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         if (!ssl3_setup_buffers(s))
 241                 {
 242                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 243                 OPENSSL_free(rdata);
 244                 pitem_free(item);
 245                 return(0);
 246                 }
 247
 248         return(1);
 249         }
 250
 251
 252 static int
 253 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 254     {
 255     pitem *item;
 256
 257     item = pqueue_pop(queue->q);
 258     if (item)
 259         {
 260         dtls1_copy_record(s, item);
 261
 262         OPENSSL_free(item->data);
 263                 pitem_free(item);
 264
 265         return(1);
 266         }
 267
 268     return(0);
 269     }
 270
 271
 272 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 273  * yet */
 274 #define dtls1_get_unprocessed_record(s) \
 275                    dtls1_retrieve_buffered_record((s), \
 276                    &((s)->d1->unprocessed_rcds))
 277
 278 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 279 #define dtls1_get_processed_record(s) \
 280                    dtls1_retrieve_buffered_record((s), \
 281                    &((s)->d1->processed_rcds))
 282
 283 static int
 284 dtls1_process_buffered_records(SSL *s)
 285     {
 286     pitem *item;
 287
 288     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 289     if (item)
 290         {
 291         DTLS1_RECORD_DATA *rdata;
 292         rdata = (DTLS1_RECORD_DATA *)item->data;
 293
 294         /* Check if epoch is current. */
 295         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 296             return(1);  /* Nothing to do. */
 297
 298         /* Process all the records. */
 299         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 300             {
 301             dtls1_get_unprocessed_record(s);
 302             if ( ! dtls1_process_record(s))
 303                 return(0);
 304             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 305                 s->s3->rrec.seq_num);
 306             }
 307         }
 308
 309     /* sync epoch numbers once all the unprocessed records
 310      * have been processed */
 311     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 312     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 313
 314     return(1);
 315     }
 316
 317
 318 #if 0
 319
 320 static int
 321 dtls1_get_buffered_record(SSL *s)
 322         {
 323         pitem *item;
 324         PQ_64BIT priority =
 325                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 326                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 327
 328         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 329                                                            nothing buffered */
 330                 return 0;
 331
 332
 333         item = pqueue_peek(s->d1->rcvd_records);
 334         if (item && item->priority == priority)
 335                 {
 336                 /* Check if we've received the record of interest.  It must be
 337                  * a handshake record, since data records as passed up without
 338                  * buffering */
 339                 DTLS1_RECORD_DATA *rdata;
 340                 item = pqueue_pop(s->d1->rcvd_records);
 341                 rdata = (DTLS1_RECORD_DATA *)item->data;
 342
 343                 if (s->s3->rbuf.buf != NULL)
 344                         OPENSSL_free(s->s3->rbuf.buf);
 345
 346                 s->packet = rdata->packet;
 347                 s->packet_length = rdata->packet_length;
 348                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 349                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 350
 351                 OPENSSL_free(item->data);
 352                 pitem_free(item);
 353
 354                 /* s->d1->next_expected_seq_num++; */
 355                 return(1);
 356                 }
 357
 358         return 0;
 359         }
 360
 361 #endif
 362
 363 static int
 364 dtls1_process_record(SSL *s)
 365 {
 366         int i,al;
 367         int clear=0;
 368         int enc_err;
 369         SSL_SESSION *sess;
 370         SSL3_RECORD *rr;
 371         unsigned int mac_size;
 372         unsigned char md[EVP_MAX_MD_SIZE];
 373
 374
 375         rr= &(s->s3->rrec);
 376         sess = s->session;
 377
 378         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 379          * and we have that many bytes in s->packet
 380          */
 381         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 382
 383         /* ok, we can now read from 's->packet' data into 'rr'
 384          * rr->input points at rr->length bytes, which
 385          * need to be copied into rr->data by either
 386          * the decryption or by the decompression
 387          * When the data is 'copied' into the rr->data buffer,
 388          * rr->input will be pointed at the new buffer */
 389
 390         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 391          * rr->length bytes of encrypted compressed stuff. */
 392
 393         /* check is not needed I believe */
 394         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 395                 {
 396                 al=SSL_AD_RECORD_OVERFLOW;
 397                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 398                 goto f_err;
 399                 }
 400
 401         /* decrypt in place in 'rr->input' */
 402         rr->data=rr->input;
 403
 404         enc_err = s->method->ssl3_enc->enc(s,0);
 405         if (enc_err <= 0)
 406                 {
 407                 if (enc_err == 0)
 408                         /* SSLerr() and ssl3_send_alert() have been called */
 409                         goto err;
 410
 411                 /* otherwise enc_err == -1 */
 412                 goto decryption_failed_or_bad_record_mac;
 413                 }
 414
 415 #ifdef TLS_DEBUG
 416 printf("dec %d\n",rr->length);
 417 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 418 printf("\n");
 419 #endif
 420
 421         /* r->length is now the compressed data plus mac */
 422         if (    (sess == NULL) ||
 423                 (s->enc_read_ctx == NULL) ||
 424                 (s->read_hash == NULL))
 425         clear=1;
 426
 427         if (!clear)
 428                 {
 429                 mac_size=EVP_MD_size(s->read_hash);
 430
 431                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 432                         {
 433 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 434                         al=SSL_AD_RECORD_OVERFLOW;
 435                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 436                         goto f_err;
 437 #else
 438                         goto decryption_failed_or_bad_record_mac;
 439 #endif
 440                         }
 441                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 442                 if (rr->length < mac_size)
 443                         {
 444 #if 0 /* OK only for stream ciphers */
 445                         al=SSL_AD_DECODE_ERROR;
 446                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 447                         goto f_err;
 448 #else
 449                         goto decryption_failed_or_bad_record_mac;
 450 #endif
 451                         }
 452                 rr->length-=mac_size;
 453                 i=s->method->ssl3_enc->mac(s,md,0);
 454                 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 455                         {
 456                         goto decryption_failed_or_bad_record_mac;
 457                         }
 458                 }
 459
 460         /* r->length is now just compressed */
 461         if (s->expand != NULL)
 462                 {
 463                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 464                         {
 465                         al=SSL_AD_RECORD_OVERFLOW;
 466                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 467                         goto f_err;
 468                         }
 469                 if (!ssl3_do_uncompress(s))
 470                         {
 471                         al=SSL_AD_DECOMPRESSION_FAILURE;
 472                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 473                         goto f_err;
 474                         }
 475                 }
 476
 477         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 478                 {
 479                 al=SSL_AD_RECORD_OVERFLOW;
 480                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 481                 goto f_err;
 482                 }
 483
 484         rr->off=0;
 485         /* So at this point the following is true
 486          * ssl->s3->rrec.type   is the type of record
 487          * ssl->s3->rrec.length == number of bytes in record
 488          * ssl->s3->rrec.off    == offset to first valid byte
 489          * ssl->s3->rrec.data   == where to take bytes from, increment
 490          *                         after use :-).
