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                         if (version != s->version)
 283                                 {
 284                                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 285                                 /* Send back error using their
 286                                  * version number :-) */
 287                                 s->version=version;
 288                                 al=SSL_AD_PROTOCOL_VERSION;
 289                                 goto f_err;
 290                                 }
 291                         }
 292
 293                 if ((version>>8) != SSL3_VERSION_MAJOR)
 294                         {
 295                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 296                         goto err;
 297                         }
 298
 299                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
 300                         {
 301                         al=SSL_AD_RECORD_OVERFLOW;
 302                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 303                         goto f_err;
 304                         }
 305
 306                 /* now s->rstate == SSL_ST_READ_BODY */
 307                 }
 308
 309         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 310
 311         if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
 312                 {
 313                 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
 314                 i=rr->length;
 315                 n=ssl3_read_n(s,i,i,1);
 316                 if (n <= 0) return(n); /* error or non-blocking io */
 317                 /* now n == rr->length,
 318                  * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
 319                 }
 320
 321         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 322
 323         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 324          * and we have that many bytes in s->packet
 325          */
 326         rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
 327
 328         /* ok, we can now read from 's->packet' data into 'rr'
 329          * rr->input points at rr->length bytes, which
 330          * need to be copied into rr->data by either
 331          * the decryption or by the decompression
 332          * When the data is 'copied' into the rr->data buffer,
 333          * rr->input will be pointed at the new buffer */
 334
 335         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 336          * rr->length bytes of encrypted compressed stuff. */
 337
 338         /* check is not needed I believe */
 339         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
 340                 {
 341                 al=SSL_AD_RECORD_OVERFLOW;
 342                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 343                 goto f_err;
 344                 }
 345
 346         /* decrypt in place in 'rr->input' */
 347         rr->data=rr->input;
 348
 349         enc_err = s->method->ssl3_enc->enc(s,0);
 350         if (enc_err <= 0)
 351                 {
 352                 if (enc_err == 0)
 353                         /* SSLerr() and ssl3_send_alert() have been called */
 354                         goto err;
 355
 356                 /* Otherwise enc_err == -1, which indicates bad padding
 357                  * (rec->length has not been changed in this case).
 358                  * To minimize information leaked via timing, we will perform
 359                  * the MAC computation anyway. */
 360                 decryption_failed_or_bad_record_mac = 1;
 361                 }
 362
 363 #ifdef TLS_DEBUG
 364 printf("dec %d\n",rr->length);
 365 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 366 printf("\n");
 367 #endif
 368
 369         /* r->length is now the compressed data plus mac */
 370         if (    (sess == NULL) ||
 371                 (s->enc_read_ctx == NULL) ||
 372                 (s->read_hash == NULL))
 373                 clear=1;
 374
 375         if (!clear)
 376                 {
 377                 mac_size=EVP_MD_size(s->read_hash);
 378
 379                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
 380                         {
 381 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 382                         al=SSL_AD_RECORD_OVERFLOW;
 383                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 384                         goto f_err;
 385 #else
 386                         decryption_failed_or_bad_record_mac = 1;
 387 #endif
 388                         }
 389                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 390                 if (rr->length >= mac_size)
