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 #if PQ_64BIT_IS_INTEGER
 182 static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num);
 183 #endif
 184 static void dtls1_clear_timeouts(SSL *s);
 185
 186 /* copy buffered record into SSL structure */
 187 static int
 188 dtls1_copy_record(SSL *s, pitem *item)
 189     {
 190     DTLS1_RECORD_DATA *rdata;
 191
 192     rdata = (DTLS1_RECORD_DATA *)item->data;
 193
 194     if (s->s3->rbuf.buf != NULL)
 195         OPENSSL_free(s->s3->rbuf.buf);
 196
 197     s->packet = rdata->packet;
 198     s->packet_length = rdata->packet_length;
 199     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 200     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 201
 202     return(1);
 203     }
 204
 205
 206 static int
 207 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 208         {
 209         DTLS1_RECORD_DATA *rdata;
 210         pitem *item;
 211
 212         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 213         item = pitem_new(priority, rdata);
 214         if (rdata == NULL || item == NULL)
 215                 {
 216                 if (rdata != NULL) OPENSSL_free(rdata);
 217                 if (item != NULL) pitem_free(item);
 218
 219                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 220                 return(0);
 221                 }
 222
 223         rdata->packet = s->packet;
 224         rdata->packet_length = s->packet_length;
 225         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 226         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 227
 228         item->data = rdata;
 229
 230         /* insert should not fail, since duplicates are dropped */
 231         if (pqueue_insert(queue->q, item) == NULL)
 232                 {
 233                 OPENSSL_free(rdata);
 234                 pitem_free(item);
 235                 return(0);
 236                 }
 237
 238         s->packet = NULL;
 239         s->packet_length = 0;
 240         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 241         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 242
 243         ssl3_setup_buffers(s);
 244
 245         return(1);
 246         }
 247
 248
 249 static int
 250 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 251     {
 252     pitem *item;
 253
 254     item = pqueue_pop(queue->q);
 255     if (item)
 256         {
 257         dtls1_copy_record(s, item);
 258
 259         OPENSSL_free(item->data);
 260                 pitem_free(item);
 261
 262         return(1);
 263         }
 264
 265     return(0);
 266     }
 267
 268
 269 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 270  * yet */
 271 #define dtls1_get_unprocessed_record(s) \
 272                    dtls1_retrieve_buffered_record((s), \
 273                    &((s)->d1->unprocessed_rcds))
 274
 275 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 276 #define dtls1_get_processed_record(s) \
 277                    dtls1_retrieve_buffered_record((s), \
 278                    &((s)->d1->processed_rcds))
 279
 280 static int
 281 dtls1_process_buffered_records(SSL *s)
 282     {
 283     pitem *item;
 284
 285     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 286     if (item)
 287         {
 288         DTLS1_RECORD_DATA *rdata;
 289         rdata = (DTLS1_RECORD_DATA *)item->data;
 290
 291         /* Check if epoch is current. */
 292         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 293             return(1);  /* Nothing to do. */
 294
 295         /* Process all the records. */
 296         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 297             {
 298             dtls1_get_unprocessed_record(s);
 299             if ( ! dtls1_process_record(s))
 300                 return(0);
 301             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 302                 s->s3->rrec.seq_num);
 303             }
 304         }
 305
 306     /* sync epoch numbers once all the unprocessed records
 307      * have been processed */
 308     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 309     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 310
 311     return(1);
 312     }
 313
 314
 315 #if 0
 316
 317 static int
 318 dtls1_get_buffered_record(SSL *s)
 319         {
 320         pitem *item;
 321         PQ_64BIT priority =
 322                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 323                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 324
 325         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 326                                                            nothing buffered */
 327                 return 0;
 328
 329
 330         item = pqueue_peek(s->d1->rcvd_records);
 331         if (item && item->priority == priority)
 332                 {
 333                 /* Check if we've received the record of interest.  It must be
 334                  * a handshake record, since data records as passed up without
 335                  * buffering */
 336                 DTLS1_RECORD_DATA *rdata;
 337                 item = pqueue_pop(s->d1->rcvd_records);
 338                 rdata = (DTLS1_RECORD_DATA *)item->data;
 339
 340                 if (s->s3->rbuf.buf != NULL)
 341                         OPENSSL_free(s->s3->rbuf.buf);
 342
 343                 s->packet = rdata->packet;
 344                 s->packet_length = rdata->packet_length;
 345                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 346                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 347
 348                 OPENSSL_free(item->data);
 349                 pitem_free(item);
 350
 351                 /* s->d1->next_expected_seq_num++; */
 352                 return(1);
 353                 }
 354
 355         return 0;
 356         }
 357
 358 #endif
 359
 360 static int
 361 dtls1_process_record(SSL *s)
 362 {
 363         int i,al;
 364         int clear=0;
 365         int enc_err;
 366         SSL_SESSION *sess;
 367         SSL3_RECORD *rr;
 368         unsigned int mac_size;
 369         unsigned char md[EVP_MAX_MD_SIZE];
 370
 371
 372         rr= &(s->s3->rrec);
 373         sess = s->session;
 374
 375         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 376          * and we have that many bytes in s->packet
 377          */
 378         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 379
 380         /* ok, we can now read from 's->packet' data into 'rr'
 381          * rr->input points at rr->length bytes, which
 382          * need to be copied into rr->data by either
 383          * the decryption or by the decompression
 384          * When the data is 'copied' into the rr->data buffer,
 385          * rr->input will be pointed at the new buffer */
 386
 387         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 388          * rr->length bytes of encrypted compressed stuff. */
 389
 390         /* check is not needed I believe */
 391         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 392                 {
 393                 al=SSL_AD_RECORD_OVERFLOW;
 394                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 395                 goto f_err;
 396                 }
 397
 398         /* decrypt in place in 'rr->input' */
 399         rr->data=rr->input;
 400
 401         enc_err = s->method->ssl3_enc->enc(s,0);
 402         if (enc_err <= 0)
 403                 {
 404                 if (enc_err == 0)
 405                         /* SSLerr() and ssl3_send_alert() have been called */
 406                         goto err;
 407
 408                 /* otherwise enc_err == -1 */
 409                 goto decryption_failed_or_bad_record_mac;
 410                 }
 411
 412 #ifdef TLS_DEBUG
 413 printf("dec %d\n",rr->length);
 414 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 415 printf("\n");
 416 #endif
 417
 418         /* r->length is now the compressed data plus mac */
 419         if (    (sess == NULL) ||
 420                 (s->enc_read_ctx == NULL) ||
 421                 (s->read_hash == NULL))
 422         clear=1;
 423
 424         if (!clear)
 425                 {
