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 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
 125         int len, int peek);
 126 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
 127         PQ_64BIT *seq_num);
 128 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
 129 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
 130     unsigned int *is_next_epoch);
 131 #if 0
 132 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
 133         unsigned short *priority, unsigned long *offset);
 134 #endif
 135 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
 136         PQ_64BIT priority);
 137 static int dtls1_process_record(SSL *s);
 138 #if !(defined(OPENSSL_SYS_VMS) || defined(VMS_TEST))
 139 static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num);
 140 #endif
 141 static void dtls1_clear_timeouts(SSL *s);
 142
 143 /* copy buffered record into SSL structure */
 144 static int
 145 dtls1_copy_record(SSL *s, pitem *item)
 146     {
 147     DTLS1_RECORD_DATA *rdata;
 148
 149     rdata = (DTLS1_RECORD_DATA *)item->data;
 150
 151     if (s->s3->rbuf.buf != NULL)
 152         OPENSSL_free(s->s3->rbuf.buf);
 153
 154     s->packet = rdata->packet;
 155     s->packet_length = rdata->packet_length;
 156     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 157     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 158
 159     return(1);
 160     }
 161
 162
 163 static int
 164 dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT priority)
 165 {
 166     DTLS1_RECORD_DATA *rdata;
 167         pitem *item;
 168
 169         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 170         item = pitem_new(priority, rdata);
 171         if (rdata == NULL || item == NULL)
 172                 {
 173                 if (rdata != NULL) OPENSSL_free(rdata);
 174                 if (item != NULL) pitem_free(item);
 175
 176                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 177                 return(0);
 178                 }
 179
 180         rdata->packet = s->packet;
 181         rdata->packet_length = s->packet_length;
 182         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 183         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 184
 185         item->data = rdata;
 186
 187         /* insert should not fail, since duplicates are dropped */
 188         if (pqueue_insert(queue->q, item) == NULL)
 189                 {
 190                 OPENSSL_free(rdata);
 191                 pitem_free(item);
 192                 return(0);
 193                 }
 194
 195         s->packet = NULL;
 196         s->packet_length = 0;
 197         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 198         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 199
 200         ssl3_setup_buffers(s);
 201
 202         return(1);
 203     }
 204
 205
 206 static int
 207 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 208     {
 209     pitem *item;
 210
 211     item = pqueue_pop(queue->q);
 212     if (item)
 213         {
 214         dtls1_copy_record(s, item);
 215
 216         OPENSSL_free(item->data);
 217                 pitem_free(item);
 218
 219         return(1);
 220         }
 221
 222     return(0);
 223     }
 224
 225
 226 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 227  * yet */
 228 #define dtls1_get_unprocessed_record(s) \
 229                    dtls1_retrieve_buffered_record((s), \
 230                    &((s)->d1->unprocessed_rcds))
 231
 232 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 233 #define dtls1_get_processed_record(s) \
 234                    dtls1_retrieve_buffered_record((s), \
 235                    &((s)->d1->processed_rcds))
 236
 237 static int
 238 dtls1_process_buffered_records(SSL *s)
 239     {
 240     pitem *item;
 241
 242     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 243     if (item)
 244         {
 245         DTLS1_RECORD_DATA *rdata;
 246         rdata = (DTLS1_RECORD_DATA *)item->data;
 247
 248         /* Check if epoch is current. */
 249         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 250             return(1);  /* Nothing to do. */
 251
 252         /* Process all the records. */
 253         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 254             {
 255             dtls1_get_unprocessed_record(s);
 256             if ( ! dtls1_process_record(s))
 257                 return(0);
 258             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 259                 s->s3->rrec.seq_num);
 260             }
 261         }
 262
 263     /* sync epoch numbers once all the unprocessed records
 264      * have been processed */
 265     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 266     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 267
 268     return(1);
 269     }
 270
 271
 272 #if 0
 273
 274 static int
 275 dtls1_get_buffered_record(SSL *s)
 276         {
 277         pitem *item;
 278         PQ_64BIT priority =
 279                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 280                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 281
 282         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 283                                                            nothing buffered */
 284                 return 0;
 285
 286
 287         item = pqueue_peek(s->d1->rcvd_records);
 288         if (item && item->priority == priority)
 289                 {
 290                 /* Check if we've received the record of interest.  It must be
 291                  * a handshake record, since data records as passed up without
 292                  * buffering */
 293                 DTLS1_RECORD_DATA *rdata;
 294                 item = pqueue_pop(s->d1->rcvd_records);
 295                 rdata = (DTLS1_RECORD_DATA *)item->data;
 296
 297                 if (s->s3->rbuf.buf != NULL)
 298                         OPENSSL_free(s->s3->rbuf.buf);
 299
 300                 s->packet = rdata->packet;
 301                 s->packet_length = rdata->packet_length;
 302                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 303                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 304
 305                 OPENSSL_free(item->data);
 306                 pitem_free(item);
 307
 308                 /* s->d1->next_expected_seq_num++; */
 309                 return(1);
 310                 }
 311
 312         return 0;
 313         }
 314
 315 #endif
 316
 317 static int
 318 dtls1_process_record(SSL *s)
 319 {
 320     int i,al;
 321         int clear=0;
 322     int enc_err;
 323         SSL_SESSION *sess;
 324     SSL3_RECORD *rr;
 325         unsigned int mac_size;
 326         unsigned char md[EVP_MAX_MD_SIZE];
 327
 328
 329         rr= &(s->s3->rrec);
 330     sess = s->session;
 331
 332         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 333          * and we have that many bytes in s->packet
 334          */
 335         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 336
 337         /* ok, we can now read from 's->packet' data into 'rr'
 338          * rr->input points at rr->length bytes, which
 339          * need to be copied into rr->data by either
 340          * the decryption or by the decompression
 341          * When the data is 'copied' into the rr->data buffer,
 342          * rr->input will be pointed at the new buffer */
 343
 344         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 345          * rr->length bytes of encrypted compressed stuff. */
 346
 347         /* check is not needed I believe */
 348         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 349                 {
 350                 al=SSL_AD_RECORD_OVERFLOW;
 351                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 352                 goto f_err;
 353                 }
 354
 355         /* decrypt in place in 'rr->input' */
 356         rr->data=rr->input;
 357
 358         enc_err = s->method->ssl3_enc->enc(s,0);
 359         if (enc_err <= 0)
 360                 {
 361                 if (enc_err == 0)
 362                         /* SSLerr() and ssl3_send_alert() have been called */
 363                         goto err;
 364
 365                 /* otherwise enc_err == -1 */
 366                 goto decryption_failed_or_bad_record_mac;
 367                 }
 368
 369 #ifdef TLS_DEBUG
 370 printf("dec %d\n",rr->length);
 371 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 372 printf("\n");
 373 #endif
 374
 375         /* r->length is now the compressed data plus mac */
 376 if (    (sess == NULL) ||
 377                 (s->enc_read_ctx == NULL) ||
 378                 (s->read_hash == NULL))
 379     clear=1;
 380
 381         if (!clear)
 382                 {
 383                 mac_size=EVP_MD_size(s->read_hash);
 384
 385                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 386                         {
