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 <limits.h>
 114 #include <errno.h>
 115 #define USE_SOCKETS
 116 #include "ssl_locl.h"
 117 #include <openssl/evp.h>
 118 #include <openssl/buffer.h>
 119
 120 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 121                          unsigned int len, int create_empty_fragment);
 122 static int ssl3_get_record(SSL *s);
 123
 124 int ssl3_read_n(SSL *s, int n, int max, int extend)
 125         {
 126         /* If extend == 0, obtain new n-byte packet; if extend == 1, increase
 127          * packet by another n bytes.
 128          * The packet will be in the sub-array of s->s3->rbuf.buf specified
 129          * by s->packet and s->packet_length.
 130          * (If s->read_ahead is set, 'max' bytes may be stored in rbuf
 131          * [plus s->packet_length bytes if extend == 1].)
 132          */
 133         int i,len,left;
 134         long align=0;
 135         unsigned char *pkt;
 136         SSL3_BUFFER *rb;
 137
 138         if (n <= 0) return n;
 139
 140         rb    = &(s->s3->rbuf);
 141         if (rb->buf == NULL)
 142                 if (!ssl3_setup_read_buffer(s))
 143                         return -1;
 144
 145         left  = rb->left;
 146 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 147         align = (long)rb->buf + SSL3_RT_HEADER_LENGTH;
 148         align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 149 #endif
 150
 151         if (!extend)
 152                 {
 153                 /* start with empty packet ... */
 154                 if (left == 0)
 155                         rb->offset = align;
 156                 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH)
 157                         {
 158                         /* check if next packet length is large
 159                          * enough to justify payload alignment... */
 160                         pkt = rb->buf + rb->offset;
 161                         if (pkt[0] == SSL3_RT_APPLICATION_DATA
 162                             && (pkt[3]<<8|pkt[4]) >= 128)
 163                                 {
 164                                 /* Note that even if packet is corrupted
 165                                  * and its length field is insane, we can
 166                                  * only be led to wrong decision about
 167                                  * whether memmove will occur or not.
 168                                  * Header values has no effect on memmove
 169                                  * arguments and therefore no buffer
 170                                  * overrun can be triggered. */
 171                                 memmove (rb->buf+align,pkt,left);
 172                                 rb->offset = align;
 173                                 }
 174                         }
 175                 s->packet = rb->buf + rb->offset;
 176                 s->packet_length = 0;
 177                 /* ... now we can act as if 'extend' was set */
 178                 }
 179
 180         /* For DTLS/UDP reads should not span multiple packets
 181          * because the read operation returns the whole packet
 182          * at once (as long as it fits into the buffer). */
 183         if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
 184                 {
 185                 if (left == 0 && extend)
 186                         return 0;
 187                 if (left > 0 && n > left)
 188                         n = left;
 189                 }
 190
 191         /* if there is enough in the buffer from a previous read, take some */
 192         if (left >= n)
 193                 {
 194                 s->packet_length+=n;
 195                 rb->left=left-n;
 196                 rb->offset+=n;
 197                 return(n);
 198                 }
 199
 200         /* else we need to read more data */
 201
 202         len = s->packet_length;
 203         pkt = rb->buf+align;
 204         /* Move any available bytes to front of buffer:
 205          * 'len' bytes already pointed to by 'packet',
 206          * 'left' extra ones at the end */
 207         if (s->packet != pkt) /* len > 0 */
 208                 {
 209                 memmove(pkt, s->packet, len+left);
 210                 s->packet = pkt;
 211                 rb->offset = len + align;
 212                 }
 213
 214         if (n > (int)(rb->len - rb->offset)) /* does not happen */
 215                 {
 216                 SSLerr(SSL_F_SSL3_READ_N,ERR_R_INTERNAL_ERROR);
 217                 return -1;
 218                 }
 219
 220         if (!s->read_ahead)
 221                 /* ignore max parameter */
 222                 max = n;
 223         else
 224                 {
 225                 if (max < n)
 226                         max = n;
 227                 if (max > (int)(rb->len - rb->offset))
 228                         max = rb->len - rb->offset;
 229                 }
 230
 231         while (left < n)
 232                 {
 233                 /* Now we have len+left bytes at the front of s->s3->rbuf.buf
 234                  * and need to read in more until we have len+n (up to
 235                  * len+max if possible) */
 236
 237                 clear_sys_error();
 238                 if (s->rbio != NULL)
 239                         {
 240                         s->rwstate=SSL_READING;
 241                         i=BIO_read(s->rbio,pkt+len+left, max-left);
 242                         }
 243                 else
 244                         {
 245                         SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
 246                         i = -1;
 247                         }
 248
 249                 if (i <= 0)
 250                         {
 251                         rb->left = left;
 252                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
 253                             SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
 254                                 if (len+left == 0)
 255                                         ssl3_release_read_buffer(s);
 256                         return(i);
 257                         }
 258                 left+=i;
 259                 /* reads should *never* span multiple packets for DTLS because
 260                  * the underlying transport protocol is message oriented as opposed
 261                  * to byte oriented as in the TLS case. */
 262                 if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
 263                         {
 264                         if (n > left)
 265                                 n = left; /* makes the while condition false */
 266                         }
 267                 }
 268
 269         /* done reading, now the book-keeping */
 270         rb->offset += n;
 271         rb->left = left - n;
 272         s->packet_length += n;
 273         s->rwstate=SSL_NOTHING;
 274         return(n);
 275         }
 276
 277 /* MAX_EMPTY_RECORDS defines the number of consecutive, empty records that will
 278  * be processed per call to ssl3_get_record. Without this limit an attacker
 279  * could send empty records at a faster rate than we can process and cause
 280  * ssl3_get_record to loop forever. */
 281 #define MAX_EMPTY_RECORDS 32
 282
 283 /* Call this to get a new input record.
