ssl/d1_pkt.c

   1 /* ssl/d1_pkt.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <stdio.h>
 117 #include <errno.h>
 118 #define USE_SOCKETS
 119 #include "ssl_locl.h"
 120 #include <openssl/evp.h>
 121 #include <openssl/buffer.h>
 122 #include <openssl/pqueue.h>
 123
 124 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
 125 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
 126 {       int ret,sat,brw,i;
 127
 128         if (sizeof(long) == 8) do
 129         {       const union { long one; char little; } is_endian = {1};
 130                 long l;
 131
 132                 if (is_endian.little)                   break;
 133                 /* not reached on little-endians */
 134                 /* following test is redundant, because input is
 135                  * always aligned, but I take no chances... */
 136                 if (((size_t)v1|(size_t)v2)&0x7)        break;
 137
 138                 l  = *((long *)v1);
 139                 l -= *((long *)v2);
 140                 if (l>128)              return 128;
 141                 else if (l<-128)        return -128;
 142                 else                    return (int)l;
 143         } while (0);
 144
 145         ret = (int)v1[7]-(int)v2[7];
 146         sat = 0;
 147         brw = ret>>8;   /* brw is either 0 or -1 */
 148         if (ret & 0x80)
 149         {       for (i=6;i>=0;i--)
 150                 {       brw += (int)v1[i]-(int)v2[i];
 151                         sat |= ~brw;
 152                         brw >>= 8;
 153                 }
 154         }
 155         else
 156         {       for (i=6;i>=0;i--)
 157                 {       brw += (int)v1[i]-(int)v2[i];
 158                         sat |= brw;
 159                         brw >>= 8;
 160                 }
 161         }
 162         brw <<= 8;      /* brw is either 0 or -256 */
 163
 164         if (sat&0xff)   return brw | 0x80;
 165         else            return brw + (ret&0xFF);
 166 }
 167
 168 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
 169         int len, int peek);
 170 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
 171 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
 172 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
 173     unsigned int *is_next_epoch);
 174 #if 0
 175 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
 176         unsigned short *priority, unsigned long *offset);
 177 #endif
 178 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
 179         unsigned char *priority);
 180 static int dtls1_process_record(SSL *s);
 181 static void dtls1_clear_timeouts(SSL *s);
 182
 183 /* copy buffered record into SSL structure */
 184 static int
 185 dtls1_copy_record(SSL *s, pitem *item)
 186     {
 187     DTLS1_RECORD_DATA *rdata;
 188
 189     rdata = (DTLS1_RECORD_DATA *)item->data;
 190
 191     if (s->s3->rbuf.buf != NULL)
 192         OPENSSL_free(s->s3->rbuf.buf);
 193
 194     s->packet = rdata->packet;
 195     s->packet_length = rdata->packet_length;
 196     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 197     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 198
 199     return(1);
 200     }
 201
 202
 203 static int
 204 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 205         {
 206         DTLS1_RECORD_DATA *rdata;
 207         pitem *item;
 208
 209         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 210         item = pitem_new(priority, rdata);
 211         if (rdata == NULL || item == NULL)
 212                 {
 213                 if (rdata != NULL) OPENSSL_free(rdata);
 214                 if (item != NULL) pitem_free(item);
 215
 216                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 217                 return(0);
 218                 }
 219
 220         rdata->packet = s->packet;
 221         rdata->packet_length = s->packet_length;
 222         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 223         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 224
 225         item->data = rdata;
 226
 227         /* insert should not fail, since duplicates are dropped */
 228         if (pqueue_insert(queue->q, item) == NULL)
 229                 {
 230                 OPENSSL_free(rdata);
 231                 pitem_free(item);
 232                 return(0);
 233                 }
 234
 235         s->packet = NULL;
 236         s->packet_length = 0;
 237         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 238         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 239
 240         ssl3_setup_buffers(s);
 241
 242         return(1);
 243         }
 244
 245
 246 static int
 247 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 248     {
 249     pitem *item;
 250
 251     item = pqueue_pop(queue->q);
 252     if (item)
 253         {
 254         dtls1_copy_record(s, item);
 255
 256         OPENSSL_free(item->data);
 257                 pitem_free(item);
 258
 259         return(1);
 260         }
 261
 262     return(0);
 263     }
 264
 265
 266 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 267  * yet */
 268 #define dtls1_get_unprocessed_record(s) \
 269                    dtls1_retrieve_buffered_record((s), \
 270                    &((s)->d1->unprocessed_rcds))
 271
 272 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 273 #define dtls1_get_processed_record(s) \
 274                    dtls1_retrieve_buffered_record((s), \
 275                    &((s)->d1->processed_rcds))
 276
 277 static int
 278 dtls1_process_buffered_records(SSL *s)
 279     {
 280     pitem *item;
 281
 282     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 283     if (item)
 284         {
 285         DTLS1_RECORD_DATA *rdata;
 286         rdata = (DTLS1_RECORD_DATA *)item->data;
 287
 288         /* Check if epoch is current. */
 289         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 290             return(1);  /* Nothing to do. */
 291
 292         /* Process all the records. */
 293         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 294             {
 295             dtls1_get_unprocessed_record(s);
 296             if ( ! dtls1_process_record(s))
 297                 return(0);
 298             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 299                 s->s3->rrec.seq_num);
 300             }
 301         }
 302
 303     /* sync epoch numbers once all the unprocessed records
 304      * have been processed */
 305     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 306     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 307
 308     return(1);
 309     }
 310
 311
 312 #if 0
 313
 314 static int
 315 dtls1_get_buffered_record(SSL *s)
 316         {
 317         pitem *item;
 318         PQ_64BIT priority =
 319                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 320                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 321
 322         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 323                                                            nothing buffered */
 324                 return 0;
 325
 326
 327         item = pqueue_peek(s->d1->rcvd_records);