 391                         {
 392                         rr->length -= mac_size;
 393                         mac = &rr->data[rr->length];
 394                         }
 395                 else
 396                         {
 397                         /* record (minus padding) is too short to contain a MAC */
 398 #if 0 /* OK only for stream ciphers */
 399                         al=SSL_AD_DECODE_ERROR;
 400                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
 401                         goto f_err;
 402 #else
 403                         decryption_failed_or_bad_record_mac = 1;
 404                         rr->length = 0;
 405 #endif
 406                         }
 407                 i=s->method->ssl3_enc->mac(s,md,0);
 408                 if (mac == NULL || memcmp(md, mac, mac_size) != 0)
 409                         {
 410                         decryption_failed_or_bad_record_mac = 1;
 411                         }
 412                 }
 413
 414         if (decryption_failed_or_bad_record_mac)
 415                 {
 416                 /* A separate 'decryption_failed' alert was introduced with TLS 1.0,
 417                  * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 418                  * failure is directly visible from the ciphertext anyway,
 419                  * we should not reveal which kind of error occured -- this
 420                  * might become visible to an attacker (e.g. via a logfile) */
 421                 al=SSL_AD_BAD_RECORD_MAC;
 422                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 423                 goto f_err;
 424                 }
 425
 426         /* r->length is now just compressed */
 427         if (s->expand != NULL)
 428                 {
 429                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
 430                         {
 431                         al=SSL_AD_RECORD_OVERFLOW;
 432                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 433                         goto f_err;
 434                         }
 435                 if (!ssl3_do_uncompress(s))
 436                         {
 437                         al=SSL_AD_DECOMPRESSION_FAILURE;
 438                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
 439                         goto f_err;
 440                         }
 441                 }
 442
 443         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
 444                 {
 445                 al=SSL_AD_RECORD_OVERFLOW;
 446                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 447                 goto f_err;
 448                 }
 449
 450         rr->off=0;
 451         /* So at this point the following is true
 452          * ssl->s3->rrec.type   is the type of record
 453          * ssl->s3->rrec.length == number of bytes in record
 454          * ssl->s3->rrec.off    == offset to first valid byte
 455          * ssl->s3->rrec.data   == where to take bytes from, increment
 456          *                         after use :-).
 457          */
 458
 459         /* we have pulled in a full packet so zero things */
 460         s->packet_length=0;
 461
 462         /* just read a 0 length packet */
 463         if (rr->length == 0) goto again;
 464
 465         return(1);
 466
 467 f_err:
 468         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 469 err:
 470         return(ret);
 471         }
 472
 473 int ssl3_do_uncompress(SSL *ssl)
 474         {
 475 #ifndef OPENSSL_NO_COMP
 476         int i;
 477         SSL3_RECORD *rr;
 478
 479         rr= &(ssl->s3->rrec);
 480         i=COMP_expand_block(ssl->expand,rr->comp,
 481                 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
 482         if (i < 0)
 483                 return(0);
 484         else
 485                 rr->length=i;
 486         rr->data=rr->comp;
 487 #endif
 488         return(1);
 489         }
 490
 491 int ssl3_do_compress(SSL *ssl)
 492         {
 493 #ifndef OPENSSL_NO_COMP
 494         int i;
 495         SSL3_RECORD *wr;
 496
 497         wr= &(ssl->s3->wrec);
 498         i=COMP_compress_block(ssl->compress,wr->data,
 499                 SSL3_RT_MAX_COMPRESSED_LENGTH,
 500                 wr->input,(int)wr->length);
 501         if (i < 0)
 502                 return(0);
 503         else
 504                 wr->length=i;
 505
 506         wr->input=wr->data;
 507 #endif
 508         return(1);
 509         }
 510
 511 /* Call this to write data in records of type 'type'
 512  * It will return <= 0 if not all data has been sent or non-blocking IO.