 426                 mac_size=EVP_MD_size(s->read_hash);
 427
 428                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 429                         {
 430 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 431                         al=SSL_AD_RECORD_OVERFLOW;
 432                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 433                         goto f_err;
 434 #else
 435                         goto decryption_failed_or_bad_record_mac;
 436 #endif
 437                         }
 438                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 439                 if (rr->length < mac_size)
 440                         {
 441 #if 0 /* OK only for stream ciphers */
 442                         al=SSL_AD_DECODE_ERROR;
 443                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 444                         goto f_err;
 445 #else
 446                         goto decryption_failed_or_bad_record_mac;
 447 #endif
 448                         }
 449                 rr->length-=mac_size;
 450                 i=s->method->ssl3_enc->mac(s,md,0);
 451                 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 452                         {
 453                         goto decryption_failed_or_bad_record_mac;
 454                         }
 455                 }
 456
 457         /* r->length is now just compressed */
 458         if (s->expand != NULL)
 459                 {
 460                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 461                         {
 462                         al=SSL_AD_RECORD_OVERFLOW;
 463                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 464                         goto f_err;
 465                         }
 466                 if (!ssl3_do_uncompress(s))
 467                         {
 468                         al=SSL_AD_DECOMPRESSION_FAILURE;
 469                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 470                         goto f_err;
 471                         }
 472                 }
 473
 474         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 475                 {
 476                 al=SSL_AD_RECORD_OVERFLOW;
 477                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 478                 goto f_err;
 479                 }
 480
 481         rr->off=0;
 482         /* So at this point the following is true
 483          * ssl->s3->rrec.type   is the type of record
 484          * ssl->s3->rrec.length == number of bytes in record
 485          * ssl->s3->rrec.off    == offset to first valid byte
 486          * ssl->s3->rrec.data   == where to take bytes from, increment
 487          *                         after use :-).
 488          */
 489
 490         /* we have pulled in a full packet so zero things */
 491         s->packet_length=0;
 492         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 493         return(1);
 494
 495 decryption_failed_or_bad_record_mac:
 496         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
 497          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 498          * failure is directly visible from the ciphertext anyway,
 499          * we should not reveal which kind of error occured -- this
 500          * might become visible to an attacker (e.g. via logfile) */
 501         al=SSL_AD_BAD_RECORD_MAC;
 502         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 503 f_err:
 504         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 505 err:
 506         return(0);
 507 }
 508
 509
 510 /* Call this to get a new input record.
 511  * It will return <= 0 if more data is needed, normally due to an error
 512  * or non-blocking IO.
 513  * When it finishes, one packet has been decoded and can be found in
 514  * ssl->s3->rrec.type    - is the type of record
 515  * ssl->s3->rrec.data,   - data
 516  * ssl->s3->rrec.length, - number of bytes
 517  */
 518 /* used only by dtls1_read_bytes */
 519 int dtls1_get_record(SSL *s)
 520         {
 521         int ssl_major,ssl_minor,al;
 522         int i,n;
 523         SSL3_RECORD *rr;
 524         SSL_SESSION *sess;
 525         unsigned char *p;
 526         short version;
 527         DTLS1_BITMAP *bitmap;
 528         unsigned int is_next_epoch;
 529
 530         rr= &(s->s3->rrec);
 531         sess=s->session;
 532
 533         /* The epoch may have changed.  If so, process all the
 534          * pending records.  This is a non-blocking operation. */
 535         if ( ! dtls1_process_buffered_records(s))
 536             return 0;
 537
 538         /* if we're renegotiating, then there may be buffered records */
 539         if (dtls1_get_processed_record(s))
 540                 return 1;
 541
 542         /* get something from the wire */
 543 again:
 544         /* check if we have the header */
 545         if (    (s->rstate != SSL_ST_READ_BODY) ||
 546                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 547                 {
 548                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 549                 /* read timeout is handled by dtls1_read_bytes */
 550                 if (n <= 0) return(n); /* error or non-blocking */
 551
 552                 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
 553
 554                 s->rstate=SSL_ST_READ_BODY;
 555
 556                 p=s->packet;
 557
 558                 /* Pull apart the header into the DTLS1_RECORD */
 559                 rr->type= *(p++);
 560                 ssl_major= *(p++);
 561                 ssl_minor= *(p++);
 562                 version=(ssl_major<<8)|ssl_minor;
 563
 564                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 565                 n2s(p,rr->epoch);
 566
 567                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 568                 p+=6;
 569
 570                 n2s(p,rr->length);
 571
 572                 /* Lets check version */
 573                 if (s->first_packet)
 574                         {
 575                         s->first_packet=0;
 576                         }
 577                 else
 578                         {
 579                         if (version != s->version)
 580                                 {
 581                                 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 582                                 /* Send back error using their
 583                                  * version number :-) */
 584                                 s->version=version;
 585                                 al=SSL_AD_PROTOCOL_VERSION;
 586                                 goto f_err;
 587                                 }
 588                         }
 589
 590                 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00))
 591                         {
 592                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 593                         goto err;
 594                         }
 595
 596                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 597                         {
 598                         al=SSL_AD_RECORD_OVERFLOW;
 599                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 600                         goto f_err;
 601                         }
 602
 603                 /* now s->rstate == SSL_ST_READ_BODY */
 604                 }
 605
 606         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 607
 608         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 609                 {
 610                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 611                 i=rr->length;
 612                 n=ssl3_read_n(s,i,i,1);
 613                 if (n <= 0) return(n); /* error or non-blocking io */
 614
 615                 /* this packet contained a partial record, dump it */
 616                 if ( n != i)
 617                         {
 618                         s->packet_length = 0;
 619                         goto again;
 620                         }
 621
 622                 /* now n == rr->length,
 623                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 624                 }
