crypto/openssl/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 #include <openssl/rand.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 && n > left)
 186                         n = left;
 187                 }
 188
 189         /* if there is enough in the buffer from a previous read, take some */
 190         if (left >= n)
 191                 {
 192                 s->packet_length+=n;
 193                 rb->left=left-n;
 194                 rb->offset+=n;
 195                 return(n);
 196                 }
 197
 198         /* else we need to read more data */
 199
 200         len = s->packet_length;
 201         pkt = rb->buf+align;
 202         /* Move any available bytes to front of buffer:
 203          * 'len' bytes already pointed to by 'packet',
 204          * 'left' extra ones at the end */
 205         if (s->packet != pkt) /* len > 0 */
 206                 {
 207                 memmove(pkt, s->packet, len+left);
 208                 s->packet = pkt;
 209                 rb->offset = len + align;
 210                 }
 211
 212         if (n > (int)(rb->len - rb->offset)) /* does not happen */
 213                 {
 214                 SSLerr(SSL_F_SSL3_READ_N,ERR_R_INTERNAL_ERROR);
 215                 return -1;
 216                 }
 217
 218         if (!s->read_ahead)
 219                 /* ignore max parameter */
 220                 max = n;
 221         else
 222                 {
 223                 if (max < n)
 224                         max = n;
 225                 if (max > (int)(rb->len - rb->offset))
 226                         max = rb->len - rb->offset;
 227                 }
 228
 229         while (left < n)
 230                 {
 231                 /* Now we have len+left bytes at the front of s->s3->rbuf.buf
 232                  * and need to read in more until we have len+n (up to
 233                  * len+max if possible) */
 234
 235                 clear_sys_error();
 236                 if (s->rbio != NULL)
 237                         {
 238                         s->rwstate=SSL_READING;
 239                         i=BIO_read(s->rbio,pkt+len+left, max-left);
 240                         }
 241                 else
 242                         {
 243                         SSLerr(SSL_F_SSL3_READ_N,SSL_R_READ_BIO_NOT_SET);
 244                         i = -1;
 245                         }
 246
 247                 if (i <= 0)
 248                         {
 249                         rb->left = left;
 250                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
 251                             SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
 252                                 if (len+left == 0)
 253                                         ssl3_release_read_buffer(s);
 254                         return(i);
 255                         }
 256                 left+=i;
 257                 /* reads should *never* span multiple packets for DTLS because
 258                  * the underlying transport protocol is message oriented as opposed
 259                  * to byte oriented as in the TLS case. */
 260                 if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
 261                         {
 262                         if (n > left)
 263                                 n = left; /* makes the while condition false */
 264                         }
 265                 }
 266
 267         /* done reading, now the book-keeping */
 268         rb->offset += n;
 269         rb->left = left - n;
 270         s->packet_length += n;
 271         s->rwstate=SSL_NOTHING;
 272         return(n);
 273         }
 274
 275 /* Call this to get a new input record.
 276  * It will return <= 0 if more data is needed, normally due to an error
 277  * or non-blocking IO.
 278  * When it finishes, one packet has been decoded and can be found in
 279  * ssl->s3->rrec.type    - is the type of record
 280  * ssl->s3->rrec.data,   - data
 281  * ssl->s3->rrec.length, - number of bytes
 282  */
 283 /* used only by ssl3_read_bytes */
 284 static int ssl3_get_record(SSL *s)
 285         {
 286         int ssl_major,ssl_minor,al;
 287         int enc_err,n,i,ret= -1;
 288         SSL3_RECORD *rr;
 289         SSL_SESSION *sess;
 290         unsigned char *p;
 291         unsigned char md[EVP_MAX_MD_SIZE];
 292         short version;
 293         unsigned mac_size, orig_len;
 294         size_t extra;
 295
 296         rr= &(s->s3->rrec);
 297         sess=s->session;
 298
 299         if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
 300                 extra=SSL3_RT_MAX_EXTRA;
 301         else
 302                 extra=0;
 303         if (extra && !s->s3->init_extra)
 304                 {
 305                 /* An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER
 306                  * set after ssl3_setup_buffers() was done */
 307                 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
 308                 return -1;
 309                 }
 310
 311 again:
 312         /* check if we have the header */
 313         if (    (s->rstate != SSL_ST_READ_BODY) ||
 314                 (s->packet_length < SSL3_RT_HEADER_LENGTH))
 315                 {
 316                 n=ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 317                 if (n <= 0) return(n); /* error or non-blocking */
 318                 s->rstate=SSL_ST_READ_BODY;
 319
 320                 p=s->packet;
 321
 322                 /* Pull apart the header into the SSL3_RECORD */
 323                 rr->type= *(p++);
 324                 ssl_major= *(p++);
 325                 ssl_minor= *(p++);
 326                 version=(ssl_major<<8)|ssl_minor;
 327                 n2s(p,rr->length);
 328 #if 0
 329 fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
 330 #endif
 331
 332                 /* Lets check version */
 333                 if (!s->first_packet)
 334                         {
 335                         if (version != s->version)
 336                                 {
 337                                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 338                                 if ((s->version & 0xFF00) == (version & 0xFF00))
 339                                         /* Send back error using their minor version number :-) */
 340                                         s->version = (unsigned short)version;
 341                                 al=SSL_AD_PROTOCOL_VERSION;
 342                                 goto f_err;
 343                                 }
 344                         }
 345
 346                 if ((version>>8) != SSL3_VERSION_MAJOR)
 347                         {
 348                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 349                         goto err;
 350                         }
 351
 352                 if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH)
 353                         {
 354                         al=SSL_AD_RECORD_OVERFLOW;
 355                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 356                         goto f_err;
 357                         }
 358
 359                 /* now s->rstate == SSL_ST_READ_BODY */
 360                 }
 361
 362         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 363
 364         if (rr->length > s->packet_length-SSL3_RT_HEADER_LENGTH)
 365                 {
 366                 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
 367                 i=rr->length;
 368                 n=ssl3_read_n(s,i,i,1);
 369                 if (n <= 0) return(n); /* error or non-blocking io */
 370                 /* now n == rr->length,
 371                  * and s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length */
 372                 }
 373
 374         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 375
 376         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 377          * and we have that many bytes in s->packet
 378          */
 379         rr->input= &(s->packet[SSL3_RT_HEADER_LENGTH]);
 380
 381         /* ok, we can now read from 's->packet' data into 'rr'
 382          * rr->input points at rr->length bytes, which
 383          * need to be copied into rr->data by either
 384          * the decryption or by the decompression
 385          * When the data is 'copied' into the rr->data buffer,
 386          * rr->input will be pointed at the new buffer */
 387
 388         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 389          * rr->length bytes of encrypted compressed stuff. */
 390
 391         /* check is not needed I believe */
 392         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH+extra)
 393                 {
 394                 al=SSL_AD_RECORD_OVERFLOW;
 395                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 396                 goto f_err;
 397                 }
 398
 399         /* decrypt in place in 'rr->input' */
 400         rr->data=rr->input;
 401         orig_len=rr->length;
 402
 403         enc_err = s->method->ssl3_enc->enc(s,0);
 404         /* enc_err is:
 405          *    0: (in non-constant time) if the record is publically invalid.