 387 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 388                         al=SSL_AD_RECORD_OVERFLOW;
 389                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 390                         goto f_err;
 391 #else
 392                         goto decryption_failed_or_bad_record_mac;
 393 #endif
 394                         }
 395                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 396                 if (rr->length < mac_size)
 397                         {
 398 #if 0 /* OK only for stream ciphers */
 399                         al=SSL_AD_DECODE_ERROR;
 400                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 401                         goto f_err;
 402 #else
 403                         goto decryption_failed_or_bad_record_mac;
 404 #endif
 405                         }
 406                 rr->length-=mac_size;
 407                 i=s->method->ssl3_enc->mac(s,md,0);
 408                 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 409                         {
 410                         goto decryption_failed_or_bad_record_mac;
 411                         }
 412                 }
 413
 414         /* r->length is now just compressed */
 415         if (s->expand != NULL)
 416                 {
 417                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 418                         {
 419                         al=SSL_AD_RECORD_OVERFLOW;
 420                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 421                         goto f_err;
 422                         }
 423                 if (!ssl3_do_uncompress(s))
 424                         {
 425                         al=SSL_AD_DECOMPRESSION_FAILURE;
 426                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 427                         goto f_err;
 428                         }
 429                 }
 430
 431         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 432                 {
 433                 al=SSL_AD_RECORD_OVERFLOW;
 434                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 435                 goto f_err;
 436                 }
 437
 438         rr->off=0;
 439         /* So at this point the following is true
 440          * ssl->s3->rrec.type   is the type of record
 441          * ssl->s3->rrec.length == number of bytes in record
 442          * ssl->s3->rrec.off    == offset to first valid byte
 443          * ssl->s3->rrec.data   == where to take bytes from, increment
 444          *                         after use :-).
 445          */
 446
 447         /* we have pulled in a full packet so zero things */
 448         s->packet_length=0;
 449     dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 450     return(1);
 451
 452 decryption_failed_or_bad_record_mac:
 453         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
 454          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 455          * failure is directly visible from the ciphertext anyway,
 456          * we should not reveal which kind of error occured -- this
 457          * might become visible to an attacker (e.g. via logfile) */
 458         al=SSL_AD_BAD_RECORD_MAC;
 459         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 460 f_err:
 461         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 462 err:
 463         return(0);
 464 }
 465
 466
 467 /* Call this to get a new input record.
 468  * It will return <= 0 if more data is needed, normally due to an error
 469  * or non-blocking IO.
 470  * When it finishes, one packet has been decoded and can be found in
 471  * ssl->s3->rrec.type    - is the type of record
 472  * ssl->s3->rrec.data,   - data
 473  * ssl->s3->rrec.length, - number of bytes
 474  */
 475 /* used only by dtls1_read_bytes */
 476 int dtls1_get_record(SSL *s)
 477         {
 478         int ssl_major,ssl_minor,al;
 479         int i,n;
 480         SSL3_RECORD *rr;
 481         SSL_SESSION *sess;
 482         unsigned char *p;
 483         short version;
 484         DTLS1_BITMAP *bitmap;
 485     unsigned int is_next_epoch;
 486
 487         rr= &(s->s3->rrec);
 488         sess=s->session;
 489
 490     /* The epoch may have changed.  If so, process all the
 491      * pending records.  This is a non-blocking operation. */
 492     if ( ! dtls1_process_buffered_records(s))
 493         return 0;
 494
 495         /* if we're renegotiating, then there may be buffered records */
 496         if (dtls1_get_processed_record(s))
 497                 return 1;
 498
 499         /* get something from the wire */
 500 again:
 501         /* check if we have the header */
 502         if (    (s->rstate != SSL_ST_READ_BODY) ||
 503                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 504                 {
 505                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 506                 /* read timeout is handled by dtls1_read_bytes */
 507                 if (n <= 0) return(n); /* error or non-blocking */
 508
 509                 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
 510
 511                 s->rstate=SSL_ST_READ_BODY;
 512
 513                 p=s->packet;
 514
 515                 /* Pull apart the header into the DTLS1_RECORD */
 516                 rr->type= *(p++);
 517                 ssl_major= *(p++);
 518                 ssl_minor= *(p++);
 519                 version=(ssl_major<<8)|ssl_minor;
 520
 521         /* sequence number is 64 bits, with top 2 bytes = epoch */
 522                 n2s(p,rr->epoch);
 523
 524                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 525                 p+=6;
 526
 527                 n2s(p,rr->length);
 528
 529                 /* Lets check version */
 530                 if (s->first_packet)
 531                         {
 532                         s->first_packet=0;
 533                         }
 534                 else
 535                         {
 536                         if (version != s->version)
 537                                 {
 538                                 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 539                                 /* Send back error using their
 540                                  * version number :-) */
 541                                 s->version=version;
 542                                 al=SSL_AD_PROTOCOL_VERSION;
 543                                 goto f_err;
 544                                 }
 545                         }
 546
 547                 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00))
 548                         {
 549                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 550                         goto err;
 551                         }
 552
 553                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 554                         {
 555                         al=SSL_AD_RECORD_OVERFLOW;
 556                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 557                         goto f_err;
 558                         }
 559
 560                 /* now s->rstate == SSL_ST_READ_BODY */
 561                 }
 562
 563         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 564
 565         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 566                 {
 567                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 568                 i=rr->length;
 569                 n=ssl3_read_n(s,i,i,1);
 570                 if (n <= 0) return(n); /* error or non-blocking io */
 571
 572                 /* this packet contained a partial record, dump it */
 573                 if ( n != i)
 574                         {
 575                         s->packet_length = 0;
 576                         goto again;
 577                         }
 578
 579                 /* now n == rr->length,
 580                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 581                 }
 582         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 583
 584         /* match epochs.  NULL means the packet is dropped on the floor */
 585         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 586         if ( bitmap == NULL)
 587         {
 588         s->packet_length = 0;  /* dump this record */
 589         goto again;   /* get another record */
 590                 }
 591
 592         /* check whether this is a repeat, or aged record */
 593         if ( ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))
 594                 {
 595                 s->packet_length=0; /* dump this record */
 596                 goto again;     /* get another record */
 597                 }
 598
 599         /* just read a 0 length packet */
 600         if (rr->length == 0) goto again;
 601
 602     /* If this record is from the next epoch (either HM or ALERT), buffer it
 603      * since it cannot be processed at this time.