 625         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 626
 627         /* match epochs.  NULL means the packet is dropped on the floor */
 628         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 629         if ( bitmap == NULL)
 630                 {
 631                 s->packet_length = 0;  /* dump this record */
 632                 goto again;   /* get another record */
 633                 }
 634
 635         /* check whether this is a repeat, or aged record */
 636         if ( ! dtls1_record_replay_check(s, bitmap))
 637                 {
 638                 s->packet_length=0; /* dump this record */
 639                 goto again;     /* get another record */
 640                 }
 641
 642         /* just read a 0 length packet */
 643         if (rr->length == 0) goto again;
 644
 645         /* If this record is from the next epoch (either HM or ALERT),
 646          * buffer it since it cannot be processed at this time. Records
 647          * from the next epoch are marked as received even though they
 648          * are not processed, so as to prevent any potential resource
 649          * DoS attack */
 650         if (is_next_epoch)
 651                 {
 652                 dtls1_record_bitmap_update(s, bitmap);
 653                 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 654                 s->packet_length = 0;
 655                 goto again;
 656                 }
 657
 658         if ( ! dtls1_process_record(s))
 659                 return(0);
 660
 661         dtls1_clear_timeouts(s);  /* done waiting */
 662         return(1);
 663
 664 f_err:
 665         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 666 err:
 667         return(0);
 668         }
 669
 670 /* Return up to 'len' payload bytes received in 'type' records.
 671  * 'type' is one of the following:
 672  *
 673  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 674  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 675  *   -  0 (during a shutdown, no data has to be returned)
 676  *
 677  * If we don't have stored data to work from, read a SSL/TLS record first
 678  * (possibly multiple records if we still don't have anything to return).
 679  *
 680  * This function must handle any surprises the peer may have for us, such as
 681  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 682  * a surprise, but handled as if it were), or renegotiation requests.
 683  * Also if record payloads contain fragments too small to process, we store
 684  * them until there is enough for the respective protocol (the record protocol
 685  * may use arbitrary fragmentation and even interleaving):
 686  *     Change cipher spec protocol
 687  *             just 1 byte needed, no need for keeping anything stored
 688  *     Alert protocol
 689  *             2 bytes needed (AlertLevel, AlertDescription)
 690  *     Handshake protocol
 691  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 692  *             to detect unexpected Client Hello and Hello Request messages
 693  *             here, anything else is handled by higher layers
 694  *     Application data protocol
 695  *             none of our business
 696  */
 697 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 698         {
 699         int al,i,j,ret;
 700         unsigned int n;
 701         SSL3_RECORD *rr;
 702         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 703
 704         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 705                 if (!ssl3_setup_buffers(s))
 706                         return(-1);
 707
 708     /* XXX: check what the second '&& type' is about */
 709         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 710                 (type != SSL3_RT_HANDSHAKE) && type) ||
 711             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 712                 {
 713                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 714                 return -1;
 715                 }
 716
 717         /* check whether there's a handshake message (client hello?) waiting */
 718         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 719                 return ret;
 720
 721         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 722
 723         if (!s->in_handshake && SSL_in_init(s))
 724                 {
 725                 /* type == SSL3_RT_APPLICATION_DATA */
 726                 i=s->handshake_func(s);
 727                 if (i < 0) return(i);
 728                 if (i == 0)
 729                         {
 730                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 731                         return(-1);
 732                         }
 733                 }
 734
 735 start:
 736         s->rwstate=SSL_NOTHING;
 737
 738         /* s->s3->rrec.type         - is the type of record
 739          * s->s3->rrec.data,    - data
 740          * s->s3->rrec.off,     - offset into 'data' for next read
 741          * s->s3->rrec.length,  - number of bytes. */
 742         rr = &(s->s3->rrec);
 743
 744         /* get new packet if necessary */
 745         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 746                 {
 747                 ret=dtls1_get_record(s);
 748                 if (ret <= 0)
 749                         {
 750                         ret = dtls1_read_failed(s, ret);
 751                         /* anything other than a timeout is an error */
 752                         if (ret <= 0)
 753                                 return(ret);
 754                         else
 755                                 goto start;
 756                         }
 757                 }
 758
 759         /* we now have a packet which can be read and processed */
 760
 761         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 762                                        * reset by ssl3_get_finished */
 763                 && (rr->type != SSL3_RT_HANDSHAKE))
 764                 {
 765                 al=SSL_AD_UNEXPECTED_MESSAGE;
 766                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
 767                 goto err;
 768                 }
 769
 770         /* If the other end has shut down, throw anything we read away
 771          * (even in 'peek' mode) */
 772         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 773                 {
 774                 rr->length=0;
 775                 s->rwstate=SSL_NOTHING;
 776                 return(0);
 777                 }
 778
 779
 780         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 781                 {
 782                 /* make sure that we are not getting application data when we
 783                  * are doing a handshake for the first time */
 784                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 785                         (s->enc_read_ctx == NULL))
 786                         {
 787                         al=SSL_AD_UNEXPECTED_MESSAGE;
 788                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 789                         goto f_err;
 790                         }
 791
 792                 if (len <= 0) return(len);
 793
 794                 if ((unsigned int)len > rr->length)
 795                         n = rr->length;
 796                 else
 797                         n = (unsigned int)len;
 798
 799                 memcpy(buf,&(rr->data[rr->off]),n);
 800                 if (!peek)
 801                         {
 802                         rr->length-=n;
 803                         rr->off+=n;
 804                         if (rr->length == 0)
 805                                 {
 806                                 s->rstate=SSL_ST_READ_HEADER;
 807                                 rr->off=0;
 808                                 }
 809                         }
 810                 return(n);
 811                 }
 812
 813
 814         /* If we get here, then type != rr->type; if we have a handshake
 815          * message, then it was unexpected (Hello Request or Client Hello). */
 816
 817         /* In case of record types for which we have 'fragment' storage,
 818          * fill that so that we can process the data at a fixed place.