 284  * It will return <= 0 if more data is needed, normally due to an error
 285  * or non-blocking IO.
 286  * When it finishes, one packet has been decoded and can be found in
 287  * ssl->s3->rrec.type    - is the type of record
 288  * ssl->s3->rrec.data,   - data
 289  * ssl->s3->rrec.length, - number of bytes
 290  */
 291 /* used only by ssl3_read_bytes */
 292 static int ssl3_get_record(SSL *s)
 293         {
 294         int ssl_major,ssl_minor,al;
 295         int enc_err,n,i,ret= -1;
 296         SSL3_RECORD *rr;
 297         SSL_SESSION *sess;
 298         unsigned char *p;
 299         unsigned char md[EVP_MAX_MD_SIZE];
 300         short version;
 301         unsigned mac_size, orig_len;
 302         size_t extra;
 303         unsigned empty_record_count = 0;
 304
 305         rr= &(s->s3->rrec);
 306         sess=s->session;
 307
 308         if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
 309                 extra=SSL3_RT_MAX_EXTRA;
 310         else
 311                 extra=0;
 312         if (extra && !s->s3->init_extra)
 313                 {
 314                 /* An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
 315                  * set after ssl3_setup_buffers() was done */
 316                 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
 317                 return -1;
 318                 }
 319
 320 again:
 321         /* check if we have the header */
 322         if (    (s->rstate != SSL_ST_READ_BODY) ||
 323                 (s->packet_length < SSL3_RT_HEADER_LENGTH))
 324                 {
 325                 n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 326                 if (n <= 0) return(n); /* error or non-blocking */
 327                 s->rstate=SSL_ST_READ_BODY;
 328
 329                 p=s->packet;
 330
 331                 /* Pull apart the header into the SSL3_RECORD */
 332                 rr->type= *(p++);
 333                 ssl_major= *(p++);
 334                 ssl_minor= *(p++);
 335                 version=(ssl_major<<8)|ssl_minor;
 336                 n2s(p,rr->length);
 337 #if 0
 338 fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
 339 #endif
 340
 341                 /* Lets check version */
 342                 if (!s->first_packet)
 343                         {
 344                         if (version != s->version)
 345                                 {
 346                                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 347                                 if ((s->version & 0xFF00) == (version & 0xFF00))
 348                                         /* Send back error using their minor version number :-) */
 349                                         s->version = (unsigned short)version;
 350                                 al=SSL_AD_PROTOCOL_VERSION;
 351                                 goto f_err;
 352                                 }
 353                         }
 354
 355                 if ((version>>8) != SSL3_VERSION_MAJOR)
 356                         {
 357                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 358                         goto err;
 359                         }
 360
 361                 if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH)
 362                         {
 363                         al=SSL_AD_RECORD_OVERFLOW;
 364                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 365                         goto f_err;
 366                         }
 367
 368                 /* now s->rstate == SSL_ST_READ_BODY */
 369                 }
 370
 371         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 372
 373         if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
 374                 {
 375                 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
 376                 i=rr->length;
 377                 n=ssl3_read_n(s,i,i,1);
 378                 if (n <= 0) return(n); /* error or non-blocking io */
 379                 /* now n == rr->length,
 380                  * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
 381                 }
 382
 383         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 384
 385         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 386          * and we have that many bytes in s->packet
 387          */
 388         rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
 389
 390         /* ok, we can now read from 's->packet' data into 'rr'
 391          * rr->input points at rr->length bytes, which
 392          * need to be copied into rr->data by either
 393          * the decryption or by the decompression
 394          * When the data is 'copied' into the rr->data buffer,
 395          * rr->input will be pointed at the new buffer */
 396
 397         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 398          * rr->length bytes of encrypted compressed stuff. */
 399
 400         /* check is not needed I believe */
 401         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
 402                 {
 403                 al=SSL_AD_RECORD_OVERFLOW;
 404                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 405                 goto f_err;
 406                 }
 407
 408         /* decrypt in place in 'rr->input' */
 409         rr->data=rr->input;
 410
 411         enc_err = s->method->ssl3_enc->enc(s,0);
 412         /* enc_err is:
 413          *    0: (in non-constant time) if the record is publically invalid.
 414          *    1: if the padding is valid
 415          *    -1: if the padding is invalid */
 416         if (enc_err == 0)
 417                 {
 418                 al=SSL_AD_DECRYPTION_FAILED;
 419                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
 420                 goto f_err;
 421                 }
 422
 423 #ifdef TLS_DEBUG
 424 printf("dec %d\n",rr->length);
 425 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 426 printf("\n");
 427 #endif
 428
 429         /* r->length is now the compressed data plus mac */
 430         if ((sess != NULL) &&
 431             (s->enc_read_ctx != NULL) &&
 432             (EVP_MD_CTX_md(s->read_hash) != NULL))
 433                 {
 434                 /* s->read_hash != NULL => mac_size != -1 */
 435                 unsigned char *mac = NULL;
 436                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
 437                 mac_size=EVP_MD_CTX_size(s->read_hash);
 438                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
 439
 440                 /* kludge: *_cbc_remove_padding passes padding length in rr->type */
 441                 orig_len = rr->length+((unsigned int)rr->type>>8);
 442
 443                 /* orig_len is the length of the record before any padding was
 444                  * removed. This is public information, as is the MAC in use,
 445                  * therefore we can safely process the record in a different
 446                  * amount of time if it's too short to possibly contain a MAC.
