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  * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
  60  *
  61  * Redistribution and use in source and binary forms, with or without
  62  * modification, are permitted provided that the following conditions
  63  * are met:
  64  *
  65  * 1. Redistributions of source code must retain the above copyright
  66  *    notice, this list of conditions and the following disclaimer.
  67  *
  68  * 2. Redistributions in binary form must reproduce the above copyright
  69  *    notice, this list of conditions and the following disclaimer in
  70  *    the documentation and/or other materials provided with the
  71  *    distribution.
  72  *
  73  * 3. All advertising materials mentioning features or use of this
  74  *    software must display the following acknowledgment:
  75  *    "This product includes software developed by the OpenSSL Project
  76  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  77  *
  78  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  79  *    endorse or promote products derived from this software without
  80  *    prior written permission. For written permission, please contact
  81  *    openssl-core@openssl.org.
  82  *
  83  * 5. Products derived from this software may not be called "OpenSSL"
  84  *    nor may "OpenSSL" appear in their names without prior written
  85  *    permission of the OpenSSL Project.
  86  *
  87  * 6. Redistributions of any form whatsoever must retain the following
  88  *    acknowledgment:
  89  *    "This product includes software developed by the OpenSSL Project
  90  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  91  *
  92  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  93  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  94  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  95  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  96  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  97  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  98  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  99  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 100  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 101  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 102  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 103  * OF THE POSSIBILITY OF SUCH DAMAGE.
 104  * ====================================================================
 105  *
 106  * This product includes cryptographic software written by Eric Young
 107  * (eay@cryptsoft.com).  This product includes software written by Tim
 108  * Hudson (tjh@cryptsoft.com).
 109  *
 110  */
 111
 112 #include <stdio.h>
 113 #include <errno.h>
 114 #define USE_SOCKETS
 115 #include "ssl_locl.h"
 116 #include <openssl/evp.h>
 117 #include <openssl/buffer.h>
 118
 119 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 120                          unsigned int len, int create_empty_fragment);
 121 static int ssl3_get_record(SSL *s);
 122
 123 int ssl3_read_n(SSL *s, int n, int max, int extend)
 124         {
 125         /* If extend == 0, obtain new n-byte packet; if extend == 1, increase
 126          * packet by another n bytes.
 127          * The packet will be in the sub-array of s->s3->rbuf.buf specified
 128          * by s->packet and s->packet_length.
 129          * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
 130          * [plus s->packet_length bytes if extend == 1].)
 131          */
 132         int i,off,newb;
 133
 134         if (!extend)
 135                 {
 136                 /* start with empty packet ... */
 137                 if (s->s3->rbuf.left == 0)
 138                         s->s3->rbuf.offset = 0;
 139                 s->packet = s->s3->rbuf.buf + s->s3->rbuf.offset;
 140                 s->packet_length = 0;
 141                 /* ... now we can act as if 'extend' was set */
 142                 }
 143
 144         /* extend reads should not span multiple packets for DTLS */
 145         if ( SSL_version(s) == DTLS1_VERSION &&
 146                 extend)
 147                 {
 148                 if ( s->s3->rbuf.left > 0 && n > s->s3->rbuf.left)
 149                         n = s->s3->rbuf.left;
 150                 }
 151
 152         /* if there is enough in the buffer from a previous read, take some */
 153         if (s->s3->rbuf.left >= (int)n)
 154                 {
 155                 s->packet_length+=n;
 156                 s->s3->rbuf.left-=n;
 157                 s->s3->rbuf.offset+=n;
 158                 return(n);
 159                 }
 160
 161         /* else we need to read more data */
 162         if (!s->read_ahead)
 163                 max=n;
 164
 165         {
 166                 /* avoid buffer overflow */
 167                 int max_max = s->s3->rbuf.len - s->packet_length;
 168                 if (max > max_max)
 169                         max = max_max;
 170         }
 171         if (n > max) /* does not happen */
 172                 {
 173                 SSLerr(SSL_F_SSL3_READ_N,ERR_R_INTERNAL_ERROR);
 174                 return -1;
 175                 }
 176
 177         off = s->packet_length;
 178         newb = s->s3->rbuf.left;
 179         /* Move any available bytes to front of buffer:
 180          * 'off' bytes already pointed to by 'packet',
 181          * 'newb' extra ones at the end */
 182         if (s->packet != s->s3->rbuf.buf)
 183                 {
 184                 /*  off > 0 */
 185                 memmove(s->s3->rbuf.buf, s->packet, off+newb);
 186                 s->packet = s->s3->rbuf.buf;
 187                 }
 188
 189         while (newb < n)
 190                 {
 191                 /* Now we have off+newb bytes at the front of s->s3->rbuf.buf and need
 192                  * to read in more until we have off+n (up to off+max if possible) */
 193
 194                 clear_sys_error();
 195                 if (s->rbio != NULL)
 196                         {
 197                         s->rwstate=SSL_READING;
 198                         i=BIO_read(s->rbio,     &(s->s3->rbuf.buf[off+newb]), max-newb);
 199                         }
 200                 else
 201                         {
 202                         SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
 203                         i = -1;
 204                         }
 205
 206                 if (i <= 0)
 207                         {
 208                         s->s3->rbuf.left = newb;
 209                         return(i);
 210                         }
 211                 newb+=i;
 212                 }
 213
 214         /* done reading, now the book-keeping */
 215         s->s3->rbuf.offset = off + n;
 216         s->s3->rbuf.left = newb - n;
 217         s->packet_length += n;
 218         s->rwstate=SSL_NOTHING;
 219         return(n);
 220         }
 221
 222 /* Call this to get a new input record.