 328         if (item && item->priority == priority)
 329                 {
 330                 /* Check if we've received the record of interest.  It must be
 331                  * a handshake record, since data records as passed up without
 332                  * buffering */
 333                 DTLS1_RECORD_DATA *rdata;
 334                 item = pqueue_pop(s->d1->rcvd_records);
 335                 rdata = (DTLS1_RECORD_DATA *)item->data;
 336
 337                 if (s->s3->rbuf.buf != NULL)
 338                         OPENSSL_free(s->s3->rbuf.buf);
 339
 340                 s->packet = rdata->packet;
 341                 s->packet_length = rdata->packet_length;
 342                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 343                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 344
 345                 OPENSSL_free(item->data);
 346                 pitem_free(item);
 347
 348                 /* s->d1->next_expected_seq_num++; */
 349                 return(1);
 350                 }
 351
 352         return 0;
 353         }
 354
 355 #endif
 356
 357 static int
 358 dtls1_process_record(SSL *s)
 359 {
 360         int i,al;
 361         int clear=0;
 362         int enc_err;
 363         SSL_SESSION *sess;
 364         SSL3_RECORD *rr;
 365         unsigned int mac_size;
 366         unsigned char md[EVP_MAX_MD_SIZE];
 367
 368
 369         rr= &(s->s3->rrec);
 370         sess = s->session;
 371
 372         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 373          * and we have that many bytes in s->packet
 374          */
 375         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 376
 377         /* ok, we can now read from 's->packet' data into 'rr'
 378          * rr->input points at rr->length bytes, which
 379          * need to be copied into rr->data by either
 380          * the decryption or by the decompression
 381          * When the data is 'copied' into the rr->data buffer,
 382          * rr->input will be pointed at the new buffer */
 383
 384         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 385          * rr->length bytes of encrypted compressed stuff. */
 386
 387         /* check is not needed I believe */
 388         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 389                 {
 390                 al=SSL_AD_RECORD_OVERFLOW;
 391                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 392                 goto f_err;
 393                 }
 394
 395         /* decrypt in place in 'rr->input' */
 396         rr->data=rr->input;
 397
 398         enc_err = s->method->ssl3_enc->enc(s,0);
 399         if (enc_err <= 0)
 400                 {
 401                 if (enc_err == 0)
 402                         /* SSLerr() and ssl3_send_alert() have been called */
 403                         goto err;
 404
 405                 /* otherwise enc_err == -1 */
 406                 goto decryption_failed_or_bad_record_mac;
 407                 }
 408
 409 #ifdef TLS_DEBUG
 410 printf("dec %d\n",rr->length);
 411 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 412 printf("\n");
 413 #endif
 414
 415         /* r->length is now the compressed data plus mac */
 416         if (    (sess == NULL) ||
 417                 (s->enc_read_ctx == NULL) ||
 418                 (s->read_hash == NULL))
 419         clear=1;
 420
 421         if (!clear)
 422                 {
 423                 mac_size=EVP_MD_size(s->read_hash);
 424
 425                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 426                         {
 427 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 428                         al=SSL_AD_RECORD_OVERFLOW;
 429                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 430                         goto f_err;
 431 #else
 432                         goto decryption_failed_or_bad_record_mac;
 433 #endif
 434                         }
 435                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 436                 if (rr->length < mac_size)
 437                         {
 438 #if 0 /* OK only for stream ciphers */
 439                         al=SSL_AD_DECODE_ERROR;
 440                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 441                         goto f_err;
 442 #else
 443                         goto decryption_failed_or_bad_record_mac;
 444 #endif
 445                         }
 446                 rr->length-=mac_size;
 447                 i=s->method->ssl3_enc->mac(s,md,0);
 448                 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 449                         {
 450                         goto decryption_failed_or_bad_record_mac;
 451                         }
 452                 }
 453
 454         /* r->length is now just compressed */
 455         if (s->expand != NULL)
 456                 {
 457                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 458                         {
 459                         al=SSL_AD_RECORD_OVERFLOW;
 460                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 461                         goto f_err;
 462                         }
 463                 if (!ssl3_do_uncompress(s))
 464                         {
 465                         al=SSL_AD_DECOMPRESSION_FAILURE;
 466                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 467                         goto f_err;
 468                         }
 469                 }
 470
 471         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 472                 {
 473                 al=SSL_AD_RECORD_OVERFLOW;
 474                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 475                 goto f_err;
 476                 }
 477
 478         rr->off=0;
 479         /* So at this point the following is true
 480          * ssl->s3->rrec.type   is the type of record
 481          * ssl->s3->rrec.length == number of bytes in record
 482          * ssl->s3->rrec.off    == offset to first valid byte
 483          * ssl->s3->rrec.data   == where to take bytes from, increment
 484          *                         after use :-).
 485          */
 486
 487         /* we have pulled in a full packet so zero things */
 488         s->packet_length=0;
 489         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 490         return(1);
 491
 492 decryption_failed_or_bad_record_mac:
 493         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
 494          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 495          * failure is directly visible from the ciphertext anyway,
 496          * we should not reveal which kind of error occured -- this
 497          * might become visible to an attacker (e.g. via logfile) */
 498         al=SSL_AD_BAD_RECORD_MAC;
 499         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 500 f_err:
 501         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 502 err:
 503         return(0);
 504 }
 505
 506
 507 /* Call this to get a new input record.
 508  * It will return <= 0 if more data is needed, normally due to an error
 509  * or non-blocking IO.