 447                  */
 448                 if (orig_len < mac_size ||
 449                     /* CBC records must have a padding length byte too. */
 450                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
 451                      orig_len < mac_size+1))
 452                         {
 453                         al=SSL_AD_DECODE_ERROR;
 454                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
 455                         goto f_err;
 456                         }
 457
 458                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
 459                         {
 460                         /* We update the length so that the TLS header bytes
 461                          * can be constructed correctly but we need to extract
 462                          * the MAC in constant time from within the record,
 463                          * without leaking the contents of the padding bytes.
 464                          * */
 465                         mac = mac_tmp;
 466                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
 467                         rr->length -= mac_size;
 468                         }
 469                 else
 470                         {
 471                         /* In this case there's no padding, so |orig_len|
 472                          * equals |rec->length| and we checked that there's
 473                          * enough bytes for |mac_size| above. */
 474                         rr->length -= mac_size;
 475                         mac = &rr->data[rr->length];
 476                         }
 477
 478                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
 479                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
 480                         enc_err = -1;
 481                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
 482                         enc_err = -1;
 483                 }
 484
 485         if (enc_err < 0)
 486                 {
 487                 /* A separate 'decryption_failed' alert was introduced with TLS 1.0,
 488                  * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 489                  * failure is directly visible from the ciphertext anyway,
 490                  * we should not reveal which kind of error occured -- this
 491                  * might become visible to an attacker (e.g. via a logfile) */
 492                 al=SSL_AD_BAD_RECORD_MAC;
 493                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 494                 goto f_err;
 495                 }
 496
 497         /* r->length is now just compressed */
 498         if (s->expand != NULL)
 499                 {
 500                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
 501                         {
 502                         al=SSL_AD_RECORD_OVERFLOW;
 503                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 504                         goto f_err;
 505                         }
 506                 if (!ssl3_do_uncompress(s))
 507                         {
 508                         al=SSL_AD_DECOMPRESSION_FAILURE;
 509                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
 510                         goto f_err;
 511                         }
 512                 }
 513
 514         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
 515                 {
 516                 al=SSL_AD_RECORD_OVERFLOW;
 517                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 518                 goto f_err;
 519                 }
 520
 521         rr->off=0;
 522         /* So at this point the following is true
 523          * ssl->s3->rrec.type   is the type of record
 524          * ssl->s3->rrec.length == number of bytes in record
 525          * ssl->s3->rrec.off    == offset to first valid byte
 526          * ssl->s3->rrec.data   == where to take bytes from, increment
 527          *                         after use :-).
 528          */
 529
 530         /* we have pulled in a full packet so zero things */
 531         s->packet_length=0;
 532
 533         /* just read a 0 length packet */
 534         if (rr->length == 0)
 535                 {
 536                 empty_record_count++;
 537                 if (empty_record_count > MAX_EMPTY_RECORDS)
 538                         {
 539                         al=SSL_AD_UNEXPECTED_MESSAGE;
 540                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_RECORD_TOO_SMALL);
 541                         goto f_err;
 542                         }
 543                 goto again;
 544                 }
 545
 546 #if 0
 547 fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length);
 548 #endif
 549
 550         return(1);
 551
 552 f_err:
 553         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 554 err:
 555         return(ret);
 556         }
 557
 558 int ssl3_do_uncompress(SSL *ssl)
 559         {
 560 #ifndef OPENSSL_NO_COMP
 561         int i;
 562         SSL3_RECORD *rr;
 563
 564         rr= &(ssl->s3->rrec);
 565         i=COMP_expand_block(ssl->expand,rr->comp,
 566                 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
 567         if (i < 0)
 568                 return(0);
 569         else
 570                 rr->length=i;
 571         rr->data=rr->comp;
 572 #endif
 573         return(1);
 574         }
 575
 576 int ssl3_do_compress(SSL *ssl)
 577         {
 578 #ifndef OPENSSL_NO_COMP
 579         int i;
 580         SSL3_RECORD *wr;
 581
 582         wr= &(ssl->s3->wrec);
 583         i=COMP_compress_block(ssl->compress,wr->data,
 584                 SSL3_RT_MAX_COMPRESSED_LENGTH,
 585                 wr->input,(int)wr->length);
 586         if (i < 0)
 587                 return(0);
 588         else
 589                 wr->length=i;
 590
 591         wr->input=wr->data;
 592 #endif
 593         return(1);
 594         }
 595
 596 /* Call this to write data in records of type 'type'
 597  * It will return <= 0 if not all data has been sent or non-blocking IO.