 223  * It will return <= 0 if more data is needed, normally due to an error
 224  * or non-blocking IO.
 225  * When it finishes, one packet has been decoded and can be found in
 226  * ssl->s3->rrec.type    - is the type of record
 227  * ssl->s3->rrec.data,   - data
 228  * ssl->s3->rrec.length, - number of bytes
 229  */
 230 /* used only by ssl3_read_bytes */
 231 static int ssl3_get_record(SSL *s)
 232         {
 233         int ssl_major,ssl_minor,al;
 234         int enc_err,n,i,ret= -1;
 235         SSL3_RECORD *rr;
 236         SSL_SESSION *sess;
 237         unsigned char *p;
 238         unsigned char md[EVP_MAX_MD_SIZE];
 239         short version;
 240         unsigned int mac_size;
 241         int clear=0;
 242         size_t extra;
 243         int decryption_failed_or_bad_record_mac = 0;
 244         unsigned char *mac = NULL;
 245
 246         rr= &(s->s3->rrec);
 247         sess=s->session;
 248
 249         if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
 250                 extra=SSL3_RT_MAX_EXTRA;
 251         else
 252                 extra=0;
 253         if (extra != s->s3->rbuf.len - SSL3_RT_MAX_PACKET_SIZE)
 254                 {
 255                 /* actually likely an application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
 256                  * set after ssl3_setup_buffers() was done */
 257                 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
 258                 return -1;
 259                 }
 260
 261 again:
 262         /* check if we have the header */
 263         if (    (s->rstate != SSL_ST_READ_BODY) ||
 264                 (s->packet_length < SSL3_RT_HEADER_LENGTH))
 265                 {
 266                 n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 267                 if (n <= 0) return(n); /* error or non-blocking */
 268                 s->rstate=SSL_ST_READ_BODY;
 269
 270                 p=s->packet;
 271
 272                 /* Pull apart the header into the SSL3_RECORD */
 273                 rr->type= *(p++);
 274                 ssl_major= *(p++);
 275                 ssl_minor= *(p++);
 276                 version=(ssl_major<<8)|ssl_minor;
 277                 n2s(p,rr->length);
 278
 279                 /* Lets check version */
 280                 if (s->first_packet)
 281                         {
 282                         s->first_packet=0;
 283                         }
 284                 else
 285                         {
 286                         if (version != s->version)
 287                                 {
 288                                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 289                                 /* Send back error using their
 290                                  * version number :-) */
 291                                 s->version=version;
 292                                 al=SSL_AD_PROTOCOL_VERSION;
 293                                 goto f_err;
 294                                 }
 295                         }
 296
 297                 if ((version>>8) != SSL3_VERSION_MAJOR)
 298                         {
 299                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 300                         goto err;
 301                         }
 302
 303                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
 304                         {
 305                         al=SSL_AD_RECORD_OVERFLOW;
 306                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 307                         goto f_err;
 308                         }
 309
 310                 /* now s->rstate == SSL_ST_READ_BODY */
 311                 }
 312
 313         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 314
 315         if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
 316                 {
 317                 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
 318                 i=rr->length;
 319                 n=ssl3_read_n(s,i,i,1);
 320                 if (n <= 0) return(n); /* error or non-blocking io */
 321                 /* now n == rr->length,
 322                  * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
 323                 }
 324
 325         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 326
 327         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 328          * and we have that many bytes in s->packet
 329          */
 330         rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
 331
 332         /* ok, we can now read from 's->packet' data into 'rr'
 333          * rr->input points at rr->length bytes, which
 334          * need to be copied into rr->data by either
 335          * the decryption or by the decompression
 336          * When the data is 'copied' into the rr->data buffer,
 337          * rr->input will be pointed at the new buffer */
 338
 339         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 340          * rr->length bytes of encrypted compressed stuff. */
 341
 342         /* check is not needed I believe */
 343         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
 344                 {
 345                 al=SSL_AD_RECORD_OVERFLOW;
 346                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 347                 goto f_err;
 348                 }
 349
 350         /* decrypt in place in 'rr->input' */
 351         rr->data=rr->input;
 352
 353         enc_err = s->method->ssl3_enc->enc(s,0);
 354         if (enc_err <= 0)
 355                 {
 356                 if (enc_err == 0)
 357                         /* SSLerr() and ssl3_send_alert() have been called */
 358                         goto err;
 359
 360                 /* Otherwise enc_err == -1, which indicates bad padding
 361                  * (rec->length has not been changed in this case).