 819          */
 820                 {
 821                 unsigned int k, dest_maxlen = 0;
 822                 unsigned char *dest = NULL;
 823                 unsigned int *dest_len = NULL;
 824
 825                 if (rr->type == SSL3_RT_HANDSHAKE)
 826                         {
 827                         dest_maxlen = sizeof s->d1->handshake_fragment;
 828                         dest = s->d1->handshake_fragment;
 829                         dest_len = &s->d1->handshake_fragment_len;
 830                         }
 831                 else if (rr->type == SSL3_RT_ALERT)
 832                         {
 833                         dest_maxlen = sizeof(s->d1->alert_fragment);
 834                         dest = s->d1->alert_fragment;
 835                         dest_len = &s->d1->alert_fragment_len;
 836                         }
 837                 else    /* else it's a CCS message */
 838                         OPENSSL_assert(rr->type == SSL3_RT_CHANGE_CIPHER_SPEC);
 839
 840
 841                 if (dest_maxlen > 0)
 842                         {
 843             /* XDTLS:  In a pathalogical case, the Client Hello
 844              *  may be fragmented--don't always expect dest_maxlen bytes */
 845                         if ( rr->length < dest_maxlen)
 846                                 {
 847                                 s->rstate=SSL_ST_READ_HEADER;
 848                                 rr->length = 0;
 849                                 goto start;
 850                                 }
 851
 852                         /* now move 'n' bytes: */
 853                         for ( k = 0; k < dest_maxlen; k++)
 854                                 {
 855                                 dest[k] = rr->data[rr->off++];
 856                                 rr->length--;
 857                                 }
 858                         *dest_len = dest_maxlen;
 859                         }
 860                 }
 861
 862         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 863          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 864          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 865
 866         /* If we are a client, check for an incoming 'Hello Request': */
 867         if ((!s->server) &&
 868                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 869                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 870                 (s->session != NULL) && (s->session->cipher != NULL))
 871                 {
 872                 s->d1->handshake_fragment_len = 0;
 873
 874                 if ((s->d1->handshake_fragment[1] != 0) ||
 875                         (s->d1->handshake_fragment[2] != 0) ||
 876                         (s->d1->handshake_fragment[3] != 0))
 877                         {
 878                         al=SSL_AD_DECODE_ERROR;
 879                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 880                         goto err;
 881                         }
 882
 883                 /* no need to check sequence number on HELLO REQUEST messages */
 884
 885                 if (s->msg_callback)
 886                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 887                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 888
 889                 if (SSL_is_init_finished(s) &&
 890                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 891                         !s->s3->renegotiate)
 892                         {
 893                         ssl3_renegotiate(s);
 894                         if (ssl3_renegotiate_check(s))
 895                                 {
 896                                 i=s->handshake_func(s);
 897                                 if (i < 0) return(i);
 898                                 if (i == 0)
 899                                         {
 900                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 901                                         return(-1);
 902                                         }
 903
 904                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 905                                         {
 906                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 907                                                 {
 908                                                 BIO *bio;
 909                                                 /* In the case where we try to read application data,
 910                                                  * but we trigger an SSL handshake, we return -1 with
 911                                                  * the retry option set.  Otherwise renegotiation may
 912                                                  * cause nasty problems in the blocking world */
 913                                                 s->rwstate=SSL_READING;
 914                                                 bio=SSL_get_rbio(s);
 915                                                 BIO_clear_retry_flags(bio);
 916                                                 BIO_set_retry_read(bio);
 917                                                 return(-1);
 918                                                 }
 919                                         }
 920                                 }
 921                         }
 922                 /* we either finished a handshake or ignored the request,
 923                  * now try again to obtain the (application) data we were asked for */
 924                 goto start;
 925                 }
 926
 927         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
 928                 {
 929                 int alert_level = s->d1->alert_fragment[0];
 930                 int alert_descr = s->d1->alert_fragment[1];
 931
 932                 s->d1->alert_fragment_len = 0;
 933
 934                 if (s->msg_callback)
 935                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
 936                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
 937
 938                 if (s->info_callback != NULL)
 939                         cb=s->info_callback;
 940                 else if (s->ctx->info_callback != NULL)
 941                         cb=s->ctx->info_callback;
 942
 943                 if (cb != NULL)
 944                         {
 945                         j = (alert_level << 8) | alert_descr;
 946                         cb(s, SSL_CB_READ_ALERT, j);
 947                         }
 948
 949                 if (alert_level == 1) /* warning */
 950                         {
 951                         s->s3->warn_alert = alert_descr;
 952                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
 953                                 {
 954                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 955                                 return(0);
 956                                 }
 957 #if 0
 958             /* XXX: this is a possible improvement in the future */
 959                         /* now check if it's a missing record */
 960                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
 961                                 {
 962                                 unsigned short seq;
 963                                 unsigned int frag_off;
 964                                 unsigned char *p = &(s->d1->alert_fragment[2]);
 965
 966                                 n2s(p, seq);
 967                                 n2l3(p, frag_off);
 968
 969                                 dtls1_retransmit_message(s, seq, frag_off, &found);
 970                                 if ( ! found  && SSL_in_init(s))
 971                                         {
 972                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
 973                                         /* requested a message not yet sent,