 598  */
 599 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
 600         {
 601         const unsigned char *buf=buf_;
 602         unsigned int n,nw;
 603         int i,tot;
 604
 605         s->rwstate=SSL_NOTHING;
 606         OPENSSL_assert(s->s3->wnum <= INT_MAX);
 607         tot=s->s3->wnum;
 608         s->s3->wnum=0;
 609
 610         if (SSL_in_init(s) && !s->in_handshake)
 611                 {
 612                 i=s->handshake_func(s);
 613                 if (i < 0) return(i);
 614                 if (i == 0)
 615                         {
 616                         SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 617                         return -1;
 618                         }
 619                 }
 620
 621         /* ensure that if we end up with a smaller value of data to write
 622          * out than the the original len from a write which didn't complete
 623          * for non-blocking I/O and also somehow ended up avoiding
 624          * the check for this in ssl3_write_pending/SSL_R_BAD_WRITE_RETRY as
 625          * it must never be possible to end up with (len-tot) as a large
 626          * number that will then promptly send beyond the end of the users
 627          * buffer ... so we trap and report the error in a way the user
 628          * will notice
 629          */
 630         if (len < tot)
 631                 {
 632                 SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_BAD_LENGTH);
 633                 return(-1);
 634                 }
 635
 636
 637         n=(len-tot);
 638         for (;;)
 639                 {
 640                 if (n > s->max_send_fragment)
 641                         nw=s->max_send_fragment;
 642                 else
 643                         nw=n;
 644
 645                 i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
 646                 if (i <= 0)
 647                         {
 648                         s->s3->wnum=tot;
 649                         return i;
 650                         }
 651
 652                 if ((i == (int)n) ||
 653                         (type == SSL3_RT_APPLICATION_DATA &&
 654                          (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
 655                         {
 656                         /* next chunk of data should get another prepended empty fragment
 657                          * in ciphersuites with known-IV weakness: */
 658                         s->s3->empty_fragment_done = 0;
 659
 660                         return tot+i;
 661                         }
 662
 663                 n-=i;
 664                 tot+=i;
 665                 }
 666         }
 667
 668 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 669                          unsigned int len, int create_empty_fragment)
 670         {
 671         unsigned char *p,*plen;
 672         int i,mac_size,clear=0;
 673         int prefix_len=0;
 674         long align=0;
 675         SSL3_RECORD *wr;
 676         SSL3_BUFFER *wb=&(s->s3->wbuf);
 677         SSL_SESSION *sess;
 678
 679
 680         /* first check if there is a SSL3_BUFFER still being written
 681          * out.  This will happen with non blocking IO */
 682         if (wb->left != 0)
 683                 return(ssl3_write_pending(s,type,buf,len));
 684
 685         /* If we have an alert to send, lets send it */
 686         if (s->s3->alert_dispatch)
 687                 {
 688                 i=s->method->ssl_dispatch_alert(s);
 689                 if (i <= 0)
 690                         return(i);
 691                 /* if it went, fall through and send more stuff */
 692                 }
 693
 694         if (wb->buf == NULL)
 695                 if (!ssl3_setup_write_buffer(s))
 696                         return -1;
 697
 698         if (len == 0 && !create_empty_fragment)
 699                 return 0;
 700
 701         wr= &(s->s3->wrec);
 702         sess=s->session;
 703
 704         if (    (sess == NULL) ||
 705                 (s->enc_write_ctx == NULL) ||
 706                 (EVP_MD_CTX_md(s->write_hash) == NULL))
 707                 clear=1;
 708
 709         if (clear)
 710                 mac_size=0;
 711         else
 712                 {
 713                 mac_size=EVP_MD_CTX_size(s->write_hash);
 714                 if (mac_size < 0)
 715                         goto err;
 716                 }
 717
 718         /* 'create_empty_fragment' is true only when this function calls itself */
 719         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
 720                 {
 721                 /* countermeasure against known-IV weakness in CBC ciphersuites
 722                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
 723
 724                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
 725                         {
 726                         /* recursive function call with 'create_empty_fragment' set;
 727                          * this prepares and buffers the data for an empty fragment
 728                          * (these 'prefix_len' bytes are sent out later
 729                          * together with the actual payload) */
 730                         prefix_len = do_ssl3_write(s, type, buf, 0, 1);
 731                         if (prefix_len <= 0)
 732                                 goto err;
 733
 734                         if (prefix_len >
 735                 (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD))
 736                                 {
 737                                 /* insufficient space */
 738                                 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
 739                                 goto err;
 740                                 }
 741                         }
 742
 743                 s->s3->empty_fragment_done = 1;
 744                 }
 745
 746         if (create_empty_fragment)
 747                 {
 748 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 749                 /* extra fragment would be couple of cipher blocks,
 750                  * which would be multiple of SSL3_ALIGN_PAYLOAD, so
 751                  * if we want to align the real payload, then we can
 752                  * just pretent we simply have two headers. */
 753                 align = (long)wb->buf + 2*SSL3_RT_HEADER_LENGTH;
 754                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 755 #endif
 756                 p = wb->buf + align;
 757                 wb->offset  = align;
 758                 }
 759         else if (prefix_len)
 760                 {
 761                 p = wb->buf + wb->offset + prefix_len;
 762                 }
 763         else
 764                 {
 765 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 766                 align = (long)wb->buf + SSL3_RT_HEADER_LENGTH;
 767                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 768 #endif
 769                 p = wb->buf + align;
 770                 wb->offset  = align;
 771                 }
 772
 773         /* write the header */
 774
 775         *(p++)=type&0xff;
 776         wr->type=type;
 777
 778         *(p++)=(s->version>>8);
 779         *(p++)=s->version&0xff;
 780
 781         /* field where we are to write out packet length */
 782         plen=p;
 783         p+=2;
 784
 785         /* lets setup the record stuff. */
 786         wr->data=p;
 787         wr->length=(int)len;
 788         wr->input=(unsigned char *)buf;
 789
 790         /* we now 'read' from wr->input, wr->length bytes into
 791          * wr->data */
 792
 793         /* first we compress */
 794         if (s->compress != NULL)
 795                 {
 796                 if (!ssl3_do_compress(s))
 797                         {
 798                         SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
 799                         goto err;
 800                         }
 801                 }
 802         else
 803                 {
 804                 memcpy(wr->data,wr->input,wr->length);
 805                 wr->input=wr->data;
 806                 }
 807
 808         /* we should still have the output to wr->data and the input
 809          * from wr->input.  Length should be wr->length.