 362                  * To minimize information leaked via timing, we will perform
 363                  * the MAC computation anyway. */
 364                 decryption_failed_or_bad_record_mac = 1;
 365                 }
 366
 367 #ifdef TLS_DEBUG
 368 printf("dec %d\n",rr->length);
 369 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 370 printf("\n");
 371 #endif
 372
 373         /* r->length is now the compressed data plus mac */
 374         if (    (sess == NULL) ||
 375                 (s->enc_read_ctx == NULL) ||
 376                 (s->read_hash == NULL))
 377                 clear=1;
 378
 379         if (!clear)
 380                 {
 381                 mac_size=EVP_MD_size(s->read_hash);
 382
 383                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
 384                         {
 385 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 386                         al=SSL_AD_RECORD_OVERFLOW;
 387                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 388                         goto f_err;
 389 #else
 390                         decryption_failed_or_bad_record_mac = 1;
 391 #endif
 392                         }
 393                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 394                 if (rr->length >= mac_size)
 395                         {
 396                         rr->length -= mac_size;
 397                         mac = &rr->data[rr->length];
 398                         }
 399                 else
 400                         {
 401                         /* record (minus padding) is too short to contain a MAC */
 402 #if 0 /* OK only for stream ciphers */
 403                         al=SSL_AD_DECODE_ERROR;
 404                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
 405                         goto f_err;
 406 #else
 407                         decryption_failed_or_bad_record_mac = 1;
 408                         rr->length = 0;
 409 #endif
 410                         }
 411                 i=s->method->ssl3_enc->mac(s,md,0);
 412                 if (mac == NULL || memcmp(md, mac, mac_size) != 0)
 413                         {
 414                         decryption_failed_or_bad_record_mac = 1;
 415                         }
 416                 }
 417
 418         if (decryption_failed_or_bad_record_mac)
 419                 {
 420                 /* A separate 'decryption_failed' alert was introduced with TLS 1.0,
 421                  * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 422                  * failure is directly visible from the ciphertext anyway,
 423                  * we should not reveal which kind of error occured -- this
 424                  * might become visible to an attacker (e.g. via a logfile) */
 425                 al=SSL_AD_BAD_RECORD_MAC;
 426                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 427                 goto f_err;
 428                 }
 429
 430         /* r->length is now just compressed */
 431         if (s->expand != NULL)
 432                 {
 433                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
 434                         {
 435                         al=SSL_AD_RECORD_OVERFLOW;
 436                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 437                         goto f_err;
 438                         }
 439                 if (!ssl3_do_uncompress(s))
 440                         {
 441                         al=SSL_AD_DECOMPRESSION_FAILURE;
 442                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
 443                         goto f_err;
 444                         }
 445                 }
 446
 447         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
 448                 {
 449                 al=SSL_AD_RECORD_OVERFLOW;
 450                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 451                 goto f_err;
 452                 }
 453
 454         rr->off=0;
 455         /* So at this point the following is true
 456          * ssl->s3->rrec.type   is the type of record
 457          * ssl->s3->rrec.length == number of bytes in record
 458          * ssl->s3->rrec.off    == offset to first valid byte
 459          * ssl->s3->rrec.data   == where to take bytes from, increment
 460          *                         after use :-).
 461          */
 462
 463         /* we have pulled in a full packet so zero things */
 464         s->packet_length=0;
 465
 466         /* just read a 0 length packet */
 467         if (rr->length == 0) goto again;
 468
 469         return(1);
 470
 471 f_err:
 472         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 473 err:
 474         return(ret);
 475         }
 476
 477 int ssl3_do_uncompress(SSL *ssl)
 478         {
 479 #ifndef OPENSSL_NO_COMP
 480         int i;
 481         SSL3_RECORD *rr;
 482
 483         rr= &(ssl->s3->rrec);
 484         i=COMP_expand_block(ssl->expand,rr->comp,
 485                 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
 486         if (i < 0)
 487                 return(0);
 488         else
 489                 rr->length=i;
 490         rr->data=rr->comp;
 491 #endif
 492         return(1);
 493         }
 494
 495 int ssl3_do_compress(SSL *ssl)
 496         {
 497 #ifndef OPENSSL_NO_COMP
 498         int i;
 499         SSL3_RECORD *wr;
 500
 501         wr= &(ssl->s3->wrec);
 502         i=COMP_compress_block(ssl->compress,wr->data,
 503                 SSL3_RT_MAX_COMPRESSED_LENGTH,
 504                 wr->input,(int)wr->length);
 505         if (i < 0)
 506                 return(0);
 507         else
 508                 wr->length=i;
 509
 510         wr->input=wr->data;
 511 #endif
 512         return(1);
 513         }
 514
 515 /* Call this to write data in records of type 'type'
 516  * It will return <= 0 if not all data has been sent or non-blocking IO.