 491          */
 492
 493         /* we have pulled in a full packet so zero things */
 494         s->packet_length=0;
 495         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 496         return(1);
 497
 498 decryption_failed_or_bad_record_mac:
 499         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
 500          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 501          * failure is directly visible from the ciphertext anyway,
 502          * we should not reveal which kind of error occured -- this
 503          * might become visible to an attacker (e.g. via logfile) */
 504         al=SSL_AD_BAD_RECORD_MAC;
 505         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 506 f_err:
 507         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 508 err:
 509         return(0);
 510 }
 511
 512
 513 /* Call this to get a new input record.
 514  * It will return <= 0 if more data is needed, normally due to an error
 515  * or non-blocking IO.
 516  * When it finishes, one packet has been decoded and can be found in
 517  * ssl->s3->rrec.type    - is the type of record
 518  * ssl->s3->rrec.data,   - data
 519  * ssl->s3->rrec.length, - number of bytes
 520  */
 521 /* used only by dtls1_read_bytes */
 522 int dtls1_get_record(SSL *s)
 523         {
 524         int ssl_major,ssl_minor,al;
 525         int i,n;
 526         SSL3_RECORD *rr;
 527         SSL_SESSION *sess;
 528         unsigned char *p;
 529         short version;
 530         DTLS1_BITMAP *bitmap;
 531         unsigned int is_next_epoch;
 532
 533         rr= &(s->s3->rrec);
 534         sess=s->session;
 535
 536         /* The epoch may have changed.  If so, process all the
 537          * pending records.  This is a non-blocking operation. */
 538         if ( ! dtls1_process_buffered_records(s))
 539             return 0;
 540
 541         /* if we're renegotiating, then there may be buffered records */
 542         if (dtls1_get_processed_record(s))
 543                 return 1;
 544
 545         /* get something from the wire */
 546 again:
 547         /* check if we have the header */
 548         if (    (s->rstate != SSL_ST_READ_BODY) ||
 549                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 550                 {
 551                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 552                 /* read timeout is handled by dtls1_read_bytes */
 553                 if (n <= 0) return(n); /* error or non-blocking */
 554
 555                 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
 556
 557                 s->rstate=SSL_ST_READ_BODY;
 558
 559                 p=s->packet;
 560
 561                 /* Pull apart the header into the DTLS1_RECORD */
 562                 rr->type= *(p++);
 563                 ssl_major= *(p++);
 564                 ssl_minor= *(p++);
 565                 version=(ssl_major<<8)|ssl_minor;
 566
 567                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 568                 n2s(p,rr->epoch);
 569
 570                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 571                 p+=6;
 572
 573                 n2s(p,rr->length);
 574
 575                 /* Lets check version */
 576                 if (s->first_packet)
 577                         {
 578                         s->first_packet=0;
 579                         }
 580                 else
 581                         {
 582                         if (version != s->version)
 583                                 {
 584                                 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 585                                 /* Send back error using their
 586                                  * version number :-) */
 587                                 s->version=version;
 588                                 al=SSL_AD_PROTOCOL_VERSION;
 589                                 goto f_err;
 590                                 }
 591                         }
 592
 593                 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00))
 594                         {
 595                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 596                         goto err;
 597                         }
 598
 599                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 600                         {
 601                         al=SSL_AD_RECORD_OVERFLOW;
 602                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 603                         goto f_err;
 604                         }
 605
 606                 /* now s->rstate == SSL_ST_READ_BODY */
 607                 }
 608
 609         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 610
 611         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 612                 {
 613                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 614                 i=rr->length;
 615                 n=ssl3_read_n(s,i,i,1);
 616                 if (n <= 0) return(n); /* error or non-blocking io */
 617
 618                 /* this packet contained a partial record, dump it */
 619                 if ( n != i)
 620                         {
 621                         s->packet_length = 0;
 622                         goto again;
 623                         }
 624
 625                 /* now n == rr->length,
 626                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 627                 }
 628         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 629
 630         /* match epochs.  NULL means the packet is dropped on the floor */
 631         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 632         if ( bitmap == NULL)
 633                 {
 634                 s->packet_length = 0;  /* dump this record */
 635                 goto again;   /* get another record */
 636                 }
 637
 638         /* check whether this is a repeat, or aged record */
 639         if ( ! dtls1_record_replay_check(s, bitmap))
 640                 {
 641                 s->packet_length=0; /* dump this record */
 642                 goto again;     /* get another record */
 643                 }
 644
 645         /* just read a 0 length packet */
 646         if (rr->length == 0) goto again;
 647
 648         /* If this record is from the next epoch (either HM or ALERT),
 649          * buffer it since it cannot be processed at this time. Records
 650          * from the next epoch are marked as received even though they
 651          * are not processed, so as to prevent any potential resource
 652          * DoS attack */
 653         if (is_next_epoch)
 654                 {
 655                 dtls1_record_bitmap_update(s, bitmap);
 656                 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 657                 s->packet_length = 0;
 658                 goto again;
 659                 }
 660
 661         if ( ! dtls1_process_record(s))
 662                 return(0);
 663
 664         dtls1_clear_timeouts(s);  /* done waiting */
 665         return(1);
 666
 667 f_err:
 668         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 669 err:
 670         return(0);
 671         }
 672
 673 /* Return up to 'len' payload bytes received in 'type' records.
