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