 510  * When it finishes, one packet has been decoded and can be found in
 511  * ssl->s3->rrec.type    - is the type of record
 512  * ssl->s3->rrec.data,   - data
 513  * ssl->s3->rrec.length, - number of bytes
 514  */
 515 /* used only by dtls1_read_bytes */
 516 int dtls1_get_record(SSL *s)
 517         {
 518         int ssl_major,ssl_minor,al;
 519         int i,n;
 520         SSL3_RECORD *rr;
 521         SSL_SESSION *sess;
 522         unsigned char *p;
 523         short version;
 524         DTLS1_BITMAP *bitmap;
 525         unsigned int is_next_epoch;
 526
 527         rr= &(s->s3->rrec);
 528         sess=s->session;
 529
 530         /* The epoch may have changed.  If so, process all the
 531          * pending records.  This is a non-blocking operation. */
 532         if ( ! dtls1_process_buffered_records(s))
 533             return 0;
 534
 535         /* if we're renegotiating, then there may be buffered records */
 536         if (dtls1_get_processed_record(s))
 537                 return 1;
 538
 539         /* get something from the wire */
 540 again:
 541         /* check if we have the header */
 542         if (    (s->rstate != SSL_ST_READ_BODY) ||
 543                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 544                 {
 545                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 546                 /* read timeout is handled by dtls1_read_bytes */
 547                 if (n <= 0) return(n); /* error or non-blocking */
 548
 549                 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
 550
 551                 s->rstate=SSL_ST_READ_BODY;
 552
 553                 p=s->packet;
 554
 555                 /* Pull apart the header into the DTLS1_RECORD */
 556                 rr->type= *(p++);
 557                 ssl_major= *(p++);
 558                 ssl_minor= *(p++);
 559                 version=(ssl_major<<8)|ssl_minor;
 560
 561                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 562                 n2s(p,rr->epoch);
 563
 564                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 565                 p+=6;
 566
 567                 n2s(p,rr->length);
 568
 569                 /* Lets check version */
 570                 if (s->first_packet)
 571                         {
 572                         s->first_packet=0;
 573                         }
 574                 else
 575                         {
 576                         if (version != s->version)
 577                                 {
 578                                 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 579                                 /* Send back error using their
 580                                  * version number :-) */
 581                                 s->version=version;
 582                                 al=SSL_AD_PROTOCOL_VERSION;
 583                                 goto f_err;
 584                                 }
 585                         }
 586
 587                 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00))
 588                         {
 589                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 590                         goto err;
 591                         }
 592
 593                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 594                         {
 595                         al=SSL_AD_RECORD_OVERFLOW;
 596                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 597                         goto f_err;
 598                         }
 599
 600                 /* now s->rstate == SSL_ST_READ_BODY */
 601                 }
 602
 603         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 604
 605         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 606                 {
 607                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 608                 i=rr->length;
 609                 n=ssl3_read_n(s,i,i,1);
 610                 if (n <= 0) return(n); /* error or non-blocking io */
 611
 612                 /* this packet contained a partial record, dump it */
 613                 if ( n != i)
 614                         {
 615                         s->packet_length = 0;
 616                         goto again;
 617                         }
 618
 619                 /* now n == rr->length,
 620                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 621                 }
 622         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 623
 624         /* match epochs.  NULL means the packet is dropped on the floor */
 625         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 626         if ( bitmap == NULL)
 627                 {
 628                 s->packet_length = 0;  /* dump this record */
 629                 goto again;   /* get another record */
 630                 }
 631
 632         /* check whether this is a repeat, or aged record */
 633         if ( ! dtls1_record_replay_check(s, bitmap))
 634                 {
 635                 s->packet_length=0; /* dump this record */
 636                 goto again;     /* get another record */
 637                 }
 638
 639         /* just read a 0 length packet */
 640         if (rr->length == 0) goto again;
 641
 642         /* If this record is from the next epoch (either HM or ALERT),
 643          * buffer it since it cannot be processed at this time. Records
 644          * from the next epoch are marked as received even though they
 645          * are not processed, so as to prevent any potential resource
 646          * DoS attack */
 647         if (is_next_epoch)
 648                 {
 649                 dtls1_record_bitmap_update(s, bitmap);
 650                 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 651                 s->packet_length = 0;
 652                 goto again;
 653                 }
 654
 655         if ( ! dtls1_process_record(s))
 656                 return(0);
 657
 658         dtls1_clear_timeouts(s);  /* done waiting */
 659         return(1);
 660
 661 f_err:
 662         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 663 err:
 664         return(0);
 665         }
 666
 667 /* Return up to 'len' payload bytes received in 'type' records.
 668  * 'type' is one of the following:
 669  *
 670  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 671  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 672  *   -  0 (during a shutdown, no data has to be returned)
 673  *
 674  * If we don't have stored data to work from, read a SSL/TLS record first
 675  * (possibly multiple records if we still don't have anything to return).
 676  *
 677  * This function must handle any surprises the peer may have for us, such as
 678  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 679  * a surprise, but handled as if it were), or renegotiation requests.