 513  */
 514 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
 515         {
 516         const unsigned char *buf=buf_;
 517         unsigned int tot,n,nw;
 518         int i;
 519
 520         s->rwstate=SSL_NOTHING;
 521         tot=s->s3->wnum;
 522         s->s3->wnum=0;
 523
 524         if (SSL_in_init(s) && !s->in_handshake)
 525                 {
 526                 i=s->handshake_func(s);
 527                 if (i < 0) return(i);
 528                 if (i == 0)
 529                         {
 530                         SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 531                         return -1;
 532                         }
 533                 }
 534
 535         n=(len-tot);
 536         for (;;)
 537                 {
 538                 if (n > SSL3_RT_MAX_PLAIN_LENGTH)
 539                         nw=SSL3_RT_MAX_PLAIN_LENGTH;
 540                 else
 541                         nw=n;
 542
 543                 i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
 544                 if (i <= 0)
 545                         {
 546                         s->s3->wnum=tot;
 547                         return i;
 548                         }
 549
 550                 if ((i == (int)n) ||
 551                         (type == SSL3_RT_APPLICATION_DATA &&
 552                          (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
 553                         {
 554                         /* next chunk of data should get another prepended empty fragment
 555                          * in ciphersuites with known-IV weakness: */
 556                         s->s3->empty_fragment_done = 0;
 557
 558                         return tot+i;
 559                         }
 560
 561                 n-=i;
 562                 tot+=i;
 563                 }
 564         }
 565
 566 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 567                          unsigned int len, int create_empty_fragment)
 568         {
 569         unsigned char *p,*plen;
 570         int i,mac_size,clear=0;
 571         int prefix_len = 0;
 572         SSL3_RECORD *wr;
 573         SSL3_BUFFER *wb;
 574         SSL_SESSION *sess;
 575
 576         /* first check if there is a SSL3_BUFFER still being written
 577          * out.  This will happen with non blocking IO */
 578         if (s->s3->wbuf.left != 0)
 579                 return(ssl3_write_pending(s,type,buf,len));
 580
 581         /* If we have an alert to send, lets send it */
 582         if (s->s3->alert_dispatch)
 583                 {
 584                 i=s->method->ssl_dispatch_alert(s);
 585                 if (i <= 0)
 586                         return(i);
 587                 /* if it went, fall through and send more stuff */
 588                 }
 589
 590         if (len == 0 && !create_empty_fragment)
 591                 return 0;
 592
 593         wr= &(s->s3->wrec);
 594         wb= &(s->s3->wbuf);
 595         sess=s->session;
 596
 597         if (    (sess == NULL) ||
 598                 (s->enc_write_ctx == NULL) ||
 599                 (s->write_hash == NULL))
 600                 clear=1;
 601
 602         if (clear)
 603                 mac_size=0;
 604         else
 605                 mac_size=EVP_MD_size(s->write_hash);
 606
 607         /* 'create_empty_fragment' is true only when this function calls itself */
 608         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
 609                 {
 610                 /* countermeasure against known-IV weakness in CBC ciphersuites
 611                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
 612
 613                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
 614                         {
 615                         /* recursive function call with 'create_empty_fragment' set;
 616                          * this prepares and buffers the data for an empty fragment
 617                          * (these 'prefix_len' bytes are sent out later
 618                          * together with the actual payload) */
 619                         prefix_len = do_ssl3_write(s, type, buf, 0, 1);
 620                         if (prefix_len <= 0)
 621                                 goto err;
 622
 623                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
 624                                 {
 625                                 /* insufficient space */
 626                                 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
 627                                 goto err;
 628                                 }
 629                         }
 630
 631                 s->s3->empty_fragment_done = 1;
 632                 }
 633
 634         p = wb->buf + prefix_len;
 635
 636         /* write the header */
 637
 638         *(p++)=type&0xff;
 639         wr->type=type;
 640
 641         *(p++)=(s->version>>8);
 642         *(p++)=s->version&0xff;
 643
 644         /* field where we are to write out packet length */
 645         plen=p;
 646         p+=2;
 647
 648         /* lets setup the record stuff. */
 649         wr->data=p;
 650         wr->length=(int)len;
 651         wr->input=(unsigned char *)buf;
 652
 653         /* we now 'read' from wr->input, wr->length bytes into
 654          * wr->data */
 655
 656         /* first we compress */
 657         if (s->compress != NULL)
 658                 {
 659                 if (!ssl3_do_compress(s))
 660                         {
 661                         SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
 662                         goto err;
 663                         }
 664                 }
 665         else
 666                 {
 667                 memcpy(wr->data,wr->input,wr->length);
 668                 wr->input=wr->data;
 669                 }
 670
 671         /* we should still have the output to wr->data and the input
 672          * from wr->input.  Length should be wr->length.
