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