of bytes
 182  */
 183 static int ssl3_get_record(SSL *s)
 184         {
 185         int ssl_major,ssl_minor,al;
 186         int n,i,ret= -1;
 187         SSL3_BUFFER *rb;
 188         SSL3_RECORD *rr;
 189         SSL_SESSION *sess;
 190         unsigned char *p;
 191         unsigned char md[EVP_MAX_MD_SIZE];
 192         short version;
 193         unsigned int mac_size;
 194         int clear=0,extra;
 195
 196         rr= &(s->s3->rrec);
 197         rb= &(s->s3->rbuf);
 198         sess=s->session;
 199
 200         if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
 201                 extra=SSL3_RT_MAX_EXTRA;
 202         else
 203                 extra=0;
 204
 205 again:
 206         /* check if we have the header */
 207         if (    (s->rstate != SSL_ST_READ_BODY) ||
 208                 (s->packet_length < SSL3_RT_HEADER_LENGTH))
 209                 {
 210                 n=ssl3_read_n(s,SSL3_RT_HEADER_LENGTH,
 211                         SSL3_RT_MAX_PACKET_SIZE,0);
 212                 if (n <= 0) return(n); /* error or non-blocking */
 213                 s->rstate=SSL_ST_READ_BODY;
 214
 215                 p=s->packet;
 216
 217                 /* Pull apart the header into the SSL3_RECORD */
 218                 rr->type= *(p++);
 219                 ssl_major= *(p++);
 220                 ssl_minor= *(p++);
 221                 version=(ssl_major<<8)|ssl_minor;
 222                 n2s(p,rr->length);
 223
 224                 /* Lets check version */
 225                 if (s->first_packet)
 226                         {
 227                         s->first_packet=0;
 228                         }
 229                 else
 230                         {
 231                         if (version != s->version)
 232                                 {
 233                                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 234                                 /* Send back error using their
 235                                  * version number :-) */
 236                                 s->version=version;
 237                                 al=SSL_AD_PROTOCOL_VERSION;
 238                                 goto f_err;
 239                                 }
 240                         }
 241
 242                 if ((version>>8) != SSL3_VERSION_MAJOR)
 243                         {
 244                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 245                         goto err;
 246                         }
 247
 248                 if (rr->length >
 249                         (unsigned int)SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
 250                         {
 251                         al=SSL_AD_RECORD_OVERFLOW;
 252                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 253                         goto f_err;
 254                         }
 255
 256                 s->rstate=SSL_ST_READ_BODY;
 257                 }
 258
 259         /* get and decode the data */
 260         if (s->rstate == SSL_ST_READ_BODY)
 261                 {
 262                 if (rr->length > (s->packet_length-SSL3_RT_HEADER_LENGTH))
 263                         {
 264                         i=rr->length;
 265                         /*-(s->packet_length-SSL3_RT_HEADER_LENGTH); */
 266                         n=ssl3_read_n(s,i,i,1);
 267                         if (n <= 0) return(n); /* error or non-blocking io */
 268                         }
 269                 s->rstate=SSL_ST_READ_HEADER;
 270                 }
 271
 272         /* At this point, we have the data in s->packet and there should be
 273          * s->packet_length bytes, we must not 'overrun' this buffer :-)
 274          * One of the following functions will copy the data from the
 275          * s->packet buffer */
 276
 277         rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
 278
 279         /* ok, we can now read from 's->packet' data into 'rr'
 280          * rr->input points at rr->length bytes, which
 281          * need to be copied into rr->data by either
 282          * the decryption or by the decompression
 283          * When the data is 'copied' into the rr->data buffer,
 284          * rr->input will be pointed at the new buffer */
 285
 286         /* Set the state for the following operations */
 287         s->rstate=SSL_ST_READ_HEADER;
 288
 289         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 290          * rr->length bytes of encrypted compressed stuff. */
 291
 292         /* check is not needed I belive */
 293         if (rr->length > (unsigned int)SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
 294                 {
 295                 al=SSL_AD_RECORD_OVERFLOW;
 296                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 297                 goto f_err;