 810          * wr->data still points in the wb->buf */
 811
 812         if (mac_size != 0)
 813                 {
 814                 if (s->method->ssl3_enc->mac(s,&(p[wr->length]),1) < 0)
 815                         goto err;
 816                 wr->length+=mac_size;
 817                 wr->input=p;
 818                 wr->data=p;
 819                 }
 820
 821         if(s->method->ssl3_enc->enc(s,1)<1) goto err;
 822
 823         /* record length after mac and block padding */
 824         s2n(wr->length,plen);
 825
 826         /* we should now have
 827          * wr->data pointing to the encrypted data, which is
 828          * wr->length long */
 829         wr->type=type; /* not needed but helps for debugging */
 830         wr->length+=SSL3_RT_HEADER_LENGTH;
 831
 832         if (create_empty_fragment)
 833                 {
 834                 /* we are in a recursive call;
 835                  * just return the length, don't write out anything here
 836                  */
 837                 return wr->length;
 838                 }
 839
 840         /* now let's set up wb */
 841         wb->left = prefix_len + wr->length;
 842
 843         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
 844         s->s3->wpend_tot=len;
 845         s->s3->wpend_buf=buf;
 846         s->s3->wpend_type=type;
 847         s->s3->wpend_ret=len;
 848
 849         /* we now just need to write the buffer */
 850         return ssl3_write_pending(s,type,buf,len);
 851 err:
 852         return -1;
 853         }
 854
 855 /* if s->s3->wbuf.left != 0, we need to call this */
 856 int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
 857         unsigned int len)
 858         {
 859         int i;
 860         SSL3_BUFFER *wb=&(s->s3->wbuf);
 861
 862 /* XXXX */
 863         if ((s->s3->wpend_tot > (int)len)
 864                 || ((s->s3->wpend_buf != buf) &&
 865                         !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))
 866                 || (s->s3->wpend_type != type))
 867                 {
 868                 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
 869                 return(-1);
 870                 }
 871
 872         for (;;)
 873                 {
 874                 clear_sys_error();
 875                 if (s->wbio != NULL)
 876                         {
 877                         s->rwstate=SSL_WRITING;
 878                         i=BIO_write(s->wbio,
 879                                 (char *)&(wb->buf[wb->offset]),
 880                                 (unsigned int)wb->left);
 881                         }
 882                 else
 883                         {
 884                         SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
 885                         i= -1;
 886                         }
 887                 if (i == wb->left)
 888                         {
 889                         wb->left=0;
 890                         wb->offset+=i;
 891                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
 892                             SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
 893                                 ssl3_release_write_buffer(s);
 894                         s->rwstate=SSL_NOTHING;
 895                         return(s->s3->wpend_ret);
 896                         }
 897                 else if (i <= 0) {
 898                         if (s->version == DTLS1_VERSION ||
 899                             s->version == DTLS1_BAD_VER) {
 900                                 /* For DTLS, just drop it. That's kind of the whole
 901                                    point in using a datagram service */
 902                                 wb->left = 0;
 903                         }
 904                         return(i);
 905                 }
 906                 wb->offset+=i;
 907                 wb->left-=i;
 908                 }
 909         }
 910
 911 /* Return up to 'len' payload bytes received in 'type' records.
 912  * 'type' is one of the following:
 913  *
 914  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 915  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 916  *   -  0 (during a shutdown, no data has to be returned)
 917  *
 918  * If we don't have stored data to work from, read a SSL/TLS record first
 919  * (possibly multiple records if we still don't have anything to return).
 920  *
 921  * This function must handle any surprises the peer may have for us, such as
 922  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 923  * a surprise, but handled as if it were), or renegotiation requests.
 924  * Also if record payloads contain fragments too small to process, we store
 925  * them until there is enough for the respective protocol (the record protocol
 926  * may use arbitrary fragmentation and even interleaving):
 927  *     Change cipher spec protocol
 928  *             just 1 byte needed, no need for keeping anything stored
 929  *     Alert protocol
 930  *             2 bytes needed (AlertLevel, AlertDescription)
 931  *     Handshake protocol
 932  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 933  *             to detect unexpected Client Hello and Hello Request messages
 934  *             here, anything else is handled by higher layers
 935  *     Application data protocol
 936  *             none of our business
 937  */
 938 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 939         {
 940         int al,i,j,ret;
 941         unsigned int n;
 942         SSL3_RECORD *rr;
 943         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 944
 945         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 946                 if (!ssl3_setup_read_buffer(s))
 947                         return(-1);
 948
 949         if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE)) ||
 950             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 951                 {
 952                 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
 953                 return -1;
 954                 }
 955
 956         if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
 957                 /* (partially) satisfy request from storage */
 958                 {
 959                 unsigned char *src = s->s3->handshake_fragment;
 960                 unsigned char *dst = buf;
 961                 unsigned int k;
 962
 963                 /* peek == 0 */
 964                 n = 0;
 965                 while ((len > 0) && (s->s3->handshake_fragment_len > 0))
 966                         {
 967                         *dst++ = *src++;
 968                         len--; s->s3->handshake_fragment_len--;
 969                         n++;
 970                         }
 971                 /* move any remaining fragment bytes: */
 972                 for (k = 0; k < s->s3->handshake_fragment_len; k++)
 973                         s->s3->handshake_fragment[k] = *src++;
 974                 return n;
 975         }
 976
 977         /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 978
 979         if (!s->in_handshake && SSL_in_init(s))
 980                 {
 981                 /* type == SSL3_RT_APPLICATION_DATA */
 982                 i=s->handshake_func(s);
 983                 if (i < 0) return(i);
 984                 if (i == 0)
 985                         {
 986                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 987                         return(-1);
 988                         }
 989                 }
 990 start:
 991         s->rwstate=SSL_NOTHING;
 992
 993         /* s->s3->rrec.type         - is the type of record
 994          * s->s3->rrec.data,    - data
 995          * s->s3->rrec.off,     - offset into 'data' for next read
 996          * s->s3->rrec.length,  - number of bytes. */
 997         rr = &(s->s3->rrec);
 998
 999         /* get new packet if necessary */
1000         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
1001                 {
1002                 ret=ssl3_get_record(s);