 604      * Records from the next epoch are marked as received even though they are
 605      * not processed, so as to prevent any potential resource DoS attack */
 606     if (is_next_epoch)
 607         {
 608         dtls1_record_bitmap_update(s, bitmap);
 609         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 610         s->packet_length = 0;
 611         goto again;
 612         }
 613
 614     if ( ! dtls1_process_record(s))
 615         return(0);
 616
 617         dtls1_clear_timeouts(s);  /* done waiting */
 618         return(1);
 619
 620 f_err:
 621         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 622 err:
 623         return(0);
 624         }
 625
 626 /* Return up to 'len' payload bytes received in 'type' records.
 627  * 'type' is one of the following:
 628  *
 629  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 630  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 631  *   -  0 (during a shutdown, no data has to be returned)
 632  *
 633  * If we don't have stored data to work from, read a SSL/TLS record first
 634  * (possibly multiple records if we still don't have anything to return).
 635  *
 636  * This function must handle any surprises the peer may have for us, such as
 637  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 638  * a surprise, but handled as if it were), or renegotiation requests.
 639  * Also if record payloads contain fragments too small to process, we store
 640  * them until there is enough for the respective protocol (the record protocol
 641  * may use arbitrary fragmentation and even interleaving):
 642  *     Change cipher spec protocol
 643  *             just 1 byte needed, no need for keeping anything stored
 644  *     Alert protocol
 645  *             2 bytes needed (AlertLevel, AlertDescription)
 646  *     Handshake protocol
 647  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 648  *             to detect unexpected Client Hello and Hello Request messages
 649  *             here, anything else is handled by higher layers
 650  *     Application data protocol
 651  *             none of our business
 652  */
 653 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 654         {
 655         int al,i,j,ret;
 656         unsigned int n;
 657         SSL3_RECORD *rr;
 658         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 659
 660         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 661                 if (!ssl3_setup_buffers(s))
 662                         return(-1);
 663
 664     /* XXX: check what the second '&& type' is about */
 665         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 666                 (type != SSL3_RT_HANDSHAKE) && type) ||
 667             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 668                 {
 669                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 670                 return -1;
 671                 }
 672
 673         /* check whether there's a handshake message (client hello?) waiting */
 674         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 675                 return ret;
 676
 677         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 678
 679         if (!s->in_handshake && SSL_in_init(s))
 680                 {
 681                 /* type == SSL3_RT_APPLICATION_DATA */
 682                 i=s->handshake_func(s);
 683                 if (i < 0) return(i);
 684                 if (i == 0)
 685                         {
 686                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 687                         return(-1);
 688                         }
 689                 }
 690
 691 start:
 692         s->rwstate=SSL_NOTHING;
 693
 694         /* s->s3->rrec.type         - is the type of record
 695          * s->s3->rrec.data,    - data
 696          * s->s3->rrec.off,     - offset into 'data' for next read
 697          * s->s3->rrec.length,  - number of bytes. */
 698         rr = &(s->s3->rrec);
 699
 700         /* get new packet if necessary */
 701         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 702                 {
 703                 ret=dtls1_get_record(s);
 704                 if (ret <= 0)
 705                         {
 706                         ret = dtls1_read_failed(s, ret);
 707                         /* anything other than a timeout is an error */
 708                         if (ret <= 0)
 709                                 return(ret);
 710                         else
 711                                 goto start;
 712                         }
 713                 }
 714
 715         /* we now have a packet which can be read and processed */
 716
 717         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 718                                        * reset by ssl3_get_finished */
 719                 && (rr->type != SSL3_RT_HANDSHAKE))
 720                 {
 721                 al=SSL_AD_UNEXPECTED_MESSAGE;
 722                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
 723                 goto err;
 724                 }
 725
 726         /* If the other end has shut down, throw anything we read away
 727          * (even in 'peek' mode) */
 728         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 729                 {
 730                 rr->length=0;
 731                 s->rwstate=SSL_NOTHING;
 732                 return(0);
 733                 }
 734
 735
 736         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 737                 {
 738                 /* make sure that we are not getting application data when we
 739                  * are doing a handshake for the first time */
 740                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 741                         (s->enc_read_ctx == NULL))
 742                         {
 743                         al=SSL_AD_UNEXPECTED_MESSAGE;
 744                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 745                         goto f_err;
 746                         }
 747
 748                 if (len <= 0) return(len);
 749
 750                 if ((unsigned int)len > rr->length)
 751                         n = rr->length;
 752                 else
 753                         n = (unsigned int)len;
 754
 755                 memcpy(buf,&(rr->data[rr->off]),n);
 756                 if (!peek)
 757                         {
 758                         rr->length-=n;
 759                         rr->off+=n;
 760                         if (rr->length == 0)
 761                                 {
 762                                 s->rstate=SSL_ST_READ_HEADER;
 763                                 rr->off=0;
 764                                 }
 765                         }
 766                 return(n);
 767                 }
 768
 769
 770         /* If we get here, then type != rr->type; if we have a handshake
 771          * message, then it was unexpected (Hello Request or Client Hello). */
 772
 773         /* In case of record types for which we have 'fragment' storage,
 774          * fill that so that we can process the data at a fixed place.