 298                 }
 299
 300         /* decrypt in place in 'rr->input' */
 301         rr->data=rr->input;
 302
 303         if (!s->method->ssl3_enc->enc(s,0))
 304                 {
 305                 al=SSL_AD_DECRYPT_ERROR;
 306                 goto f_err;
 307                 }
 308 #ifdef TLS_DEBUG
 309 printf("dec %d\n",rr->length);
 310 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 311 printf("\n");
 312 #endif
 313         /* r->length is now the compressed data plus mac */
 314         if (    (sess == NULL) ||
 315                 (s->enc_read_ctx == NULL) ||
 316                 (s->read_hash == NULL))
 317                 clear=1;
 318
 319         if (!clear)
 320                 {
 321                 mac_size=EVP_MD_size(s->read_hash);
 322
 323                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
 324                         {
 325                         al=SSL_AD_RECORD_OVERFLOW;
 326                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 327                         goto f_err;
 328                         }
 329                 /* check MAC for rr->input' */
 330                 if (rr->length < mac_size)
 331                         {
 332                         al=SSL_AD_DECODE_ERROR;
 333                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
 334                         goto f_err;
 335                         }
 336                 rr->length-=mac_size;
 337                 i=s->method->ssl3_enc->mac(s,md,0);
 338                 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 339                         {
 340                         al=SSL_AD_BAD_RECORD_MAC;
 341                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_MAC_DECODE);
 342                         ret= -1;
 343                         goto f_err;
 344                         }
 345                 }
 346
 347         /* r->length is now just compressed */
 348         if (s->expand != NULL)
 349                 {
 350                 if (rr->length >
 351                         (unsigned int)SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
 352                         {
 353                         al=SSL_AD_RECORD_OVERFLOW;
 354                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 355                         goto f_err;
 356                         }
 357                 if (!do_uncompress(s))
 358                         {
 359                         al=SSL_AD_DECOMPRESSION_FAILURE;
 360                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
 361                         goto f_err;
 362                         }
 363                 }
 364
 365         if (rr->length > (unsigned int)SSL3_RT_MAX_PLAIN_LENGTH+extra)
 366                 {
 367                 al=SSL_AD_RECORD_OVERFLOW;
 368                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 369                 goto f_err;
 370                 }
 371
 372         rr->off=0;
 373         /* So at this point the following is true
 374          * ssl->s3->rrec.type   is the type of record
 375          * ssl->s3->rrec.length == number of bytes in record
 376          * ssl->s3->rrec.off    == offset to first valid byte
 377          * ssl->s3->rrec.data   == where to take bytes from, increment
 378          *                         after use :-).
 379          */
 380
 381         /* we have pulled in a full packet so zero things */
 382         s->packet_length=0;
 383
 384         /* just read a 0 length packet */
 385         if (rr->length == 0) goto again;
 386
 387         return(1);
 388 f_err:
 389         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 390 err:
 391         return(ret);
 392         }
 393
 394 static int do_uncompress(SSL *ssl)
 395         {
 396         int i;
 397         SSL3_RECORD *rr;
 398
 399         rr= &(ssl->s3->rrec);
 400         i=COMP_expand_block(ssl->expand,rr->comp,
 401                 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
 402         if (i < 0)
 403                 return(0);
 404         else
 405                 rr->length=i;
 406         rr->data=rr->comp;
 407
 408         return(1);
 409         }
 410
 411 static int do_compress(SSL *ssl)
 412         {
 413         int i;
 414         SSL3_RECORD *wr;
 415
 416         wr= &(ssl->s3->wrec);
 417         i=COMP_compress_block(ssl->compress,wr->data,
 418                 SSL3_RT_MAX_COMPRESSED_LENGTH,
 419                 wr->input,(int)wr->length);
 420         if (i < 0)
 421                 return(0);
 422         else
 423                 wr->length=i;
 424
 425         wr->input=wr->data;
 426         return(1);
 427         }
 428
 429 /* Call this to write data
 430  * It will return <= 0 if not all data has been sent or non-blocking IO.