 517  */
 518 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
 519         {
 520         const unsigned char *buf=buf_;
 521         unsigned int tot,n,nw;
 522         int i;
 523
 524         s->rwstate=SSL_NOTHING;
 525         tot=s->s3->wnum;
 526         s->s3->wnum=0;
 527
 528         if (SSL_in_init(s) && !s->in_handshake)
 529                 {
 530                 i=s->handshake_func(s);
 531                 if (i < 0) return(i);
 532                 if (i == 0)
 533                         {
 534                         SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 535                         return -1;
 536                         }
 537                 }
 538
 539         n=(len-tot);
 540         for (;;)
 541                 {
 542                 if (n > SSL3_RT_MAX_PLAIN_LENGTH)
 543                         nw=SSL3_RT_MAX_PLAIN_LENGTH;
 544                 else
 545                         nw=n;
 546
 547                 i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
 548                 if (i <= 0)
 549                         {
 550                         s->s3->wnum=tot;
 551                         return i;
 552                         }
 553
 554                 if ((i == (int)n) ||
 555                         (type == SSL3_RT_APPLICATION_DATA &&
 556                          (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
 557                         {
 558                         /* next chunk of data should get another prepended empty fragment
 559                          * in ciphersuites with known-IV weakness: */
 560                         s->s3->empty_fragment_done = 0;
 561
 562                         return tot+i;
 563                         }
 564
 565                 n-=i;
 566                 tot+=i;
 567                 }
 568         }
 569
 570 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 571                          unsigned int len, int create_empty_fragment)
 572         {
 573         unsigned char *p,*plen;
 574         int i,mac_size,clear=0;
 575         int prefix_len = 0;
 576         SSL3_RECORD *wr;
 577         SSL3_BUFFER *wb;
 578         SSL_SESSION *sess;
 579
 580         /* first check if there is a SSL3_BUFFER still being written
 581          * out.  This will happen with non blocking IO */
 582         if (s->s3->wbuf.left != 0)
 583                 return(ssl3_write_pending(s,type,buf,len));
 584
 585         /* If we have an alert to send, lets send it */
 586         if (s->s3->alert_dispatch)
 587                 {
 588                 i=s->method->ssl_dispatch_alert(s);
 589                 if (i <= 0)
 590                         return(i);
 591                 /* if it went, fall through and send more stuff */
 592                 }
 593
 594         if (len == 0 && !create_empty_fragment)
 595                 return 0;
 596
 597         wr= &(s->s3->wrec);
 598         wb= &(s->s3->wbuf);
 599         sess=s->session;
 600
 601         if (    (sess == NULL) ||
 602                 (s->enc_write_ctx == NULL) ||
 603                 (s->write_hash == NULL))
 604                 clear=1;
 605
 606         if (clear)
 607                 mac_size=0;
 608         else
 609                 mac_size=EVP_MD_size(s->write_hash);
 610
 611         /* 'create_empty_fragment' is true only when this function calls itself */
 612         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
 613                 {
 614                 /* countermeasure against known-IV weakness in CBC ciphersuites
 615                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
 616
 617                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
 618                         {
 619                         /* recursive function call with 'create_empty_fragment' set;
 620                          * this prepares and buffers the data for an empty fragment
 621                          * (these 'prefix_len' bytes are sent out later
 622                          * together with the actual payload) */
 623                         prefix_len = do_ssl3_write(s, type, buf, 0, 1);
 624                         if (prefix_len <= 0)
 625                                 goto err;
 626
 627                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
 628                                 {
 629                                 /* insufficient space */
 630                                 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
 631                                 goto err;
 632                                 }
 633                         }
 634
 635                 s->s3->empty_fragment_done = 1;
 636                 }
 637
 638         p = wb->buf + prefix_len;
 639
 640         /* write the header */
 641
 642         *(p++)=type&0xff;
 643         wr->type=type;
 644
 645         *(p++)=(s->version>>8);
 646         *(p++)=s->version&0xff;
 647
 648         /* field where we are to write out packet length */
 649         plen=p;
 650         p+=2;
 651
 652         /* lets setup the record stuff. */
 653         wr->data=p;
 654         wr->length=(int)len;
 655         wr->input=(unsigned char *)buf;
 656
 657         /* we now 'read' from wr->input, wr->length bytes into
 658          * wr->data */
 659
 660         /* first we compress */
 661         if (s->compress != NULL)
 662                 {
 663                 if (!ssl3_do_compress(s))
 664                         {
 665                         SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
 666                         goto err;
 667                         }
 668                 }
 669         else
 670                 {
 671                 memcpy(wr->data,wr->input,wr->length);
 672                 wr->input=wr->data;
 673                 }
 674
 675         /* we should still have the output to wr->data and the input
 676          * from wr->input.  Length should be wr->length.
