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 #include <openssl/rand.h>
 124
 125 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
 126         int len, int peek);
 127 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
 128         PQ_64BIT *seq_num);
 129 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
 130 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
 131     unsigned int *is_next_epoch);
 132 #if 0
 133 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
 134         unsigned short *priority, unsigned long *offset);
 135 #endif
 136 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
 137         PQ_64BIT priority);
 138 static int dtls1_process_record(SSL *s);
 139 #if PQ_64BIT_IS_INTEGER
 140 static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num);
 141 #endif
 142 static void dtls1_clear_timeouts(SSL *s);
 143
 144 /* copy buffered record into SSL structure */
 145 static int
 146 dtls1_copy_record(SSL *s, pitem *item)
 147     {
 148     DTLS1_RECORD_DATA *rdata;
 149
 150     rdata = (DTLS1_RECORD_DATA *)item->data;
 151
 152     if (s->s3->rbuf.buf != NULL)
 153         OPENSSL_free(s->s3->rbuf.buf);
 154
 155     s->packet = rdata->packet;
 156     s->packet_length = rdata->packet_length;
 157     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 158     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 159
 160     return(1);
 161     }
 162
 163
 164 static int
 165 dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT priority)
 166 {
 167     DTLS1_RECORD_DATA *rdata;
 168         pitem *item;
 169
 170         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 171         item = pitem_new(priority, rdata);
 172         if (rdata == NULL || item == NULL)
 173                 {
 174                 if (rdata != NULL) OPENSSL_free(rdata);
 175                 if (item != NULL) pitem_free(item);
 176
 177                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 178                 return(0);
 179                 }
 180
 181         rdata->packet = s->packet;
 182         rdata->packet_length = s->packet_length;
 183         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 184         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 185
 186         item->data = rdata;
 187
 188         /* insert should not fail, since duplicates are dropped */
 189         if (pqueue_insert(queue->q, item) == NULL)
 190                 {
 191                 OPENSSL_free(rdata);
 192                 pitem_free(item);
 193                 return(0);
 194                 }
 195
 196         s->packet = NULL;
 197         s->packet_length = 0;
 198         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 199         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 200
 201         if (!ssl3_setup_buffers(s))
 202                 {
 203                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 204                 OPENSSL_free(rdata);
 205                 pitem_free(item);
 206                 return(0);
 207                 }
 208
 209         return(1);
 210     }
 211
 212
 213 static int
 214 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 215     {
 216     pitem *item;
 217
 218     item = pqueue_pop(queue->q);
 219     if (item)
 220         {
 221         dtls1_copy_record(s, item);
 222
 223         OPENSSL_free(item->data);
 224                 pitem_free(item);
 225
 226         return(1);
 227         }
 228
 229     return(0);
 230     }
 231
 232
 233 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 234  * yet */
 235 #define dtls1_get_unprocessed_record(s) \
 236                    dtls1_retrieve_buffered_record((s), \
 237                    &((s)->d1->unprocessed_rcds))
 238
 239 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 240 #define dtls1_get_processed_record(s) \
 241                    dtls1_retrieve_buffered_record((s), \
 242                    &((s)->d1->processed_rcds))
 243
 244 static int
 245 dtls1_process_buffered_records(SSL *s)
 246     {
 247     pitem *item;
 248
 249     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 250     if (item)
 251         {
 252         DTLS1_RECORD_DATA *rdata;
 253         rdata = (DTLS1_RECORD_DATA *)item->data;
 254
 255         /* Check if epoch is current. */
 256         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 257             return(1);  /* Nothing to do. */
 258
 259         /* Process all the records. */
 260         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 261             {
 262             dtls1_get_unprocessed_record(s);
 263             if ( ! dtls1_process_record(s))
 264                 return(0);
 265             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 266                 s->s3->rrec.seq_num);
 267             }
 268         }
 269
 270     /* sync epoch numbers once all the unprocessed records
 271      * have been processed */
 272     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 273     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 274
 275     return(1);
 276     }
 277
 278
 279 #if 0
 280
 281 static int
 282 dtls1_get_buffered_record(SSL *s)
 283         {
 284         pitem *item;
 285         PQ_64BIT priority =
 286                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 287                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 288
 289         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 290                                                            nothing buffered */
 291                 return 0;
 292
 293
 294         item = pqueue_peek(s->d1->rcvd_records);
 295         if (item && item->priority == priority)
 296                 {
 297                 /* Check if we've received the record of interest.  It must be
 298                  * a handshake record, since data records as passed up without
 299                  * buffering */
 300                 DTLS1_RECORD_DATA *rdata;
 301                 item = pqueue_pop(s->d1->rcvd_records);
 302                 rdata = (DTLS1_RECORD_DATA *)item->data;
 303
 304                 if (s->s3->rbuf.buf != NULL)
 305                         OPENSSL_free(s->s3->rbuf.buf);
 306
 307                 s->packet = rdata->packet;
 308                 s->packet_length = rdata->packet_length;
 309                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 310                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 311
 312                 OPENSSL_free(item->data);
 313                 pitem_free(item);
 314
 315                 /* s->d1->next_expected_seq_num++; */
 316                 return(1);
 317                 }
 318
 319         return 0;
 320         }
 321
 322 #endif
 323
 324 static int
 325 dtls1_process_record(SSL *s)
 326 {
 327     int i,al;
 328         int clear=0;
 329     int enc_err;
 330         SSL_SESSION *sess;
 331     SSL3_RECORD *rr;
 332         unsigned int mac_size;
 333         unsigned char md[EVP_MAX_MD_SIZE];
 334
 335
 336         rr= &(s->s3->rrec);
 337     sess = s->session;
 338
 339         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 340          * and we have that many bytes in s->packet
 341          */
 342         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 343
 344         /* ok, we can now read from 's->packet' data into 'rr'
 345          * rr->input points at rr->length bytes, which
 346          * need to be copied into rr->data by either
 347          * the decryption or by the decompression
 348          * When the data is 'copied' into the rr->data buffer,
 349          * rr->input will be pointed at the new buffer */
 350
 351         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 352          * rr->length bytes of encrypted compressed stuff. */
 353
 354         /* check is not needed I believe */
 355         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 356                 {
 357                 al=SSL_AD_RECORD_OVERFLOW;
 358                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 359                 goto f_err;
 360                 }
 361
 362         /* decrypt in place in 'rr->input' */
 363         rr->data=rr->input;
 364
 365         enc_err = s->method->ssl3_enc->enc(s,0);
 366         if (enc_err <= 0)
 367                 {
 368                 if (enc_err == 0)
 369                         /* SSLerr() and ssl3_send_alert() have been called */
 370                         goto err;
 371
 372                 /* otherwise enc_err == -1 */
 373                 goto decryption_failed_or_bad_record_mac;
 374                 }
 375
 376 #ifdef TLS_DEBUG
 377 printf("dec %d\n",rr->length);
 378 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 379 printf("\n");
 380 #endif
 381
 382         /* r->length is now the compressed data plus mac */
 383 if (    (sess == NULL) ||
 384                 (s->enc_read_ctx == NULL) ||
 385                 (s->read_hash == NULL))
 386     clear=1;
 387
 388         if (!clear)
 389                 {
 390                 mac_size=EVP_MD_size(s->read_hash);