 406          *    1: if the padding is valid
 407          *    -1: if the padding is invalid */
 408         if (enc_err == 0)
 409                 {
 410                 al=SSL_AD_DECRYPTION_FAILED;
 411                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
 412                 goto f_err;
 413                 }
 414
 415 #ifdef TLS_DEBUG
 416 printf("dec %d\n",rr->length);
 417 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 418 printf("\n");
 419 #endif
 420
 421         /* r->length is now the compressed data plus mac */
 422         if ((sess != NULL) &&
 423             (s->enc_read_ctx != NULL) &&
 424             (EVP_MD_CTX_md(s->read_hash) != NULL))
 425                 {
 426                 /* s->read_hash != NULL => mac_size != -1 */
 427                 unsigned char *mac = NULL;
 428                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
 429                 mac_size=EVP_MD_CTX_size(s->read_hash);
 430                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
 431
 432                 /* orig_len is the length of the record before any padding was
 433                  * removed. This is public information, as is the MAC in use,
 434                  * therefore we can safely process the record in a different
 435                  * amount of time if it's too short to possibly contain a MAC.
 436                  */
 437                 if (orig_len < mac_size ||
 438                     /* CBC records must have a padding length byte too. */
 439                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
 440                      orig_len < mac_size+1))
 441                         {
 442                         al=SSL_AD_DECODE_ERROR;
 443                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_LENGTH_TOO_SHORT);
 444                         goto f_err;
 445                         }
 446
 447                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
 448                         {
 449                         /* We update the length so that the TLS header bytes
 450                          * can be constructed correctly but we need to extract
 451                          * the MAC in constant time from within the record,
 452                          * without leaking the contents of the padding bytes.
 453                          * */
 454                         mac = mac_tmp;
 455                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
 456                         rr->length -= mac_size;
 457                         }
 458                 else
 459                         {
 460                         /* In this case there's no padding, so |orig_len|
 461                          * equals |rec->length| and we checked that there's
 462                          * enough bytes for |mac_size| above. */
 463                         rr->length -= mac_size;
 464                         mac = &rr->data[rr->length];
 465                         }
 466
 467                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
 468                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
 469                         enc_err = -1;
 470                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra+mac_size)
 471                         enc_err = -1;
 472                 }
 473
 474         if (enc_err < 0)
 475                 {
 476                 /* A separate 'decryption_failed' alert was introduced with TLS 1.0,
 477                  * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 478                  * failure is directly visible from the ciphertext anyway,
 479                  * we should not reveal which kind of error occured -- this
 480                  * might become visible to an attacker (e.g. via a logfile) */
 481                 al=SSL_AD_BAD_RECORD_MAC;
 482                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 483                 goto f_err;
 484                 }
 485
 486         /* r->length is now just compressed */
 487         if (s->expand != NULL)
 488                 {
 489                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+extra)
 490                         {
 491                         al=SSL_AD_RECORD_OVERFLOW;
 492                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 493                         goto f_err;
 494                         }
 495                 if (!ssl3_do_uncompress(s))
 496                         {
 497                         al=SSL_AD_DECOMPRESSION_FAILURE;
 498                         SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_BAD_DECOMPRESSION);
 499                         goto f_err;
 500                         }
 501                 }
 502
 503         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH+extra)
 504                 {
 505                 al=SSL_AD_RECORD_OVERFLOW;
 506                 SSLerr(SSL_F_SSL3_GET_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 507                 goto f_err;
 508                 }
 509
 510         rr->off=0;
 511         /* So at this point the following is true
 512          * ssl->s3->rrec.type   is the type of record
 513          * ssl->s3->rrec.length == number of bytes in record
 514          * ssl->s3->rrec.off    == offset to first valid byte
 515          * ssl->s3->rrec.data   == where to take bytes from, increment
 516          *                         after use :-).