 775          */
 776                 {
 777                 unsigned int k, dest_maxlen = 0;
 778                 unsigned char *dest = NULL;
 779                 unsigned int *dest_len = NULL;
 780
 781                 if (rr->type == SSL3_RT_HANDSHAKE)
 782                         {
 783                         dest_maxlen = sizeof s->d1->handshake_fragment;
 784                         dest = s->d1->handshake_fragment;
 785                         dest_len = &s->d1->handshake_fragment_len;
 786                         }
 787                 else if (rr->type == SSL3_RT_ALERT)
 788                         {
 789                         dest_maxlen = sizeof(s->d1->alert_fragment);
 790                         dest = s->d1->alert_fragment;
 791                         dest_len = &s->d1->alert_fragment_len;
 792                         }
 793                 else    /* else it's a CCS message */
 794                         OPENSSL_assert(rr->type == SSL3_RT_CHANGE_CIPHER_SPEC);
 795
 796
 797                 if (dest_maxlen > 0)
 798                         {
 799             /* XDTLS:  In a pathalogical case, the Client Hello
 800              *  may be fragmented--don't always expect dest_maxlen bytes */
 801                         if ( rr->length < dest_maxlen)
 802                                 {
 803                                 s->rstate=SSL_ST_READ_HEADER;
 804                                 rr->length = 0;
 805                                 goto start;
 806                                 }
 807
 808                         /* now move 'n' bytes: */
 809                         for ( k = 0; k < dest_maxlen; k++)
 810                                 {
 811                                 dest[k] = rr->data[rr->off++];
 812                                 rr->length--;
 813                                 }
 814                         *dest_len = dest_maxlen;
 815                         }
 816                 }
 817
 818         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 819          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 820          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 821
 822         /* If we are a client, check for an incoming 'Hello Request': */
 823         if ((!s->server) &&
 824                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 825                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 826                 (s->session != NULL) && (s->session->cipher != NULL))
 827                 {
 828                 s->d1->handshake_fragment_len = 0;
 829
 830                 if ((s->d1->handshake_fragment[1] != 0) ||
 831                         (s->d1->handshake_fragment[2] != 0) ||
 832                         (s->d1->handshake_fragment[3] != 0))
 833                         {
 834                         al=SSL_AD_DECODE_ERROR;
 835                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 836                         goto err;
 837                         }
 838
 839                 /* no need to check sequence number on HELLO REQUEST messages */
 840
 841                 if (s->msg_callback)
 842                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 843                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 844
 845                 if (SSL_is_init_finished(s) &&
 846                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 847                         !s->s3->renegotiate)
 848                         {
 849                         ssl3_renegotiate(s);
 850                         if (ssl3_renegotiate_check(s))
 851                                 {
 852                                 i=s->handshake_func(s);
 853                                 if (i < 0) return(i);
 854                                 if (i == 0)
 855                                         {
 856                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 857                                         return(-1);
 858                                         }
 859
 860                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 861                                         {
 862                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 863                                                 {
 864                                                 BIO *bio;
 865                                                 /* In the case where we try to read application data,
 866                                                  * but we trigger an SSL handshake, we return -1 with
 867                                                  * the retry option set.  Otherwise renegotiation may
 868                                                  * cause nasty problems in the blocking world */
 869                                                 s->rwstate=SSL_READING;
 870                                                 bio=SSL_get_rbio(s);
 871                                                 BIO_clear_retry_flags(bio);
 872                                                 BIO_set_retry_read(bio);
 873                                                 return(-1);
 874                                                 }
 875                                         }
 876                                 }
 877                         }
 878                 /* we either finished a handshake or ignored the request,
 879                  * now try again to obtain the (application) data we were asked for */
 880                 goto start;
 881                 }
 882
 883         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
 884                 {
 885                 int alert_level = s->d1->alert_fragment[0];
 886                 int alert_descr = s->d1->alert_fragment[1];
 887
 888                 s->d1->alert_fragment_len = 0;
 889
 890                 if (s->msg_callback)
 891                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
 892                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
 893
 894                 if (s->info_callback != NULL)
 895                         cb=s->info_callback;
 896                 else if (s->ctx->info_callback != NULL)
 897                         cb=s->ctx->info_callback;
 898
 899                 if (cb != NULL)
 900                         {
 901                         j = (alert_level << 8) | alert_descr;
 902                         cb(s, SSL_CB_READ_ALERT, j);
 903                         }
 904
 905                 if (alert_level == 1) /* warning */
 906                         {
 907                         s->s3->warn_alert = alert_descr;
 908                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
 909                                 {
 910                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 911                                 return(0);
 912                                 }
 913 #if 0
 914             /* XXX: this is a possible improvement in the future */
 915                         /* now check if it's a missing record */
 916                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
 917                                 {
 918                                 unsigned short seq;
 919                                 unsigned int frag_off;
 920                                 unsigned char *p = &(s->d1->alert_fragment[2]);
 921
 922                                 n2s(p, seq);
 923                                 n2l3(p, frag_off);
 924
 925                                 dtls1_retransmit_message(s, seq, frag_off, &found);
 926                                 if ( ! found  && SSL_in_init(s))
 927                                         {
 928                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
 929                                         /* requested a message not yet sent,