 680  * Also if record payloads contain fragments too small to process, we store
 681  * them until there is enough for the respective protocol (the record protocol
 682  * may use arbitrary fragmentation and even interleaving):
 683  *     Change cipher spec protocol
 684  *             just 1 byte needed, no need for keeping anything stored
 685  *     Alert protocol
 686  *             2 bytes needed (AlertLevel, AlertDescription)
 687  *     Handshake protocol
 688  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 689  *             to detect unexpected Client Hello and Hello Request messages
 690  *             here, anything else is handled by higher layers
 691  *     Application data protocol
 692  *             none of our business
 693  */
 694 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 695         {
 696         int al,i,j,ret;
 697         unsigned int n;
 698         SSL3_RECORD *rr;
 699         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 700
 701         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 702                 if (!ssl3_setup_buffers(s))
 703                         return(-1);
 704
 705     /* XXX: check what the second '&& type' is about */
 706         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 707                 (type != SSL3_RT_HANDSHAKE) && type) ||
 708             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 709                 {
 710                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 711                 return -1;
 712                 }
 713
 714         /* check whether there's a handshake message (client hello?) waiting */
 715         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 716                 return ret;
 717
 718         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 719
 720         if (!s->in_handshake && SSL_in_init(s))
 721                 {
 722                 /* type == SSL3_RT_APPLICATION_DATA */
 723                 i=s->handshake_func(s);
 724                 if (i < 0) return(i);
 725                 if (i == 0)
 726                         {
 727                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 728                         return(-1);
 729                         }
 730                 }
 731
 732 start:
 733         s->rwstate=SSL_NOTHING;
 734
 735         /* s->s3->rrec.type         - is the type of record
 736          * s->s3->rrec.data,    - data
 737          * s->s3->rrec.off,     - offset into 'data' for next read
 738          * s->s3->rrec.length,  - number of bytes. */
 739         rr = &(s->s3->rrec);
 740
 741         /* get new packet if necessary */
 742         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 743                 {
 744                 ret=dtls1_get_record(s);
 745                 if (ret <= 0)
 746                         {
 747                         ret = dtls1_read_failed(s, ret);
 748                         /* anything other than a timeout is an error */
 749                         if (ret <= 0)
 750                                 return(ret);
 751                         else
 752                                 goto start;
 753                         }
 754                 }
 755
 756         /* we now have a packet which can be read and processed */
 757
 758         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 759                                        * reset by ssl3_get_finished */
 760                 && (rr->type != SSL3_RT_HANDSHAKE))
 761                 {
 762                 al=SSL_AD_UNEXPECTED_MESSAGE;
 763                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
 764                 goto err;
 765                 }
 766
 767         /* If the other end has shut down, throw anything we read away
 768          * (even in 'peek' mode) */
 769         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 770                 {
 771                 rr->length=0;
 772                 s->rwstate=SSL_NOTHING;
 773                 return(0);
 774                 }
 775
 776
 777         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 778                 {
 779                 /* make sure that we are not getting application data when we
 780                  * are doing a handshake for the first time */
 781                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 782                         (s->enc_read_ctx == NULL))
 783                         {
 784                         al=SSL_AD_UNEXPECTED_MESSAGE;
 785                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 786                         goto f_err;
 787                         }
 788
 789                 if (len <= 0) return(len);
 790
 791                 if ((unsigned int)len > rr->length)
 792                         n = rr->length;
 793                 else
 794                         n = (unsigned int)len;
 795
 796                 memcpy(buf,&(rr->data[rr->off]),n);
 797                 if (!peek)
 798                         {
 799                         rr->length-=n;
 800                         rr->off+=n;
 801                         if (rr->length == 0)
 802                                 {
 803                                 s->rstate=SSL_ST_READ_HEADER;
 804                                 rr->off=0;
 805                                 }
 806                         }
 807                 return(n);
 808                 }
 809
 810
 811         /* If we get here, then type != rr->type; if we have a handshake
 812          * message, then it was unexpected (Hello Request or Client Hello). */
 813
 814         /* In case of record types for which we have 'fragment' storage,
 815          * fill that so that we can process the data at a fixed place.
 816          */
 817                 {
 818                 unsigned int k, dest_maxlen = 0;
 819                 unsigned char *dest = NULL;
 820                 unsigned int *dest_len = NULL;
 821
 822                 if (rr->type == SSL3_RT_HANDSHAKE)
 823                         {
 824                         dest_maxlen = sizeof s->d1->handshake_fragment;
 825                         dest = s->d1->handshake_fragment;
 826                         dest_len = &s->d1->handshake_fragment_len;
 827                         }
 828                 else if (rr->type == SSL3_RT_ALERT)
 829                         {
 830                         dest_maxlen = sizeof(s->d1->alert_fragment);
 831                         dest = s->d1->alert_fragment;
 832                         dest_len = &s->d1->alert_fragment_len;
 833                         }
 834                 else    /* else it's a CCS message */
 835                         OPENSSL_assert(rr->type == SSL3_RT_CHANGE_CIPHER_SPEC);
 836
 837
 838                 if (dest_maxlen > 0)
 839                         {
 840             /* XDTLS:  In a pathalogical case, the Client Hello
 841              *  may be fragmented--don't always expect dest_maxlen bytes */
 842                         if ( rr->length < dest_maxlen)
 843                                 {
 844                                 s->rstate=SSL_ST_READ_HEADER;
 845                                 rr->length = 0;
 846                                 goto start;
 847                                 }
 848
 849                         /* now move 'n' bytes: */
 850                         for ( k = 0; k < dest_maxlen; k++)
 851                                 {
 852                                 dest[k] = rr->data[rr->off++];
 853                                 rr->length--;
 854                                 }
 855                         *dest_len = dest_maxlen;
 856                         }
 857                 }
 858
 859         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 860          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 861          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 862
 863         /* If we are a client, check for an incoming 'Hello Request': */
 864         if ((!s->server) &&
 865                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 866                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 867                 (s->session != NULL) && (s->session->cipher != NULL))
 868                 {
 869                 s->d1->handshake_fragment_len = 0;
 870
 871                 if ((s->d1->handshake_fragment[1] != 0) ||
 872                         (s->d1->handshake_fragment[2] != 0) ||
 873                         (s->d1->handshake_fragment[3] != 0))
 874                         {
 875                         al=SSL_AD_DECODE_ERROR;
 876                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 877                         goto err;
 878                         }
 879
 880                 /* no need to check sequence number on HELLO REQUEST messages */
 881
 882                 if (s->msg_callback)
 883                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 884                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 885
 886                 if (SSL_is_init_finished(s) &&
 887                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 888                         !s->s3->renegotiate)
 889                         {
 890                         ssl3_renegotiate(s);
 891                         if (ssl3_renegotiate_check(s))
 892                                 {
 893                                 i=s->handshake_func(s);
 894                                 if (i < 0) return(i);
 895                                 if (i == 0)
 896                                         {
 897                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 898                                         return(-1);
 899                                         }
 900
 901                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 902                                         {
 903                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 904                                                 {
 905                                                 BIO *bio;
 906                                                 /* In the case where we try to read application data,
 907                                                  * but we trigger an SSL handshake, we return -1 with
 908                                                  * the retry option set.  Otherwise renegotiation may
 909                                                  * cause nasty problems in the blocking world */
 910                                                 s->rwstate=SSL_READING;
 911                                                 bio=SSL_get_rbio(s);