 431  */
 432 int ssl3_write_bytes(SSL *s, int type, const void *_buf, int len)
 433         {
 434         const unsigned char *buf=_buf;
 435         unsigned int tot,n,nw;
 436         int i;
 437
 438         s->rwstate=SSL_NOTHING;
 439         tot=s->s3->wnum;
 440         s->s3->wnum=0;
 441
 442         if (SSL_in_init(s) && !s->in_handshake)
 443                 {
 444                 i=s->handshake_func(s);
 445                 if (i < 0) return(i);
 446                 if (i == 0)
 447                         {
 448                         SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 449                         return(-1);
 450                         }
 451                 }
 452
 453         n=(len-tot);
 454         for (;;)
 455                 {
 456                 if (n > SSL3_RT_MAX_PLAIN_LENGTH)
 457                         nw=SSL3_RT_MAX_PLAIN_LENGTH;
 458                 else
 459                         nw=n;
 460
 461                 i=do_ssl3_write(s,type,&(buf[tot]),nw);
 462                 if (i <= 0)
 463                         {
 464                         s->s3->wnum=tot;
 465                         return(i);
 466                         }
 467
 468                 if (type == SSL3_RT_HANDSHAKE)
 469                         ssl3_finish_mac(s,&(buf[tot]),i);
 470
 471                 if (i == (int)n) return(tot+i);
 472
 473                 n-=i;
 474                 tot+=i;
 475                 }
 476         }
 477
 478 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 479                          unsigned int len)
 480         {
 481         unsigned char *p,*plen;
 482         int i,mac_size,clear=0;
 483         SSL3_RECORD *wr;
 484         SSL3_BUFFER *wb;
 485         SSL_SESSION *sess;
 486
 487         /* first check is there is a SSL3_RECORD still being written
 488          * out.  This will happen with non blocking IO */
 489         if (s->s3->wbuf.left != 0)
 490                 return(ssl3_write_pending(s,type,buf,len));
 491
 492         /* If we have an alert to send, lets send it */
 493         if (s->s3->alert_dispatch)
 494                 {
 495                 i=ssl3_dispatch_alert(s);
 496                 if (i <= 0)
 497                         return(i);
 498                 /* if it went, fall through and send more stuff */
 499                 }
 500
 501         if (len <= 0) return(len);
 502
 503         wr= &(s->s3->wrec);
 504         wb= &(s->s3->wbuf);
 505         sess=s->session;
 506
 507         if (    (sess == NULL) ||
 508                 (s->enc_write_ctx == NULL) ||
 509                 (s->write_hash == NULL))
 510                 clear=1;
 511
 512         if (clear)
 513                 mac_size=0;
 514         else
 515                 mac_size=EVP_MD_size(s->write_hash);
 516
 517         p=wb->buf;
 518
 519         /* write the header */
 520         *(p++)=type&0xff;
 521         wr->type=type;
 522
 523         *(p++)=(s->version>>8);
 524         *(p++)=s->version&0xff;
 525
 526         /* record where we are to write out packet length */
 527         plen=p;
 528         p+=2;
 529
 530         /* lets setup the record stuff. */
 531         wr->data=p;
 532         wr->length=(int)len;
 533         wr->input=(unsigned char *)buf;
 534
 535         /* we now 'read' from wr->input, wr->length bytes into
 536          * wr->data */
 537
 538         /* first we compress */
 539         if (s->compress != NULL)
 540                 {
 541                 if (!do_compress(s))
 542                         {
 543                         SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
 544                         goto err;
 545                         }
 546                 }
 547         else
 548                 {
 549                 memcpy(wr->data,wr->input,wr->length);
 550                 wr->input=wr->data;
 551                 }
 552
 553         /* we should still have the output to wr->data and the input
 554          * from wr->input.  Length should be wr->length.