 974                                            send an alert ourselves */
 975                                         ssl3_send_alert(s,SSL3_AL_WARNING,
 976                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 977                                         }
 978                                 }
 979 #endif
 980                         }
 981                 else if (alert_level == 2) /* fatal */
 982                         {
 983                         char tmp[16];
 984
 985                         s->rwstate=SSL_NOTHING;
 986                         s->s3->fatal_alert = alert_descr;
 987                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
 988                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
 989                         ERR_add_error_data(2,"SSL alert number ",tmp);
 990                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
 991                         SSL_CTX_remove_session(s->ctx,s->session);
 992                         return(0);
 993                         }
 994                 else
 995                         {
 996                         al=SSL_AD_ILLEGAL_PARAMETER;
 997                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
 998                         goto f_err;
 999                         }
1000
1001                 goto start;
1002                 }
1003
1004         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1005                 {
1006                 s->rwstate=SSL_NOTHING;
1007                 rr->length=0;
1008                 return(0);
1009                 }
1010
1011         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1012         {
1013         struct ccs_header_st ccs_hdr;
1014
1015                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1016
1017                 if ( ccs_hdr.seq == s->d1->handshake_read_seq)
1018                         {
1019                         /* 'Change Cipher Spec' is just a single byte, so we know
1020                          * exactly what the record payload has to look like */
1021                         /* XDTLS: check that epoch is consistent */
1022                         if (    (rr->length != DTLS1_CCS_HEADER_LENGTH) ||
1023                                 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1024                                 {
1025                                 i=SSL_AD_ILLEGAL_PARAMETER;
1026                                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1027                                 goto err;
1028                                 }
1029
1030                         rr->length=0;
1031
1032                         if (s->msg_callback)
1033                                 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1034                                         rr->data, 1, s, s->msg_callback_arg);
1035
1036                         s->s3->change_cipher_spec=1;
1037                         if (!ssl3_do_change_cipher_spec(s))
1038                                 goto err;
1039
1040                         /* do this whenever CCS is processed */
1041                         dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1042
1043                         /* handshake read seq is reset upon handshake completion */
1044                         s->d1->handshake_read_seq++;
1045
1046                         goto start;
1047                         }
1048                 else
1049                         {
1050                         rr->length = 0;
1051                         goto start;
1052                         }
1053                 }
1054
1055         /* Unexpected handshake message (Client Hello, or protocol violation) */
1056         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1057                 !s->in_handshake)
1058                 {
1059                 struct hm_header_st msg_hdr;
1060
1061                 /* this may just be a stale retransmit */
1062                 dtls1_get_message_header(rr->data, &msg_hdr);
1063                 if( rr->epoch != s->d1->r_epoch)
1064                         {
1065                         rr->length = 0;
1066                         goto start;
1067                         }
1068
1069                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1070                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1071                         {
1072 #if 0 /* worked only because C operator preferences are not as expected (and
1073        * because this is not really needed for clients except for detecting
1074        * protocol violations): */
1075                         s->state=SSL_ST_BEFORE|(s->server)
1076                                 ?SSL_ST_ACCEPT
1077                                 :SSL_ST_CONNECT;
1078 #else
1079                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1080 #endif
1081                         s->new_session=1;
1082                         }
1083                 i=s->handshake_func(s);
1084                 if (i < 0) return(i);
1085                 if (i == 0)
1086                         {
1087                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1088                         return(-1);
1089                         }
1090
1091                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1092                         {
1093                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1094                                 {
1095                                 BIO *bio;
1096                                 /* In the case where we try to read application data,
1097                                  * but we trigger an SSL handshake, we return -1 with
1098                                  * the retry option set.  Otherwise renegotiation may
1099                                  * cause nasty problems in the blocking world */
1100                                 s->rwstate=SSL_READING;
1101                                 bio=SSL_get_rbio(s);
1102                                 BIO_clear_retry_flags(bio);
1103                                 BIO_set_retry_read(bio);
1104                                 return(-1);
1105                                 }
1106                         }
1107                 goto start;
1108                 }
1109
1110         switch (rr->type)
1111                 {
1112         default:
1113 #ifndef OPENSSL_NO_TLS
1114                 /* TLS just ignores unknown message types */
1115                 if (s->version == TLS1_VERSION)
1116                         {
1117                         rr->length = 0;
1118                         goto start;
1119                         }
1120 #endif
1121                 al=SSL_AD_UNEXPECTED_MESSAGE;
1122                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1123                 goto f_err;
1124         case SSL3_RT_CHANGE_CIPHER_SPEC:
1125         case SSL3_RT_ALERT:
1126         case SSL3_RT_HANDSHAKE:
1127                 /* we already handled all of these, with the possible exception
1128                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1129                  * should not happen when type != rr->type */
1130                 al=SSL_AD_UNEXPECTED_MESSAGE;
1131                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1132                 goto f_err;
1133         case SSL3_RT_APPLICATION_DATA:
1134                 /* At this point, we were expecting handshake data,
1135                  * but have application data.  If the library was
1136                  * running inside ssl3_read() (i.e. in_read_app_data
1137                  * is set) and it makes sense to read application data
1138                  * at this point (session renegotiation not yet started),
1139                  * we will indulge it.