 674  * 'type' is one of the following:
 675  *
 676  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 677  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 678  *   -  0 (during a shutdown, no data has to be returned)
 679  *
 680  * If we don't have stored data to work from, read a SSL/TLS record first
 681  * (possibly multiple records if we still don't have anything to return).
 682  *
 683  * This function must handle any surprises the peer may have for us, such as
 684  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 685  * a surprise, but handled as if it were), or renegotiation requests.
 686  * Also if record payloads contain fragments too small to process, we store
 687  * them until there is enough for the respective protocol (the record protocol
 688  * may use arbitrary fragmentation and even interleaving):
 689  *     Change cipher spec protocol
 690  *             just 1 byte needed, no need for keeping anything stored
 691  *     Alert protocol
 692  *             2 bytes needed (AlertLevel, AlertDescription)
 693  *     Handshake protocol
 694  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 695  *             to detect unexpected Client Hello and Hello Request messages
 696  *             here, anything else is handled by higher layers
 697  *     Application data protocol
 698  *             none of our business
 699  */
 700 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 701         {
 702         int al,i,j,ret;
 703         unsigned int n;
 704         SSL3_RECORD *rr;
 705         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 706
 707         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 708                 if (!ssl3_setup_buffers(s))
 709                         return(-1);
 710
 711     /* XXX: check what the second '&& type' is about */
 712         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 713                 (type != SSL3_RT_HANDSHAKE) && type) ||
 714             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 715                 {
 716                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 717                 return -1;
 718                 }
 719
 720         /* check whether there's a handshake message (client hello?) waiting */
 721         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 722                 return ret;
 723
 724         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 725
 726         if (!s->in_handshake && SSL_in_init(s))
 727                 {
 728                 /* type == SSL3_RT_APPLICATION_DATA */
 729                 i=s->handshake_func(s);
 730                 if (i < 0) return(i);
 731                 if (i == 0)
 732                         {
 733                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 734                         return(-1);
 735                         }
 736                 }
 737
 738 start:
 739         s->rwstate=SSL_NOTHING;
 740
 741         /* s->s3->rrec.type         - is the type of record
 742          * s->s3->rrec.data,    - data
 743          * s->s3->rrec.off,     - offset into 'data' for next read
 744          * s->s3->rrec.length,  - number of bytes. */
 745         rr = &(s->s3->rrec);
 746
 747         /* get new packet if necessary */
 748         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 749                 {
 750                 ret=dtls1_get_record(s);
 751                 if (ret <= 0)
 752                         {
 753                         ret = dtls1_read_failed(s, ret);
 754                         /* anything other than a timeout is an error */
 755                         if (ret <= 0)
 756                                 return(ret);
 757                         else
 758                                 goto start;
 759                         }
 760                 }
 761
 762         /* we now have a packet which can be read and processed */
 763
 764         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 765                                        * reset by ssl3_get_finished */
 766                 && (rr->type != SSL3_RT_HANDSHAKE))
 767                 {
 768                 al=SSL_AD_UNEXPECTED_MESSAGE;
 769                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
 770                 goto err;
 771                 }
 772
 773         /* If the other end has shut down, throw anything we read away
 774          * (even in 'peek' mode) */
 775         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 776                 {
 777                 rr->length=0;
 778                 s->rwstate=SSL_NOTHING;
 779                 return(0);
 780                 }
 781
 782
 783         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 784                 {
 785                 /* make sure that we are not getting application data when we
 786                  * are doing a handshake for the first time */
 787                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 788                         (s->enc_read_ctx == NULL))
 789                         {
 790                         al=SSL_AD_UNEXPECTED_MESSAGE;
 791                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 792                         goto f_err;
 793                         }
 794
 795                 if (len <= 0) return(len);
 796
 797                 if ((unsigned int)len > rr->length)
 798                         n = rr->length;
 799                 else
 800                         n = (unsigned int)len;
 801
 802                 memcpy(buf,&(rr->data[rr->off]),n);
 803                 if (!peek)
 804                         {
 805                         rr->length-=n;
 806                         rr->off+=n;
 807                         if (rr->length == 0)
 808                                 {
 809                                 s->rstate=SSL_ST_READ_HEADER;
 810                                 rr->off=0;
 811                                 }
 812                         }
 813                 return(n);
 814                 }
 815
 816
 817         /* If we get here, then type != rr->type; if we have a handshake
 818          * message, then it was unexpected (Hello Request or Client Hello). */
 819
 820         /* In case of record types for which we have 'fragment' storage,
 821          * fill that so that we can process the data at a fixed place.