 391
 392                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 393                         {
 394 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 395                         al=SSL_AD_RECORD_OVERFLOW;
 396                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 397                         goto f_err;
 398 #else
 399                         goto decryption_failed_or_bad_record_mac;
 400 #endif
 401                         }
 402                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 403                 if (rr->length < mac_size)
 404                         {
 405 #if 0 /* OK only for stream ciphers */
 406                         al=SSL_AD_DECODE_ERROR;
 407                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 408                         goto f_err;
 409 #else
 410                         goto decryption_failed_or_bad_record_mac;
 411 #endif
 412                         }
 413                 rr->length-=mac_size;
 414                 i=s->method->ssl3_enc->mac(s,md,0);
 415                 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 416                         {
 417                         goto decryption_failed_or_bad_record_mac;
 418                         }
 419                 }
 420
 421         /* r->length is now just compressed */
 422         if (s->expand != NULL)
 423                 {
 424                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 425                         {
 426                         al=SSL_AD_RECORD_OVERFLOW;
 427                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 428                         goto f_err;
 429                         }
 430                 if (!ssl3_do_uncompress(s))
 431                         {
 432                         al=SSL_AD_DECOMPRESSION_FAILURE;
 433                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 434                         goto f_err;
 435                         }
 436                 }
 437
 438         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 439                 {
 440                 al=SSL_AD_RECORD_OVERFLOW;
 441                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 442                 goto f_err;
 443                 }
 444
 445         rr->off=0;
 446         /* So at this point the following is true
 447          * ssl->s3->rrec.type   is the type of record
 448          * ssl->s3->rrec.length == number of bytes in record
 449          * ssl->s3->rrec.off    == offset to first valid byte
 450          * ssl->s3->rrec.data   == where to take bytes from, increment
 451          *                         after use :-).
 452          */
 453
 454         /* we have pulled in a full packet so zero things */
 455         s->packet_length=0;
 456     dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 457     return(1);
 458
 459 decryption_failed_or_bad_record_mac:
 460         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
 461          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 462          * failure is directly visible from the ciphertext anyway,
 463          * we should not reveal which kind of error occured -- this
 464          * might become visible to an attacker (e.g. via logfile) */
 465         al=SSL_AD_BAD_RECORD_MAC;
 466         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 467 f_err:
 468         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 469 err:
 470         return(0);
 471 }
 472
 473
 474 /* Call this to get a new input record.
 475  * It will return <= 0 if more data is needed, normally due to an error
 476  * or non-blocking IO.
 477  * When it finishes, one packet has been decoded and can be found in
 478  * ssl->s3->rrec.type    - is the type of record
 479  * ssl->s3->rrec.data,   - data
 480  * ssl->s3->rrec.length, - number of bytes
 481  */
 482 /* used only by dtls1_read_bytes */
 483 int dtls1_get_record(SSL *s)
 484         {
 485         int ssl_major,ssl_minor,al;
 486         int i,n;
 487         SSL3_RECORD *rr;
 488         SSL_SESSION *sess;
 489         unsigned char *p;
 490         unsigned short version;
 491         DTLS1_BITMAP *bitmap;
 492         unsigned int is_next_epoch;
 493
 494         rr= &(s->s3->rrec);
 495         sess=s->session;
 496
 497     /* The epoch may have changed.  If so, process all the
 498      * pending records.  This is a non-blocking operation. */
 499     if ( ! dtls1_process_buffered_records(s))
 500         return 0;
 501
 502         /* if we're renegotiating, then there may be buffered records */
 503         if (dtls1_get_processed_record(s))
 504                 return 1;
 505
 506         /* get something from the wire */
 507 again:
 508         /* check if we have the header */
 509         if (    (s->rstate != SSL_ST_READ_BODY) ||
 510                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 511                 {
 512                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 513                 /* read timeout is handled by dtls1_read_bytes */
 514                 if (n <= 0) return(n); /* error or non-blocking */
 515
 516                 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
 517
 518                 s->rstate=SSL_ST_READ_BODY;
 519
 520                 p=s->packet;
 521
 522                 /* Pull apart the header into the DTLS1_RECORD */
 523                 rr->type= *(p++);
 524                 ssl_major= *(p++);
 525                 ssl_minor= *(p++);
 526                 version=(ssl_major<<8)|ssl_minor;
 527
 528                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 529                 n2s(p,rr->epoch);
 530
 531                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 532                 p+=6;
 533
 534                 n2s(p,rr->length);
 535
 536                 /* Lets check version */
 537                 if (!s->first_packet)
 538                         {
 539                         if (version != s->version && version != DTLS1_BAD_VER)
 540                                 {
 541                                 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 542                                 /* Send back error using their
 543                                  * version number :-) */
 544                                 s->version=version;
 545                                 al=SSL_AD_PROTOCOL_VERSION;
 546                                 goto f_err;
 547                                 }
 548                         }
 549
 550                 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00) &&
 551                     (version & 0xff00) != (DTLS1_BAD_VER & 0xff00))
 552                         {
 553                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 554                         goto err;
 555                         }
 556
 557                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 558                         {
 559                         al=SSL_AD_RECORD_OVERFLOW;
 560                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 561                         goto f_err;
 562                         }
 563
 564                 /* now s->rstate == SSL_ST_READ_BODY */
 565                 }
 566
 567         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 568
 569         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 570                 {
 571                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 572                 i=rr->length;
 573                 n=ssl3_read_n(s,i,i,1);
 574                 if (n <= 0) return(n); /* error or non-blocking io */
 575
 576                 /* this packet contained a partial record, dump it */
 577                 if ( n != i)
 578                         {
 579                         s->packet_length = 0;
 580                         goto again;
 581                         }
 582
 583                 /* now n == rr->length,
 584                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 585                 }
 586         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 587
 588         /* match epochs.  NULL means the packet is dropped on the floor */
 589         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 590         if ( bitmap == NULL)
 591         {
 592         s->packet_length = 0;  /* dump this record */
 593         goto again;   /* get another record */
 594                 }
 595
 596         /* check whether this is a repeat, or aged record */
 597         if ( ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))
 598                 {
 599                 s->packet_length=0; /* dump this record */
 600                 goto again;     /* get another record */
 601                 }
 602
 603         /* just read a 0 length packet */
 604         if (rr->length == 0) goto again;
 605
 606     /* If this record is from the next epoch (either HM or ALERT), buffer it
 607      * since it cannot be processed at this time.