 930                                            send an alert ourselves */
 931                                         ssl3_send_alert(s,SSL3_AL_WARNING,
 932                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 933                                         }
 934                                 }
 935 #endif
 936                         }
 937                 else if (alert_level == 2) /* fatal */
 938                         {
 939                         char tmp[16];
 940
 941                         s->rwstate=SSL_NOTHING;
 942                         s->s3->fatal_alert = alert_descr;
 943                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
 944                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
 945                         ERR_add_error_data(2,"SSL alert number ",tmp);
 946                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
 947                         SSL_CTX_remove_session(s->ctx,s->session);
 948                         return(0);
 949                         }
 950                 else
 951                         {
 952                         al=SSL_AD_ILLEGAL_PARAMETER;
 953                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
 954                         goto f_err;
 955                         }
 956
 957                 goto start;
 958                 }
 959
 960         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
 961                 {
 962                 s->rwstate=SSL_NOTHING;
 963                 rr->length=0;
 964                 return(0);
 965                 }
 966
 967         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
 968         {
 969         struct ccs_header_st ccs_hdr;
 970
 971                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
 972
 973                 if ( ccs_hdr.seq == s->d1->handshake_read_seq)
 974                         {
 975                         /* 'Change Cipher Spec' is just a single byte, so we know
 976                          * exactly what the record payload has to look like */
 977                         /* XDTLS: check that epoch is consistent */
 978                         if (    (rr->length != DTLS1_CCS_HEADER_LENGTH) ||
 979                                 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
 980                                 {
 981                                 i=SSL_AD_ILLEGAL_PARAMETER;
 982                                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
 983                                 goto err;
 984                                 }
 985
 986                         rr->length=0;
 987
 988                         if (s->msg_callback)
 989                                 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
 990                                         rr->data, 1, s, s->msg_callback_arg);
 991
 992                         s->s3->change_cipher_spec=1;
 993                         if (!ssl3_do_change_cipher_spec(s))
 994                                 goto err;
 995
 996                         /* do this whenever CCS is processed */
 997                         dtls1_reset_seq_numbers(s, SSL3_CC_READ);
 998
 999                         /* handshake read seq is reset upon handshake completion */
1000                         s->d1->handshake_read_seq++;
1001
1002                         goto start;
1003                         }
1004                 else
1005                         {
1006                         rr->length = 0;
1007                         goto start;
1008                         }
1009                 }
1010
1011         /* Unexpected handshake message (Client Hello, or protocol violation) */
1012         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1013                 !s->in_handshake)
1014                 {
1015                 struct hm_header_st msg_hdr;
1016
1017                 /* this may just be a stale retransmit */
1018                 dtls1_get_message_header(rr->data, &msg_hdr);
1019                 if( rr->epoch != s->d1->r_epoch)
1020                         {
1021                         rr->length = 0;
1022                         goto start;
1023                         }
1024
1025                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1026                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1027                         {
1028 #if 0 /* worked only because C operator preferences are not as expected (and
1029        * because this is not really needed for clients except for detecting
1030        * protocol violations): */
1031                         s->state=SSL_ST_BEFORE|(s->server)
1032                                 ?SSL_ST_ACCEPT
1033                                 :SSL_ST_CONNECT;
1034 #else
1035                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1036 #endif
1037                         s->new_session=1;
1038                         }
1039                 i=s->handshake_func(s);
1040                 if (i < 0) return(i);
1041                 if (i == 0)
1042                         {
1043                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1044                         return(-1);
1045                         }
1046
1047                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1048                         {
1049                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1050                                 {
1051                                 BIO *bio;
1052                                 /* In the case where we try to read application data,
1053                                  * but we trigger an SSL handshake, we return -1 with
1054                                  * the retry option set.  Otherwise renegotiation may
1055                                  * cause nasty problems in the blocking world */
1056                                 s->rwstate=SSL_READING;
1057                                 bio=SSL_get_rbio(s);
1058                                 BIO_clear_retry_flags(bio);
1059                                 BIO_set_retry_read(bio);
1060                                 return(-1);
1061                                 }
1062                         }
1063                 goto start;
1064                 }
1065
1066         switch (rr->type)
1067                 {
1068         default:
1069 #ifndef OPENSSL_NO_TLS
1070                 /* TLS just ignores unknown message types */
1071                 if (s->version == TLS1_VERSION)
1072                         {
1073                         rr->length = 0;
1074                         goto start;
1075                         }
1076 #endif
1077                 al=SSL_AD_UNEXPECTED_MESSAGE;
1078                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1079                 goto f_err;
1080         case SSL3_RT_CHANGE_CIPHER_SPEC:
1081         case SSL3_RT_ALERT:
1082         case SSL3_RT_HANDSHAKE:
1083                 /* we already handled all of these, with the possible exception
1084                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1085                  * should not happen when type != rr->type */
1086                 al=SSL_AD_UNEXPECTED_MESSAGE;
1087                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1088                 goto f_err;
1089         case SSL3_RT_APPLICATION_DATA:
1090                 /* At this point, we were expecting handshake data,
1091                  * but have application data.  If the library was
1092                  * running inside ssl3_read() (i.e. in_read_app_data
1093                  * is set) and it makes sense to read application data
1094                  * at this point (session renegotiation not yet started),
1095                  * we will indulge it.