 822          */
 823                 {
 824                 unsigned int k, dest_maxlen = 0;
 825                 unsigned char *dest = NULL;
 826                 unsigned int *dest_len = NULL;
 827
 828                 if (rr->type == SSL3_RT_HANDSHAKE)
 829                         {
 830                         dest_maxlen = sizeof s->d1->handshake_fragment;
 831                         dest = s->d1->handshake_fragment;
 832                         dest_len = &s->d1->handshake_fragment_len;
 833                         }
 834                 else if (rr->type == SSL3_RT_ALERT)
 835                         {
 836                         dest_maxlen = sizeof(s->d1->alert_fragment);
 837                         dest = s->d1->alert_fragment;
 838                         dest_len = &s->d1->alert_fragment_len;
 839                         }
 840                 else    /* else it's a CCS message */
 841                         OPENSSL_assert(rr->type == SSL3_RT_CHANGE_CIPHER_SPEC);
 842
 843
 844                 if (dest_maxlen > 0)
 845                         {
 846             /* XDTLS:  In a pathalogical case, the Client Hello
 847              *  may be fragmented--don't always expect dest_maxlen bytes */
 848                         if ( rr->length < dest_maxlen)
 849                                 {
 850                                 s->rstate=SSL_ST_READ_HEADER;
 851                                 rr->length = 0;
 852                                 goto start;
 853                                 }
 854
 855                         /* now move 'n' bytes: */
 856                         for ( k = 0; k < dest_maxlen; k++)
 857                                 {
 858                                 dest[k] = rr->data[rr->off++];
 859                                 rr->length--;
 860                                 }
 861                         *dest_len = dest_maxlen;
 862                         }
 863                 }
 864
 865         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 866          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 867          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 868
 869         /* If we are a client, check for an incoming 'Hello Request': */
 870         if ((!s->server) &&
 871                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 872                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 873                 (s->session != NULL) && (s->session->cipher != NULL))
 874                 {
 875                 s->d1->handshake_fragment_len = 0;
 876
 877                 if ((s->d1->handshake_fragment[1] != 0) ||
 878                         (s->d1->handshake_fragment[2] != 0) ||
 879                         (s->d1->handshake_fragment[3] != 0))
 880                         {
 881                         al=SSL_AD_DECODE_ERROR;
 882                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 883                         goto err;
 884                         }
 885
 886                 /* no need to check sequence number on HELLO REQUEST messages */
 887
 888                 if (s->msg_callback)
 889                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 890                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 891
 892                 if (SSL_is_init_finished(s) &&
 893                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 894                         !s->s3->renegotiate)
 895                         {
 896                         ssl3_renegotiate(s);
 897                         if (ssl3_renegotiate_check(s))
 898                                 {
 899                                 i=s->handshake_func(s);
 900                                 if (i < 0) return(i);
 901                                 if (i == 0)
 902                                         {
 903                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 904                                         return(-1);
 905                                         }
 906
 907                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 908                                         {
 909                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 910                                                 {
 911                                                 BIO *bio;
 912                                                 /* In the case where we try to read application data,
 913                                                  * but we trigger an SSL handshake, we return -1 with
 914                                                  * the retry option set.  Otherwise renegotiation may
 915                                                  * cause nasty problems in the blocking world */
 916                                                 s->rwstate=SSL_READING;
 917                                                 bio=SSL_get_rbio(s);
 918                                                 BIO_clear_retry_flags(bio);
 919                                                 BIO_set_retry_read(bio);
 920                                                 return(-1);
 921                                                 }
 922                                         }
 923                                 }
 924                         }
 925                 /* we either finished a handshake or ignored the request,
 926                  * now try again to obtain the (application) data we were asked for */
 927                 goto start;
 928                 }
 929
 930         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
 931                 {
 932                 int alert_level = s->d1->alert_fragment[0];
 933                 int alert_descr = s->d1->alert_fragment[1];
 934
 935                 s->d1->alert_fragment_len = 0;
 936
 937                 if (s->msg_callback)
 938                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
 939                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
 940
 941                 if (s->info_callback != NULL)
 942                         cb=s->info_callback;
 943                 else if (s->ctx->info_callback != NULL)
 944                         cb=s->ctx->info_callback;
 945
 946                 if (cb != NULL)
 947                         {
 948                         j = (alert_level << 8) | alert_descr;
 949                         cb(s, SSL_CB_READ_ALERT, j);
 950                         }
 951
 952                 if (alert_level == 1) /* warning */
 953                         {
 954                         s->s3->warn_alert = alert_descr;
 955                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
 956                                 {
 957                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 958                                 return(0);
 959                                 }
 960 #if 0
 961             /* XXX: this is a possible improvement in the future */
 962                         /* now check if it's a missing record */
 963                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
 964                                 {
 965                                 unsigned short seq;
 966                                 unsigned int frag_off;
 967                                 unsigned char *p = &(s->d1->alert_fragment[2]);
 968
 969                                 n2s(p, seq);
 970                                 n2l3(p, frag_off);
 971
 972                                 dtls1_retransmit_message(s, seq, frag_off, &found);
 973                                 if ( ! found  && SSL_in_init(s))
 974                                         {
 975                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
 976                                         /* requested a message not yet sent,