1003                 if (ret <= 0) return(ret);
1004                 }
1005
1006         /* we now have a packet which can be read and processed */
1007
1008         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
1009                                        * reset by ssl3_get_finished */
1010                 && (rr->type != SSL3_RT_HANDSHAKE))
1011                 {
1012                 al=SSL_AD_UNEXPECTED_MESSAGE;
1013                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
1014                 goto f_err;
1015                 }
1016
1017         /* If the other end has shut down, throw anything we read away
1018          * (even in 'peek' mode) */
1019         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
1020                 {
1021                 rr->length=0;
1022                 s->rwstate=SSL_NOTHING;
1023                 return(0);
1024                 }
1025
1026
1027         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
1028                 {
1029                 /* make sure that we are not getting application data when we
1030                  * are doing a handshake for the first time */
1031                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
1032                         (s->enc_read_ctx == NULL))
1033                         {
1034                         al=SSL_AD_UNEXPECTED_MESSAGE;
1035                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
1036                         goto f_err;
1037                         }
1038
1039                 if (len <= 0) return(len);
1040
1041                 if ((unsigned int)len > rr->length)
1042                         n = rr->length;
1043                 else
1044                         n = (unsigned int)len;
1045
1046                 memcpy(buf,&(rr->data[rr->off]),n);
1047                 if (!peek)
1048                         {
1049                         rr->length-=n;
1050                         rr->off+=n;
1051                         if (rr->length == 0)
1052                                 {
1053                                 s->rstate=SSL_ST_READ_HEADER;
1054                                 rr->off=0;
1055                                 if (s->mode & SSL_MODE_RELEASE_BUFFERS && s->s3->rbuf.left == 0)
1056                                         ssl3_release_read_buffer(s);
1057                                 }
1058                         }
1059                 return(n);
1060                 }
1061
1062
1063         /* If we get here, then type != rr->type; if we have a handshake
1064          * message, then it was unexpected (Hello Request or Client Hello). */
1065
1066         /* In case of record types for which we have 'fragment' storage,
1067          * fill that so that we can process the data at a fixed place.
1068          */
1069                 {
1070                 unsigned int dest_maxlen = 0;
1071                 unsigned char *dest = NULL;
1072                 unsigned int *dest_len = NULL;
1073
1074                 if (rr->type == SSL3_RT_HANDSHAKE)
1075                         {
1076                         dest_maxlen = sizeof s->s3->handshake_fragment;
1077                         dest = s->s3->handshake_fragment;
1078                         dest_len = &s->s3->handshake_fragment_len;
1079                         }
1080                 else if (rr->type == SSL3_RT_ALERT)
1081                         {
1082                         dest_maxlen = sizeof s->s3->alert_fragment;
1083                         dest = s->s3->alert_fragment;
1084                         dest_len = &s->s3->alert_fragment_len;
1085                         }
1086
1087                 if (dest_maxlen > 0)
1088                         {
1089                         n = dest_maxlen - *dest_len; /* available space in 'dest' */
1090                         if (rr->length < n)
1091                                 n = rr->length; /* available bytes */
1092
1093                         /* now move 'n' bytes: */
1094                         while (n-- > 0)
1095                                 {
1096                                 dest[(*dest_len)++] = rr->data[rr->off++];
1097                                 rr->length--;
1098                                 }
1099
1100                         if (*dest_len < dest_maxlen)
1101                                 goto start; /* fragment was too small */
1102                         }
1103                 }
1104
1105         /* s->s3->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
1106          * s->s3->alert_fragment_len == 2      iff  rr->type == SSL3_RT_ALERT.
1107          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1108
1109         /* If we are a client, check for an incoming 'Hello Request': */
1110         if ((!s->server) &&
1111                 (s->s3->handshake_fragment_len >= 4) &&
1112                 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1113                 (s->session != NULL) && (s->session->cipher != NULL))
1114                 {
1115                 s->s3->handshake_fragment_len = 0;
1116
1117                 if ((s->s3->handshake_fragment[1] != 0) ||
1118                         (s->s3->handshake_fragment[2] != 0) ||
1119                         (s->s3->handshake_fragment[3] != 0))
1120                         {
1121                         al=SSL_AD_DECODE_ERROR;
1122                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1123                         goto f_err;
1124                         }
1125
1126                 if (s->msg_callback)
1127                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
1128
1129                 if (SSL_is_init_finished(s) &&
1130                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1131                         !s->s3->renegotiate)
1132                         {
1133                         ssl3_renegotiate(s);
1134                         if (ssl3_renegotiate_check(s))
1135                                 {
1136                                 i=s->handshake_func(s);
1137                                 if (i < 0) return(i);
1138                                 if (i == 0)
1139                                         {
1140                                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1141                                         return(-1);
1142                                         }
1143
1144                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1145                                         {
1146                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1147                                                 {
1148                                                 BIO *bio;
1149                                                 /* In the case where we try to read application data,
1150                                                  * but we trigger an SSL handshake, we return -1 with
1151                                                  * the retry option set.  Otherwise renegotiation may
1152                                                  * cause nasty problems in the blocking world */
1153                                                 s->rwstate=SSL_READING;
1154                                                 bio=SSL_get_rbio(s);
1155                                                 BIO_clear_retry_flags(bio);
1156                                                 BIO_set_retry_read(bio);
1157                                                 return(-1);
1158                                                 }
1159                                         }
1160                                 }
1161                         }
1162                 /* we either finished a handshake or ignored the request,
1163                  * now try again to obtain the (application) data we were asked for */
1164                 goto start;
1165                 }
1166         /* If we are a server and get a client hello when renegotiation isn't
1167          * allowed send back a no renegotiation alert and carry on.