1140                  */
1141                 if (s->s3->in_read_app_data &&
1142                         (s->s3->total_renegotiations != 0) &&
1143                         ((
1144                                 (s->state & SSL_ST_CONNECT) &&
1145                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1146                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1147                                 ) || (
1148                                         (s->state & SSL_ST_ACCEPT) &&
1149                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1150                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1151                                         )
1152                                 ))
1153                         {
1154                         s->s3->in_read_app_data=2;
1155                         return(-1);
1156                         }
1157                 else
1158                         {
1159                         al=SSL_AD_UNEXPECTED_MESSAGE;
1160                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1161                         goto f_err;
1162                         }
1163                 }
1164         /* not reached */
1165
1166 f_err:
1167         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1168 err:
1169         return(-1);
1170         }
1171
1172 int
1173 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1174         {
1175         unsigned int n,tot;
1176         int i;
1177
1178         if (SSL_in_init(s) && !s->in_handshake)
1179                 {
1180                 i=s->handshake_func(s);
1181                 if (i < 0) return(i);
1182                 if (i == 0)
1183                         {
1184                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1185                         return -1;
1186                         }
1187                 }
1188
1189         tot = s->s3->wnum;
1190         n = len - tot;
1191
1192         while( n)
1193                 {
1194                 /* dtls1_write_bytes sends one record at a time, sized according to
1195                  * the currently known MTU */
1196                 i = dtls1_write_bytes(s, type, buf_, len);
1197                 if (i <= 0) return i;
1198
1199                 if ((i == (int)n) ||
1200                         (type == SSL3_RT_APPLICATION_DATA &&
1201                                 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1202                         {
1203                         /* next chunk of data should get another prepended empty fragment
1204                          * in ciphersuites with known-IV weakness: */
1205                         s->s3->empty_fragment_done = 0;
1206                         return tot+i;
1207                         }
1208
1209                 tot += i;
1210                 n-=i;
1211                 }
1212
1213         return tot;
1214         }
1215
1216
1217         /* this only happens when a client hello is received and a handshake
1218          * is started. */
1219 static int
1220 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1221         int len, int peek)
1222         {
1223
1224         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1225                 /* (partially) satisfy request from storage */
1226                 {
1227                 unsigned char *src = s->d1->handshake_fragment;
1228                 unsigned char *dst = buf;
1229                 unsigned int k,n;
1230
1231                 /* peek == 0 */
1232                 n = 0;
1233                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1234                         {
1235                         *dst++ = *src++;
1236                         len--; s->d1->handshake_fragment_len--;
1237                         n++;
1238                         }
1239                 /* move any remaining fragment bytes: */
1240                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1241                         s->d1->handshake_fragment[k] = *src++;
1242                 return n;
1243                 }
1244
1245         return 0;
1246         }
1247
1248
1249
1250
1251 /* Call this to write data in records of type 'type'
1252  * It will return <= 0 if not all data has been sent or non-blocking IO.
1253  */
1254 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1255         {
1256         const unsigned char *buf=buf_;
1257         unsigned int tot,n,nw;
1258         int i;
1259         unsigned int mtu;
1260
1261         s->rwstate=SSL_NOTHING;
1262         tot=s->s3->wnum;
1263
1264         n=(len-tot);
1265
1266         /* handshake layer figures out MTU for itself, but data records
1267          * are also sent through this interface, so need to figure out MTU */
1268 #if 0
1269         mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1270         mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
1271 #endif
1272         mtu = s->d1->mtu;
1273
1274         if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1275                 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1276
1277         if (n > mtu)
1278                 nw=mtu;
1279         else
1280                 nw=n;
1281
1282         i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1283         if (i <= 0)
1284                 {
1285                 s->s3->wnum=tot;
1286                 return i;
1287                 }
1288
1289         if ( (int)s->s3->wnum + i == len)
1290                 s->s3->wnum = 0;
1291         else
1292                 s->s3->wnum += i;
1293
1294         return tot + i;
1295         }
1296
1297 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1298         {
1299         unsigned char *p,*pseq;
1300         int i,mac_size,clear=0;
1301         int prefix_len = 0;
1302         SSL3_RECORD *wr;
1303         SSL3_BUFFER *wb;
1304         SSL_SESSION *sess;
1305         int bs;
1306
1307         /* first check if there is a SSL3_BUFFER still being written
1308          * out.  This will happen with non blocking IO */
1309         if (s->s3->wbuf.left != 0)
1310                 {
1311                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1312                 return(ssl3_write_pending(s,type,buf,len));
1313                 }
1314
1315         /* If we have an alert to send, lets send it */
1316         if (s->s3->alert_dispatch)
1317                 {
1318                 i=s->method->ssl_dispatch_alert(s);
1319                 if (i <= 0)
1320                         return(i);
1321                 /* if it went, fall through and send more stuff */
1322                 }
1323
1324         if (len == 0 && !create_empty_fragment)
1325                 return 0;
1326
1327         wr= &(s->s3->wrec);
1328         wb= &(s->s3->wbuf);
1329         sess=s->session;
1330
1331         if (    (sess == NULL) ||
1332                 (s->enc_write_ctx == NULL) ||
1333                 (s->write_hash == NULL))
1334                 clear=1;
1335
1336         if (clear)
1337                 mac_size=0;
1338         else
1339                 mac_size=EVP_MD_size(s->write_hash);
1340
1341         /* DTLS implements explicit IV, so no need for empty fragments */
1342 #if 0
1343         /* 'create_empty_fragment' is true only when this function calls itself */
1344         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1345                 && SSL_version(s) != DTLS1_VERSION)
1346                 {
1347                 /* countermeasure against known-IV weakness in CBC ciphersuites
1348                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1349                  */
1350
1351                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1352                         {
1353                         /* recursive function call with 'create_empty_fragment' set;
1354                          * this prepares and buffers the data for an empty fragment
1355                          * (these 'prefix_len' bytes are sent out later
1356                          * together with the actual payload) */
1357                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1358                         if (prefix_len <= 0)
1359                                 goto err;
1360
1361                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1362                                 {
1363                                 /* insufficient space */
1364                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1365                                 goto err;
1366                                 }
1367                         }
1368
1369                 s->s3->empty_fragment_done = 1;
1370                 }
1371 #endif
1372
1373         p = wb->buf + prefix_len;
1374
1375         /* write the header */
1376
1377         *(p++)=type&0xff;
1378         wr->type=type;
1379
1380         *(p++)=(s->version>>8);
1381         *(p++)=s->version&0xff;
1382
1383         /* field where we are to write out packet epoch, seq num and len */
1384         pseq=p;
1385         p+=10;
1386
1387         /* lets setup the record stuff. */
1388
1389         /* Make space for the explicit IV in case of CBC.