 608      * Records from the next epoch are marked as received even though they are
 609      * not processed, so as to prevent any potential resource DoS attack */
 610     if (is_next_epoch)
 611         {
 612         dtls1_record_bitmap_update(s, bitmap);
 613         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 614         s->packet_length = 0;
 615         goto again;
 616         }
 617
 618     if ( ! dtls1_process_record(s))
 619         return(0);
 620
 621         dtls1_clear_timeouts(s);  /* done waiting */
 622         return(1);
 623
 624 f_err:
 625         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 626 err:
 627         return(0);
 628         }
 629
 630 /* Return up to 'len' payload bytes received in 'type' records.
 631  * 'type' is one of the following:
 632  *
 633  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 634  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 635  *   -  0 (during a shutdown, no data has to be returned)
 636  *
 637  * If we don't have stored data to work from, read a SSL/TLS record first
 638  * (possibly multiple records if we still don't have anything to return).
 639  *
 640  * This function must handle any surprises the peer may have for us, such as
 641  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 642  * a surprise, but handled as if it were), or renegotiation requests.
 643  * Also if record payloads contain fragments too small to process, we store
 644  * them until there is enough for the respective protocol (the record protocol
 645  * may use arbitrary fragmentation and even interleaving):
 646  *     Change cipher spec protocol
 647  *             just 1 byte needed, no need for keeping anything stored
 648  *     Alert protocol
 649  *             2 bytes needed (AlertLevel, AlertDescription)
 650  *     Handshake protocol
 651  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 652  *             to detect unexpected Client Hello and Hello Request messages
 653  *             here, anything else is handled by higher layers
 654  *     Application data protocol
 655  *             none of our business
 656  */
 657 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 658         {
 659         int al,i,j,ret;
 660         unsigned int n;
 661         SSL3_RECORD *rr;
 662         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 663
 664         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 665                 if (!ssl3_setup_buffers(s))
 666                         return(-1);
 667
 668     /* XXX: check what the second '&& type' is about */
 669         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 670                 (type != SSL3_RT_HANDSHAKE) && type) ||
 671             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 672                 {
 673                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 674                 return -1;
 675                 }
 676
 677         /* check whether there's a handshake message (client hello?) waiting */
 678         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 679                 return ret;
 680
 681         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 682
 683         if (!s->in_handshake && SSL_in_init(s))
 684                 {
 685                 /* type == SSL3_RT_APPLICATION_DATA */
 686                 i=s->handshake_func(s);
 687                 if (i < 0) return(i);
 688                 if (i == 0)
 689                         {
 690                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 691                         return(-1);
 692                         }
 693                 }
 694
 695 start:
 696         s->rwstate=SSL_NOTHING;
 697
 698         /* s->s3->rrec.type         - is the type of record
 699          * s->s3->rrec.data,    - data
 700          * s->s3->rrec.off,     - offset into 'data' for next read
 701          * s->s3->rrec.length,  - number of bytes. */
 702         rr = &(s->s3->rrec);
 703
 704         /* get new packet if necessary */
 705         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 706                 {
 707                 ret=dtls1_get_record(s);
 708                 if (ret <= 0)
 709                         {
 710                         ret = dtls1_read_failed(s, ret);
 711                         /* anything other than a timeout is an error */
 712                         if (ret <= 0)
 713                                 return(ret);
 714                         else
 715                                 goto start;
 716                         }
 717                 }
 718
 719         /* we now have a packet which can be read and processed */
 720
 721         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 722                                        * reset by ssl3_get_finished */
 723                 && (rr->type != SSL3_RT_HANDSHAKE))
 724                 {
 725                 al=SSL_AD_UNEXPECTED_MESSAGE;
 726                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
 727                 goto err;
 728                 }
 729
 730         /* If the other end has shut down, throw anything we read away
 731          * (even in 'peek' mode) */
 732         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 733                 {
 734                 rr->length=0;
 735                 s->rwstate=SSL_NOTHING;
 736                 return(0);
 737                 }
 738
 739
 740         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 741                 {
 742                 /* make sure that we are not getting application data when we
 743                  * are doing a handshake for the first time */
 744                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 745                         (s->enc_read_ctx == NULL))
 746                         {
 747                         al=SSL_AD_UNEXPECTED_MESSAGE;
 748                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 749                         goto f_err;
 750                         }
 751
 752                 if (len <= 0) return(len);
 753
 754                 if ((unsigned int)len > rr->length)
 755                         n = rr->length;
 756                 else
 757                         n = (unsigned int)len;
 758
 759                 memcpy(buf,&(rr->data[rr->off]),n);
 760                 if (!peek)
 761                         {
 762                         rr->length-=n;
 763                         rr->off+=n;
 764                         if (rr->length == 0)
 765                                 {
 766                                 s->rstate=SSL_ST_READ_HEADER;
 767                                 rr->off=0;
 768                                 }
 769                         }
 770                 return(n);
 771                 }
 772
 773
 774         /* If we get here, then type != rr->type; if we have a handshake
 775          * message, then it was unexpected (Hello Request or Client Hello). */
 776
 777         /* In case of record types for which we have 'fragment' storage,
 778          * fill that so that we can process the data at a fixed place.