 673          * wr->data still points in the wb->buf */
 674
 675         if (mac_size != 0)
 676                 {
 677                 s->method->ssl3_enc->mac(s,&(p[wr->length]),1);
 678                 wr->length+=mac_size;
 679                 wr->input=p;
 680                 wr->data=p;
 681                 }
 682
 683         /* ssl3_enc can only have an error on read */
 684         s->method->ssl3_enc->enc(s,1);
 685
 686         /* record length after mac and block padding */
 687         s2n(wr->length,plen);
 688
 689         /* we should now have
 690          * wr->data pointing to the encrypted data, which is
 691          * wr->length long */
 692         wr->type=type; /* not needed but helps for debugging */
 693         wr->length+=SSL3_RT_HEADER_LENGTH;
 694
 695         if (create_empty_fragment)
 696                 {
 697                 /* we are in a recursive call;
 698                  * just return the length, don't write out anything here
 699                  */
 700                 return wr->length;
 701                 }
 702
 703         /* now let's set up wb */
 704         wb->left = prefix_len + wr->length;
 705         wb->offset = 0;
 706
 707         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
 708         s->s3->wpend_tot=len;
 709         s->s3->wpend_buf=buf;
 710         s->s3->wpend_type=type;
 711         s->s3->wpend_ret=len;
 712
 713         /* we now just need to write the buffer */
 714         return ssl3_write_pending(s,type,buf,len);
 715 err:
 716         return -1;
 717         }
 718
 719 /* if s->s3->wbuf.left != 0, we need to call this */
 720 int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
 721         unsigned int len)
 722         {
 723         int i;
 724
 725 /* XXXX */
 726         if ((s->s3->wpend_tot > (int)len)
 727                 || ((s->s3->wpend_buf != buf) &&
 728                         !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))
 729                 || (s->s3->wpend_type != type))
 730                 {
 731                 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
 732                 return(-1);
 733                 }
 734
 735         for (;;)
 736                 {
 737                 clear_sys_error();
 738                 if (s->wbio != NULL)
 739                         {
 740                         s->rwstate=SSL_WRITING;
 741                         i=BIO_write(s->wbio,
 742                                 (char *)&(s->s3->wbuf.buf[s->s3->wbuf.offset]),
 743                                 (unsigned int)s->s3->wbuf.left);
 744                         }
 745                 else
 746                         {
 747                         SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
 748                         i= -1;
 749                         }
 750                 if (i == s->s3->wbuf.left)
 751                         {
 752                         s->s3->wbuf.left=0;
 753                         s->rwstate=SSL_NOTHING;
 754                         return(s->s3->wpend_ret);
 755                         }
 756                 else if (i <= 0)
 757                         return(i);
 758                 s->s3->wbuf.offset+=i;
 759                 s->s3->wbuf.left-=i;
 760                 }
 761         }
 762
 763 /* Return up to 'len' payload bytes received in 'type' records.
 764  * 'type' is one of the following:
 765  *
 766  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 767  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 768  *   -  0 (during a shutdown, no data has to be returned)
 769  *
 770  * If we don't have stored data to work from, read a SSL/TLS record first
 771  * (possibly multiple records if we still don't have anything to return).
 772  *
 773  * This function must handle any surprises the peer may have for us, such as
 774  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 775  * a surprise, but handled as if it were), or renegotiation requests.
 776  * Also if record payloads contain fragments too small to process, we store
 777  * them until there is enough for the respective protocol (the record protocol
 778  * may use arbitrary fragmentation and even interleaving):
 779  *     Change cipher spec protocol
 780  *             just 1 byte needed, no need for keeping anything stored
 781  *     Alert protocol
 782  *             2 bytes needed (AlertLevel, AlertDescription)
 783  *     Handshake protocol
 784  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 785  *             to detect unexpected Client Hello and Hello Request messages
 786  *             here, anything else is handled by higher layers
 787  *     Application data protocol
 788  *             none of our business
 789  */
 790 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 791         {
 792         int al,i,j,ret;
 793         unsigned int n;
 794         SSL3_RECORD *rr;
 795         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 796
 797         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 798                 if (!ssl3_setup_buffers(s))
 799                         return(-1);
 800
 801         if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) ||
 802             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 803                 {
 804                 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
 805                 return -1;
 806                 }
 807
 808         if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
 809                 /* (partially) satisfy request from storage */
 810                 {
 811                 unsigned char *src = s->s3->handshake_fragment;
 812                 unsigned char *dst = buf;
 813                 unsigned int k;
 814
 815                 /* peek == 0 */
 816                 n = 0;
 817                 while ((len > 0) && (s->s3->handshake_fragment_len > 0))