1096                  */
1097                 if (s->s3->in_read_app_data &&
1098                         (s->s3->total_renegotiations != 0) &&
1099                         ((
1100                                 (s->state & SSL_ST_CONNECT) &&
1101                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1102                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1103                                 ) || (
1104                                         (s->state & SSL_ST_ACCEPT) &&
1105                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1106                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1107                                         )
1108                                 ))
1109                         {
1110                         s->s3->in_read_app_data=2;
1111                         return(-1);
1112                         }
1113                 else
1114                         {
1115                         al=SSL_AD_UNEXPECTED_MESSAGE;
1116                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1117                         goto f_err;
1118                         }
1119                 }
1120         /* not reached */
1121
1122 f_err:
1123         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1124 err:
1125         return(-1);
1126         }
1127
1128 int
1129 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1130         {
1131         unsigned int n,tot;
1132         int i;
1133
1134         if (SSL_in_init(s) && !s->in_handshake)
1135                 {
1136                 i=s->handshake_func(s);
1137                 if (i < 0) return(i);
1138                 if (i == 0)
1139                         {
1140                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1141                         return -1;
1142                         }
1143                 }
1144
1145         tot = s->s3->wnum;
1146         n = len - tot;
1147
1148         while( n)
1149                 {
1150                 /* dtls1_write_bytes sends one record at a time, sized according to
1151                  * the currently known MTU */
1152                 i = dtls1_write_bytes(s, type, buf_, len);
1153                 if (i <= 0) return i;
1154
1155                 if ((i == (int)n) ||
1156                         (type == SSL3_RT_APPLICATION_DATA &&
1157                                 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1158                         {
1159                         /* next chunk of data should get another prepended empty fragment
1160                          * in ciphersuites with known-IV weakness: */
1161                         s->s3->empty_fragment_done = 0;
1162                         return tot+i;
1163                         }
1164
1165                 tot += i;
1166                 n-=i;
1167                 }
1168
1169         return tot;
1170         }
1171
1172
1173         /* this only happens when a client hello is received and a handshake
1174          * is started. */
1175 static int
1176 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1177         int len, int peek)
1178         {
1179
1180         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1181                 /* (partially) satisfy request from storage */
1182                 {
1183                 unsigned char *src = s->d1->handshake_fragment;
1184                 unsigned char *dst = buf;
1185                 unsigned int k,n;
1186
1187                 /* peek == 0 */
1188                 n = 0;
1189                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1190                         {
1191                         *dst++ = *src++;
1192                         len--; s->d1->handshake_fragment_len--;
1193                         n++;
1194                         }
1195                 /* move any remaining fragment bytes: */
1196                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1197                         s->d1->handshake_fragment[k] = *src++;
1198                 return n;
1199                 }
1200
1201         return 0;
1202         }
1203
1204
1205
1206
1207 /* Call this to write data in records of type 'type'
1208  * It will return <= 0 if not all data has been sent or non-blocking IO.
1209  */
1210 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1211         {
1212         const unsigned char *buf=buf_;
1213         unsigned int tot,n,nw;
1214         int i;
1215         unsigned int mtu;
1216
1217         s->rwstate=SSL_NOTHING;
1218         tot=s->s3->wnum;
1219
1220         n=(len-tot);
1221
1222         /* handshake layer figures out MTU for itself, but data records
1223          * are also sent through this interface, so need to figure out MTU */
1224 #if 0
1225         mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1226         mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
1227 #endif
1228         mtu = s->d1->mtu;
1229
1230         if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1231                 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1232
1233         if (n > mtu)
1234                 nw=mtu;
1235         else
1236                 nw=n;
1237
1238         i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1239         if (i <= 0)
1240                 {
1241                 s->s3->wnum=tot;
1242                 return i;
1243                 }
1244
1245         if ( (int)s->s3->wnum + i == len)
1246                 s->s3->wnum = 0;
1247         else
1248                 s->s3->wnum += i;
1249
1250         return tot + i;
1251         }
1252
1253 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1254         {
1255         unsigned char *p,*pseq;
1256         int i,mac_size,clear=0;
1257         int prefix_len = 0;
1258         SSL3_RECORD *wr;
1259         SSL3_BUFFER *wb;
1260         SSL_SESSION *sess;
1261         int bs;
1262
1263         /* first check if there is a SSL3_BUFFER still being written
1264          * out.  This will happen with non blocking IO */
1265         if (s->s3->wbuf.left != 0)
1266                 {
1267                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1268                 return(ssl3_write_pending(s,type,buf,len));
1269                 }
1270
1271         /* If we have an alert to send, lets send it */
1272         if (s->s3->alert_dispatch)
1273                 {
1274                 i=s->method->ssl_dispatch_alert(s);
1275                 if (i <= 0)
1276                         return(i);
1277                 /* if it went, fall through and send more stuff */
1278                 }
1279
1280         if (len == 0 && !create_empty_fragment)
1281                 return 0;
1282
1283         wr= &(s->s3->wrec);
1284         wb= &(s->s3->wbuf);
1285         sess=s->session;
1286
1287         if (    (sess == NULL) ||
1288                 (s->enc_write_ctx == NULL) ||
1289                 (s->write_hash == NULL))
1290                 clear=1;
1291
1292         if (clear)
1293                 mac_size=0;
1294         else
1295                 mac_size=EVP_MD_size(s->write_hash);
1296
1297         /* DTLS implements explicit IV, so no need for empty fragments */
1298 #if 0
1299         /* 'create_empty_fragment' is true only when this function calls itself */
1300         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1301                 && SSL_version(s) != DTLS1_VERSION)
1302                 {
1303                 /* countermeasure against known-IV weakness in CBC ciphersuites
1304                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1305                  */
1306
1307                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1308                         {
1309                         /* recursive function call with 'create_empty_fragment' set;
1310                          * this prepares and buffers the data for an empty fragment
1311                          * (these 'prefix_len' bytes are sent out later
1312                          * together with the actual payload) */
1313                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1314                         if (prefix_len <= 0)
1315                                 goto err;
1316
1317                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1318                                 {
1319                                 /* insufficient space */
1320                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1321                                 goto err;
1322                                 }
1323                         }
1324
1325                 s->s3->empty_fragment_done = 1;
1326                 }
1327 #endif
1328
1329         p = wb->buf + prefix_len;
1330
1331         /* write the header */
1332
1333         *(p++)=type&0xff;
1334         wr->type=type;
1335
1336         *(p++)=(s->version>>8);
1337         *(p++)=s->version&0xff;
1338
1339         /* field where we are to write out packet epoch, seq num and len */
1340         pseq=p;
1341         p+=10;
1342
1343         /* lets setup the record stuff. */
1344
1345         /* Make space for the explicit IV in case of CBC.
1346          * (this is a bit of a boundary violation, but what the heck).
1347          */
1348         if ( s->enc_write_ctx &&
1349                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1350                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1351         else
1352                 bs = 0;
1353
1354         wr->data=p + bs;  /* make room for IV in case of CBC */
1355         wr->length=(int)len;
1356         wr->input=(unsigned char *)buf;
1357
1358         /* we now 'read' from wr->input, wr->length bytes into
1359          * wr->data */
1360
1361         /* first we compress */
1362         if (s->compress != NULL)
1363                 {
1364                 if (!ssl3_do_compress(s))
1365                         {
1366                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1367                         goto err;
1368                         }
1369                 }
1370         else
1371                 {
1372                 memcpy(wr->data,wr->input,wr->length);
1373                 wr->input=wr->data;
1374                 }
1375
1376         /* we should still have the output to wr->data and the input
1377          * from wr->input.  Length should be wr->length.