 779          */
 780                 {
 781                 unsigned int k, dest_maxlen = 0;
 782                 unsigned char *dest = NULL;
 783                 unsigned int *dest_len = NULL;
 784
 785                 if (rr->type == SSL3_RT_HANDSHAKE)
 786                         {
 787                         dest_maxlen = sizeof s->d1->handshake_fragment;
 788                         dest = s->d1->handshake_fragment;
 789                         dest_len = &s->d1->handshake_fragment_len;
 790                         }
 791                 else if (rr->type == SSL3_RT_ALERT)
 792                         {
 793                         dest_maxlen = sizeof(s->d1->alert_fragment);
 794                         dest = s->d1->alert_fragment;
 795                         dest_len = &s->d1->alert_fragment_len;
 796                         }
 797                 /* else it's a CCS message, or it's wrong */
 798                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 799                         {
 800                           /* Not certain if this is the right error handling */
 801                           al=SSL_AD_UNEXPECTED_MESSAGE;
 802                           SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 803                           goto f_err;
 804                         }
 805
 806
 807                 if (dest_maxlen > 0)
 808                         {
 809             /* XDTLS:  In a pathalogical case, the Client Hello
 810              *  may be fragmented--don't always expect dest_maxlen bytes */
 811                         if ( rr->length < dest_maxlen)
 812                                 {
 813                                 s->rstate=SSL_ST_READ_HEADER;
 814                                 rr->length = 0;
 815                                 goto start;
 816                                 }
 817
 818                         /* now move 'n' bytes: */
 819                         for ( k = 0; k < dest_maxlen; k++)
 820                                 {
 821                                 dest[k] = rr->data[rr->off++];
 822                                 rr->length--;
 823                                 }
 824                         *dest_len = dest_maxlen;
 825                         }
 826                 }
 827
 828         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 829          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 830          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 831
 832         /* If we are a client, check for an incoming 'Hello Request': */
 833         if ((!s->server) &&
 834                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 835                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 836                 (s->session != NULL) && (s->session->cipher != NULL))
 837                 {
 838                 s->d1->handshake_fragment_len = 0;
 839
 840                 if ((s->d1->handshake_fragment[1] != 0) ||
 841                         (s->d1->handshake_fragment[2] != 0) ||
 842                         (s->d1->handshake_fragment[3] != 0))
 843                         {
 844                         al=SSL_AD_DECODE_ERROR;
 845                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 846                         goto err;
 847                         }
 848
 849                 /* no need to check sequence number on HELLO REQUEST messages */
 850
 851                 if (s->msg_callback)
 852                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 853                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 854
 855                 if (SSL_is_init_finished(s) &&
 856                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 857                         !s->s3->renegotiate)
 858                         {
 859                         ssl3_renegotiate(s);
 860                         if (ssl3_renegotiate_check(s))
 861                                 {
 862                                 i=s->handshake_func(s);
 863                                 if (i < 0) return(i);
 864                                 if (i == 0)
 865                                         {
 866                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 867                                         return(-1);
 868                                         }
 869
 870                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 871                                         {
 872                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 873                                                 {
 874                                                 BIO *bio;
 875                                                 /* In the case where we try to read application data,
 876                                                  * but we trigger an SSL handshake, we return -1 with
 877                                                  * the retry option set.  Otherwise renegotiation may
 878                                                  * cause nasty problems in the blocking world */
 879                                                 s->rwstate=SSL_READING;
 880                                                 bio=SSL_get_rbio(s);
 881                                                 BIO_clear_retry_flags(bio);
 882                                                 BIO_set_retry_read(bio);
 883                                                 return(-1);
 884                                                 }
 885                                         }
 886                                 }
 887                         }
 888                 /* we either finished a handshake or ignored the request,
 889                  * now try again to obtain the (application) data we were asked for */
 890                 goto start;
 891                 }
 892
 893         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
 894                 {
 895                 int alert_level = s->d1->alert_fragment[0];
 896                 int alert_descr = s->d1->alert_fragment[1];
 897
 898                 s->d1->alert_fragment_len = 0;
 899
 900                 if (s->msg_callback)
 901                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
 902                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
 903
 904                 if (s->info_callback != NULL)
 905                         cb=s->info_callback;
 906                 else if (s->ctx->info_callback != NULL)
 907                         cb=s->ctx->info_callback;
 908
 909                 if (cb != NULL)
 910                         {
 911                         j = (alert_level << 8) | alert_descr;
 912                         cb(s, SSL_CB_READ_ALERT, j);
 913                         }
 914
 915                 if (alert_level == 1) /* warning */
 916                         {
 917                         s->s3->warn_alert = alert_descr;
 918                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
 919                                 {
 920                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 921                                 return(0);
 922                                 }
 923 #if 0
 924             /* XXX: this is a possible improvement in the future */
 925                         /* now check if it's a missing record */
 926                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
 927                                 {
 928                                 unsigned short seq;
 929                                 unsigned int frag_off;
 930                                 unsigned char *p = &(s->d1->alert_fragment[2]);
 931
 932                                 n2s(p, seq);
 933                                 n2l3(p, frag_off);