 517          */
 518
 519         /* we have pulled in a full packet so zero things */
 520         s->packet_length=0;
 521
 522         /* just read a 0 length packet */
 523         if (rr->length == 0) goto again;
 524
 525 #if 0
 526 fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, rr->length);
 527 #endif
 528
 529         return(1);
 530
 531 f_err:
 532         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 533 err:
 534         return(ret);
 535         }
 536
 537 int ssl3_do_uncompress(SSL *ssl)
 538         {
 539 #ifndef OPENSSL_NO_COMP
 540         int i;
 541         SSL3_RECORD *rr;
 542
 543         rr= &(ssl->s3->rrec);
 544         i=COMP_expand_block(ssl->expand,rr->comp,
 545                 SSL3_RT_MAX_PLAIN_LENGTH,rr->data,(int)rr->length);
 546         if (i < 0)
 547                 return(0);
 548         else
 549                 rr->length=i;
 550         rr->data=rr->comp;
 551 #endif
 552         return(1);
 553         }
 554
 555 int ssl3_do_compress(SSL *ssl)
 556         {
 557 #ifndef OPENSSL_NO_COMP
 558         int i;
 559         SSL3_RECORD *wr;
 560
 561         wr= &(ssl->s3->wrec);
 562         i=COMP_compress_block(ssl->compress,wr->data,
 563                 SSL3_RT_MAX_COMPRESSED_LENGTH,
 564                 wr->input,(int)wr->length);
 565         if (i < 0)
 566                 return(0);
 567         else
 568                 wr->length=i;
 569
 570         wr->input=wr->data;
 571 #endif
 572         return(1);
 573         }
 574
 575 /* Call this to write data in records of type 'type'
 576  * It will return <= 0 if not all data has been sent or non-blocking IO.
 577  */
 578 int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len)
 579         {
 580         const unsigned char *buf=buf_;
 581         unsigned int tot,n,nw;
 582         int i;
 583
 584         s->rwstate=SSL_NOTHING;
 585         tot=s->s3->wnum;
 586         s->s3->wnum=0;
 587
 588         if (SSL_in_init(s) && !s->in_handshake)
 589                 {
 590                 i=s->handshake_func(s);
 591                 if (i < 0) return(i);
 592                 if (i == 0)
 593                         {
 594                         SSLerr(SSL_F_SSL3_WRITE_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 595                         return -1;
 596                         }
 597                 }
 598
 599         n=(len-tot);
 600         for (;;)
 601                 {
 602                 if (n > s->max_send_fragment)
 603                         nw=s->max_send_fragment;
 604                 else
 605                         nw=n;
 606
 607                 i=do_ssl3_write(s, type, &(buf[tot]), nw, 0);
 608                 if (i <= 0)
 609                         {
 610                         s->s3->wnum=tot;
 611                         return i;
 612                         }
 613
 614                 if ((i == (int)n) ||
 615                         (type == SSL3_RT_APPLICATION_DATA &&
 616                          (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
 617                         {
 618                         /* next chunk of data should get another prepended empty fragment
 619                          * in ciphersuites with known-IV weakness: */
 620                         s->s3->empty_fragment_done = 0;
 621
 622                         return tot+i;
 623                         }
 624
 625                 n-=i;
 626                 tot+=i;
 627                 }
 628         }
 629
 630 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf,
 631                          unsigned int len, int create_empty_fragment)
 632         {
 633         unsigned char *p,*plen;
 634         int i,mac_size,clear=0;
 635         int prefix_len=0;
 636         int eivlen;
 637         long align=0;
 638         SSL3_RECORD *wr;
 639         SSL3_BUFFER *wb=&(s->s3->wbuf);
 640         SSL_SESSION *sess;
 641
 642         if (wb->buf == NULL)
 643                 if (!ssl3_setup_write_buffer(s))
 644                         return -1;
 645
 646         /* first check if there is a SSL3_BUFFER still being written
 647          * out.  This will happen with non blocking IO */
 648         if (wb->left != 0)
 649                 return(ssl3_write_pending(s,type,buf,len));
 650
 651         /* If we have an alert to send, lets send it */
 652         if (s->s3->alert_dispatch)
 653                 {
 654                 i=s->method->ssl_dispatch_alert(s);
 655                 if (i <= 0)
 656                         return(i);
 657                 /* if it went, fall through and send more stuff */
 658                 }
 659
 660         if (len == 0 && !create_empty_fragment)
 661                 return 0;
 662
 663         wr= &(s->s3->wrec);
 664         sess=s->session;
 665
 666         if (    (sess == NULL) ||
 667                 (s->enc_write_ctx == NULL) ||
 668                 (EVP_MD_CTX_md(s->write_hash) == NULL))
 669                 {
 670 #if 1
 671                 clear=s->enc_write_ctx?0:1;     /* must be AEAD cipher */
 672 #else
 673                 clear=1;
 674 #endif
 675                 mac_size=0;
 676                 }
 677         else
 678                 {
 679                 mac_size=EVP_MD_CTX_size(s->write_hash);
 680                 if (mac_size < 0)
 681                         goto err;
 682                 }
 683
 684         /* 'create_empty_fragment' is true only when this function calls itself */
 685         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done)
 686                 {
 687                 /* countermeasure against known-IV weakness in CBC ciphersuites
 688                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
 689
 690                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
 691                         {
 692                         /* recursive function call with 'create_empty_fragment' set;
 693                          * this prepares and buffers the data for an empty fragment
 694                          * (these 'prefix_len' bytes are sent out later
 695                          * together with the actual payload) */
 696                         prefix_len = do_ssl3_write(s, type, buf, 0, 1);
 697                         if (prefix_len <= 0)
 698                                 goto err;
 699
 700                         if (prefix_len >
 701                 (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD))
 702                                 {
 703                                 /* insufficient space */
 704                                 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR);
 705                                 goto err;
 706                                 }
 707                         }
 708
 709                 s->s3->empty_fragment_done = 1;
 710                 }
 711
 712         if (create_empty_fragment)
 713                 {
 714 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 715                 /* extra fragment would be couple of cipher blocks,
 716                  * which would be multiple of SSL3_ALIGN_PAYLOAD, so
 717                  * if we want to align the real payload, then we can
 718                  * just pretent we simply have two headers. */
 719                 align = (long)wb->buf + 2*SSL3_RT_HEADER_LENGTH;
 720                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 721 #endif