 555          * wr->data still points in the wb->buf */
 556
 557         if (mac_size != 0)
 558                 {
 559                 s->method->ssl3_enc->mac(s,&(p[wr->length]),1);
 560                 wr->length+=mac_size;
 561                 wr->input=p;
 562                 wr->data=p;
 563                 }
 564
 565         /* ssl3_enc can only have an error on read */
 566         s->method->ssl3_enc->enc(s,1);
 567
 568         /* record length after mac and block padding */
 569         s2n(wr->length,plen);
 570
 571         /* we should now have
 572          * wr->data pointing to the encrypted data, which is
 573          * wr->length long */
 574         wr->type=type; /* not needed but helps for debugging */
 575         wr->length+=SSL3_RT_HEADER_LENGTH;
 576
 577         /* Now lets setup wb */
 578         wb->left=wr->length;
 579         wb->offset=0;
 580
 581         s->s3->wpend_tot=len;
 582         s->s3->wpend_buf=buf;
 583         s->s3->wpend_type=type;
 584         s->s3->wpend_ret=len;
 585
 586         /* we now just need to write the buffer */
 587         return(ssl3_write_pending(s,type,buf,len));
 588 err:
 589         return(-1);
 590         }
 591
 592 /* if s->s3->wbuf.left != 0, we need to call this */
 593 static int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
 594                               unsigned int len)
 595         {
 596         int i;
 597
 598 /* XXXX */
 599         if ((s->s3->wpend_tot > (int)len) || (s->s3->wpend_buf != buf)
 600                 || (s->s3->wpend_type != type))
 601                 {
 602                 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
 603                 return(-1);
 604                 }
 605
 606         for (;;)
 607                 {
 608                 clear_sys_error();
 609                 if (s->wbio != NULL)
 610                         {
 611                         s->rwstate=SSL_WRITING;
 612                         i=BIO_write(s->wbio,
 613                                 (char *)&(s->s3->wbuf.buf[s->s3->wbuf.offset]),
 614                                 (unsigned int)s->s3->wbuf.left);
 615                         }
 616                 else
 617                         {
 618                         SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
 619                         i= -1;
 620                         }
 621                 if (i == s->s3->wbuf.left)
 622                         {
 623                         s->s3->wbuf.left=0;
 624                         s->rwstate=SSL_NOTHING;
 625                         return(s->s3->wpend_ret);
 626                         }
 627                 else if (i <= 0)
 628                         return(i);
 629                 s->s3->wbuf.offset+=i;
 630                 s->s3->wbuf.left-=i;
 631                 }
 632         }
 633
 634 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len)
 635         {
 636         int al,i,j,n,ret;
 637         SSL3_RECORD *rr;
 638         void (*cb)()=NULL;
 639         BIO *bio;
 640
 641         if (s->s3->rbuf.buf == NULL) /* Not initialize yet */
 642                 if (!ssl3_setup_buffers(s))
 643                         return(-1);
 644
 645         if (!s->in_handshake && SSL_in_init(s))
 646                 {
 647                 i=s->handshake_func(s);
 648                 if (i < 0) return(i);
 649                 if (i == 0)
 650                         {
 651                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 652                         return(-1);
 653                         }
 654                 }
 655 start:
 656         s->rwstate=SSL_NOTHING;
 657
 658         /* s->s3->rrec.type     - is the type of record
 659          * s->s3->rrec.data,    - data
 660          * s->s3->rrec.off,     - ofset into 'data' for next read
 661          * s->s3->rrec.length,  - number of bytes. */
 662         rr= &(s->s3->rrec);
 663
 664         /* get new packet */
 665         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 666                 {
 667                 ret=ssl3_get_record(s);
 668                 if (ret <= 0) return(ret);
 669                 }
 670
 671         /* we now have a packet which can be read and processed */
 672
 673         if (s->s3->change_cipher_spec && (rr->type != SSL3_RT_HANDSHAKE))
 674                 {
 675                 al=SSL_AD_UNEXPECTED_MESSAGE;
 676                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
 677                 goto err;
 678                 }
 679
 680         /* If the other end has shutdown, throw anything we read away */
 681         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 682                 {
 683                 rr->length=0;
 684                 s->rwstate=SSL_NOTHING;
 685                 return(0);
 686                 }
 687
 688         /* Check for an incoming 'Client Request' message */
 689         if ((rr->type == SSL3_RT_HANDSHAKE) && (rr->length == 4) &&
 690                 (rr->data[0] == SSL3_MT_CLIENT_REQUEST) &&