1168          * WARNING: experimental code, needs reviewing (steve)
1169          */
1170         if (s->server &&
1171                 SSL_is_init_finished(s) &&
1172                 !s->s3->send_connection_binding &&
1173                 (s->version > SSL3_VERSION) &&
1174                 (s->s3->handshake_fragment_len >= 4) &&
1175                 (s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
1176                 (s->session != NULL) && (s->session->cipher != NULL) &&
1177                 !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
1178
1179                 {
1180                 /*s->s3->handshake_fragment_len = 0;*/
1181                 rr->length = 0;
1182                 ssl3_send_alert(s,SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
1183                 goto start;
1184                 }
1185         if (s->s3->alert_fragment_len >= 2)
1186                 {
1187                 int alert_level = s->s3->alert_fragment[0];
1188                 int alert_descr = s->s3->alert_fragment[1];
1189
1190                 s->s3->alert_fragment_len = 0;
1191
1192                 if (s->msg_callback)
1193                         s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 2, s, s->msg_callback_arg);
1194
1195                 if (s->info_callback != NULL)
1196                         cb=s->info_callback;
1197                 else if (s->ctx->info_callback != NULL)
1198                         cb=s->ctx->info_callback;
1199
1200                 if (cb != NULL)
1201                         {
1202                         j = (alert_level << 8) | alert_descr;
1203                         cb(s, SSL_CB_READ_ALERT, j);
1204                         }
1205
1206                 if (alert_level == 1) /* warning */
1207                         {
1208                         s->s3->warn_alert = alert_descr;
1209                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1210                                 {
1211                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1212                                 return(0);
1213                                 }
1214                         /* This is a warning but we receive it if we requested
1215                          * renegotiation and the peer denied it. Terminate with
1216                          * a fatal alert because if application tried to
1217                          * renegotiatie it presumably had a good reason and
1218                          * expects it to succeed.
1219                          *
1220                          * In future we might have a renegotiation where we
1221                          * don't care if the peer refused it where we carry on.
1222                          */
1223                         else if (alert_descr == SSL_AD_NO_RENEGOTIATION)
1224                                 {
1225                                 al = SSL_AD_HANDSHAKE_FAILURE;
1226                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_NO_RENEGOTIATION);
1227                                 goto f_err;
1228                                 }
1229                         }
1230                 else if (alert_level == 2) /* fatal */
1231                         {
1232                         char tmp[16];
1233
1234                         s->rwstate=SSL_NOTHING;
1235                         s->s3->fatal_alert = alert_descr;
1236                         SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1237                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1238                         ERR_add_error_data(2,"SSL alert number ",tmp);
1239                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1240                         SSL_CTX_remove_session(s->ctx,s->session);
1241                         return(0);
1242                         }
1243                 else
1244                         {
1245                         al=SSL_AD_ILLEGAL_PARAMETER;
1246                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1247                         goto f_err;
1248                         }
1249
1250                 goto start;
1251                 }
1252
1253         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1254                 {
1255                 s->rwstate=SSL_NOTHING;
1256                 rr->length=0;
1257                 return(0);
1258                 }
1259
1260         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1261                 {
1262                 /* 'Change Cipher Spec' is just a single byte, so we know
1263                  * exactly what the record payload has to look like */
1264                 if (    (rr->length != 1) || (rr->off != 0) ||
1265                         (rr->data[0] != SSL3_MT_CCS))
1266                         {
1267                         al=SSL_AD_ILLEGAL_PARAMETER;
1268                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1269                         goto f_err;
1270                         }
1271
1272                 /* Check we have a cipher to change to */
1273                 if (s->s3->tmp.new_cipher == NULL)
1274                         {
1275                         al=SSL_AD_UNEXPECTED_MESSAGE;
1276                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1277                         goto f_err;
1278                         }
1279
1280                 if (!(s->s3->flags & SSL3_FLAGS_CCS_OK))
1281                         {
1282                         al=SSL_AD_UNEXPECTED_MESSAGE;
1283                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1284                         goto f_err;
1285                         }
1286
1287                 s->s3->flags &= ~SSL3_FLAGS_CCS_OK;
1288
1289                 rr->length=0;
1290
1291                 if (s->msg_callback)
1292                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
1293
1294                 s->s3->change_cipher_spec=1;
1295                 if (!ssl3_do_change_cipher_spec(s))
1296                         goto err;
1297                 else
1298                         goto start;
1299                 }
1300
1301         /* Unexpected handshake message (Client Hello, or protocol violation) */
1302         if ((s->s3->handshake_fragment_len >= 4) &&     !s->in_handshake)
1303                 {
1304                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1305                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1306                         {
1307 #if 0 /* worked only because C operator preferences are not as expected (and
1308        * because this is not really needed for clients except for detecting
1309        * protocol violations): */
1310                         s->state=SSL_ST_BEFORE|(s->server)
1311                                 ?SSL_ST_ACCEPT
1312                                 :SSL_ST_CONNECT;
1313 #else
1314                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1315 #endif
1316                         s->new_session=1;
1317                         }
1318                 i=s->handshake_func(s);
1319                 if (i < 0) return(i);
1320                 if (i == 0)
1321                         {
1322                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1323                         return(-1);
1324                         }
1325
1326                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1327                         {
1328                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1329                                 {
1330                                 BIO *bio;
1331                                 /* In the case where we try to read application data,
1332                                  * but we trigger an SSL handshake, we return -1 with
1333                                  * the retry option set.  Otherwise renegotiation may
1334                                  * cause nasty problems in the blocking world */
1335                                 s->rwstate=SSL_READING;
1336                                 bio=SSL_get_rbio(s);
1337                                 BIO_clear_retry_flags(bio);
1338                                 BIO_set_retry_read(bio);
1339                                 return(-1);
1340                                 }
1341                         }
1342                 goto start;
1343                 }
1344
1345         switch (rr->type)
1346                 {
1347         default:
1348 #ifndef OPENSSL_NO_TLS
1349                 /* TLS just ignores unknown message types */
1350                 if (s->version == TLS1_VERSION)
1351                         {
1352                         rr->length = 0;
1353                         goto start;
1354                         }
1355 #endif
1356                 al=SSL_AD_UNEXPECTED_MESSAGE;
1357                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1358                 goto f_err;
1359         case SSL3_RT_CHANGE_CIPHER_SPEC:
1360         case SSL3_RT_ALERT:
1361         case SSL3_RT_HANDSHAKE:
1362                 /* we already handled all of these, with the possible exception
1363                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1364                  * should not happen when type != rr->type */
1365                 al=SSL_AD_UNEXPECTED_MESSAGE;
1366                 SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
1367                 goto f_err;
1368         case SSL3_RT_APPLICATION_DATA:
1369                 /* At this point, we were expecting handshake data,
1370                  * but have application data.  If the library was
1371                  * running inside ssl3_read() (i.e. in_read_app_data
1372                  * is set) and it makes sense to read application data
1373                  * at this point (session renegotiation not yet started),
1374                  * we will indulge it.