 722                 p = wb->buf + align;
 723                 wb->offset  = align;
 724                 }
 725         else if (prefix_len)
 726                 {
 727                 p = wb->buf + wb->offset + prefix_len;
 728                 }
 729         else
 730                 {
 731 #if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0
 732                 align = (long)wb->buf + SSL3_RT_HEADER_LENGTH;
 733                 align = (-align)&(SSL3_ALIGN_PAYLOAD-1);
 734 #endif
 735                 p = wb->buf + align;
 736                 wb->offset  = align;
 737                 }
 738
 739         /* write the header */
 740
 741         *(p++)=type&0xff;
 742         wr->type=type;
 743
 744         *(p++)=(s->version>>8);
 745         /* Some servers hang if iniatial client hello is larger than 256
 746          * bytes and record version number > TLS 1.0
 747          */
 748         if (s->state == SSL3_ST_CW_CLNT_HELLO_B
 749                                 && !s->renegotiate
 750                                 && TLS1_get_version(s) > TLS1_VERSION)
 751                 *(p++) = 0x1;
 752         else
 753                 *(p++)=s->version&0xff;
 754
 755         /* field where we are to write out packet length */
 756         plen=p;
 757         p+=2;
 758         /* Explicit IV length, block ciphers and TLS version 1.1 or later */
 759         if (s->enc_write_ctx && s->version >= TLS1_1_VERSION)
 760                 {
 761                 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
 762                 if (mode == EVP_CIPH_CBC_MODE)
 763                         {
 764                         eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
 765                         if (eivlen <= 1)
 766                                 eivlen = 0;
 767                         }
 768                 /* Need explicit part of IV for GCM mode */
 769                 else if (mode == EVP_CIPH_GCM_MODE)
 770                         eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
 771                 else
 772                         eivlen = 0;
 773                 }
 774         else
 775                 eivlen = 0;
 776
 777         /* lets setup the record stuff. */
 778         wr->data=p + eivlen;
 779         wr->length=(int)len;
 780         wr->input=(unsigned char *)buf;
 781
 782         /* we now 'read' from wr->input, wr->length bytes into
 783          * wr->data */
 784
 785         /* first we compress */
 786         if (s->compress != NULL)
 787                 {
 788                 if (!ssl3_do_compress(s))
 789                         {
 790                         SSLerr(SSL_F_DO_SSL3_WRITE,SSL_R_COMPRESSION_FAILURE);
 791                         goto err;
 792                         }
 793                 }
 794         else
 795                 {
 796                 memcpy(wr->data,wr->input,wr->length);
 797                 wr->input=wr->data;
 798                 }
 799
 800         /* we should still have the output to wr->data and the input
 801          * from wr->input.  Length should be wr->length.
 802          * wr->data still points in the wb->buf */
 803
 804         if (mac_size != 0)
 805                 {
 806                 if (s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0)
 807                         goto err;
 808                 wr->length+=mac_size;
 809                 }
 810
 811         wr->input=p;
 812         wr->data=p;
 813
 814         if (eivlen)
 815                 {
 816         /*      if (RAND_pseudo_bytes(p, eivlen) <= 0)
 817                         goto err; */
 818                 wr->length += eivlen;
 819                 }
 820
 821         /* ssl3_enc can only have an error on read */
 822         s->method->ssl3_enc->enc(s,1);
 823
 824         /* record length after mac and block padding */
 825         s2n(wr->length,plen);
 826
 827         /* we should now have
 828          * wr->data pointing to the encrypted data, which is
 829          * wr->length long */
 830         wr->type=type; /* not needed but helps for debugging */
 831         wr->length+=SSL3_RT_HEADER_LENGTH;
 832
 833         if (create_empty_fragment)
 834                 {
 835                 /* we are in a recursive call;
 836                  * just return the length, don't write out anything here
 837                  */
 838                 return wr->length;
 839                 }
 840
 841         /* now let's set up wb */
 842         wb->left = prefix_len + wr->length;
 843
 844         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
 845         s->s3->wpend_tot=len;
 846         s->s3->wpend_buf=buf;
 847         s->s3->wpend_type=type;
 848         s->s3->wpend_ret=len;
 849
 850         /* we now just need to write the buffer */
 851         return ssl3_write_pending(s,type,buf,len);
 852 err:
 853         return -1;
 854         }
 855
 856 /* if s->s3->wbuf.left != 0, we need to call this */
 857 int ssl3_write_pending(SSL *s, int type, const unsigned char *buf,
 858         unsigned int len)
 859         {
 860         int i;
 861         SSL3_BUFFER *wb=&(s->s3->wbuf);
 862
 863 /* XXXX */
 864         if ((s->s3->wpend_tot > (int)len)
 865                 || ((s->s3->wpend_buf != buf) &&
 866                         !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER))
 867                 || (s->s3->wpend_type != type))
 868                 {
 869                 SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BAD_WRITE_RETRY);
 870                 return(-1);
 871                 }
 872
 873         for (;;)
 874                 {
 875                 clear_sys_error();
 876                 if (s->wbio != NULL)
 877                         {
 878                         s->rwstate=SSL_WRITING;
 879                         i=BIO_write(s->wbio,
 880                                 (char *)&(wb->buf[wb->offset]),
 881                                 (unsigned int)wb->left);
 882                         }
 883                 else
 884                         {
 885                         SSLerr(SSL_F_SSL3_WRITE_PENDING,SSL_R_BIO_NOT_SET);
 886                         i= -1;
 887                         }
 888                 if (i == wb->left)
 889                         {
 890                         wb->left=0;
 891                         wb->offset+=i;
 892                         if (s->mode & SSL_MODE_RELEASE_BUFFERS &&
 893                             SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
 894                                 ssl3_release_write_buffer(s);
 895                         s->rwstate=SSL_NOTHING;
 896                         return(s->s3->wpend_ret);
 897                         }
 898                 else if (i <= 0) {
 899                         if (s->version == DTLS1_VERSION ||
 900                             s->version == DTLS1_BAD_VER) {
 901                                 /* For DTLS, just drop it. That's kind of the whole
 902                                    point in using a datagram service */
 903                                 wb->left = 0;
 904                         }
 905                         return(i);
 906                 }
 907                 wb->offset+=i;
 908                 wb->left-=i;
 909                 }
 910         }
 911
 912 /* Return up to 'len' payload bytes received in 'type' records.