 818                         {
 819                         *dst++ = *src++;
 820                         len--; s->s3->handshake_fragment_len--;
 821                         n++;
 822                         }
 823                 /* move any remaining fragment bytes: */
 824                 for (k = 0; k < s->s3->handshake_fragment_len; k++)
 825                         s->s3->handshake_fragment[k] = *src++;
 826                 return n;
 827         }
 828
 829         /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 830
 831         if (!s->in_handshake && SSL_in_init(s))
 832                 {
 833                 /* type == SSL3_RT_APPLICATION_DATA */
 834                 i=s->handshake_func(s);
 835                 if (i < 0) return(i);
 836                 if (i == 0)
 837                         {
 838                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 839                         return(-1);
 840                         }
 841                 }
 842 start:
 843         s->rwstate=SSL_NOTHING;
 844
 845         /* s->s3->rrec.type         - is the type of record
 846          * s->s3->rrec.data,    - data
 847          * s->s3->rrec.off,     - offset into 'data' for next read
 848          * s->s3->rrec.length,  - number of bytes. */
 849         rr = &(s->s3->rrec);
 850
 851         /* get new packet if necessary */
 852         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 853                 {
 854                 ret=ssl3_get_record(s);
 855                 if (ret <= 0) return(ret);
 856                 }
 857
 858         /* we now have a packet which can be read and processed */
 859
 860         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 861                                        * reset by ssl3_get_finished */
 862                 && (rr->type != SSL3_RT_HANDSHAKE))
 863                 {
 864                 al=SSL_AD_UNEXPECTED_MESSAGE;
 865                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
 866                 goto f_err;
 867                 }
 868
 869         /* If the other end has shut down, throw anything we read away
 870          * (even in 'peek' mode) */
 871         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 872                 {
 873                 rr->length=0;
 874                 s->rwstate=SSL_NOTHING;
 875                 return(0);
 876                 }
 877
 878
 879         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 880                 {
 881                 /* make sure that we are not getting application data when we
 882                  * are doing a handshake for the first time */
 883                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 884                         (s->enc_read_ctx == NULL))
 885                         {
 886                         al=SSL_AD_UNEXPECTED_MESSAGE;
 887                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 888                         goto f_err;
 889                         }
 890
 891                 if (len <= 0) return(len);
 892
 893                 if ((unsigned int)len > rr->length)
 894                         n = rr->length;
 895                 else
 896                         n = (unsigned int)len;
 897
 898                 memcpy(buf,&(rr->data[rr->off]),n);
 899                 if (!peek)
 900                         {
 901                         rr->length-=n;
 902                         rr->off+=n;
 903                         if (rr->length == 0)
 904                                 {
 905                                 s->rstate=SSL_ST_READ_HEADER;
 906                                 rr->off=0;
 907                                 }
 908                         }
 909                 return(n);
 910                 }
 911
 912
 913         /* If we get here, then type != rr->type; if we have a handshake
 914          * message, then it was unexpected (Hello Request or Client Hello). */
 915
 916         /* In case of record types for which we have 'fragment' storage,
 917          * fill that so that we can process the data at a fixed place.
 918          */
 919                 {
 920                 unsigned int dest_maxlen = 0;
 921                 unsigned char *dest = NULL;
 922                 unsigned int *dest_len = NULL;
 923
 924                 if (rr->type == SSL3_RT_HANDSHAKE)
 925                         {
 926                         dest_maxlen = sizeof s->s3->handshake_fragment;
 927                         dest = s->s3->handshake_fragment;
 928                         dest_len = &s->s3->handshake_fragment_len;
 929                         }
 930                 else if (rr->type == SSL3_RT_ALERT)
 931                         {
 932                         dest_maxlen = sizeof s->s3->alert_fragment;
 933                         dest = s->s3->alert_fragment;
 934                         dest_len = &s->s3->alert_fragment_len;
 935                         }
 936
 937                 if (dest_maxlen > 0)
 938                         {
 939                         n = dest_maxlen - *dest_len; /* available space in 'dest' */
 940                         if (rr->length < n)
 941                                 n = rr->length; /* available bytes */
 942
 943                         /* now move 'n' bytes: */
 944                         while (n-- > 0)
 945                                 {
 946                                 dest[(*dest_len)++] = rr->data[rr->off++];
 947                                 rr->length--;
 948                                 }
 949
 950                         if (*dest_len < dest_maxlen)
 951                                 goto start; /* fragment was too small */
 952                         }
 953                 }
 954
 955         /* s->s3->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
 956          * s->s3->alert_fragment_len == 2      iff  rr->type == SSL3_RT_ALERT.