 677          * wr->data still points in the wb->buf */
 678
 679         if (mac_size != 0)
 680                 {
 681                 s->method->ssl3_enc->mac(s,&(p[wr->length]),1);
 682                 wr->length+=mac_size;
 683                 wr->input=p;
 684                 wr->data=p;
 685                 }
 686
 687         /* ssl3_enc can only have an error on read */
 688         s->method->ssl3_enc->enc(s,1);
 689
 690         /* record length after mac and block padding */
 691         s2n(wr->length,plen);
 692
 693         /* we should now have
 694          * wr->data pointing to the encrypted data, which is
 695          * wr->length long */
 696         wr->type=type; /* not needed but helps for debugging */
 697         wr->length+=SSL3_RT_HEADER_LENGTH;
 698
 699         if (create_empty_fragment)
 700                 {
 701                 /* we are in a recursive call;
 702                  * just return the length, don't write out anything here
 703                  */
 704                 return wr->length;
 705                 }
 706
 707         /* now let's set up wb */
 708         wb->left = prefix_len + wr->length;
 709         wb->offset = 0;
 710
 711         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
 712         s->s3->wpend_tot=len;
 713         s->s3->wpend_buf=buf;
 714         s->s3->wpend_type=type;
 715         s->s3->wpend_ret=len;
 716
 717         /* we now just need to write the buffer */
 718         return ssl3_write_pending(s,type,buf,len);
 719 err:
 720         return -1;
 721         }
 722
 723 /* if s->s3->wbuf.left != 0, we need to call this */
 724 int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
 725         unsigned int len)
 726         {
 727         int i;
 728
 729 /* XXXX */
 730         if ((s->s3->wpend_tot > (int)len)
 731                 || ((s->s3->wpend_buf != buf) &&
 732                         !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))
 733                 || (s->s3->wpend_type != type))
 734                 {
 735                 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
 736                 return(-1);
 737                 }
 738
 739         for (;;)
 740                 {
 741                 clear_sys_error();
 742                 if (s->wbio != NULL)
 743                         {
 744                         s->rwstate=SSL_WRITING;
 745                         i=BIO_write(s->wbio,
 746                                 (char *)&(s->s3->wbuf.buf[s->s3->wbuf.offset]),
 747                                 (unsigned int)s->s3->wbuf.left);
 748                         }
 749                 else
 750                         {
 751                         SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
 752                         i= -1;
 753                         }
 754                 if (i == s->s3->wbuf.left)
 755                         {
 756                         s->s3->wbuf.left=0;
 757                         s->rwstate=SSL_NOTHING;
 758                         return(s->s3->wpend_ret);
 759                         }
 760                 else if (i <= 0)
 761                         return(i);
 762                 s->s3->wbuf.offset+=i;
 763                 s->s3->wbuf.left-=i;
 764                 }
 765         }
 766
 767 /* Return up to 'len' payload bytes received in 'type' records.
 768  * 'type' is one of the following:
 769  *
 770  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 771  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 772  *   -  0 (during a shutdown, no data has to be returned)
 773  *
 774  * If we don't have stored data to work from, read a SSL/TLS record first
 775  * (possibly multiple records if we still don't have anything to return).
 776  *
 777  * This function must handle any surprises the peer may have for us, such as
 778  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 779  * a surprise, but handled as if it were), or renegotiation requests.
 780  * Also if record payloads contain fragments too small to process, we store
 781  * them until there is enough for the respective protocol (the record protocol
 782  * may use arbitrary fragmentation and even interleaving):
 783  *     Change cipher spec protocol
 784  *             just 1 byte needed, no need for keeping anything stored
 785  *     Alert protocol
 786  *             2 bytes needed (AlertLevel, AlertDescription)
 787  *     Handshake protocol
 788  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 789  *             to detect unexpected Client Hello and Hello Request messages
 790  *             here, anything else is handled by higher layers
 791  *     Application data protocol
 792  *             none of our business
 793  */
 794 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 795         {
 796         int al,i,j,ret;
 797         unsigned int n;
 798         SSL3_RECORD *rr;
 799         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 800
 801         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 802                 if (!ssl3_setup_buffers(s))
 803                         return(-1);
 804
 805         if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) ||
 806             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 807                 {
 808                 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
 809                 return -1;
 810                 }
 811
 812         if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
 813                 /* (partially) satisfy request from storage */
 814                 {
 815                 unsigned char *src = s->s3->handshake_fragment;
 816                 unsigned char *dst = buf;
 817                 unsigned int k;
 818
 819                 /* peek == 0 */
 820                 n = 0;
 821                 while ((len > 0) && (s->s3->handshake_fragment_len > 0))