 913  * 'type' is one of the following:
 914  *
 915  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 916  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 917  *   -  0 (during a shutdown, no data has to be returned)
 918  *
 919  * If we don't have stored data to work from, read a SSL/TLS record first
 920  * (possibly multiple records if we still don't have anything to return).
 921  *
 922  * This function must handle any surprises the peer may have for us, such as
 923  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 924  * a surprise, but handled as if it were), or renegotiation requests.
 925  * Also if record payloads contain fragments too small to process, we store
 926  * them until there is enough for the respective protocol (the record protocol
 927  * may use arbitrary fragmentation and even interleaving):
 928  *     Change cipher spec protocol
 929  *             just 1 byte needed, no need for keeping anything stored
 930  *     Alert protocol
 931  *             2 bytes needed (AlertLevel, AlertDescription)
 932  *     Handshake protocol
 933  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 934  *             to detect unexpected Client Hello and Hello Request messages
 935  *             here, anything else is handled by higher layers
 936  *     Application data protocol
 937  *             none of our business
 938  */
 939 int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 940         {
 941         int al,i,j,ret;
 942         unsigned int n;
 943         SSL3_RECORD *rr;
 944         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 945
 946         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 947                 if (!ssl3_setup_read_buffer(s))
 948                         return(-1);
 949
 950         if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE) && type) ||
 951             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 952                 {
 953                 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR);
 954                 return -1;
 955                 }
 956
 957         if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0))
 958                 /* (partially) satisfy request from storage */
 959                 {
 960                 unsigned char *src = s->s3->handshake_fragment;
 961                 unsigned char *dst = buf;
 962                 unsigned int k;
 963
 964                 /* peek == 0 */
 965                 n = 0;
 966                 while ((len > 0) && (s->s3->handshake_fragment_len > 0))
 967                         {
 968                         *dst++ = *src++;
 969                         len--; s->s3->handshake_fragment_len--;
 970                         n++;
 971                         }
 972                 /* move any remaining fragment bytes: */
 973                 for (k = 0; k < s->s3->handshake_fragment_len; k++)
 974                         s->s3->handshake_fragment[k] = *src++;
 975                 return n;
 976         }
 977
 978         /* Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 979
 980         if (!s->in_handshake && SSL_in_init(s))
 981                 {
 982                 /* type == SSL3_RT_APPLICATION_DATA */
 983                 i=s->handshake_func(s);
 984                 if (i < 0) return(i);
 985                 if (i == 0)
 986                         {
 987                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 988                         return(-1);
 989                         }
 990                 }
 991 start:
 992         s->rwstate=SSL_NOTHING;
 993
 994         /* s->s3->rrec.type         - is the type of record
 995          * s->s3->rrec.data,    - data
 996          * s->s3->rrec.off,     - offset into 'data' for next read
 997          * s->s3->rrec.length,  - number of bytes. */
 998         rr = &(s->s3->rrec);
 999
1000         /* get new packet if necessary */
1001         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
1002                 {
1003                 ret=ssl3_get_record(s);
1004                 if (ret <= 0) return(ret);
1005                 }
1006
1007         /* we now have a packet which can be read and processed */
1008
1009         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
1010                                        * reset by ssl3_get_finished */
1011                 && (rr->type != SSL3_RT_HANDSHAKE))
1012                 {
1013                 al=SSL_AD_UNEXPECTED_MESSAGE;
1014                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
1015                 goto f_err;
1016                 }
1017
1018         /* If the other end has shut down, throw anything we read away
1019          * (even in 'peek' mode) */
1020         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
1021                 {
1022                 rr->length=0;
1023                 s->rwstate=SSL_NOTHING;
1024                 return(0);
1025                 }
1026
1027
1028         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
1029                 {
1030                 /* make sure that we are not getting application data when we
1031                  * are doing a handshake for the first time */
1032                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
1033                         (s->enc_read_ctx == NULL))
1034                         {
1035                         al=SSL_AD_UNEXPECTED_MESSAGE;
1036                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
1037                         goto f_err;
1038                         }
1039
1040                 if (len <= 0) return(len);
1041
1042                 if ((unsigned int)len > rr->length)
1043                         n = rr->length;
1044                 else
1045                         n = (unsigned int)len;
1046
1047                 memcpy(buf,&(rr->data[rr->off]),n);
1048                 if (!peek)
1049                         {
1050                         rr->length-=n;
1051                         rr->off+=n;
1052                         if (rr->length == 0)
1053                                 {
1054                                 s->rstate=SSL_ST_READ_HEADER;
1055                                 rr->off=0;
1056                                 if (s->mode & SSL_MODE_RELEASE_BUFFERS)
1057                                         ssl3_release_read_buffer(s);
1058                                 }
1059                         }
1060                 return(n);
1061                 }
1062
1063
1064         /* If we get here, then type != rr->type; if we have a handshake
1065          * message, then it was unexpected (Hello Request or Client Hello). */
1066
1067         /* In case of record types for which we have 'fragment' storage,
1068          * fill that so that we can process the data at a fixed place.