 977                                            send an alert ourselves */
 978                                         ssl3_send_alert(s,SSL3_AL_WARNING,
 979                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 980                                         }
 981                                 }
 982 #endif
 983                         }
 984                 else if (alert_level == 2) /* fatal */
 985                         {
 986                         char tmp[16];
 987
 988                         s->rwstate=SSL_NOTHING;
 989                         s->s3->fatal_alert = alert_descr;
 990                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
 991                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
 992                         ERR_add_error_data(2,"SSL alert number ",tmp);
 993                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
 994                         SSL_CTX_remove_session(s->ctx,s->session);
 995                         return(0);
 996                         }
 997                 else
 998                         {
 999                         al=SSL_AD_ILLEGAL_PARAMETER;
1000                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1001                         goto f_err;
1002                         }
1003
1004                 goto start;
1005                 }
1006
1007         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1008                 {
1009                 s->rwstate=SSL_NOTHING;
1010                 rr->length=0;
1011                 return(0);
1012                 }
1013
1014         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1015         {
1016         struct ccs_header_st ccs_hdr;
1017
1018                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1019
1020                 if ( ccs_hdr.seq == s->d1->handshake_read_seq)
1021                         {
1022                         /* 'Change Cipher Spec' is just a single byte, so we know
1023                          * exactly what the record payload has to look like */
1024                         /* XDTLS: check that epoch is consistent */
1025                         if (    (rr->length != DTLS1_CCS_HEADER_LENGTH) ||
1026                                 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1027                                 {
1028                                 i=SSL_AD_ILLEGAL_PARAMETER;
1029                                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1030                                 goto err;
1031                                 }
1032
1033                         rr->length=0;
1034
1035                         if (s->msg_callback)
1036                                 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1037                                         rr->data, 1, s, s->msg_callback_arg);
1038
1039                         s->s3->change_cipher_spec=1;
1040                         if (!ssl3_do_change_cipher_spec(s))
1041                                 goto err;
1042
1043                         /* do this whenever CCS is processed */
1044                         dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1045
1046                         /* handshake read seq is reset upon handshake completion */
1047                         s->d1->handshake_read_seq++;
1048
1049                         goto start;
1050                         }
1051                 else
1052                         {
1053                         rr->length = 0;
1054                         goto start;
1055                         }
1056                 }
1057
1058         /* Unexpected handshake message (Client Hello, or protocol violation) */
1059         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1060                 !s->in_handshake)
1061                 {
1062                 struct hm_header_st msg_hdr;
1063
1064                 /* this may just be a stale retransmit */
1065                 dtls1_get_message_header(rr->data, &msg_hdr);
1066                 if( rr->epoch != s->d1->r_epoch)
1067                         {
1068                         rr->length = 0;
1069                         goto start;
1070                         }
1071
1072                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1073                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1074                         {
1075 #if 0 /* worked only because C operator preferences are not as expected (and
1076        * because this is not really needed for clients except for detecting
1077        * protocol violations): */
1078                         s->state=SSL_ST_BEFORE|(s->server)
1079                                 ?SSL_ST_ACCEPT
1080                                 :SSL_ST_CONNECT;
1081 #else
1082                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1083 #endif
1084                         s->new_session=1;
1085                         }
1086                 i=s->handshake_func(s);
1087                 if (i < 0) return(i);
1088                 if (i == 0)
1089                         {
1090                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1091                         return(-1);
1092                         }
1093
1094                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1095                         {
1096                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1097                                 {
1098                                 BIO *bio;
1099                                 /* In the case where we try to read application data,
1100                                  * but we trigger an SSL handshake, we return -1 with
1101                                  * the retry option set.  Otherwise renegotiation may
1102                                  * cause nasty problems in the blocking world */
1103                                 s->rwstate=SSL_READING;
1104                                 bio=SSL_get_rbio(s);
1105                                 BIO_clear_retry_flags(bio);
1106                                 BIO_set_retry_read(bio);
1107                                 return(-1);
1108                                 }
1109                         }
1110                 goto start;
1111                 }
1112
1113         switch (rr->type)
1114                 {
1115         default:
1116 #ifndef OPENSSL_NO_TLS
1117                 /* TLS just ignores unknown message types */
1118                 if (s->version == TLS1_VERSION)
1119                         {
1120                         rr->length = 0;
1121                         goto start;
1122                         }
1123 #endif
1124                 al=SSL_AD_UNEXPECTED_MESSAGE;
1125                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1126                 goto f_err;
1127         case SSL3_RT_CHANGE_CIPHER_SPEC:
1128         case SSL3_RT_ALERT:
1129         case SSL3_RT_HANDSHAKE:
1130                 /* we already handled all of these, with the possible exception
1131                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1132                  * should not happen when type != rr->type */
1133                 al=SSL_AD_UNEXPECTED_MESSAGE;
1134                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1135                 goto f_err;
1136         case SSL3_RT_APPLICATION_DATA:
1137                 /* At this point, we were expecting handshake data,
1138                  * but have application data.  If the library was
1139                  * running inside ssl3_read() (i.e. in_read_app_data
1140                  * is set) and it makes sense to read application data
1141                  * at this point (session renegotiation not yet started),
1142                  * we will indulge it.