 822                         {
 823                         *dst++ = *src++;
 824                         len--; s->s3->handshake_fragment_len--;
 825                         n++;
 826                         }
 827                 /* move any remaining fragment bytes: */
 828                 for (k = 0; k < s->s3->handshake_fragment_len; k++)
 829                         s->s3->handshake_fragment[k] = *src++;
 830                 return n;
 831         }
 832
 833         /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 834
 835         if (!s->in_handshake && SSL_in_init(s))
 836                 {
 837                 /* type == SSL3_RT_APPLICATION_DATA */
 838                 i=s->handshake_func(s);
 839                 if (i < 0) return(i);
 840                 if (i == 0)
 841                         {
 842                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 843                         return(-1);
 844                         }
 845                 }
 846 start:
 847         s->rwstate=SSL_NOTHING;
 848
 849         /* s->s3->rrec.type         - is the type of record
 850          * s->s3->rrec.data,    - data
 851          * s->s3->rrec.off,     - offset into 'data' for next read
 852          * s->s3->rrec.length,  - number of bytes. */
 853         rr = &(s->s3->rrec);
 854
 855         /* get new packet if necessary */
 856         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 857                 {
 858                 ret=ssl3_get_record(s);
 859                 if (ret <= 0) return(ret);
 860                 }
 861
 862         /* we now have a packet which can be read and processed */
 863
 864         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 865                                        * reset by ssl3_get_finished */
 866                 && (rr->type != SSL3_RT_HANDSHAKE))
 867                 {
 868                 al=SSL_AD_UNEXPECTED_MESSAGE;
 869                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
 870                 goto f_err;
 871                 }
 872
 873         /* If the other end has shut down, throw anything we read away
 874          * (even in 'peek' mode) */
 875         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 876                 {
 877                 rr->length=0;
 878                 s->rwstate=SSL_NOTHING;
 879                 return(0);
 880                 }
 881
 882
 883         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 884                 {
 885                 /* make sure that we are not getting application data when we
 886                  * are doing a handshake for the first time */
 887                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 888                         (s->enc_read_ctx == NULL))
 889                         {
 890                         al=SSL_AD_UNEXPECTED_MESSAGE;
 891                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 892                         goto f_err;
 893                         }
 894
 895                 if (len <= 0) return(len);
 896
 897                 if ((unsigned int)len > rr->length)
 898                         n = rr->length;
 899                 else
 900                         n = (unsigned int)len;
 901
 902                 memcpy(buf,&(rr->data[rr->off]),n);
 903                 if (!peek)
 904                         {
 905                         rr->length-=n;
 906                         rr->off+=n;
 907                         if (rr->length == 0)
 908                                 {
 909                                 s->rstate=SSL_ST_READ_HEADER;
 910                                 rr->off=0;
 911                                 }
 912                         }
 913                 return(n);
 914                 }
 915
 916
 917         /* If we get here, then type != rr->type; if we have a handshake
 918          * message, then it was unexpected (Hello Request or Client Hello). */
 919
 920         /* In case of record types for which we have 'fragment' storage,
 921          * fill that so that we can process the data at a fixed place.
 922          */
 923                 {
 924                 unsigned int dest_maxlen = 0;
 925                 unsigned char *dest = NULL;
 926                 unsigned int *dest_len = NULL;
 927
 928                 if (rr->type == SSL3_RT_HANDSHAKE)
 929                         {
 930                         dest_maxlen = sizeof s->s3->handshake_fragment;
 931                         dest = s->s3->handshake_fragment;
 932                         dest_len = &s->s3->handshake_fragment_len;
 933                         }
 934                 else if (rr->type == SSL3_RT_ALERT)
 935                         {
 936                         dest_maxlen = sizeof s->s3->alert_fragment;
 937                         dest = s->s3->alert_fragment;
 938                         dest_len = &s->s3->alert_fragment_len;
 939                         }
 940
 941                 if (dest_maxlen > 0)
 942                         {
 943                         n = dest_maxlen - *dest_len; /* available space in 'dest' */
 944                         if (rr->length < n)
 945                                 n = rr->length; /* available bytes */
 946
 947                         /* now move 'n' bytes: */
 948                         while (n-- > 0)
 949                                 {
 950                                 dest[(*dest_len)++] = rr->data[rr->off++];
 951                                 rr->length--;
 952                                 }
 953
 954                         if (*dest_len < dest_maxlen)
 955                                 goto start; /* fragment was too small */
 956                         }
 957                 }
 958
 959         /* s->s3->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
 960          * s->s3->alert_fragment_len == 2      iff  rr->type == SSL3_RT_ALERT.