 934
 935                                 dtls1_retransmit_message(s, seq, frag_off, &found);
 936                                 if ( ! found  && SSL_in_init(s))
 937                                         {
 938                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
 939                                         /* requested a message not yet sent,
 940                                            send an alert ourselves */
 941                                         ssl3_send_alert(s,SSL3_AL_WARNING,
 942                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 943                                         }
 944                                 }
 945 #endif
 946                         }
 947                 else if (alert_level == 2) /* fatal */
 948                         {
 949                         char tmp[16];
 950
 951                         s->rwstate=SSL_NOTHING;
 952                         s->s3->fatal_alert = alert_descr;
 953                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
 954                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
 955                         ERR_add_error_data(2,"SSL alert number ",tmp);
 956                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
 957                         SSL_CTX_remove_session(s->ctx,s->session);
 958                         return(0);
 959                         }
 960                 else
 961                         {
 962                         al=SSL_AD_ILLEGAL_PARAMETER;
 963                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
 964                         goto f_err;
 965                         }
 966
 967                 goto start;
 968                 }
 969
 970         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
 971                 {
 972                 s->rwstate=SSL_NOTHING;
 973                 rr->length=0;
 974                 return(0);
 975                 }
 976
 977         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
 978                 {
 979                 struct ccs_header_st ccs_hdr;
 980
 981                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
 982
 983                 /* 'Change Cipher Spec' is just a single byte, so we know
 984                  * exactly what the record payload has to look like */
 985                 /* XDTLS: check that epoch is consistent */
 986                 if (    (s->client_version == DTLS1_BAD_VER && rr->length != 3) ||
 987                         (s->client_version != DTLS1_BAD_VER && rr->length != DTLS1_CCS_HEADER_LENGTH) ||
 988                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
 989                         {
 990                         i=SSL_AD_ILLEGAL_PARAMETER;
 991                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
 992                         goto err;
 993                         }
 994
 995                 rr->length=0;
 996
 997                 if (s->msg_callback)
 998                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
 999                                 rr->data, 1, s, s->msg_callback_arg);
1000
1001                 s->s3->change_cipher_spec=1;
1002                 if (!ssl3_do_change_cipher_spec(s))
1003                         goto err;
1004
1005                 /* do this whenever CCS is processed */
1006                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1007
1008                 /* handshake read seq is reset upon handshake completion */
1009                 s->d1->handshake_read_seq++;
1010
1011                 goto start;
1012                 }
1013
1014         /* Unexpected handshake message (Client Hello, or protocol violation) */
1015         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1016                 !s->in_handshake)
1017                 {
1018                 struct hm_header_st msg_hdr;
1019
1020                 /* this may just be a stale retransmit */
1021                 dtls1_get_message_header(rr->data, &msg_hdr);
1022                 if( rr->epoch != s->d1->r_epoch)
1023                         {
1024                         rr->length = 0;
1025                         goto start;
1026                         }
1027
1028                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1029                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1030                         {
1031 #if 0 /* worked only because C operator preferences are not as expected (and
1032        * because this is not really needed for clients except for detecting
1033        * protocol violations): */
1034                         s->state=SSL_ST_BEFORE|(s->server)
1035                                 ?SSL_ST_ACCEPT
1036                                 :SSL_ST_CONNECT;
1037 #else
1038                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1039 #endif
1040                         s->new_session=1;
1041                         }
1042                 i=s->handshake_func(s);
1043                 if (i < 0) return(i);
1044                 if (i == 0)
1045                         {
1046                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1047                         return(-1);
1048                         }
1049
1050                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1051                         {
1052                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1053                                 {
1054                                 BIO *bio;
1055                                 /* In the case where we try to read application data,
1056                                  * but we trigger an SSL handshake, we return -1 with
1057                                  * the retry option set.  Otherwise renegotiation may
1058                                  * cause nasty problems in the blocking world */
1059                                 s->rwstate=SSL_READING;
1060                                 bio=SSL_get_rbio(s);
1061                                 BIO_clear_retry_flags(bio);
1062                                 BIO_set_retry_read(bio);
1063                                 return(-1);
1064                                 }
1065                         }
1066                 goto start;
1067                 }
1068
1069         switch (rr->type)
1070                 {
1071         default:
1072 #ifndef OPENSSL_NO_TLS
1073                 /* TLS just ignores unknown message types */
1074                 if (s->version == TLS1_VERSION)
1075                         {
1076                         rr->length = 0;
1077                         goto start;
1078                         }
1079 #endif
1080                 al=SSL_AD_UNEXPECTED_MESSAGE;
1081                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1082                 goto f_err;
1083         case SSL3_RT_CHANGE_CIPHER_SPEC:
1084         case SSL3_RT_ALERT:
1085         case SSL3_RT_HANDSHAKE:
1086                 /* we already handled all of these, with the possible exception
1087                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1088                  * should not happen when type != rr->type */
1089                 al=SSL_AD_UNEXPECTED_MESSAGE;
1090                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1091                 goto f_err;
1092         case SSL3_RT_APPLICATION_DATA:
1093                 /* At this point, we were expecting handshake data,
1094                  * but have application data.  If the library was
1095                  * running inside ssl3_read() (i.e. in_read_app_data
1096                  * is set) and it makes sense to read application data
1097                  * at this point (session renegotiation not yet started),
1098                  * we will indulge it.