1390          * (this is a bit of a boundary violation, but what the heck).
1391          */
1392         if ( s->enc_write_ctx &&
1393                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1394                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1395         else
1396                 bs = 0;
1397
1398         wr->data=p + bs;  /* make room for IV in case of CBC */
1399         wr->length=(int)len;
1400         wr->input=(unsigned char *)buf;
1401
1402         /* we now 'read' from wr->input, wr->length bytes into
1403          * wr->data */
1404
1405         /* first we compress */
1406         if (s->compress != NULL)
1407                 {
1408                 if (!ssl3_do_compress(s))
1409                         {
1410                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1411                         goto err;
1412                         }
1413                 }
1414         else
1415                 {
1416                 memcpy(wr->data,wr->input,wr->length);
1417                 wr->input=wr->data;
1418                 }
1419
1420         /* we should still have the output to wr->data and the input
1421          * from wr->input.  Length should be wr->length.
1422          * wr->data still points in the wb->buf */
1423
1424         if (mac_size != 0)
1425                 {
1426                 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1427                 wr->length+=mac_size;
1428                 }
1429
1430         /* this is true regardless of mac size */
1431         wr->input=p;
1432         wr->data=p;
1433
1434
1435         /* ssl3_enc can only have an error on read */
1436         wr->length += bs;  /* bs != 0 in case of CBC.  The enc fn provides
1437                                                 * the randomness */
1438         s->method->ssl3_enc->enc(s,1);
1439
1440         /* record length after mac and block padding */
1441 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1442         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1443
1444         /* there's only one epoch between handshake and app data */
1445
1446         s2n(s->d1->w_epoch, pseq);
1447
1448         /* XDTLS: ?? */
1449 /*      else
1450         s2n(s->d1->handshake_epoch, pseq); */
1451
1452         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1453         pseq+=6;
1454         s2n(wr->length,pseq);
1455
1456         /* we should now have
1457          * wr->data pointing to the encrypted data, which is
1458          * wr->length long */
1459         wr->type=type; /* not needed but helps for debugging */
1460         wr->length+=DTLS1_RT_HEADER_LENGTH;
1461
1462 #if 0  /* this is now done at the message layer */
1463         /* buffer the record, making it easy to handle retransmits */
1464         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1465                 dtls1_buffer_record(s, wr->data, wr->length,
1466                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1467 #endif
1468
1469         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1470
1471         if (create_empty_fragment)
1472                 {
1473                 /* we are in a recursive call;
1474                  * just return the length, don't write out anything here
1475                  */
1476                 return wr->length;
1477                 }
1478
1479         /* now let's set up wb */
1480         wb->left = prefix_len + wr->length;
1481         wb->offset = 0;
1482
1483         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1484         s->s3->wpend_tot=len;
1485         s->s3->wpend_buf=buf;
1486         s->s3->wpend_type=type;
1487         s->s3->wpend_ret=len;
1488
1489         /* we now just need to write the buffer */
1490         return ssl3_write_pending(s,type,buf,len);
1491 err:
1492         return -1;
1493         }
1494
1495
1496
1497 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1498         {
1499         int cmp;
1500         unsigned int shift;
1501         const unsigned char *seq = s->s3->read_sequence;
1502
1503         cmp = satsub64be(seq,bitmap->max_seq_num);
1504         if (cmp > 0)
1505                 {
1506                 memcpy (s->s3->rrec.seq_num,seq,8);
1507                 return 1; /* this record in new */
1508                 }
1509         shift = -cmp;
1510         if (shift >= sizeof(bitmap->map)*8)
1511                 return 0; /* stale, outside the window */
1512         else if (bitmap->map & (1UL<<shift))
1513                 return 0; /* record previously received */
1514
1515         memcpy (s->s3->rrec.seq_num,seq,8);
1516         return 1;
1517         }
1518
1519
1520 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1521         {
1522         int cmp;
1523         unsigned int shift;
1524         const unsigned char *seq = s->s3->read_sequence;
1525
1526         cmp = satsub64be(seq,bitmap->max_seq_num);
1527         if (cmp > 0)
1528                 {
1529                 shift = cmp;
1530                 if (shift < sizeof(bitmap->map)*8)
1531                         bitmap->map <<= shift, bitmap->map |= 1UL;
1532                 else
1533                         bitmap->map = 1UL;
1534                 memcpy(bitmap->max_seq_num,seq,8);
1535                 }
1536         else    {
1537                 shift = -cmp;
1538                 if (shift < sizeof(bitmap->map)*8)
1539                         bitmap->map |= 1UL<<shift;
1540                 }
1541         }
1542
1543
1544 int dtls1_dispatch_alert(SSL *s)
1545         {
1546         int i,j;
1547         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1548         unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */
1549         unsigned char *ptr = &buf[0];
1550
1551         s->s3->alert_dispatch=0;
1552
1553         memset(buf, 0x00, sizeof(buf));
1554         *ptr++ = s->s3->send_alert[0];
1555         *ptr++ = s->s3->send_alert[1];
1556
1557         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1558                 {
1559                 s2n(s->d1->handshake_read_seq, ptr);
1560 #if 0
1561                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1562
1563                 else
1564                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1565 #endif
1566
1567 #if 0
1568                 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);
1569 #endif
1570                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1571                 }