 961          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 962
 963         /* If we are a client, check for an incoming 'Hello Request': */
 964         if ((!s->server) &&
 965                 (s->s3->handshake_fragment_len >= 4) &&
 966                 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 967                 (s->session != NULL) && (s->session->cipher != NULL))
 968                 {
 969                 s->s3->handshake_fragment_len = 0;
 970
 971                 if ((s->s3->handshake_fragment[1] != 0) ||
 972                         (s->s3->handshake_fragment[2] != 0) ||
 973                         (s->s3->handshake_fragment[3] != 0))
 974                         {
 975                         al=SSL_AD_DECODE_ERROR;
 976                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 977                         goto f_err;
 978                         }
 979
 980                 if (s->msg_callback)
 981                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
 982
 983                 if (SSL_is_init_finished(s) &&
 984                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 985                         !s->s3->renegotiate)
 986                         {
 987                         ssl3_renegotiate(s);
 988                         if (ssl3_renegotiate_check(s))
 989                                 {
 990                                 i=s->handshake_func(s);
 991                                 if (i < 0) return(i);
 992                                 if (i == 0)
 993                                         {
 994                                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 995                                         return(-1);
 996                                         }
 997
 998                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 999                                         {
1000                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1001                                                 {
1002                                                 BIO *bio;
1003                                                 /* In the case where we try to read application data,
1004                                                  * but we trigger an SSL handshake, we return -1 with
1005                                                  * the retry option set.  Otherwise renegotiation may
1006                                                  * cause nasty problems in the blocking world */
1007                                                 s->rwstate=SSL_READING;
1008                                                 bio=SSL_get_rbio(s);
1009                                                 BIO_clear_retry_flags(bio);
1010                                                 BIO_set_retry_read(bio);
1011                                                 return(-1);
1012                                                 }
1013                                         }
1014                                 }
1015                         }
1016                 /* we either finished a handshake or ignored the request,
1017                  * now try again to obtain the (application) data we were asked for */
1018                 goto start;
1019                 }
1020
1021         if (s->s3->alert_fragment_len >= 2)
1022                 {
1023                 int alert_level = s->s3->alert_fragment[0];
1024                 int alert_descr = s->s3->alert_fragment[1];
1025
1026                 s->s3->alert_fragment_len = 0;
1027
1028                 if (s->msg_callback)
1029                         s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 2, s, s->msg_callback_arg);
1030
1031                 if (s->info_callback != NULL)
1032                         cb=s->info_callback;
1033                 else if (s->ctx->info_callback != NULL)
1034                         cb=s->ctx->info_callback;
1035
1036                 if (cb != NULL)
1037                         {
1038                         j = (alert_level << 8) | alert_descr;
1039                         cb(s, SSL_CB_READ_ALERT, j);
1040                         }
1041
1042                 if (alert_level == 1) /* warning */
1043                         {
1044                         s->s3->warn_alert = alert_descr;
1045                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1046                                 {
1047                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1048                                 return(0);
1049                                 }
1050                         }
1051                 else if (alert_level == 2) /* fatal */
1052                         {
1053                         char tmp[16];
1054
1055                         s->rwstate=SSL_NOTHING;
1056                         s->s3->fatal_alert = alert_descr;
1057                         SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1058                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1059                         ERR_add_error_data(2,"SSL alert number ",tmp);
1060                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1061                         SSL_CTX_remove_session(s->ctx,s->session);
1062                         return(0);
1063                         }
1064                 else
1065                         {
1066                         al=SSL_AD_ILLEGAL_PARAMETER;
1067                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1068                         goto f_err;
1069                         }
1070
1071                 goto start;
1072                 }
1073
1074         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1075                 {
1076                 s->rwstate=SSL_NOTHING;
1077                 rr->length=0;
1078                 return(0);
1079                 }
1080
1081         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1082                 {
1083                 /* 'Change Cipher Spec' is just a single byte, so we know
1084                  * exactly what the record payload has to look like */
1085                 if (    (rr->length != 1) || (rr->off != 0) ||
1086                         (rr->data[0] != SSL3_MT_CCS))
1087                         {
1088                         al=SSL_AD_ILLEGAL_PARAMETER;
1089                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1090                         goto f_err;
1091                         }
1092
1093                 /* Check we have a cipher to change to */
1094                 if (s->s3->tmp.new_cipher == NULL)
1095                         {
1096                         al=SSL_AD_UNEXPECTED_MESSAGE;
1097                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1098                         goto f_err;
1099                         }
1100
1101                 rr->length=0;
1102
1103                 if (s->msg_callback)
1104                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
1105
1106                 s->s3->change_cipher_spec=1;
1107                 if (!ssl3_do_change_cipher_spec(s))
1108                         goto err;
1109                 else
1110                         goto start;
1111                 }
1112
1113         /* Unexpected handshake message (Client Hello, or protocol violation) */
1114         if ((s->s3->handshake_fragment_len >= 4) &&     !s->in_handshake)
1115                 {
1116                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1117                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1118                         {
1119 #if 0 /* worked only because C operator preferences are not as expected (and
1120        * because this is not really needed for clients except for detecting
1121        * protocol violations): */
1122                         s->state=SSL_ST_BEFORE|(s->server)
1123                                 ?SSL_ST_ACCEPT
1124                                 :SSL_ST_CONNECT;
1125 #else
1126                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1127 #endif
1128                         s->new_session=1;
1129                         }
1130                 i=s->handshake_func(s);
1131                 if (i < 0) return(i);
1132                 if (i == 0)
1133                         {
1134                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1135                         return(-1);
1136                         }
1137
1138                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1139                         {
1140                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1141                                 {
1142                                 BIO *bio;
1143                                 /* In the case where we try to read application data,
1144                                  * but we trigger an SSL handshake, we return -1 with
1145                                  * the retry option set.  Otherwise renegotiation may
1146                                  * cause nasty problems in the blocking world */
1147                                 s->rwstate=SSL_READING;
1148                                 bio=SSL_get_rbio(s);
1149                                 BIO_clear_retry_flags(bio);
1150                                 BIO_set_retry_read(bio);
1151                                 return(-1);
1152                                 }
1153                         }
1154                 goto start;
1155                 }
1156
1157         switch (rr->type)
1158                 {
1159         default:
1160 #ifndef OPENSSL_NO_TLS
1161                 /* TLS just ignores unknown message types */
1162                 if (s->version == TLS1_VERSION)
1163                         {
1164                         rr->length = 0;
1165                         goto start;
1166                         }
1167 #endif
1168                 al=SSL_AD_UNEXPECTED_MESSAGE;
1169                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1170                 goto f_err;
1171         case SSL3_RT_CHANGE_CIPHER_SPEC:
1172         case SSL3_RT_ALERT:
1173         case SSL3_RT_HANDSHAKE:
1174                 /* we already handled all of these, with the possible exception
1175                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1176                  * should not happen when type != rr->type */
1177                 al=SSL_AD_UNEXPECTED_MESSAGE;
1178                 SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
1179                 goto f_err;
1180         case SSL3_RT_APPLICATION_DATA:
1181                 /* At this point, we were expecting handshake data,
1182                  * but have application data.  If the library was
1183                  * running inside ssl3_read() (i.e. in_read_app_data
1184                  * is set) and it makes sense to read application data
1185                  * at this point (session renegotiation not yet started),
1186                  * we will indulge it.