1099                  */
1100                 if (s->s3->in_read_app_data &&
1101                         (s->s3->total_renegotiations != 0) &&
1102                         ((
1103                                 (s->state & SSL_ST_CONNECT) &&
1104                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1105                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1106                                 ) || (
1107                                         (s->state & SSL_ST_ACCEPT) &&
1108                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1109                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1110                                         )
1111                                 ))
1112                         {
1113                         s->s3->in_read_app_data=2;
1114                         return(-1);
1115                         }
1116                 else
1117                         {
1118                         al=SSL_AD_UNEXPECTED_MESSAGE;
1119                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1120                         goto f_err;
1121                         }
1122                 }
1123         /* not reached */
1124
1125 f_err:
1126         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1127 err:
1128         return(-1);
1129         }
1130
1131 int
1132 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1133         {
1134         unsigned int n,tot;
1135         int i;
1136
1137         if (SSL_in_init(s) && !s->in_handshake)
1138                 {
1139                 i=s->handshake_func(s);
1140                 if (i < 0) return(i);
1141                 if (i == 0)
1142                         {
1143                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1144                         return -1;
1145                         }
1146                 }
1147
1148         tot = s->s3->wnum;
1149         n = len - tot;
1150
1151         while( n)
1152                 {
1153                 /* dtls1_write_bytes sends one record at a time, sized according to
1154                  * the currently known MTU */
1155                 i = dtls1_write_bytes(s, type, buf_, len);
1156                 if (i <= 0) return i;
1157
1158                 if ((i == (int)n) ||
1159                         (type == SSL3_RT_APPLICATION_DATA &&
1160                                 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1161                         {
1162                         /* next chunk of data should get another prepended empty fragment
1163                          * in ciphersuites with known-IV weakness: */
1164                         s->s3->empty_fragment_done = 0;
1165                         return tot+i;
1166                         }
1167
1168                 tot += i;
1169                 n-=i;
1170                 }
1171
1172         return tot;
1173         }
1174
1175
1176         /* this only happens when a client hello is received and a handshake
1177          * is started. */
1178 static int
1179 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1180         int len, int peek)
1181         {
1182
1183         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1184                 /* (partially) satisfy request from storage */
1185                 {
1186                 unsigned char *src = s->d1->handshake_fragment;
1187                 unsigned char *dst = buf;
1188                 unsigned int k,n;
1189
1190                 /* peek == 0 */
1191                 n = 0;
1192                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1193                         {
1194                         *dst++ = *src++;
1195                         len--; s->d1->handshake_fragment_len--;
1196                         n++;
1197                         }
1198                 /* move any remaining fragment bytes: */
1199                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1200                         s->d1->handshake_fragment[k] = *src++;
1201                 return n;
1202                 }
1203
1204         return 0;
1205         }
1206
1207
1208
1209
1210 /* Call this to write data in records of type 'type'
1211  * It will return <= 0 if not all data has been sent or non-blocking IO.
1212  */
1213 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1214         {
1215         const unsigned char *buf=buf_;
1216         unsigned int tot,n,nw;
1217         int i;
1218         unsigned int mtu;
1219
1220         s->rwstate=SSL_NOTHING;
1221         tot=s->s3->wnum;
1222
1223         n=(len-tot);
1224
1225         /* handshake layer figures out MTU for itself, but data records
1226          * are also sent through this interface, so need to figure out MTU */
1227 #if 0
1228         mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1229         mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
1230 #endif
1231         mtu = s->d1->mtu;
1232
1233         if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1234                 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1235
1236         if (n > mtu)
1237                 nw=mtu;
1238         else
1239                 nw=n;
1240
1241         i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1242         if (i <= 0)
1243                 {
1244                 s->s3->wnum=tot;
1245                 return i;
1246                 }
1247
1248         if ( (int)s->s3->wnum + i == len)
1249                 s->s3->wnum = 0;
1250         else
1251                 s->s3->wnum += i;
1252
1253         return tot + i;
1254         }
1255
1256 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1257         {
1258         unsigned char *p,*pseq;
1259         int i,mac_size,clear=0;
1260         int prefix_len = 0;
1261         SSL3_RECORD *wr;
1262         SSL3_BUFFER *wb;
1263         SSL_SESSION *sess;
1264         int bs;
1265
1266         /* first check if there is a SSL3_BUFFER still being written
1267          * out.  This will happen with non blocking IO */
1268         if (s->s3->wbuf.left != 0)
1269                 {
1270                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1271                 return(ssl3_write_pending(s,type,buf,len));
1272                 }
1273
1274         /* If we have an alert to send, lets send it */
1275         if (s->s3->alert_dispatch)
1276                 {
1277                 i=s->method->ssl_dispatch_alert(s);
1278                 if (i <= 0)
1279                         return(i);
1280                 /* if it went, fall through and send more stuff */
1281                 }
1282
1283         if (len == 0 && !create_empty_fragment)
1284                 return 0;
1285
1286         wr= &(s->s3->wrec);
1287         wb= &(s->s3->wbuf);
1288         sess=s->session;
1289
1290         if (    (sess == NULL) ||
1291                 (s->enc_write_ctx == NULL) ||
1292                 (s->write_hash == NULL))
1293                 clear=1;
1294
1295         if (clear)
1296                 mac_size=0;
1297         else
1298                 mac_size=EVP_MD_size(s->write_hash);
1299
1300         /* DTLS implements explicit IV, so no need for empty fragments */
1301 #if 0
1302         /* 'create_empty_fragment' is true only when this function calls itself */
1303         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1304                 && SSL_version(s) != DTLS1_VERSION)
1305                 {
1306                 /* countermeasure against known-IV weakness in CBC ciphersuites
1307                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1308                  */
1309
1310                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1311                         {
1312                         /* recursive function call with 'create_empty_fragment' set;
1313                          * this prepares and buffers the data for an empty fragment
1314                          * (these 'prefix_len' bytes are sent out later
1315                          * together with the actual payload) */
1316                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1317                         if (prefix_len <= 0)
1318                                 goto err;
1319
1320                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1321                                 {
1322                                 /* insufficient space */
1323                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1324                                 goto err;
1325                                 }
1326                         }
1327
1328                 s->s3->empty_fragment_done = 1;
1329                 }
1330 #endif
1331
1332         p = wb->buf + prefix_len;
1333
1334         /* write the header */
1335
1336         *(p++)=type&0xff;
1337         wr->type=type;
1338
1339         if (s->client_version == DTLS1_BAD_VER)
1340                 *(p++) = DTLS1_BAD_VER>>8,
1341                 *(p++) = DTLS1_BAD_VER&0xff;
1342         else
1343                 *(p++)=(s->version>>8),
1344                 *(p++)=s->version&0xff;
1345
1346         /* field where we are to write out packet epoch, seq num and len */
1347         pseq=p;
1348         p+=10;
1349
1350         /* lets setup the record stuff. */
1351
1352         /* Make space for the explicit IV in case of CBC.
1353          * (this is a bit of a boundary violation, but what the heck).
1354          */
1355         if ( s->enc_write_ctx &&
1356                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1357                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1358         else
1359                 bs = 0;
1360
1361         wr->data=p + bs;  /* make room for IV in case of CBC */
1362         wr->length=(int)len;
1363         wr->input=(unsigned char *)buf;
1364
1365         /* we now 'read' from wr->input, wr->length bytes into
1366          * wr->data */
1367
1368         /* first we compress */
1369         if (s->compress != NULL)
1370                 {
1371                 if (!ssl3_do_compress(s))
1372                         {
1373                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1374                         goto err;
1375                         }
1376                 }
1377         else
1378                 {
1379                 memcpy(wr->data,wr->input,wr->length);
1380                 wr->input=wr->data;
1381                 }
1382
1383         /* we should still have the output to wr->data and the input
1384          * from wr->input.  Length should be wr->length.