 691                 (s->session != NULL) && (s->session->cipher != NULL))
 692                 {
 693                 if ((rr->data[1] != 0) || (rr->data[2] != 0) ||
 694                         (rr->data[3] != 0))
 695                         {
 696                         al=SSL_AD_DECODE_ERROR;
 697                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CLIENT_REQUEST);
 698                         goto err;
 699                         }
 700
 701                 if (SSL_is_init_finished(s) &&
 702                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 703                         !s->s3->renegotiate)
 704                         {
 705                         ssl3_renegotiate(s);
 706                         if (ssl3_renegotiate_check(s))
 707                                 {
 708                                 n=s->handshake_func(s);
 709                                 if (n < 0) return(n);
 710                                 if (n == 0)
 711                                         {
 712                                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 713                                         return(-1);
 714                                         }
 715                                 }
 716                         }
 717                 rr->length=0;
 718 /* ZZZ */       goto start;
 719                 }
 720
 721         /* if it is not the type we want, or we have shutdown and want
 722          * the peer shutdown */
 723         if ((rr->type != type) || (s->shutdown & SSL_SENT_SHUTDOWN))
 724                 {
 725                 if (rr->type == SSL3_RT_ALERT)
 726                         {
 727                         if ((rr->length != 2) || (rr->off != 0))
 728                                 {
 729                                 al=SSL_AD_DECODE_ERROR;
 730                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_ALERT_RECORD);
 731                                 goto f_err;
 732                                 }
 733
 734                         i=rr->data[0];
 735                         n=rr->data[1];
 736
 737                         /* clear from buffer */
 738                         rr->length=0;
 739
 740                         if (s->info_callback != NULL)
 741                                 cb=s->info_callback;
 742                         else if (s->ctx->info_callback != NULL)
 743                                 cb=s->ctx->info_callback;
 744
 745                         if (cb != NULL)
 746                                 {
 747                                 j=(i<<8)|n;
 748                                 cb(s,SSL_CB_READ_ALERT,j);
 749                                 }
 750
 751                         if (i == 1)
 752                                 {
 753                                 s->s3->warn_alert=n;
 754                                 if (n == SSL_AD_CLOSE_NOTIFY)
 755                                         {
 756                                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
 757                                         return(0);
 758                                         }
 759                                 }
 760                         else if (i == 2)
 761                                 {
 762                                 char tmp[16];
 763
 764                                 s->rwstate=SSL_NOTHING;
 765                                 s->s3->fatal_alert=n;
 766                                 SSLerr(SSL_F_SSL3_READ_BYTES,
 767                                         SSL_AD_REASON_OFFSET+n);
 768                                 sprintf(tmp,"%d",n);
 769                                 ERR_add_error_data(2,"SSL alert number ",tmp);
 770                                 s->shutdown|=SSL_RECEIVED_SHUTDOWN;
 771                                 SSL_CTX_remove_session(s->ctx,s->session);
 772                                 return(0);
 773                                 }
 774                         else
 775                                 {
 776                                 al=SSL_AD_ILLEGAL_PARAMETER;
 777                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
 778                                 goto f_err;
 779                                 }
 780
 781                         rr->length=0;
 782                         goto start;
 783                         }
 784
 785                 if (s->shutdown & SSL_SENT_SHUTDOWN)
 786                         {
 787                         s->rwstate=SSL_NOTHING;
 788                         rr->length=0;
 789                         return(0);
 790                         }
 791
 792                 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
 793                         {
 794                         if (    (rr->length != 1) || (rr->off != 0) ||
 795                                 (rr->data[0] != SSL3_MT_CCS))
 796                                 {
 797                                 i=SSL_AD_ILLEGAL_PARAMETER;