1375                  */
1376                 if (s->s3->in_read_app_data &&
1377                         (s->s3->total_renegotiations != 0) &&
1378                         ((
1379                                 (s->state & SSL_ST_CONNECT) &&
1380                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1381                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1382                                 ) || (
1383                                         (s->state & SSL_ST_ACCEPT) &&
1384                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1385                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1386                                         )
1387                                 ))
1388                         {
1389                         s->s3->in_read_app_data=2;
1390                         return(-1);
1391                         }
1392                 else
1393                         {
1394                         al=SSL_AD_UNEXPECTED_MESSAGE;
1395                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1396                         goto f_err;
1397                         }
1398                 }
1399         /* not reached */
1400
1401 f_err:
1402         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1403 err:
1404         return(-1);
1405         }
1406
1407 int ssl3_do_change_cipher_spec(SSL *s)
1408         {
1409         int i;
1410         const char *sender;
1411         int slen;
1412
1413         if (s->state & SSL_ST_ACCEPT)
1414                 i=SSL3_CHANGE_CIPHER_SERVER_READ;
1415         else
1416                 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
1417
1418         if (s->s3->tmp.key_block == NULL)
1419                 {
1420                 if (s->session == NULL || s->session->master_key_length == 0)
1421                         {
1422                         /* might happen if dtls1_read_bytes() calls this */
1423                         SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
1424                         return (0);
1425                         }
1426
1427                 s->session->cipher=s->s3->tmp.new_cipher;
1428                 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
1429                 }
1430
1431         if (!s->method->ssl3_enc->change_cipher_state(s,i))
1432                 return(0);
1433
1434         /* we have to record the message digest at
1435          * this point so we can get it before we read
1436          * the finished message */
1437         if (s->state & SSL_ST_CONNECT)
1438                 {
1439                 sender=s->method->ssl3_enc->server_finished_label;
1440                 slen=s->method->ssl3_enc->server_finished_label_len;
1441                 }
1442         else
1443                 {
1444                 sender=s->method->ssl3_enc->client_finished_label;
1445                 slen=s->method->ssl3_enc->client_finished_label_len;
1446                 }
1447
1448         s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
1449                 sender,slen,s->s3->tmp.peer_finish_md);
1450
1451         return(1);
1452         }
1453
1454 int ssl3_send_alert(SSL *s, int level, int desc)
1455         {
1456         /* Map tls/ssl alert value to correct one */
1457         desc=s->method->ssl3_enc->alert_value(desc);
1458         if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
1459                 desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
1460         if (desc < 0) return -1;
1461         /* If a fatal one, remove from cache */
1462         if ((level == 2) && (s->session != NULL))
1463                 SSL_CTX_remove_session(s->ctx,s->session);
1464
1465         s->s3->alert_dispatch=1;
1466         s->s3->send_alert[0]=level;
1467         s->s3->send_alert[1]=desc;
1468         if (s->s3->wbuf.left == 0) /* data still being written out? */
1469                 return s->method->ssl_dispatch_alert(s);
1470         /* else data is still being written out, we will get written
1471          * some time in the future */
1472         return -1;
1473         }
1474
1475 int ssl3_dispatch_alert(SSL *s)
1476         {
1477         int i,j;
1478         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1479
1480         s->s3->alert_dispatch=0;
1481         i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
1482         if (i <= 0)
1483                 {
1484                 s->s3->alert_dispatch=1;
1485                 }
1486         else
1487                 {
1488                 /* Alert sent to BIO.  If it is important, flush it now.
1489                  * If the message does not get sent due to non-blocking IO,
1490                  * we will not worry too much. */
1491                 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1492                         (void)BIO_flush(s->wbio);
1493
1494                 if (s->msg_callback)
1495                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, s->msg_callback_arg);
1496
1497                 if (s->info_callback != NULL)
1498                         cb=s->info_callback;
1499                 else if (s->ctx->info_callback != NULL)
1500                         cb=s->ctx->info_callback;
1501
1502                 if (cb != NULL)
1503                         {
1504                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1505                         cb(s,SSL_CB_WRITE_ALERT,j);
1506                         }
1507                 }
1508         return(i);
1509         }