1572
1573         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1574         if (i <= 0)
1575                 {
1576                 s->s3->alert_dispatch=1;
1577                 /* fprintf( stderr, "not done with alert\n" ); */
1578                 }
1579         else
1580                 {
1581                 if ( s->s3->send_alert[0] == SSL3_AL_FATAL ||
1582                         s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1583                         (void)BIO_flush(s->wbio);
1584
1585                 if (s->msg_callback)
1586                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1587                                 2, s, s->msg_callback_arg);
1588
1589                 if (s->info_callback != NULL)
1590                         cb=s->info_callback;
1591                 else if (s->ctx->info_callback != NULL)
1592                         cb=s->ctx->info_callback;
1593
1594                 if (cb != NULL)
1595                         {
1596                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1597                         cb(s,SSL_CB_WRITE_ALERT,j);
1598                         }
1599                 }
1600         return(i);
1601         }
1602
1603
1604 static DTLS1_BITMAP *
1605 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1606     {
1607
1608     *is_next_epoch = 0;
1609
1610     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1611     if (rr->epoch == s->d1->r_epoch)
1612         return &s->d1->bitmap;
1613
1614     /* Only HM and ALERT messages can be from the next epoch */
1615     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1616         (rr->type == SSL3_RT_HANDSHAKE ||
1617             rr->type == SSL3_RT_ALERT))
1618         {
1619         *is_next_epoch = 1;
1620         return &s->d1->next_bitmap;
1621         }
1622
1623     return NULL;
1624     }
1625
1626 #if 0
1627 static int
1628 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1629         unsigned long *offset)
1630         {
1631
1632         /* alerts are passed up immediately */
1633         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1634                 rr->type == SSL3_RT_ALERT)
1635                 return 0;
1636
1637         /* Only need to buffer if a handshake is underway.
1638          * (this implies that Hello Request and Client Hello are passed up
1639          * immediately) */
1640         if ( SSL_in_init(s))
1641                 {
1642                 unsigned char *data = rr->data;
1643                 /* need to extract the HM/CCS sequence number here */
1644                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1645                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1646                         {
1647                         unsigned short seq_num;
1648                         struct hm_header_st msg_hdr;
1649                         struct ccs_header_st ccs_hdr;
1650
1651                         if ( rr->type == SSL3_RT_HANDSHAKE)
1652                                 {
1653                                 dtls1_get_message_header(data, &msg_hdr);
1654                                 seq_num = msg_hdr.seq;
1655                                 *offset = msg_hdr.frag_off;
1656                                 }
1657                         else
1658                                 {
1659                                 dtls1_get_ccs_header(data, &ccs_hdr);
1660                                 seq_num = ccs_hdr.seq;
1661                                 *offset = 0;
1662                                 }
1663
1664                         /* this is either a record we're waiting for, or a
1665                          * retransmit of something we happened to previously
1666                          * receive (higher layers will drop the repeat silently */
1667                         if ( seq_num < s->d1->handshake_read_seq)
1668                                 return 0;
1669                         if (rr->type == SSL3_RT_HANDSHAKE &&
1670                                 seq_num == s->d1->handshake_read_seq &&
1671                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1672                                 return 0;
1673                         else if ( seq_num == s->d1->handshake_read_seq &&
1674                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1675                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1676                                 return 0;
1677                         else
1678                                 {
1679                                 *priority = seq_num;
1680                                 return 1;
1681                                 }
1682                         }
1683                 else /* unknown record type */
1684                         return 0;
1685                 }
1686
1687         return 0;
1688         }
1689 #endif
1690
1691 void
1692 dtls1_reset_seq_numbers(SSL *s, int rw)
1693         {
1694         unsigned char *seq;
1695         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1696
1697         if ( rw & SSL3_CC_READ)
1698                 {
1699                 seq = s->s3->read_sequence;
1700                 s->d1->r_epoch++;
1701                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1702                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1703                 }
1704         else
1705                 {
1706                 seq = s->s3->write_sequence;
1707                 s->d1->w_epoch++;
1708                 }
1709
1710         memset(seq, 0x00, seq_bytes);
1711         }
1712
1713 #if PQ_64BIT_IS_INTEGER
1714 static PQ_64BIT
1715 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
1716        {
1717        PQ_64BIT _num;
1718
1719        _num = (((PQ_64BIT)bytes[0]) << 56) |
1720                (((PQ_64BIT)bytes[1]) << 48) |
1721                (((PQ_64BIT)bytes[2]) << 40) |
1722                (((PQ_64BIT)bytes[3]) << 32) |
1723                (((PQ_64BIT)bytes[4]) << 24) |
1724                (((PQ_64BIT)bytes[5]) << 16) |
1725                (((PQ_64BIT)bytes[6]) <<  8) |
1726                (((PQ_64BIT)bytes[7])      );
1727
1728            *num = _num ;
1729        return _num;
1730        }
1731 #endif
1732
1733
1734 static void
1735 dtls1_clear_timeouts(SSL *s)
1736         {
1737         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1738         }