1385          * wr->data still points in the wb->buf */
1386
1387         if (mac_size != 0)
1388                 {
1389                 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1390                 wr->length+=mac_size;
1391                 }
1392
1393         /* this is true regardless of mac size */
1394         wr->input=p;
1395         wr->data=p;
1396
1397
1398         /* ssl3_enc can only have an error on read */
1399         if (bs) /* bs != 0 in case of CBC */
1400                 {
1401                 RAND_pseudo_bytes(p,bs);
1402                 /* master IV and last CBC residue stand for
1403                  * the rest of randomness */
1404                 wr->length += bs;
1405                 }
1406
1407         s->method->ssl3_enc->enc(s,1);
1408
1409         /* record length after mac and block padding */
1410 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1411         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1412
1413         /* there's only one epoch between handshake and app data */
1414
1415         s2n(s->d1->w_epoch, pseq);
1416
1417         /* XDTLS: ?? */
1418 /*      else
1419         s2n(s->d1->handshake_epoch, pseq); */
1420
1421         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1422         pseq+=6;
1423         s2n(wr->length,pseq);
1424
1425         /* we should now have
1426          * wr->data pointing to the encrypted data, which is
1427          * wr->length long */
1428         wr->type=type; /* not needed but helps for debugging */
1429         wr->length+=DTLS1_RT_HEADER_LENGTH;
1430
1431 #if 0  /* this is now done at the message layer */
1432         /* buffer the record, making it easy to handle retransmits */
1433         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1434                 dtls1_buffer_record(s, wr->data, wr->length,
1435                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1436 #endif
1437
1438         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1439
1440         if (create_empty_fragment)
1441                 {
1442                 /* we are in a recursive call;
1443                  * just return the length, don't write out anything here
1444                  */
1445                 return wr->length;
1446                 }
1447
1448         /* now let's set up wb */
1449         wb->left = prefix_len + wr->length;
1450         wb->offset = 0;
1451
1452         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1453         s->s3->wpend_tot=len;
1454         s->s3->wpend_buf=buf;
1455         s->s3->wpend_type=type;
1456         s->s3->wpend_ret=len;
1457
1458         /* we now just need to write the buffer */
1459         return ssl3_write_pending(s,type,buf,len);
1460 err:
1461         return -1;
1462         }
1463
1464
1465
1466 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
1467         PQ_64BIT *seq_num)
1468         {
1469 #if PQ_64BIT_IS_INTEGER
1470         PQ_64BIT mask = 0x0000000000000001L;
1471 #endif
1472         PQ_64BIT rcd_num, tmp;
1473
1474         pq_64bit_init(&rcd_num);
1475         pq_64bit_init(&tmp);
1476
1477         /* this is the sequence number for the record just read */
1478         pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1479
1480
1481         if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1482                 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1483                 {
1484                 pq_64bit_assign(seq_num, &rcd_num);
1485                 pq_64bit_free(&rcd_num);
1486                 pq_64bit_free(&tmp);
1487                 return 1;  /* this record is new */
1488                 }
1489
1490         pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1491
1492         if ( pq_64bit_get_word(&tmp) > bitmap->length)
1493                 {
1494                 pq_64bit_free(&rcd_num);
1495                 pq_64bit_free(&tmp);
1496                 return 0;  /* stale, outside the window */
1497                 }
1498
1499 #if PQ_64BIT_IS_BIGNUM
1500         {
1501         int offset;
1502         pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1503         pq_64bit_sub_word(&tmp, 1);
1504         offset = pq_64bit_get_word(&tmp);
1505         if ( pq_64bit_is_bit_set(&(bitmap->map), offset))
1506                 {
1507                 pq_64bit_free(&rcd_num);
1508                 pq_64bit_free(&tmp);
1509                 return 0;
1510                 }
1511         }
1512 #else
1513         mask <<= (bitmap->max_seq_num - rcd_num - 1);
1514         if (bitmap->map & mask)
1515                 return 0; /* record previously received */
1516 #endif
1517
1518         pq_64bit_assign(seq_num, &rcd_num);
1519         pq_64bit_free(&rcd_num);
1520         pq_64bit_free(&tmp);
1521         return 1;
1522         }
1523
1524
1525 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1526         {
1527         unsigned int shift;
1528         PQ_64BIT rcd_num;
1529         PQ_64BIT tmp;
1530         PQ_64BIT_CTX *ctx;
1531
1532         pq_64bit_init(&rcd_num);
1533         pq_64bit_init(&tmp);
1534
1535         pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1536
1537         /* unfortunate code complexity due to 64-bit manipulation support
1538          * on 32-bit machines */
1539         if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1540                 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1541                 {
1542                 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num));
1543                 pq_64bit_add_word(&tmp, 1);
1544
1545                 shift = (unsigned int)pq_64bit_get_word(&tmp);
1546
1547                 pq_64bit_lshift(&(tmp), &(bitmap->map), shift);
1548                 pq_64bit_assign(&(bitmap->map), &tmp);
1549
1550                 pq_64bit_set_bit(&(bitmap->map), 0);
1551                 pq_64bit_add_word(&rcd_num, 1);
1552                 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num);
1553
1554                 pq_64bit_assign_word(&tmp, 1);
1555                 pq_64bit_lshift(&tmp, &tmp, bitmap->length);
1556                 ctx = pq_64bit_ctx_new(&ctx);
1557                 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx);
1558                 pq_64bit_ctx_free(ctx);
1559                 }
1560         else
1561                 {
1562                 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1563                 pq_64bit_sub_word(&tmp, 1);
1564                 shift = (unsigned int)pq_64bit_get_word(&tmp);
1565
1566                 pq_64bit_set_bit(&(bitmap->map), shift);
1567                 }
1568
1569         pq_64bit_free(&rcd_num);
1570         pq_64bit_free(&tmp);
1571         }
1572
1573
1574 int dtls1_dispatch_alert(SSL *s)
1575         {
1576         int i,j;
1577         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1578         unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */
1579         unsigned char *ptr = &buf[0];
1580
1581         s->s3->alert_dispatch=0;
1582
1583         memset(buf, 0x00, sizeof(buf));
1584         *ptr++ = s->s3->send_alert[0];
1585         *ptr++ = s->s3->send_alert[1];
1586
1587         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1588                 {
1589                 s2n(s->d1->handshake_read_seq, ptr);