1187                  */
1188                 if (s->s3->in_read_app_data &&
1189                         (s->s3->total_renegotiations != 0) &&
1190                         ((
1191                                 (s->state & SSL_ST_CONNECT) &&
1192                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1193                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1194                                 ) || (
1195                                         (s->state & SSL_ST_ACCEPT) &&
1196                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1197                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1198                                         )
1199                                 ))
1200                         {
1201                         s->s3->in_read_app_data=2;
1202                         return(-1);
1203                         }
1204                 else
1205                         {
1206                         al=SSL_AD_UNEXPECTED_MESSAGE;
1207                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1208                         goto f_err;
1209                         }
1210                 }
1211         /* not reached */
1212
1213 f_err:
1214         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1215 err:
1216         return(-1);
1217         }
1218
1219 int ssl3_do_change_cipher_spec(SSL *s)
1220         {
1221         int i;
1222         const char *sender;
1223         int slen;
1224
1225         if (s->state & SSL_ST_ACCEPT)
1226                 i=SSL3_CHANGE_CIPHER_SERVER_READ;
1227         else
1228                 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
1229
1230         if (s->s3->tmp.key_block == NULL)
1231                 {
1232                 s->session->cipher=s->s3->tmp.new_cipher;
1233                 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
1234                 }
1235
1236         if (!s->method->ssl3_enc->change_cipher_state(s,i))
1237                 return(0);
1238
1239         /* we have to record the message digest at
1240          * this point so we can get it before we read
1241          * the finished message */
1242         if (s->state & SSL_ST_CONNECT)
1243                 {
1244                 sender=s->method->ssl3_enc->server_finished_label;
1245                 slen=s->method->ssl3_enc->server_finished_label_len;
1246                 }
1247         else
1248                 {
1249                 sender=s->method->ssl3_enc->client_finished_label;
1250                 slen=s->method->ssl3_enc->client_finished_label_len;
1251                 }
1252
1253         s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
1254                 &(s->s3->finish_dgst1),
1255                 &(s->s3->finish_dgst2),
1256                 sender,slen,s->s3->tmp.peer_finish_md);
1257
1258         return(1);
1259         }
1260
1261 void ssl3_send_alert(SSL *s, int level, int desc)
1262         {
1263         /* Map tls/ssl alert value to correct one */
1264         desc=s->method->ssl3_enc->alert_value(desc);
1265         if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
1266                 desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
1267         if (desc < 0) return;
1268         /* If a fatal one, remove from cache */
1269         if ((level == 2) && (s->session != NULL))
1270                 SSL_CTX_remove_session(s->ctx,s->session);
1271
1272         s->s3->alert_dispatch=1;
1273         s->s3->send_alert[0]=level;
1274         s->s3->send_alert[1]=desc;
1275         if (s->s3->wbuf.left == 0) /* data still being written out? */
1276                 s->method->ssl_dispatch_alert(s);
1277         /* else data is still being written out, we will get written
1278          * some time in the future */
1279         }
1280
1281 int ssl3_dispatch_alert(SSL *s)
1282         {
1283         int i,j;
1284         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1285
1286         s->s3->alert_dispatch=0;
1287         i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
1288         if (i <= 0)
1289                 {
1290                 s->s3->alert_dispatch=1;
1291                 }
1292         else
1293                 {
1294                 /* Alert sent to BIO.  If it is important, flush it now.
1295                  * If the message does not get sent due to non-blocking IO,
1296                  * we will not worry too much. */
1297                 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1298                         (void)BIO_flush(s->wbio);
1299
1300                 if (s->msg_callback)
1301                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, s->msg_callback_arg);
1302
1303                 if (s->info_callback != NULL)
1304                         cb=s->info_callback;
1305                 else if (s->ctx->info_callback != NULL)
1306                         cb=s->ctx->info_callback;
1307
1308                 if (cb != NULL)
1309                         {
1310                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1311                         cb(s,SSL_CB_WRITE_ALERT,j);
1312                         }
1313                 }
1314         return(i);
1315         }