 957          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 958
 959         /* If we are a client, check for an incoming 'Hello Request': */
 960         if ((!s->server) &&
 961                 (s->s3->handshake_fragment_len >= 4) &&
 962                 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 963                 (s->session != NULL) && (s->session->cipher != NULL))
 964                 {
 965                 s->s3->handshake_fragment_len = 0;
 966
 967                 if ((s->s3->handshake_fragment[1] != 0) ||
 968                         (s->s3->handshake_fragment[2] != 0) ||
 969                         (s->s3->handshake_fragment[3] != 0))
 970                         {
 971                         al=SSL_AD_DECODE_ERROR;
 972                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 973                         goto f_err;
 974                         }
 975
 976                 if (s->msg_callback)
 977                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
 978
 979                 if (SSL_is_init_finished(s) &&
 980                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 981                         !s->s3->renegotiate)
 982                         {
 983                         ssl3_renegotiate(s);
 984                         if (ssl3_renegotiate_check(s))
 985                                 {
 986                                 i=s->handshake_func(s);
 987                                 if (i < 0) return(i);
 988                                 if (i == 0)
 989                                         {
 990                                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 991                                         return(-1);
 992                                         }
 993
 994                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 995                                         {
 996                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 997                                                 {
 998                                                 BIO *bio;
 999                                                 /* In the case where we try to read application data,
1000                                                  * but we trigger an SSL handshake, we return -1 with
1001                                                  * the retry option set.  Otherwise renegotiation may
1002                                                  * cause nasty problems in the blocking world */
1003                                                 s->rwstate=SSL_READING;
1004                                                 bio=SSL_get_rbio(s);
1005                                                 BIO_clear_retry_flags(bio);
1006                                                 BIO_set_retry_read(bio);
1007                                                 return(-1);
1008                                                 }
1009                                         }
1010                                 }
1011                         }
1012                 /* we either finished a handshake or ignored the request,
1013                  * now try again to obtain the (application) data we were asked for */
1014                 goto start;
1015                 }
1016
1017         if (s->s3->alert_fragment_len >= 2)
1018                 {
1019                 int alert_level = s->s3->alert_fragment[0];
1020                 int alert_descr = s->s3->alert_fragment[1];
1021
1022                 s->s3->alert_fragment_len = 0;
1023
1024                 if (s->msg_callback)
1025                         s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 2, s, s->msg_callback_arg);
1026
1027                 if (s->info_callback != NULL)
1028                         cb=s->info_callback;
1029                 else if (s->ctx->info_callback != NULL)
1030                         cb=s->ctx->info_callback;
1031
1032                 if (cb != NULL)
1033                         {
1034                         j = (alert_level << 8) | alert_descr;
1035                         cb(s, SSL_CB_READ_ALERT, j);
1036                         }
1037
1038                 if (alert_level == 1) /* warning */
1039                         {
1040                         s->s3->warn_alert = alert_descr;
1041                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1042                                 {
1043                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1044                                 return(0);
1045                                 }
1046                         }
1047                 else if (alert_level == 2) /* fatal */
1048                         {
1049                         char tmp[16];
1050
1051                         s->rwstate=SSL_NOTHING;
1052                         s->s3->fatal_alert = alert_descr;
1053                         SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1054                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1055                         ERR_add_error_data(2,"SSL alert number ",tmp);
1056                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1057                         SSL_CTX_remove_session(s->ctx,s->session);
1058                         return(0);
1059                         }
1060                 else
1061                         {
1062                         al=SSL_AD_ILLEGAL_PARAMETER;
1063                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1064                         goto f_err;