 912                                                 BIO_clear_retry_flags(bio);
 913                                                 BIO_set_retry_read(bio);
 914                                                 return(-1);
 915                                                 }
 916                                         }
 917                                 }
 918                         }
 919                 /* we either finished a handshake or ignored the request,
 920                  * now try again to obtain the (application) data we were asked for */
 921                 goto start;
 922                 }
 923
 924         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
 925                 {
 926                 int alert_level = s->d1->alert_fragment[0];
 927                 int alert_descr = s->d1->alert_fragment[1];
 928
 929                 s->d1->alert_fragment_len = 0;
 930
 931                 if (s->msg_callback)
 932                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
 933                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
 934
 935                 if (s->info_callback != NULL)
 936                         cb=s->info_callback;
 937                 else if (s->ctx->info_callback != NULL)
 938                         cb=s->ctx->info_callback;
 939
 940                 if (cb != NULL)
 941                         {
 942                         j = (alert_level << 8) | alert_descr;
 943                         cb(s, SSL_CB_READ_ALERT, j);
 944                         }
 945
 946                 if (alert_level == 1) /* warning */
 947                         {
 948                         s->s3->warn_alert = alert_descr;
 949                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
 950                                 {
 951                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 952                                 return(0);
 953                                 }
 954 #if 0
 955             /* XXX: this is a possible improvement in the future */
 956                         /* now check if it's a missing record */
 957                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
 958                                 {
 959                                 unsigned short seq;
 960                                 unsigned int frag_off;
 961                                 unsigned char *p = &(s->d1->alert_fragment[2]);
 962
 963                                 n2s(p, seq);
 964                                 n2l3(p, frag_off);
 965
 966                                 dtls1_retransmit_message(s, seq, frag_off, &found);
 967                                 if ( ! found  && SSL_in_init(s))
 968                                         {
 969                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
 970                                         /* requested a message not yet sent,
 971                                            send an alert ourselves */
 972                                         ssl3_send_alert(s,SSL3_AL_WARNING,
 973                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 974                                         }
 975                                 }
 976 #endif
 977                         }
 978                 else if (alert_level == 2) /* fatal */
 979                         {
 980                         char tmp[16];
 981
 982                         s->rwstate=SSL_NOTHING;
 983                         s->s3->fatal_alert = alert_descr;
 984                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
 985                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
 986                         ERR_add_error_data(2,"SSL alert number ",tmp);
 987                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
 988                         SSL_CTX_remove_session(s->ctx,s->session);
 989                         return(0);
 990                         }
 991                 else
 992                         {
 993                         al=SSL_AD_ILLEGAL_PARAMETER;
 994                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
 995                         goto f_err;
 996                         }
 997
 998                 goto start;
 999                 }
1000
1001         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1002                 {
1003                 s->rwstate=SSL_NOTHING;
1004                 rr->length=0;
1005                 return(0);
1006                 }
1007
1008         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1009         {
1010         struct ccs_header_st ccs_hdr;
1011
1012                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1013
1014                 if ( ccs_hdr.seq == s->d1->handshake_read_seq)
1015                         {
1016                         /* 'Change Cipher Spec' is just a single byte, so we know
1017                          * exactly what the record payload has to look like */
1018                         /* XDTLS: check that epoch is consistent */
1019                         if (    (rr->length != DTLS1_CCS_HEADER_LENGTH) ||
1020                                 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1021                                 {
1022                                 i=SSL_AD_ILLEGAL_PARAMETER;
1023                                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1024                                 goto err;
1025                                 }
1026
1027                         rr->length=0;
1028
1029                         if (s->msg_callback)
1030                                 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1031                                         rr->data, 1, s, s->msg_callback_arg);
1032
1033                         s->s3->change_cipher_spec=1;
1034                         if (!ssl3_do_change_cipher_spec(s))
1035                                 goto err;
1036
1037                         /* do this whenever CCS is processed */
1038                         dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1039
1040                         /* handshake read seq is reset upon handshake completion */
1041                         s->d1->handshake_read_seq++;
1042
1043                         goto start;
1044                         }
1045                 else
1046                         {
1047                         rr->length = 0;
1048                         goto start;
1049                         }
1050                 }
1051
1052         /* Unexpected handshake message (Client Hello, or protocol violation) */
1053         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1054                 !s->in_handshake)
1055                 {
1056                 struct hm_header_st msg_hdr;
1057
1058                 /* this may just be a stale retransmit */
1059                 dtls1_get_message_header(rr->data, &msg_hdr);
1060                 if( rr->epoch != s->d1->r_epoch)
1061                         {
1062                         rr->length = 0;
1063                         goto start;
1064                         }
1065
1066                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1067                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1068                         {
1069 #if 0 /* worked only because C operator preferences are not as expected (and
1070        * because this is not really needed for clients except for detecting
1071        * protocol violations): */
1072                         s->state=SSL_ST_BEFORE|(s->server)
1073                                 ?SSL_ST_ACCEPT
1074                                 :SSL_ST_CONNECT;
1075 #else
1076                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1077 #endif
1078                         s->new_session=1;
1079                         }
1080                 i=s->handshake_func(s);
1081                 if (i < 0) return(i);
1082                 if (i == 0)
1083                         {
1084                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1085                         return(-1);
1086                         }
1087
1088                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1089                         {
1090                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1091                                 {
1092                                 BIO *bio;
1093                                 /* In the case where we try to read application data,
1094                                  * but we trigger an SSL handshake, we return -1 with
1095                                  * the retry option set.  Otherwise renegotiation may
1096                                  * cause nasty problems in the blocking world */
1097                                 s->rwstate=SSL_READING;
1098                                 bio=SSL_get_rbio(s);
1099                                 BIO_clear_retry_flags(bio);
1100                                 BIO_set_retry_read(bio);
1101                                 return(-1);
1102                                 }
1103                         }
1104                 goto start;
1105                 }
1106
1107         switch (rr->type)
1108                 {
1109         default:
1110 #ifndef OPENSSL_NO_TLS
1111                 /* TLS just ignores unknown message types */
1112                 if (s->version == TLS1_VERSION)
1113                         {
1114                         rr->length = 0;
1115                         goto start;
1116                         }
1117 #endif
1118                 al=SSL_AD_UNEXPECTED_MESSAGE;
1119                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1120                 goto f_err;
1121         case SSL3_RT_CHANGE_CIPHER_SPEC:
1122         case SSL3_RT_ALERT:
1123         case SSL3_RT_HANDSHAKE:
1124                 /* we already handled all of these, with the possible exception
1125                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1126                  * should not happen when type != rr->type */
1127                 al=SSL_AD_UNEXPECTED_MESSAGE;
1128                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1129                 goto f_err;
1130         case SSL3_RT_APPLICATION_DATA:
1131                 /* At this point, we were expecting handshake data,
1132                  * but have application data.  If the library was
1133                  * running inside ssl3_read() (i.e. in_read_app_data
1134                  * is set) and it makes sense to read application data
1135                  * at this point (session renegotiation not yet started),
1136                  * we will indulge it.