1590 #if 0
1591                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1592
1593                 else
1594                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1595 #endif
1596
1597 #if 0
1598                 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);
1599 #endif
1600                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1601                 }
1602
1603         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1604         if (i <= 0)
1605                 {
1606                 s->s3->alert_dispatch=1;
1607                 /* fprintf( stderr, "not done with alert\n" ); */
1608                 }
1609         else
1610                 {
1611                 if ( s->s3->send_alert[0] == SSL3_AL_FATAL ||
1612                         s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1613                         (void)BIO_flush(s->wbio);
1614
1615                 if (s->msg_callback)
1616                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1617                                 2, s, s->msg_callback_arg);
1618
1619                 if (s->info_callback != NULL)
1620                         cb=s->info_callback;
1621                 else if (s->ctx->info_callback != NULL)
1622                         cb=s->ctx->info_callback;
1623
1624                 if (cb != NULL)
1625                         {
1626                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1627                         cb(s,SSL_CB_WRITE_ALERT,j);
1628                         }
1629                 }
1630         return(i);
1631         }
1632
1633
1634 static DTLS1_BITMAP *
1635 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1636     {
1637
1638     *is_next_epoch = 0;
1639
1640     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1641     if (rr->epoch == s->d1->r_epoch)
1642         return &s->d1->bitmap;
1643
1644     /* Only HM and ALERT messages can be from the next epoch */
1645     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1646         (rr->type == SSL3_RT_HANDSHAKE ||
1647             rr->type == SSL3_RT_ALERT))
1648         {
1649         *is_next_epoch = 1;
1650         return &s->d1->next_bitmap;
1651         }
1652
1653     return NULL;
1654     }
1655
1656 #if 0
1657 static int
1658 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1659         unsigned long *offset)
1660         {
1661
1662         /* alerts are passed up immediately */
1663         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1664                 rr->type == SSL3_RT_ALERT)
1665                 return 0;
1666
1667         /* Only need to buffer if a handshake is underway.
1668          * (this implies that Hello Request and Client Hello are passed up
1669          * immediately) */
1670         if ( SSL_in_init(s))
1671                 {
1672                 unsigned char *data = rr->data;
1673                 /* need to extract the HM/CCS sequence number here */
1674                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1675                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1676                         {
1677                         unsigned short seq_num;
1678                         struct hm_header_st msg_hdr;
1679                         struct ccs_header_st ccs_hdr;
1680
1681                         if ( rr->type == SSL3_RT_HANDSHAKE)
1682                                 {
1683                                 dtls1_get_message_header(data, &msg_hdr);
1684                                 seq_num = msg_hdr.seq;
1685                                 *offset = msg_hdr.frag_off;
1686                                 }
1687                         else
1688                                 {
1689                                 dtls1_get_ccs_header(data, &ccs_hdr);
1690                                 seq_num = ccs_hdr.seq;
1691                                 *offset = 0;
1692                                 }
1693
1694                         /* this is either a record we're waiting for, or a
1695                          * retransmit of something we happened to previously
1696                          * receive (higher layers will drop the repeat silently */
1697                         if ( seq_num < s->d1->handshake_read_seq)
1698                                 return 0;
1699                         if (rr->type == SSL3_RT_HANDSHAKE &&
1700                                 seq_num == s->d1->handshake_read_seq &&
1701                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1702                                 return 0;
1703                         else if ( seq_num == s->d1->handshake_read_seq &&
1704                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1705                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1706                                 return 0;
1707                         else
1708                                 {
1709                                 *priority = seq_num;
1710                                 return 1;
1711                                 }
1712                         }
1713                 else /* unknown record type */
1714                         return 0;
1715                 }
1716
1717         return 0;
1718         }
1719 #endif
1720
1721 void
1722 dtls1_reset_seq_numbers(SSL *s, int rw)
1723         {
1724         unsigned char *seq;
1725         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1726
1727         if ( rw & SSL3_CC_READ)
1728                 {
1729                 seq = s->s3->read_sequence;
1730                 s->d1->r_epoch++;
1731
1732                 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map));
1733                 s->d1->bitmap.length = s->d1->next_bitmap.length;
1734                 pq_64bit_assign(&(s->d1->bitmap.max_seq_num),
1735                         &(s->d1->next_bitmap.max_seq_num));
1736
1737                 pq_64bit_free(&(s->d1->next_bitmap.map));
1738                 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
1739                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1740                 pq_64bit_init(&(s->d1->next_bitmap.map));
1741                 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
1742                 }
1743         else
1744                 {
1745                 seq = s->s3->write_sequence;
1746                 s->d1->w_epoch++;
1747                 }
1748
1749         memset(seq, 0x00, seq_bytes);
1750         }
1751
1752 #if PQ_64BIT_IS_INTEGER
1753 static PQ_64BIT
1754 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
1755        {
1756        PQ_64BIT _num;
1757
1758        _num = (((PQ_64BIT)bytes[0]) << 56) |
1759                (((PQ_64BIT)bytes[1]) << 48) |
1760                (((PQ_64BIT)bytes[2]) << 40) |
1761                (((PQ_64BIT)bytes[3]) << 32) |
1762                (((PQ_64BIT)bytes[4]) << 24) |
1763                (((PQ_64BIT)bytes[5]) << 16) |
1764                (((PQ_64BIT)bytes[6]) <<  8) |
1765                (((PQ_64BIT)bytes[7])      );
1766
1767            *num = _num ;
1768        return _num;
1769        }
1770 #endif
1771
1772
1773 static void
1774 dtls1_clear_timeouts(SSL *s)
1775         {
1776         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1777         }