1069          */
1070                 {
1071                 unsigned int dest_maxlen = 0;
1072                 unsigned char *dest = NULL;
1073                 unsigned int *dest_len = NULL;
1074
1075                 if (rr->type == SSL3_RT_HANDSHAKE)
1076                         {
1077                         dest_maxlen = sizeof s->s3->handshake_fragment;
1078                         dest = s->s3->handshake_fragment;
1079                         dest_len = &s->s3->handshake_fragment_len;
1080                         }
1081                 else if (rr->type == SSL3_RT_ALERT)
1082                         {
1083                         dest_maxlen = sizeof s->s3->alert_fragment;
1084                         dest = s->s3->alert_fragment;
1085                         dest_len = &s->s3->alert_fragment_len;
1086                         }
1087 #ifndef OPENSSL_NO_HEARTBEATS
1088                 else if (rr->type == TLS1_RT_HEARTBEAT)
1089                         {
1090                         tls1_process_heartbeat(s);
1091
1092                         /* Exit and notify application to read again */
1093                         rr->length = 0;
1094                         s->rwstate=SSL_READING;
1095                         BIO_clear_retry_flags(SSL_get_rbio(s));
1096                         BIO_set_retry_read(SSL_get_rbio(s));
1097                         return(-1);
1098                         }
1099 #endif
1100
1101                 if (dest_maxlen > 0)
1102                         {
1103                         n = dest_maxlen - *dest_len; /* available space in 'dest' */
1104                         if (rr->length < n)
1105                                 n = rr->length; /* available bytes */
1106
1107                         /* now move 'n' bytes: */
1108                         while (n-- > 0)
1109                                 {
1110                                 dest[(*dest_len)++] = rr->data[rr->off++];
1111                                 rr->length--;
1112                                 }
1113
1114                         if (*dest_len < dest_maxlen)
1115                                 goto start; /* fragment was too small */
1116                         }
1117                 }
1118
1119         /* s->s3->handshake_fragment_len == 4  iff  rr->type == SSL3_RT_HANDSHAKE;
1120          * s->s3->alert_fragment_len == 2      iff  rr->type == SSL3_RT_ALERT.
1121          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1122
1123         /* If we are a client, check for an incoming 'Hello Request': */
1124         if ((!s->server) &&
1125                 (s->s3->handshake_fragment_len >= 4) &&
1126                 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1127                 (s->session != NULL) && (s->session->cipher != NULL))
1128                 {
1129                 s->s3->handshake_fragment_len = 0;
1130
1131                 if ((s->s3->handshake_fragment[1] != 0) ||
1132                         (s->s3->handshake_fragment[2] != 0) ||
1133                         (s->s3->handshake_fragment[3] != 0))
1134                         {
1135                         al=SSL_AD_DECODE_ERROR;
1136                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1137                         goto f_err;
1138                         }
1139
1140                 if (s->msg_callback)
1141                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->s3->handshake_fragment, 4, s, s->msg_callback_arg);
1142
1143                 if (SSL_is_init_finished(s) &&
1144                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1145                         !s->s3->renegotiate)
1146                         {
1147                         ssl3_renegotiate(s);
1148                         if (ssl3_renegotiate_check(s))
1149                                 {
1150                                 i=s->handshake_func(s);
1151                                 if (i < 0) return(i);
1152                                 if (i == 0)
1153                                         {
1154                                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1155                                         return(-1);
1156                                         }
1157
1158                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1159                                         {
1160                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1161                                                 {
1162                                                 BIO *bio;
1163                                                 /* In the case where we try to read application data,
1164                                                  * but we trigger an SSL handshake, we return -1 with
1165                                                  * the retry option set.  Otherwise renegotiation may
1166                                                  * cause nasty problems in the blocking world */
1167                                                 s->rwstate=SSL_READING;
1168                                                 bio=SSL_get_rbio(s);
1169                                                 BIO_clear_retry_flags(bio);
1170                                                 BIO_set_retry_read(bio);
1171                                                 return(-1);
1172                                                 }
1173                                         }
1174                                 }
1175                         }
1176                 /* we either finished a handshake or ignored the request,
1177                  * now try again to obtain the (application) data we were asked for */
1178                 goto start;
1179                 }
1180         /* If we are a server and get a client hello when renegotiation isn't
1181          * allowed send back a no renegotiation alert and carry on.