1065                         }
1066
1067                 goto start;
1068                 }
1069
1070         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1071                 {
1072                 s->rwstate=SSL_NOTHING;
1073                 rr->length=0;
1074                 return(0);
1075                 }
1076
1077         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1078                 {
1079                 /* 'Change Cipher Spec' is just a single byte, so we know
1080                  * exactly what the record payload has to look like */
1081                 if (    (rr->length != 1) || (rr->off != 0) ||
1082                         (rr->data[0] != SSL3_MT_CCS))
1083                         {
1084                         al=SSL_AD_ILLEGAL_PARAMETER;
1085                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1086                         goto f_err;
1087                         }
1088
1089                 /* Check we have a cipher to change to */
1090                 if (s->s3->tmp.new_cipher == NULL)
1091                         {
1092                         al=SSL_AD_UNEXPECTED_MESSAGE;
1093                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1094                         goto f_err;
1095                         }
1096
1097                 rr->length=0;
1098
1099                 if (s->msg_callback)
1100                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
1101
1102                 s->s3->change_cipher_spec=1;
1103                 if (!ssl3_do_change_cipher_spec(s))
1104                         goto err;
1105                 else
1106                         goto start;
1107                 }
1108
1109         /* Unexpected handshake message (Client Hello, or protocol violation) */
1110         if ((s->s3->handshake_fragment_len >= 4) &&     !s->in_handshake)
1111                 {
1112                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1113                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1114                         {
1115 #if 0 /* worked only because C operator preferences are not as expected (and
1116        * because this is not really needed for clients except for detecting
1117        * protocol violations): */
1118                         s->state=SSL_ST_BEFORE|(s->server)
1119                                 ?SSL_ST_ACCEPT
1120                                 :SSL_ST_CONNECT;
1121 #else
1122                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1123 #endif
1124                         s->new_session=1;
1125                         }
1126                 i=s->handshake_func(s);
1127                 if (i < 0) return(i);
1128                 if (i == 0)
1129                         {
1130                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1131                         return(-1);
1132                         }
1133
1134                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1135                         {
1136                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1137                                 {
1138                                 BIO *bio;
1139                                 /* In the case where we try to read application data,
1140                                  * but we trigger an SSL handshake, we return -1 with
1141                                  * the retry option set.  Otherwise renegotiation may
1142                                  * cause nasty problems in the blocking world */
1143                                 s->rwstate=SSL_READING;
1144                                 bio=SSL_get_rbio(s);
1145                                 BIO_clear_retry_flags(bio);
1146                                 BIO_set_retry_read(bio);
1147                                 return(-1);
1148                                 }
1149                         }
1150                 goto start;
1151                 }
1152
1153         switch (rr->type)
1154                 {
1155         default:
1156 #ifndef OPENSSL_NO_TLS
1157                 /* TLS just ignores unknown message types */
1158                 if (s->version == TLS1_VERSION)
1159                         {
1160                         rr->length = 0;
1161                         goto start;
1162                         }
1163 #endif
1164                 al=SSL_AD_UNEXPECTED_MESSAGE;
1165                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1166                 goto f_err;
1167         case SSL3_RT_CHANGE_CIPHER_SPEC:
1168         case SSL3_RT_ALERT:
1169         case SSL3_RT_HANDSHAKE:
1170                 /* we already handled all of these, with the possible exception
1171                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1172                  * should not happen when type != rr->type */
1173                 al=SSL_AD_UNEXPECTED_MESSAGE;
1174                 SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
1175                 goto f_err;
1176         case SSL3_RT_APPLICATION_DATA:
1177                 /* At this point, we were expecting handshake data,
1178                  * but have application data.  If the library was
1179                  * running inside ssl3_read() (i.e. in_read_app_data
1180                  * is set) and it makes sense to read application data
1181                  * at this point (session renegotiation not yet started),
1182                  * we will indulge it.