1143                  */
1144                 if (s->s3->in_read_app_data &&
1145                         (s->s3->total_renegotiations != 0) &&
1146                         ((
1147                                 (s->state & SSL_ST_CONNECT) &&
1148                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1149                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1150                                 ) || (
1151                                         (s->state & SSL_ST_ACCEPT) &&
1152                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1153                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1154                                         )
1155                                 ))
1156                         {
1157                         s->s3->in_read_app_data=2;
1158                         return(-1);
1159                         }
1160                 else
1161                         {
1162                         al=SSL_AD_UNEXPECTED_MESSAGE;
1163                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1164                         goto f_err;
1165                         }
1166                 }
1167         /* not reached */
1168
1169 f_err:
1170         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1171 err:
1172         return(-1);
1173         }
1174
1175 int
1176 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1177         {
1178         unsigned int n,tot;
1179         int i;
1180
1181         if (SSL_in_init(s) && !s->in_handshake)
1182                 {
1183                 i=s->handshake_func(s);
1184                 if (i < 0) return(i);
1185                 if (i == 0)
1186                         {
1187                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1188                         return -1;
1189                         }
1190                 }
1191
1192         tot = s->s3->wnum;
1193         n = len - tot;
1194
1195         while( n)
1196                 {
1197                 /* dtls1_write_bytes sends one record at a time, sized according to
1198                  * the currently known MTU */
1199                 i = dtls1_write_bytes(s, type, buf_, len);
1200                 if (i <= 0) return i;
1201
1202                 if ((i == (int)n) ||
1203                         (type == SSL3_RT_APPLICATION_DATA &&
1204                                 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1205                         {
1206                         /* next chunk of data should get another prepended empty fragment
1207                          * in ciphersuites with known-IV weakness: */
1208                         s->s3->empty_fragment_done = 0;
1209                         return tot+i;
1210                         }
1211
1212                 tot += i;
1213                 n-=i;
1214                 }
1215
1216         return tot;
1217         }
1218
1219
1220         /* this only happens when a client hello is received and a handshake
1221          * is started. */
1222 static int
1223 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1224         int len, int peek)
1225         {
1226
1227         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1228                 /* (partially) satisfy request from storage */
1229                 {
1230                 unsigned char *src = s->d1->handshake_fragment;
1231                 unsigned char *dst = buf;
1232                 unsigned int k,n;
1233
1234                 /* peek == 0 */
1235                 n = 0;
1236                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1237                         {
1238                         *dst++ = *src++;
1239                         len--; s->d1->handshake_fragment_len--;
1240                         n++;
1241                         }
1242                 /* move any remaining fragment bytes: */
1243                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1244                         s->d1->handshake_fragment[k] = *src++;
1245                 return n;
1246                 }
1247
1248         return 0;
1249         }
1250
1251
1252
1253
1254 /* Call this to write data in records of type 'type'
1255  * It will return <= 0 if not all data has been sent or non-blocking IO.
1256  */
1257 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1258         {
1259         const unsigned char *buf=buf_;
1260         unsigned int tot,n,nw;
1261         int i;
1262         unsigned int mtu;
1263
1264         s->rwstate=SSL_NOTHING;
1265         tot=s->s3->wnum;
1266
1267         n=(len-tot);
1268
1269         /* handshake layer figures out MTU for itself, but data records
1270          * are also sent through this interface, so need to figure out MTU */
1271 #if 0
1272         mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1273         mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
1274 #endif
1275         mtu = s->d1->mtu;
1276
1277         if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1278                 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1279
1280         if (n > mtu)
1281                 nw=mtu;
1282         else
1283                 nw=n;
1284
1285         i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1286         if (i <= 0)
1287                 {
1288                 s->s3->wnum=tot;
1289                 return i;
1290                 }
1291
1292         if ( (int)s->s3->wnum + i == len)
1293                 s->s3->wnum = 0;
1294         else
1295                 s->s3->wnum += i;
1296
1297         return tot + i;
1298         }
1299
1300 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1301         {
1302         unsigned char *p,*pseq;
1303         int i,mac_size,clear=0;
1304         int prefix_len = 0;
1305         SSL3_RECORD *wr;
1306         SSL3_BUFFER *wb;
1307         SSL_SESSION *sess;
1308         int bs;
1309
1310         /* first check if there is a SSL3_BUFFER still being written
1311          * out.  This will happen with non blocking IO */
1312         if (s->s3->wbuf.left != 0)
1313                 {
1314                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1315                 return(ssl3_write_pending(s,type,buf,len));
1316                 }
1317
1318         /* If we have an alert to send, lets send it */
1319         if (s->s3->alert_dispatch)
1320                 {
1321                 i=s->method->ssl_dispatch_alert(s);
1322                 if (i <= 0)
1323                         return(i);
1324                 /* if it went, fall through and send more stuff */
1325                 }
1326
1327         if (len == 0 && !create_empty_fragment)
1328                 return 0;
1329
1330         wr= &(s->s3->wrec);
1331         wb= &(s->s3->wbuf);
1332         sess=s->session;
1333
1334         if (    (sess == NULL) ||
1335                 (s->enc_write_ctx == NULL) ||
1336                 (s->write_hash == NULL))
1337                 clear=1;
1338
1339         if (clear)
1340                 mac_size=0;
1341         else
1342                 mac_size=EVP_MD_size(s->write_hash);
1343
1344         /* DTLS implements explicit IV, so no need for empty fragments */
1345 #if 0
1346         /* 'create_empty_fragment' is true only when this function calls itself */
1347         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1348                 && SSL_version(s) != DTLS1_VERSION)
1349                 {
1350                 /* countermeasure against known-IV weakness in CBC ciphersuites
1351                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1352                  */
1353
1354                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1355                         {
1356                         /* recursive function call with 'create_empty_fragment' set;
1357                          * this prepares and buffers the data for an empty fragment
1358                          * (these 'prefix_len' bytes are sent out later
1359                          * together with the actual payload) */
1360                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1361                         if (prefix_len <= 0)
1362                                 goto err;
1363
1364                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1365                                 {
1366                                 /* insufficient space */
1367                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1368                                 goto err;
1369                                 }
1370                         }
1371
1372                 s->s3->empty_fragment_done = 1;
1373                 }
1374 #endif
1375
1376         p = wb->buf + prefix_len;
1377
1378         /* write the header */
1379
1380         *(p++)=type&0xff;
1381         wr->type=type;
1382
1383         *(p++)=(s->version>>8);
1384         *(p++)=s->version&0xff;
1385
1386         /* field where we are to write out packet epoch, seq num and len */
1387         pseq=p;
1388         p+=10;
1389
1390         /* lets setup the record stuff. */
1391
1392         /* Make space for the explicit IV in case of CBC.