 798                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
 799                                 goto err;
 800                                 }
 801
 802                         rr->length=0;
 803                         s->s3->change_cipher_spec=1;
 804                         if (!do_change_cipher_spec(s))
 805                                 goto err;
 806                         else
 807                                 goto start;
 808                         }
 809
 810                 /* else we have a handshake */
 811                 if ((rr->type == SSL3_RT_HANDSHAKE) &&
 812                         !s->in_handshake)
 813                         {
 814                         if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
 815                                 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
 816                                 {
 817                                 s->state=SSL_ST_BEFORE|(s->server)
 818                                                 ?SSL_ST_ACCEPT
 819                                                 :SSL_ST_CONNECT;
 820                                 s->new_session=1;
 821                                 }
 822                         n=s->handshake_func(s);
 823                         if (n < 0) return(n);
 824                         if (n == 0)
 825                                 {
 826                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 827                                 return(-1);
 828                                 }
 829
 830                         /* In the case where we try to read application data
 831                          * the first time, but we trigger an SSL handshake, we
 832                          * return -1 with the retry option set.  I do this
 833                          * otherwise renegotiation can cause nasty problems
 834                          * in the non-blocking world */
 835
 836                         s->rwstate=SSL_READING;
 837                         bio=SSL_get_rbio(s);
 838                         BIO_clear_retry_flags(bio);
 839                         BIO_set_retry_read(bio);
 840                         return(-1);
 841                         }
 842
 843                 switch (rr->type)
 844                         {
 845                 default:
 846 #ifndef NO_TLS
 847                         /* TLS just ignores unknown message types */
 848                         if (s->version == TLS1_VERSION)
 849                                 {
 850                                 goto start;
 851                                 }
 852 #endif
 853                 case SSL3_RT_CHANGE_CIPHER_SPEC:
 854                 case SSL3_RT_ALERT:
 855                 case SSL3_RT_HANDSHAKE:
 856                         al=SSL_AD_UNEXPECTED_MESSAGE;
 857                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 858                         goto f_err;
 859                 case SSL3_RT_APPLICATION_DATA:
 860                         /* At this point, we were expecting something else,
 861                          * but have application data.  What we do is set the
 862                          * error, and return -1.  On the way out, if the
 863                          * library was running inside ssl3_read() and it makes
 864                          * sense to read application data at this point, we
 865                          * will indulge it.  This will mostly happen during
 866                          * session renegotiation.
 867                          */
 868                         if (s->s3->in_read_app_data &&
 869                                 (s->s3->total_renegotiations != 0) &&
 870                                 ((
 871                                   (s->state & SSL_ST_CONNECT) &&
 872                                   (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
 873                                   (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
 874                                  ) || (
 875                                   (s->state & SSL_ST_ACCEPT) &&
 876                                   (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
 877                                   (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
 878                                  )
 879                                 ))
 880                                 {
 881                                 s->s3->in_read_app_data=0;
 882                                 return(-1);
 883                                 }
 884                         else
 885                                 {
 886                                 al=SSL_AD_UNEXPECTED_MESSAGE;
 887                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 888                                 goto f_err;
 889                                 }
 890                         }
 891                 }
 892
 893         /* make sure that we are not getting application data when we