1182          * WARNING: experimental code, needs reviewing (steve)
1183          */
1184         if (s->server &&
1185                 SSL_is_init_finished(s) &&
1186                 !s->s3->send_connection_binding &&
1187                 (s->version > SSL3_VERSION) &&
1188                 (s->s3->handshake_fragment_len >= 4) &&
1189                 (s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) &&
1190                 (s->session != NULL) && (s->session->cipher != NULL) &&
1191                 !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION))
1192
1193                 {
1194                 /*s->s3->handshake_fragment_len = 0;*/
1195                 rr->length = 0;
1196                 ssl3_send_alert(s,SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
1197                 goto start;
1198                 }
1199         if (s->s3->alert_fragment_len >= 2)
1200                 {
1201                 int alert_level = s->s3->alert_fragment[0];
1202                 int alert_descr = s->s3->alert_fragment[1];
1203
1204                 s->s3->alert_fragment_len = 0;
1205
1206                 if (s->msg_callback)
1207                         s->msg_callback(0, s->version, SSL3_RT_ALERT, s->s3->alert_fragment, 2, s, s->msg_callback_arg);
1208
1209                 if (s->info_callback != NULL)
1210                         cb=s->info_callback;
1211                 else if (s->ctx->info_callback != NULL)
1212                         cb=s->ctx->info_callback;
1213
1214                 if (cb != NULL)
1215                         {
1216                         j = (alert_level << 8) | alert_descr;
1217                         cb(s, SSL_CB_READ_ALERT, j);
1218                         }
1219
1220                 if (alert_level == 1) /* warning */
1221                         {
1222                         s->s3->warn_alert = alert_descr;
1223                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1224                                 {
1225                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1226                                 return(0);
1227                                 }
1228                         /* This is a warning but we receive it if we requested
1229                          * renegotiation and the peer denied it. Terminate with
1230                          * a fatal alert because if application tried to
1231                          * renegotiatie it presumably had a good reason and
1232                          * expects it to succeed.
1233                          *
1234                          * In future we might have a renegotiation where we
1235                          * don't care if the peer refused it where we carry on.
1236                          */
1237                         else if (alert_descr == SSL_AD_NO_RENEGOTIATION)
1238                                 {
1239                                 al = SSL_AD_HANDSHAKE_FAILURE;
1240                                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_NO_RENEGOTIATION);
1241                                 goto f_err;
1242                                 }
1243 #ifdef SSL_AD_MISSING_SRP_USERNAME
1244                         else if (alert_descr == SSL_AD_MISSING_SRP_USERNAME)
1245                                 return(0);
1246 #endif
1247                         }
1248                 else if (alert_level == 2) /* fatal */
1249                         {
1250                         char tmp[16];
1251
1252                         s->rwstate=SSL_NOTHING;
1253                         s->s3->fatal_alert = alert_descr;
1254                         SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1255                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1256                         ERR_add_error_data(2,"SSL alert number ",tmp);
1257                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1258                         SSL_CTX_remove_session(s->ctx,s->session);
1259                         return(0);
1260                         }
1261                 else
1262                         {
1263                         al=SSL_AD_ILLEGAL_PARAMETER;
1264                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1265                         goto f_err;
1266                         }
1267
1268                 goto start;
1269                 }
1270
1271         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1272                 {
1273                 s->rwstate=SSL_NOTHING;
1274                 rr->length=0;
1275                 return(0);
1276                 }
1277
1278         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1279                 {
1280                 /* 'Change Cipher Spec' is just a single byte, so we know
1281                  * exactly what the record payload has to look like */
1282                 if (    (rr->length != 1) || (rr->off != 0) ||
1283                         (rr->data[0] != SSL3_MT_CCS))
1284                         {
1285                         al=SSL_AD_ILLEGAL_PARAMETER;
1286                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1287                         goto f_err;
1288                         }
1289
1290                 /* Check we have a cipher to change to */
1291                 if (s->s3->tmp.new_cipher == NULL)
1292                         {
1293                         al=SSL_AD_UNEXPECTED_MESSAGE;
1294                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_CCS_RECEIVED_EARLY);
1295                         goto f_err;
1296                         }
1297
1298                 rr->length=0;
1299
1300                 if (s->msg_callback)
1301                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, s->msg_callback_arg);
1302
1303                 s->s3->change_cipher_spec=1;
1304                 if (!ssl3_do_change_cipher_spec(s))
1305                         goto err;
1306                 else
1307                         goto start;
1308                 }
1309
1310         /* Unexpected handshake message (Client Hello, or protocol violation) */
1311         if ((s->s3->handshake_fragment_len >= 4) &&     !s->in_handshake)
1312                 {
1313                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1314                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1315                         {
1316 #if 0 /* worked only because C operator preferences are not as expected (and
1317        * because this is not really needed for clients except for detecting
1318        * protocol violations): */
1319                         s->state=SSL_ST_BEFORE|(s->server)
1320                                 ?SSL_ST_ACCEPT
1321                                 :SSL_ST_CONNECT;
1322 #else
1323                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1324 #endif
1325                         s->renegotiate=1;
1326                         s->new_session=1;
1327                         }
1328                 i=s->handshake_func(s);
1329                 if (i < 0) return(i);
1330                 if (i == 0)
1331                         {
1332                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1333                         return(-1);
1334                         }
1335
1336                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1337                         {
1338                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1339                                 {
1340                                 BIO *bio;
1341                                 /* In the case where we try to read application data,
1342                                  * but we trigger an SSL handshake, we return -1 with
1343                                  * the retry option set.  Otherwise renegotiation may
1344                                  * cause nasty problems in the blocking world */
1345                                 s->rwstate=SSL_READING;
1346                                 bio=SSL_get_rbio(s);
1347                                 BIO_clear_retry_flags(bio);
1348                                 BIO_set_retry_read(bio);
1349                                 return(-1);
1350                                 }
1351                         }
1352                 goto start;
1353                 }
1354
1355         switch (rr->type)
1356                 {
1357         default:
1358 #ifndef OPENSSL_NO_TLS
1359                 /* TLS up to v1.1 just ignores unknown message types:
1360                  * TLS v1.2 give an unexpected message alert.