1183                  */
1184                 if (s->s3->in_read_app_data &&
1185                         (s->s3->total_renegotiations != 0) &&
1186                         ((
1187                                 (s->state & SSL_ST_CONNECT) &&
1188                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1189                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1190                                 ) || (
1191                                         (s->state & SSL_ST_ACCEPT) &&
1192                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1193                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1194                                         )
1195                                 ))
1196                         {
1197                         s->s3->in_read_app_data=2;
1198                         return(-1);
1199                         }
1200                 else
1201                         {
1202                         al=SSL_AD_UNEXPECTED_MESSAGE;
1203                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1204                         goto f_err;
1205                         }
1206                 }
1207         /* not reached */
1208
1209 f_err:
1210         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1211 err:
1212         return(-1);
1213         }
1214
1215 int ssl3_do_change_cipher_spec(SSL *s)
1216         {
1217         int i;
1218         const char *sender;
1219         int slen;
1220
1221         if (s->state & SSL_ST_ACCEPT)
1222                 i=SSL3_CHANGE_CIPHER_SERVER_READ;
1223         else
1224                 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
1225
1226         if (s->s3->tmp.key_block == NULL)
1227                 {
1228                 if (s->session == NULL)
1229                         {
1230                         /* might happen if dtls1_read_bytes() calls this */
1231                         SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
1232                         return (0);
1233                         }
1234
1235                 s->session->cipher=s->s3->tmp.new_cipher;
1236                 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
1237                 }
1238
1239         if (!s->method->ssl3_enc->change_cipher_state(s,i))
1240                 return(0);
1241
1242         /* we have to record the message digest at
1243          * this point so we can get it before we read
1244          * the finished message */
1245         if (s->state & SSL_ST_CONNECT)
1246                 {
1247                 sender=s->method->ssl3_enc->server_finished_label;
1248                 slen=s->method->ssl3_enc->server_finished_label_len;
1249                 }
1250         else
1251                 {
1252                 sender=s->method->ssl3_enc->client_finished_label;
1253                 slen=s->method->ssl3_enc->client_finished_label_len;
1254                 }
1255
1256         s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
1257                 &(s->s3->finish_dgst1),
1258                 &(s->s3->finish_dgst2),
1259                 sender,slen,s->s3->tmp.peer_finish_md);
1260
1261         return(1);
1262         }
1263
1264 void ssl3_send_alert(SSL *s, int level, int desc)
1265         {
1266         /* Map tls/ssl alert value to correct one */
1267         desc=s->method->ssl3_enc->alert_value(desc);
1268         if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
1269                 desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
1270         if (desc < 0) return;
1271         /* If a fatal one, remove from cache */
1272         if ((level == 2) && (s->session != NULL))
1273                 SSL_CTX_remove_session(s->ctx,s->session);
1274
1275         s->s3->alert_dispatch=1;
1276         s->s3->send_alert[0]=level;
1277         s->s3->send_alert[1]=desc;
1278         if (s->s3->wbuf.left == 0) /* data still being written out? */
1279                 s->method->ssl_dispatch_alert(s);
1280         /* else data is still being written out, we will get written
1281          * some time in the future */
1282         }
1283
1284 int ssl3_dispatch_alert(SSL *s)
1285         {
1286         int i,j;
1287         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1288
1289         s->s3->alert_dispatch=0;
1290         i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
1291         if (i <= 0)
1292                 {
1293                 s->s3->alert_dispatch=1;
1294                 }
1295         else
1296                 {
1297                 /* Alert sent to BIO.  If it is important, flush it now.
1298                  * If the message does not get sent due to non-blocking IO,
1299                  * we will not worry too much. */
1300                 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1301                         (void)BIO_flush(s->wbio);
1302
1303                 if (s->msg_callback)
1304                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, s->msg_callback_arg);
1305
1306                 if (s->info_callback != NULL)
1307                         cb=s->info_callback;
1308                 else if (s->ctx->info_callback != NULL)
1309                         cb=s->ctx->info_callback;
1310
1311                 if (cb != NULL)
1312                         {
1313                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1314                         cb(s,SSL_CB_WRITE_ALERT,j);
1315                         }
1316                 }
1317         return(i);
1318         }