 894          * are doing a handshake for the first time */
 895         if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 896                 (s->enc_read_ctx == NULL))
 897                 {
 898                 al=SSL_AD_UNEXPECTED_MESSAGE;
 899                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 900                 goto f_err;
 901                 }
 902
 903         if (len <= 0) return(len);
 904
 905         if ((unsigned int)len > rr->length)
 906                 n=rr->length;
 907         else
 908                 n=len;
 909
 910         memcpy(buf,&(rr->data[rr->off]),(unsigned int)n);
 911         rr->length-=n;
 912         rr->off+=n;
 913         if (rr->length <= 0)
 914                 {
 915                 s->rstate=SSL_ST_READ_HEADER;
 916                 rr->off=0;
 917                 }
 918
 919         if (type == SSL3_RT_HANDSHAKE)
 920                 ssl3_finish_mac(s,buf,n);
 921         return(n);
 922 f_err:
 923         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 924 err:
 925         return(-1);
 926         }
 927
 928 static int do_change_cipher_spec(SSL *s)
 929         {
 930         int i;
 931         unsigned char *sender;
 932         int slen;
 933
 934         if (s->state & SSL_ST_ACCEPT)
 935                 i=SSL3_CHANGE_CIPHER_SERVER_READ;
 936         else
 937                 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
 938
 939         if (s->s3->tmp.key_block == NULL)
 940                 {
 941                 s->session->cipher=s->s3->tmp.new_cipher;
 942                 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
 943                 }
 944
 945         if (!s->method->ssl3_enc->change_cipher_state(s,i))
 946                 return(0);
 947
 948         /* we have to record the message digest at
 949          * this point so we can get it before we read
 950          * the finished message */
 951         if (s->state & SSL_ST_CONNECT)
 952                 {
 953                 sender=s->method->ssl3_enc->server_finished;
 954                 slen=s->method->ssl3_enc->server_finished_len;
 955                 }
 956         else
 957                 {
 958                 sender=s->method->ssl3_enc->client_finished;
 959                 slen=s->method->ssl3_enc->client_finished_len;
 960                 }
 961
 962         s->method->ssl3_enc->final_finish_mac(s,
 963                 &(s->s3->finish_dgst1),
 964                 &(s->s3->finish_dgst2),
 965                 sender,slen,&(s->s3->tmp.finish_md[0]));
 966
 967         return(1);
 968         }
 969
 970 int ssl3_do_write(SSL *s, int type)
 971         {
 972         int ret;
 973
 974         ret=ssl3_write_bytes(s,type,&s->init_buf->data[s->init_off],
 975                              s->init_num);
 976         if (ret == s->init_num)
 977                 return(1);
 978         if (ret < 0) return(-1);
 979         s->init_off+=ret;
 980         s->init_num-=ret;
 981         return(0);
 982         }
 983
 984 void ssl3_send_alert(SSL *s, int level, int desc)
 985         {
 986         /* Map tls/ssl alert value to correct one */
 987         desc=s->method->ssl3_enc->alert_value(desc);
 988         if (desc < 0) return;
 989         /* If a fatal one, remove from cache */
 990         if ((level == 2) && (s->session != NULL))
 991                 SSL_CTX_remove_session(s->ctx,s->session);
 992
 993         s->s3->alert_dispatch=1;
 994         s->s3->send_alert[0]=level;
 995         s->s3->send_alert[1]=desc;
 996         if (s->s3->wbuf.left == 0) /* data still being written out */
 997                 ssl3_dispatch_alert(s);
 998         /* else data is still being written out, we will get written
 999          * some time in the future */
1000         }
1001
1002 int ssl3_dispatch_alert(SSL *s)
1003         {
1004         int i,j;
1005         void (*cb)()=NULL;
1006
1007         s->s3->alert_dispatch=0;
1008         i=do_ssl3_write(s,SSL3_RT_ALERT,&s->s3->send_alert[0],2);
1009         if (i <= 0)
1010                 {
1011                 s->s3->alert_dispatch=1;
1012                 }
1013         else
1014                 {
1015                 /* If it is important, send it now.  If the message
1016                  * does not get sent due to non-blocking IO, we will
1017                  * not worry too much. */
1018                 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1019                         BIO_flush(s->wbio);
1020
1021                 if (s->info_callback != NULL)
1022                         cb=s->info_callback;
1023                 else if (s->ctx->info_callback != NULL)
1024                         cb=s->ctx->info_callback;
1025
1026                 if (cb != NULL)
1027                         {
1028                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1029                         cb(s,SSL_CB_WRITE_ALERT,j);
1030                         }
1031                 }
1032         return(i);
1033         }
1034