1378          * wr->data still points in the wb->buf */
1379
1380         if (mac_size != 0)
1381                 {
1382                 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1383                 wr->length+=mac_size;
1384                 }
1385
1386         /* this is true regardless of mac size */
1387         wr->input=p;
1388         wr->data=p;
1389
1390
1391         /* ssl3_enc can only have an error on read */
1392         wr->length += bs;  /* bs != 0 in case of CBC.  The enc fn provides
1393                                                 * the randomness */
1394         s->method->ssl3_enc->enc(s,1);
1395
1396         /* record length after mac and block padding */
1397 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1398         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1399
1400         /* there's only one epoch between handshake and app data */
1401
1402         s2n(s->d1->w_epoch, pseq);
1403
1404         /* XDTLS: ?? */
1405 /*      else
1406         s2n(s->d1->handshake_epoch, pseq); */
1407
1408         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1409         pseq+=6;
1410         s2n(wr->length,pseq);
1411
1412         /* we should now have
1413          * wr->data pointing to the encrypted data, which is
1414          * wr->length long */
1415         wr->type=type; /* not needed but helps for debugging */
1416         wr->length+=DTLS1_RT_HEADER_LENGTH;
1417
1418 #if 0  /* this is now done at the message layer */
1419         /* buffer the record, making it easy to handle retransmits */
1420         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1421                 dtls1_buffer_record(s, wr->data, wr->length,
1422                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1423 #endif
1424
1425         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1426
1427         if (create_empty_fragment)
1428                 {
1429                 /* we are in a recursive call;
1430                  * just return the length, don't write out anything here
1431                  */
1432                 return wr->length;
1433                 }
1434
1435         /* now let's set up wb */
1436         wb->left = prefix_len + wr->length;
1437         wb->offset = 0;
1438
1439         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1440         s->s3->wpend_tot=len;
1441         s->s3->wpend_buf=buf;
1442         s->s3->wpend_type=type;
1443         s->s3->wpend_ret=len;
1444
1445         /* we now just need to write the buffer */
1446         return ssl3_write_pending(s,type,buf,len);
1447 err:
1448         return -1;
1449         }
1450
1451
1452
1453 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
1454         PQ_64BIT *seq_num)
1455         {
1456 #if !(defined(OPENSSL_SYS_VMS) || defined(VMS_TEST))
1457         PQ_64BIT mask = 0x0000000000000001L;
1458 #endif
1459         PQ_64BIT rcd_num, tmp;
1460
1461         pq_64bit_init(&rcd_num);
1462         pq_64bit_init(&tmp);
1463
1464         /* this is the sequence number for the record just read */
1465         pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1466
1467
1468         if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1469                 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1470                 {
1471                 pq_64bit_assign(seq_num, &rcd_num);
1472                 pq_64bit_free(&rcd_num);
1473                 pq_64bit_free(&tmp);
1474                 return 1;  /* this record is new */
1475                 }
1476
1477         pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1478
1479         if ( pq_64bit_get_word(&tmp) > bitmap->length)
1480                 {
1481                 pq_64bit_free(&rcd_num);
1482                 pq_64bit_free(&tmp);
1483                 return 0;  /* stale, outside the window */
1484                 }
1485
1486 #if (defined(OPENSSL_SYS_VMS) || defined(VMS_TEST))
1487         {
1488         int offset;
1489         pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1490         pq_64bit_sub_word(&tmp, 1);
1491         offset = pq_64bit_get_word(&tmp);
1492         if ( pq_64bit_is_bit_set(&(bitmap->map), offset))
1493                 {
1494                 pq_64bit_free(&rcd_num);
1495                 pq_64bit_free(&tmp);
1496                 return 0;
1497                 }
1498         }
1499 #else
1500         mask <<= (bitmap->max_seq_num - rcd_num - 1);
1501         if (bitmap->map & mask)
1502                 return 0; /* record previously received */
1503 #endif
1504
1505         pq_64bit_assign(seq_num, &rcd_num);
1506         pq_64bit_free(&rcd_num);
1507         pq_64bit_free(&tmp);
1508         return 1;
1509         }
1510
1511
1512 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1513         {
1514         unsigned int shift;
1515         PQ_64BIT rcd_num;
1516         PQ_64BIT tmp;
1517         PQ_64BIT_CTX *ctx;
1518
1519         pq_64bit_init(&rcd_num);
1520         pq_64bit_init(&tmp);
1521
1522         pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1523
1524         /* unfortunate code complexity due to 64-bit manipulation support
1525          * on 32-bit machines */
1526         if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1527                 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1528                 {
1529                 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num));
1530                 pq_64bit_add_word(&tmp, 1);
1531
1532                 shift = (unsigned int)pq_64bit_get_word(&tmp);
1533
1534                 pq_64bit_lshift(&(tmp), &(bitmap->map), shift);
1535                 pq_64bit_assign(&(bitmap->map), &tmp);
1536
1537                 pq_64bit_set_bit(&(bitmap->map), 0);
1538                 pq_64bit_add_word(&rcd_num, 1);
1539                 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num);
1540
1541                 pq_64bit_assign_word(&tmp, 1);
1542                 pq_64bit_lshift(&tmp, &tmp, bitmap->length);
1543                 ctx = pq_64bit_ctx_new(&ctx);
1544                 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx);
1545                 pq_64bit_ctx_free(ctx);
1546                 }
1547         else
1548                 {
1549                 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1550                 pq_64bit_sub_word(&tmp, 1);
1551                 shift = (unsigned int)pq_64bit_get_word(&tmp);
1552
1553                 pq_64bit_set_bit(&(bitmap->map), shift);
1554                 }
1555
1556         pq_64bit_free(&rcd_num);
1557         pq_64bit_free(&tmp);
1558         }
1559
1560
1561 int dtls1_dispatch_alert(SSL *s)
1562         {
1563         int i,j;
1564         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1565         unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */
1566         unsigned char *ptr = &buf[0];
1567
1568         s->s3->alert_dispatch=0;
1569
1570         memset(buf, 0x00, sizeof(buf));
1571         *ptr++ = s->s3->send_alert[0];
1572         *ptr++ = s->s3->send_alert[1];
1573
1574         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1575                 {
1576                 s2n(s->d1->handshake_read_seq, ptr);
1577 #if 0
1578                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1579