1137                  */
1138                 if (s->s3->in_read_app_data &&
1139                         (s->s3->total_renegotiations != 0) &&
1140                         ((
1141                                 (s->state & SSL_ST_CONNECT) &&
1142                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1143                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1144                                 ) || (
1145                                         (s->state & SSL_ST_ACCEPT) &&
1146                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1147                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1148                                         )
1149                                 ))
1150                         {
1151                         s->s3->in_read_app_data=2;
1152                         return(-1);
1153                         }
1154                 else
1155                         {
1156                         al=SSL_AD_UNEXPECTED_MESSAGE;
1157                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1158                         goto f_err;
1159                         }
1160                 }
1161         /* not reached */
1162
1163 f_err:
1164         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1165 err:
1166         return(-1);
1167         }
1168
1169 int
1170 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1171         {
1172         unsigned int n,tot;
1173         int i;
1174
1175         if (SSL_in_init(s) && !s->in_handshake)
1176                 {
1177                 i=s->handshake_func(s);
1178                 if (i < 0) return(i);
1179                 if (i == 0)
1180                         {
1181                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1182                         return -1;
1183                         }
1184                 }
1185
1186         tot = s->s3->wnum;
1187         n = len - tot;
1188
1189         while( n)
1190                 {
1191                 /* dtls1_write_bytes sends one record at a time, sized according to
1192                  * the currently known MTU */
1193                 i = dtls1_write_bytes(s, type, buf_, len);
1194                 if (i <= 0) return i;
1195
1196                 if ((i == (int)n) ||
1197                         (type == SSL3_RT_APPLICATION_DATA &&
1198                                 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1199                         {
1200                         /* next chunk of data should get another prepended empty fragment
1201                          * in ciphersuites with known-IV weakness: */
1202                         s->s3->empty_fragment_done = 0;
1203                         return tot+i;
1204                         }
1205
1206                 tot += i;
1207                 n-=i;
1208                 }
1209
1210         return tot;
1211         }
1212
1213
1214         /* this only happens when a client hello is received and a handshake
1215          * is started. */
1216 static int
1217 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1218         int len, int peek)
1219         {
1220
1221         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1222                 /* (partially) satisfy request from storage */
1223                 {
1224                 unsigned char *src = s->d1->handshake_fragment;
1225                 unsigned char *dst = buf;
1226                 unsigned int k,n;
1227
1228                 /* peek == 0 */
1229                 n = 0;
1230                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1231                         {
1232                         *dst++ = *src++;
1233                         len--; s->d1->handshake_fragment_len--;
1234                         n++;
1235                         }
1236                 /* move any remaining fragment bytes: */
1237                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1238                         s->d1->handshake_fragment[k] = *src++;
1239                 return n;
1240                 }
1241
1242         return 0;
1243         }
1244
1245
1246
1247
1248 /* Call this to write data in records of type 'type'
1249  * It will return <= 0 if not all data has been sent or non-blocking IO.