1393          * (this is a bit of a boundary violation, but what the heck).
1394          */
1395         if ( s->enc_write_ctx &&
1396                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1397                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1398         else
1399                 bs = 0;
1400
1401         wr->data=p + bs;  /* make room for IV in case of CBC */
1402         wr->length=(int)len;
1403         wr->input=(unsigned char *)buf;
1404
1405         /* we now 'read' from wr->input, wr->length bytes into
1406          * wr->data */
1407
1408         /* first we compress */
1409         if (s->compress != NULL)
1410                 {
1411                 if (!ssl3_do_compress(s))
1412                         {
1413                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1414                         goto err;
1415                         }
1416                 }
1417         else
1418                 {
1419                 memcpy(wr->data,wr->input,wr->length);
1420                 wr->input=wr->data;
1421                 }
1422
1423         /* we should still have the output to wr->data and the input
1424          * from wr->input.  Length should be wr->length.
1425          * wr->data still points in the wb->buf */
1426
1427         if (mac_size != 0)
1428                 {
1429                 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1430                 wr->length+=mac_size;
1431                 }
1432
1433         /* this is true regardless of mac size */
1434         wr->input=p;
1435         wr->data=p;
1436
1437
1438         /* ssl3_enc can only have an error on read */
1439         wr->length += bs;  /* bs != 0 in case of CBC.  The enc fn provides
1440                                                 * the randomness */
1441         s->method->ssl3_enc->enc(s,1);
1442
1443         /* record length after mac and block padding */
1444 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1445         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1446
1447         /* there's only one epoch between handshake and app data */
1448
1449         s2n(s->d1->w_epoch, pseq);
1450
1451         /* XDTLS: ?? */
1452 /*      else
1453         s2n(s->d1->handshake_epoch, pseq); */
1454
1455         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1456         pseq+=6;
1457         s2n(wr->length,pseq);
1458
1459         /* we should now have
1460          * wr->data pointing to the encrypted data, which is
1461          * wr->length long */
1462         wr->type=type; /* not needed but helps for debugging */
1463         wr->length+=DTLS1_RT_HEADER_LENGTH;
1464
1465 #if 0  /* this is now done at the message layer */
1466         /* buffer the record, making it easy to handle retransmits */
1467         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1468                 dtls1_buffer_record(s, wr->data, wr->length,
1469                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1470 #endif
1471
1472         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1473
1474         if (create_empty_fragment)
1475                 {
1476                 /* we are in a recursive call;
1477                  * just return the length, don't write out anything here
1478                  */
1479                 return wr->length;
1480                 }
1481
1482         /* now let's set up wb */
1483         wb->left = prefix_len + wr->length;
1484         wb->offset = 0;
1485
1486         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1487         s->s3->wpend_tot=len;
1488         s->s3->wpend_buf=buf;
1489         s->s3->wpend_type=type;
1490         s->s3->wpend_ret=len;
1491
1492         /* we now just need to write the buffer */
1493         return ssl3_write_pending(s,type,buf,len);
1494 err:
1495         return -1;
1496         }
1497
1498
1499
1500 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1501         {
1502         int cmp;
1503         unsigned int shift;
1504         const unsigned char *seq = s->s3->read_sequence;
1505
1506         cmp = satsub64be(seq,bitmap->max_seq_num);
1507         if (cmp > 0)
1508                 {
1509                 memcpy (s->s3->rrec.seq_num,seq,8);
1510                 return 1; /* this record in new */
1511                 }
1512         shift = -cmp;
1513         if (shift >= sizeof(bitmap->map)*8)
1514                 return 0; /* stale, outside the window */
1515         else if (bitmap->map & (1UL<<shift))
1516                 return 0; /* record previously received */
1517
1518         memcpy (s->s3->rrec.seq_num,seq,8);
1519         return 1;
1520         }
1521
1522
1523 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1524         {
1525         int cmp;
1526         unsigned int shift;
1527         const unsigned char *seq = s->s3->read_sequence;
1528
1529         cmp = satsub64be(seq,bitmap->max_seq_num);
1530         if (cmp > 0)
1531                 {
1532                 shift = cmp;
1533                 if (shift < sizeof(bitmap->map)*8)
1534                         bitmap->map <<= shift, bitmap->map |= 1UL;
1535                 else
1536                         bitmap->map = 1UL;
1537                 memcpy(bitmap->max_seq_num,seq,8);
1538                 }
1539         else    {
1540                 shift = -cmp;
1541                 if (shift < sizeof(bitmap->map)*8)
1542                         bitmap->map |= 1UL<<shift;
1543                 }
1544         }
1545
1546
1547 int dtls1_dispatch_alert(SSL *s)
1548         {
1549         int i,j;
1550         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1551         unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */
1552         unsigned char *ptr = &buf[0];
1553
1554         s->s3->alert_dispatch=0;
1555
1556         memset(buf, 0x00, sizeof(buf));
1557         *ptr++ = s->s3->send_alert[0];
1558         *ptr++ = s->s3->send_alert[1];
1559
1560 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1561         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1562                 {
1563                 s2n(s->d1->handshake_read_seq, ptr);
1564 #if 0
1565                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1566