1361                  */
1362                 if (s->version >= TLS1_VERSION && s->version <= TLS1_1_VERSION)
1363                         {
1364                         rr->length = 0;
1365                         goto start;
1366                         }
1367 #endif
1368                 al=SSL_AD_UNEXPECTED_MESSAGE;
1369                 SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1370                 goto f_err;
1371         case SSL3_RT_CHANGE_CIPHER_SPEC:
1372         case SSL3_RT_ALERT:
1373         case SSL3_RT_HANDSHAKE:
1374                 /* we already handled all of these, with the possible exception
1375                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1376                  * should not happen when type != rr->type */
1377                 al=SSL_AD_UNEXPECTED_MESSAGE;
1378                 SSLerr(SSL_F_SSL3_READ_BYTES,ERR_R_INTERNAL_ERROR);
1379                 goto f_err;
1380         case SSL3_RT_APPLICATION_DATA:
1381                 /* At this point, we were expecting handshake data,
1382                  * but have application data.  If the library was
1383                  * running inside ssl3_read() (i.e. in_read_app_data
1384                  * is set) and it makes sense to read application data
1385                  * at this point (session renegotiation not yet started),
1386                  * we will indulge it.
1387                  */
1388                 if (s->s3->in_read_app_data &&
1389                         (s->s3->total_renegotiations != 0) &&
1390                         ((
1391                                 (s->state & SSL_ST_CONNECT) &&
1392                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1393                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1394                                 ) || (
1395                                         (s->state & SSL_ST_ACCEPT) &&
1396                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1397                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1398                                         )
1399                                 ))
1400                         {
1401                         s->s3->in_read_app_data=2;
1402                         return(-1);
1403                         }
1404                 else
1405                         {
1406                         al=SSL_AD_UNEXPECTED_MESSAGE;
1407                         SSLerr(SSL_F_SSL3_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1408                         goto f_err;
1409                         }
1410                 }
1411         /* not reached */
1412
1413 f_err:
1414         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1415 err:
1416         return(-1);
1417         }
1418
1419 int ssl3_do_change_cipher_spec(SSL *s)
1420         {
1421         int i;
1422         const char *sender;
1423         int slen;
1424
1425         if (s->state & SSL_ST_ACCEPT)
1426                 i=SSL3_CHANGE_CIPHER_SERVER_READ;
1427         else
1428                 i=SSL3_CHANGE_CIPHER_CLIENT_READ;
1429
1430         if (s->s3->tmp.key_block == NULL)
1431                 {
1432                 if (s->session == NULL)
1433                         {
1434                         /* might happen if dtls1_read_bytes() calls this */
1435                         SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC,SSL_R_CCS_RECEIVED_EARLY);
1436                         return (0);
1437                         }
1438
1439                 s->session->cipher=s->s3->tmp.new_cipher;
1440                 if (!s->method->ssl3_enc->setup_key_block(s)) return(0);
1441                 }
1442
1443         if (!s->method->ssl3_enc->change_cipher_state(s,i))
1444                 return(0);
1445
1446         /* we have to record the message digest at
1447          * this point so we can get it before we read
1448          * the finished message */
1449         if (s->state & SSL_ST_CONNECT)
1450                 {
1451                 sender=s->method->ssl3_enc->server_finished_label;
1452                 slen=s->method->ssl3_enc->server_finished_label_len;
1453                 }
1454         else
1455                 {
1456                 sender=s->method->ssl3_enc->client_finished_label;
1457                 slen=s->method->ssl3_enc->client_finished_label_len;
1458                 }
1459
1460         s->s3->tmp.peer_finish_md_len = s->method->ssl3_enc->final_finish_mac(s,
1461                 sender,slen,s->s3->tmp.peer_finish_md);
1462
1463         return(1);
1464         }
1465
1466 int ssl3_send_alert(SSL *s, int level, int desc)
1467         {
1468         /* Map tls/ssl alert value to correct one */
1469         desc=s->method->ssl3_enc->alert_value(desc);
1470         if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION)
1471                 desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have protocol_version alerts */
1472         if (desc < 0) return -1;
1473         /* If a fatal one, remove from cache */
1474         if ((level == 2) && (s->session != NULL))
1475                 SSL_CTX_remove_session(s->ctx,s->session);
1476
1477         s->s3->alert_dispatch=1;
1478         s->s3->send_alert[0]=level;
1479         s->s3->send_alert[1]=desc;
1480         if (s->s3->wbuf.left == 0) /* data still being written out? */
1481                 return s->method->ssl_dispatch_alert(s);
1482         /* else data is still being written out, we will get written
1483          * some time in the future */
1484         return -1;
1485         }
1486
1487 int ssl3_dispatch_alert(SSL *s)
1488         {
1489         int i,j;
1490         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1491
1492         s->s3->alert_dispatch=0;
1493         i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0);
1494         if (i <= 0)
1495                 {
1496                 s->s3->alert_dispatch=1;
1497                 }
1498         else
1499                 {
1500                 /* Alert sent to BIO.  If it is important, flush it now.
1501                  * If the message does not get sent due to non-blocking IO,
1502                  * we will not worry too much. */
1503                 if (s->s3->send_alert[0] == SSL3_AL_FATAL)
1504                         (void)BIO_flush(s->wbio);
1505
1506                 if (s->msg_callback)
1507                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 2, s, s->msg_callback_arg);
1508
1509                 if (s->info_callback != NULL)
1510                         cb=s->info_callback;
1511                 else if (s->ctx->info_callback != NULL)
1512                         cb=s->ctx->info_callback;
1513
1514                 if (cb != NULL)
1515                         {
1516                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1517                         cb(s,SSL_CB_WRITE_ALERT,j);
1518                         }
1519                 }
1520         return(i);
1521         }