1250  */
1251 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1252         {
1253         const unsigned char *buf=buf_;
1254         unsigned int tot,n,nw;
1255         int i;
1256         unsigned int mtu;
1257
1258         s->rwstate=SSL_NOTHING;
1259         tot=s->s3->wnum;
1260
1261         n=(len-tot);
1262
1263         /* handshake layer figures out MTU for itself, but data records
1264          * are also sent through this interface, so need to figure out MTU */
1265 #if 0
1266         mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1267         mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
1268 #endif
1269         mtu = s->d1->mtu;
1270
1271         if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1272                 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1273
1274         if (n > mtu)
1275                 nw=mtu;
1276         else
1277                 nw=n;
1278
1279         i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1280         if (i <= 0)
1281                 {
1282                 s->s3->wnum=tot;
1283                 return i;
1284                 }
1285
1286         if ( (int)s->s3->wnum + i == len)
1287                 s->s3->wnum = 0;
1288         else
1289                 s->s3->wnum += i;
1290
1291         return tot + i;
1292         }
1293
1294 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1295         {
1296         unsigned char *p,*pseq;
1297         int i,mac_size,clear=0;
1298         int prefix_len = 0;
1299         SSL3_RECORD *wr;
1300         SSL3_BUFFER *wb;
1301         SSL_SESSION *sess;
1302         int bs;
1303
1304         /* first check if there is a SSL3_BUFFER still being written
1305          * out.  This will happen with non blocking IO */
1306         if (s->s3->wbuf.left != 0)
1307                 {
1308                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1309                 return(ssl3_write_pending(s,type,buf,len));
1310                 }
1311
1312         /* If we have an alert to send, lets send it */
1313         if (s->s3->alert_dispatch)
1314                 {
1315                 i=s->method->ssl_dispatch_alert(s);
1316                 if (i <= 0)
1317                         return(i);
1318                 /* if it went, fall through and send more stuff */
1319                 }
1320
1321         if (len == 0 && !create_empty_fragment)
1322                 return 0;
1323
1324         wr= &(s->s3->wrec);
1325         wb= &(s->s3->wbuf);
1326         sess=s->session;
1327
1328         if (    (sess == NULL) ||
1329                 (s->enc_write_ctx == NULL) ||
1330                 (s->write_hash == NULL))
1331                 clear=1;
1332
1333         if (clear)
1334                 mac_size=0;
1335         else
1336                 mac_size=EVP_MD_size(s->write_hash);
1337
1338         /* DTLS implements explicit IV, so no need for empty fragments */
1339 #if 0
1340         /* 'create_empty_fragment' is true only when this function calls itself */
1341         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1342                 && SSL_version(s) != DTLS1_VERSION)
1343                 {
1344                 /* countermeasure against known-IV weakness in CBC ciphersuites
1345                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1346                  */
1347
1348                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1349                         {
1350                         /* recursive function call with 'create_empty_fragment' set;
1351                          * this prepares and buffers the data for an empty fragment
1352                          * (these 'prefix_len' bytes are sent out later
1353                          * together with the actual payload) */
1354                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1355                         if (prefix_len <= 0)
1356                                 goto err;
1357
1358                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1359                                 {
1360                                 /* insufficient space */
1361                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1362                                 goto err;
1363                                 }
1364                         }
1365
1366                 s->s3->empty_fragment_done = 1;
1367                 }
1368 #endif
1369
1370         p = wb->buf + prefix_len;
1371
1372         /* write the header */
1373
1374         *(p++)=type&0xff;
1375         wr->type=type;
1376
1377         *(p++)=(s->version>>8);
1378         *(p++)=s->version&0xff;
1379
1380         /* field where we are to write out packet epoch, seq num and len */
1381         pseq=p;
1382         p+=10;
1383
1384         /* lets setup the record stuff. */
1385
1386         /* Make space for the explicit IV in case of CBC.
1387          * (this is a bit of a boundary violation, but what the heck).
1388          */
1389         if ( s->enc_write_ctx &&
1390                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1391                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1392         else
1393                 bs = 0;
1394
1395         wr->data=p + bs;  /* make room for IV in case of CBC */
1396         wr->length=(int)len;
1397         wr->input=(unsigned char *)buf;
1398
1399         /* we now 'read' from wr->input, wr->length bytes into
1400          * wr->data */
1401
1402         /* first we compress */
1403         if (s->compress != NULL)
1404                 {
1405                 if (!ssl3_do_compress(s))
1406                         {
1407                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1408                         goto err;
1409                         }
1410                 }
1411         else
1412                 {
1413                 memcpy(wr->data,wr->input,wr->length);
1414                 wr->input=wr->data;
1415                 }
1416
1417         /* we should still have the output to wr->data and the input
1418          * from wr->input.  Length should be wr->length.
1419          * wr->data still points in the wb->buf */
1420
1421         if (mac_size != 0)
1422                 {
1423                 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1424                 wr->length+=mac_size;
1425                 }
1426
1427         /* this is true regardless of mac size */
1428         wr->input=p;
1429         wr->data=p;
1430
1431
1432         /* ssl3_enc can only have an error on read */
1433         wr->length += bs;  /* bs != 0 in case of CBC.  The enc fn provides
1434                                                 * the randomness */
1435         s->method->ssl3_enc->enc(s,1);
1436
1437         /* record length after mac and block padding */
1438 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1439         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1440
1441         /* there's only one epoch between handshake and app data */
1442
1443         s2n(s->d1->w_epoch, pseq);
1444
1445         /* XDTLS: ?? */
1446 /*      else
1447         s2n(s->d1->handshake_epoch, pseq); */
1448
1449         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1450         pseq+=6;
1451         s2n(wr->length,pseq);
1452
1453         /* we should now have
1454          * wr->data pointing to the encrypted data, which is
1455          * wr->length long */
1456         wr->type=type; /* not needed but helps for debugging */
1457         wr->length+=DTLS1_RT_HEADER_LENGTH;
1458
1459 #if 0  /* this is now done at the message layer */
1460         /* buffer the record, making it easy to handle retransmits */
1461         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1462                 dtls1_buffer_record(s, wr->data, wr->length,
1463                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1464 #endif
1465
1466         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1467
1468         if (create_empty_fragment)
1469                 {
1470                 /* we are in a recursive call;
1471                  * just return the length, don't write out anything here
1472                  */
1473                 return wr->length;
1474                 }
1475
1476         /* now let's set up wb */
1477         wb->left = prefix_len + wr->length;
1478         wb->offset = 0;
1479
1480         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1481         s->s3->wpend_tot=len;
1482         s->s3->wpend_buf=buf;
1483         s->s3->wpend_type=type;
1484         s->s3->wpend_ret=len;
1485