1580                 else
1581                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1582 #endif
1583
1584 #if 0
1585                 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);
1586 #endif
1587                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1588                 }
1589
1590         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1591         if (i <= 0)
1592                 {
1593                 s->s3->alert_dispatch=1;
1594                 /* fprintf( stderr, "not done with alert\n" ); */
1595                 }
1596         else
1597                 {
1598                 if ( s->s3->send_alert[0] == SSL3_AL_FATAL ||
1599                         s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1600                         (void)BIO_flush(s->wbio);
1601
1602                 if (s->msg_callback)
1603                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1604                                 2, s, s->msg_callback_arg);
1605
1606                 if (s->info_callback != NULL)
1607                         cb=s->info_callback;
1608                 else if (s->ctx->info_callback != NULL)
1609                         cb=s->ctx->info_callback;
1610
1611                 if (cb != NULL)
1612                         {
1613                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1614                         cb(s,SSL_CB_WRITE_ALERT,j);
1615                         }
1616                 }
1617         return(i);
1618         }
1619
1620
1621 static DTLS1_BITMAP *
1622 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1623     {
1624
1625     *is_next_epoch = 0;
1626
1627     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1628     if (rr->epoch == s->d1->r_epoch)
1629         return &s->d1->bitmap;
1630
1631     /* Only HM and ALERT messages can be from the next epoch */
1632     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1633         (rr->type == SSL3_RT_HANDSHAKE ||
1634             rr->type == SSL3_RT_ALERT))
1635         {
1636         *is_next_epoch = 1;
1637         return &s->d1->next_bitmap;
1638         }
1639
1640     return NULL;
1641     }
1642
1643 #if 0
1644 static int
1645 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1646         unsigned long *offset)
1647         {
1648
1649         /* alerts are passed up immediately */
1650         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1651                 rr->type == SSL3_RT_ALERT)
1652                 return 0;
1653
1654         /* Only need to buffer if a handshake is underway.
1655          * (this implies that Hello Request and Client Hello are passed up
1656          * immediately) */
1657         if ( SSL_in_init(s))
1658                 {
1659                 unsigned char *data = rr->data;
1660                 /* need to extract the HM/CCS sequence number here */
1661                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1662                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1663                         {
1664                         unsigned short seq_num;
1665                         struct hm_header_st msg_hdr;
1666                         struct ccs_header_st ccs_hdr;
1667
1668                         if ( rr->type == SSL3_RT_HANDSHAKE)
1669                                 {
1670                                 dtls1_get_message_header(data, &msg_hdr);
1671                                 seq_num = msg_hdr.seq;
1672                                 *offset = msg_hdr.frag_off;
1673                                 }
1674                         else
1675                                 {
1676                                 dtls1_get_ccs_header(data, &ccs_hdr);
1677                                 seq_num = ccs_hdr.seq;
1678                                 *offset = 0;
1679                                 }
1680
1681                         /* this is either a record we're waiting for, or a
1682                          * retransmit of something we happened to previously
1683                          * receive (higher layers will drop the repeat silently */
1684                         if ( seq_num < s->d1->handshake_read_seq)
1685                                 return 0;
1686                         if (rr->type == SSL3_RT_HANDSHAKE &&
1687                                 seq_num == s->d1->handshake_read_seq &&
1688                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1689                                 return 0;
1690                         else if ( seq_num == s->d1->handshake_read_seq &&
1691                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1692                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1693                                 return 0;
1694                         else
1695                                 {
1696                                 *priority = seq_num;
1697                                 return 1;
1698                                 }
1699                         }
1700                 else /* unknown record type */
1701                         return 0;
1702                 }
1703
1704         return 0;
1705         }
1706 #endif
1707
1708 void
1709 dtls1_reset_seq_numbers(SSL *s, int rw)
1710         {
1711         unsigned char *seq;
1712         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1713
1714         if ( rw & SSL3_CC_READ)
1715                 {
1716                 seq = s->s3->read_sequence;
1717                 s->d1->r_epoch++;
1718
1719                 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map));
1720                 s->d1->bitmap.length = s->d1->next_bitmap.length;
1721                 pq_64bit_assign(&(s->d1->bitmap.max_seq_num),
1722                         &(s->d1->next_bitmap.max_seq_num));
1723
1724                 pq_64bit_free(&(s->d1->next_bitmap.map));
1725                 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
1726                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1727                 pq_64bit_init(&(s->d1->next_bitmap.map));
1728                 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
1729                 }
1730         else
1731                 {
1732                 seq = s->s3->write_sequence;
1733                 s->d1->w_epoch++;
1734                 }
1735
1736         memset(seq, 0x00, seq_bytes);
1737         }
1738
1739 #if !(defined(OPENSSL_SYS_VMS) || defined(VMS_TEST))
1740 static PQ_64BIT
1741 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
1742        {
1743        PQ_64BIT _num;
1744
1745        _num = (((PQ_64BIT)bytes[0]) << 56) |
1746                (((PQ_64BIT)bytes[1]) << 48) |
1747                (((PQ_64BIT)bytes[2]) << 40) |
1748                (((PQ_64BIT)bytes[3]) << 32) |
1749                (((PQ_64BIT)bytes[4]) << 24) |
1750                (((PQ_64BIT)bytes[5]) << 16) |
1751                (((PQ_64BIT)bytes[6]) <<  8) |
1752                (((PQ_64BIT)bytes[7])      );
1753
1754            *num = _num ;
1755        return _num;
1756        }
1757 #endif
1758
1759
1760 static void
1761 dtls1_clear_timeouts(SSL *s)
1762         {
1763         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1764         }