1567                 else
1568                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1569 #endif
1570
1571 #if 0
1572                 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);
1573 #endif
1574                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1575                 }
1576 #endif
1577
1578         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1579         if (i <= 0)
1580                 {
1581                 s->s3->alert_dispatch=1;
1582                 /* fprintf( stderr, "not done with alert\n" ); */
1583                 }
1584         else
1585                 {
1586                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1587 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1588                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1589 #endif
1590                     )
1591                         (void)BIO_flush(s->wbio);
1592
1593                 if (s->msg_callback)
1594                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1595                                 2, s, s->msg_callback_arg);
1596
1597                 if (s->info_callback != NULL)
1598                         cb=s->info_callback;
1599                 else if (s->ctx->info_callback != NULL)
1600                         cb=s->ctx->info_callback;
1601
1602                 if (cb != NULL)
1603                         {
1604                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1605                         cb(s,SSL_CB_WRITE_ALERT,j);
1606                         }
1607                 }
1608         return(i);
1609         }
1610
1611
1612 static DTLS1_BITMAP *
1613 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1614     {
1615
1616     *is_next_epoch = 0;
1617
1618     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1619     if (rr->epoch == s->d1->r_epoch)
1620         return &s->d1->bitmap;
1621
1622     /* Only HM and ALERT messages can be from the next epoch */
1623     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1624         (rr->type == SSL3_RT_HANDSHAKE ||
1625             rr->type == SSL3_RT_ALERT))
1626         {
1627         *is_next_epoch = 1;
1628         return &s->d1->next_bitmap;
1629         }
1630
1631     return NULL;
1632     }
1633
1634 #if 0
1635 static int
1636 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1637         unsigned long *offset)
1638         {
1639
1640         /* alerts are passed up immediately */
1641         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1642                 rr->type == SSL3_RT_ALERT)
1643                 return 0;
1644
1645         /* Only need to buffer if a handshake is underway.
1646          * (this implies that Hello Request and Client Hello are passed up
1647          * immediately) */
1648         if ( SSL_in_init(s))
1649                 {
1650                 unsigned char *data = rr->data;
1651                 /* need to extract the HM/CCS sequence number here */
1652                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1653                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1654                         {
1655                         unsigned short seq_num;
1656                         struct hm_header_st msg_hdr;
1657                         struct ccs_header_st ccs_hdr;
1658
1659                         if ( rr->type == SSL3_RT_HANDSHAKE)
1660                                 {
1661                                 dtls1_get_message_header(data, &msg_hdr);
1662                                 seq_num = msg_hdr.seq;
1663                                 *offset = msg_hdr.frag_off;
1664                                 }
1665                         else
1666                                 {
1667                                 dtls1_get_ccs_header(data, &ccs_hdr);
1668                                 seq_num = ccs_hdr.seq;
1669                                 *offset = 0;
1670                                 }
1671
1672                         /* this is either a record we're waiting for, or a
1673                          * retransmit of something we happened to previously
1674                          * receive (higher layers will drop the repeat silently */
1675                         if ( seq_num < s->d1->handshake_read_seq)
1676                                 return 0;
1677                         if (rr->type == SSL3_RT_HANDSHAKE &&
1678                                 seq_num == s->d1->handshake_read_seq &&
1679                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1680                                 return 0;
1681                         else if ( seq_num == s->d1->handshake_read_seq &&
1682                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1683                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1684                                 return 0;
1685                         else
1686                                 {
1687                                 *priority = seq_num;
1688                                 return 1;
1689                                 }
1690                         }
1691                 else /* unknown record type */
1692                         return 0;
1693                 }
1694
1695         return 0;
1696         }
1697 #endif
1698
1699 void
1700 dtls1_reset_seq_numbers(SSL *s, int rw)
1701         {
1702         unsigned char *seq;
1703         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1704
1705         if ( rw & SSL3_CC_READ)
1706                 {
1707                 seq = s->s3->read_sequence;
1708                 s->d1->r_epoch++;
1709                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1710                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1711                 }
1712         else
1713                 {
1714                 seq = s->s3->write_sequence;
1715                 s->d1->w_epoch++;
1716                 }
1717
1718         memset(seq, 0x00, seq_bytes);
1719         }
1720
1721
1722 static void
1723 dtls1_clear_timeouts(SSL *s)
1724         {
1725         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1726         }