1486         /* we now just need to write the buffer */
1487         return ssl3_write_pending(s,type,buf,len);
1488 err:
1489         return -1;
1490         }
1491
1492
1493
1494 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1495         {
1496         int cmp;
1497         unsigned int shift;
1498         const unsigned char *seq = s->s3->read_sequence;
1499
1500         cmp = satsub64be(seq,bitmap->max_seq_num);
1501         if (cmp > 0)
1502                 {
1503                 memcpy (s->s3->rrec.seq_num,seq,8);
1504                 return 1; /* this record in new */
1505                 }
1506         shift = -cmp;
1507         if (shift >= sizeof(bitmap->map)*8)
1508                 return 0; /* stale, outside the window */
1509         else if (bitmap->map & (1UL<<shift))
1510                 return 0; /* record previously received */
1511
1512         memcpy (s->s3->rrec.seq_num,seq,8);
1513         return 1;
1514         }
1515
1516
1517 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1518         {
1519         int cmp;
1520         unsigned int shift;
1521         const unsigned char *seq = s->s3->read_sequence;
1522
1523         cmp = satsub64be(seq,bitmap->max_seq_num);
1524         if (cmp > 0)
1525                 {
1526                 shift = cmp;
1527                 if (shift < sizeof(bitmap->map)*8)
1528                         bitmap->map <<= shift, bitmap->map |= 1UL;
1529                 else
1530                         bitmap->map = 1UL;
1531                 memcpy(bitmap->max_seq_num,seq,8);
1532                 }
1533         else    {
1534                 shift = -cmp;
1535                 if (shift < sizeof(bitmap->map)*8)
1536                         bitmap->map |= 1UL<<shift;
1537                 }
1538         }
1539
1540
1541 int dtls1_dispatch_alert(SSL *s)
1542         {
1543         int i,j;
1544         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1545         unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */
1546         unsigned char *ptr = &buf[0];
1547
1548         s->s3->alert_dispatch=0;
1549
1550         memset(buf, 0x00, sizeof(buf));
1551         *ptr++ = s->s3->send_alert[0];
1552         *ptr++ = s->s3->send_alert[1];
1553
1554         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1555                 {
1556                 s2n(s->d1->handshake_read_seq, ptr);
1557 #if 0
1558                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1559
1560                 else
1561                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1562 #endif
1563
1564 #if 0
1565                 fprintf(stderr, "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n",s->d1->handshake_read_seq,s->d1->r_msg_hdr.seq);
1566 #endif
1567                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1568                 }
1569
1570         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1571         if (i <= 0)
1572                 {
1573                 s->s3->alert_dispatch=1;
1574                 /* fprintf( stderr, "not done with alert\n" ); */
1575                 }
1576         else
1577                 {
1578                 if ( s->s3->send_alert[0] == SSL3_AL_FATAL ||
1579                         s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1580                         (void)BIO_flush(s->wbio);
1581
1582                 if (s->msg_callback)
1583                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1584                                 2, s, s->msg_callback_arg);
1585
1586                 if (s->info_callback != NULL)
1587                         cb=s->info_callback;
1588                 else if (s->ctx->info_callback != NULL)
1589                         cb=s->ctx->info_callback;
1590
1591                 if (cb != NULL)
1592                         {
1593                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1594                         cb(s,SSL_CB_WRITE_ALERT,j);
1595                         }
1596                 }
1597         return(i);
1598         }
1599
1600
1601 static DTLS1_BITMAP *
1602 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1603     {
1604
1605     *is_next_epoch = 0;
1606
1607     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1608     if (rr->epoch == s->d1->r_epoch)
1609         return &s->d1->bitmap;
1610
1611     /* Only HM and ALERT messages can be from the next epoch */
1612     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1613         (rr->type == SSL3_RT_HANDSHAKE ||
1614             rr->type == SSL3_RT_ALERT))
1615         {
1616         *is_next_epoch = 1;
1617         return &s->d1->next_bitmap;
1618         }
1619
1620     return NULL;
1621     }
1622
1623 #if 0
1624 static int
1625 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1626         unsigned long *offset)
1627         {
1628
1629         /* alerts are passed up immediately */
1630         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1631                 rr->type == SSL3_RT_ALERT)
1632                 return 0;
1633
1634         /* Only need to buffer if a handshake is underway.
1635          * (this implies that Hello Request and Client Hello are passed up
1636          * immediately) */
1637         if ( SSL_in_init(s))
1638                 {
1639                 unsigned char *data = rr->data;
1640                 /* need to extract the HM/CCS sequence number here */
1641                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1642                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1643                         {
1644                         unsigned short seq_num;
1645                         struct hm_header_st msg_hdr;
1646                         struct ccs_header_st ccs_hdr;
1647
1648                         if ( rr->type == SSL3_RT_HANDSHAKE)
1649                                 {
1650                                 dtls1_get_message_header(data, &msg_hdr);
1651                                 seq_num = msg_hdr.seq;
1652                                 *offset = msg_hdr.frag_off;
1653                                 }
1654                         else
1655                                 {
1656                                 dtls1_get_ccs_header(data, &ccs_hdr);
1657                                 seq_num = ccs_hdr.seq;
1658                                 *offset = 0;
1659                                 }
1660
1661                         /* this is either a record we're waiting for, or a
1662                          * retransmit of something we happened to previously
1663                          * receive (higher layers will drop the repeat silently */
1664                         if ( seq_num < s->d1->handshake_read_seq)
1665                                 return 0;
1666                         if (rr->type == SSL3_RT_HANDSHAKE &&
1667                                 seq_num == s->d1->handshake_read_seq &&
1668                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1669                                 return 0;
1670                         else if ( seq_num == s->d1->handshake_read_seq &&
1671                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1672                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1673                                 return 0;
1674                         else
1675                                 {
1676                                 *priority = seq_num;
1677                                 return 1;
1678                                 }
1679                         }
1680                 else /* unknown record type */
1681                         return 0;
1682                 }
1683
1684         return 0;
1685         }
1686 #endif
1687
1688 void
1689 dtls1_reset_seq_numbers(SSL *s, int rw)
1690         {
1691         unsigned char *seq;
1692         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1693
1694         if ( rw & SSL3_CC_READ)
1695                 {
1696                 seq = s->s3->read_sequence;
1697                 s->d1->r_epoch++;
1698                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1699                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1700                 }
1701         else
1702                 {
1703                 seq = s->s3->write_sequence;
1704                 s->d1->w_epoch++;
1705                 }
1706
1707         memset(seq, 0x00, seq_bytes);
1708         }
1709
1710
1711 static void
1712 dtls1_clear_timeouts(SSL *s)
1713         {
1714         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1715         }