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         unsigned long long *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         unsigned long long priority);
 137 static int dtls1_process_record(SSL *s);
 138 static unsigned long long bytes_to_long_long(unsigned char *bytes);
 139 static void long_long_to_bytes(unsigned long long num, unsigned char *bytes);
 140 static void dtls1_clear_timeouts(SSL *s);
 141
 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, unsigned long long priority)
 165 {
 166     DTLS1_RECORD_DATA *rdata;
 167         pitem *item;
 168
 169         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 170         item = pitem_new(priority, rdata);
 171         if (rdata == NULL || item == NULL)
 172                 {
 173                 if (rdata != NULL) OPENSSL_free(rdata);
 174                 if (item != NULL) pitem_free(item);
 175
 176                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 177                 return(0);
 178                 }
 179
 180         rdata->packet = s->packet;
 181         rdata->packet_length = s->packet_length;
 182         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 183         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 184
 185         item->data = rdata;
 186
 187         /* insert should not fail, since duplicates are dropped */
 188         if (pqueue_insert(queue->q, item) == NULL)
 189                 {
 190                 OPENSSL_free(rdata);
 191                 pitem_free(item);
 192                 return(0);
 193                 }
 194
 195         s->packet = NULL;
 196         s->packet_length = 0;
 197         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 198         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 199
 200         ssl3_setup_buffers(s);
 201
 202         return(1);
 203     }
 204
 205
 206 static int
 207 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 208     {
 209     pitem *item;
 210
 211     item = pqueue_pop(queue->q);
 212     if (item)
 213         {
 214         dtls1_copy_record(s, item);
 215
 216         OPENSSL_free(item->data);
 217                 pitem_free(item);
 218
 219         return(1);
 220         }
 221
 222     return(0);
 223     }
 224
 225
 226 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 227  * yet */
 228 #define dtls1_get_unprocessed_record(s) \
 229                    dtls1_retrieve_buffered_record((s), \
 230                    &((s)->d1->unprocessed_rcds))
 231
 232 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 233 #define dtls1_get_processed_record(s) \
 234                    dtls1_retrieve_buffered_record((s), \
 235                    &((s)->d1->processed_rcds))
 236
 237 static int
 238 dtls1_process_buffered_records(SSL *s)
 239     {
 240     pitem *item;
 241
 242     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 243     if (item)
 244         {
 245         DTLS1_RECORD_DATA *rdata;
 246         rdata = (DTLS1_RECORD_DATA *)item->data;
 247
 248         /* Check if epoch is current. */
 249         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 250             return(1);  /* Nothing to do. */
 251
 252         /* Process all the records. */
 253         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 254             {
 255             dtls1_get_unprocessed_record(s);
 256             if ( ! dtls1_process_record(s))
 257                 return(0);
 258             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 259                 s->s3->rrec.seq_num);
 260             }
 261         }
 262
 263     /* sync epoch numbers once all the unprocessed records
 264      * have been processed */
 265     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 266     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 267
 268     return(1);
 269     }
 270
 271
 272 #if 0
 273
 274 static int
 275 dtls1_get_buffered_record(SSL *s)
 276         {
 277         pitem *item;
 278         unsigned long long priority =
 279                 (((unsigned long long)s->d1->handshake_read_seq) << 32) |
 280                 ((unsigned long long)s->d1->r_msg_hdr.frag_off);
 281
 282         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 283                                                            nothing buffered */
 284                 return 0;
 285
 286
 287         item = pqueue_peek(s->d1->rcvd_records);
 288         if (item && item->priority == priority)
 289                 {
 290                 /* Check if we've received the record of interest.  It must be
 291                  * a handshake record, since data records as passed up without
 292                  * buffering */
 293                 DTLS1_RECORD_DATA *rdata;
 294                 item = pqueue_pop(s->d1->rcvd_records);
 295                 rdata = (DTLS1_RECORD_DATA *)item->data;
 296
 297                 if (s->s3->rbuf.buf != NULL)
 298                         OPENSSL_free(s->s3->rbuf.buf);
 299
 300                 s->packet = rdata->packet;
 301                 s->packet_length = rdata->packet_length;
 302                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 303                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 304
 305                 OPENSSL_free(item->data);
 306                 pitem_free(item);
 307
 308                 /* s->d1->next_expected_seq_num++; */
 309                 return(1);
 310                 }
 311
 312         return 0;
 313         }
 314
 315 #endif
 316
 317 static int
 318 dtls1_process_record(SSL *s)
 319 {
 320     int i,al;
 321         int clear=0;
 322     int enc_err;
 323         SSL_SESSION *sess;
 324     SSL3_RECORD *rr;
 325         unsigned int mac_size;
 326         unsigned char md[EVP_MAX_MD_SIZE];
 327
 328
 329         rr= &(s->s3->rrec);
 330     sess = s->session;
 331
 332         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 333          * and we have that many bytes in s->packet
 334          */
 335         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 336
 337         /* ok, we can now read from 's->packet' data into 'rr'
 338          * rr->input points at rr->length bytes, which
 339          * need to be copied into rr->data by either
 340          * the decryption or by the decompression
 341          * When the data is 'copied' into the rr->data buffer,
 342          * rr->input will be pointed at the new buffer */
 343
 344         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 345          * rr->length bytes of encrypted compressed stuff. */
 346
 347         /* check is not needed I believe */
 348         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 349                 {
 350                 al=SSL_AD_RECORD_OVERFLOW;
 351                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 352                 goto f_err;
 353                 }
 354
 355         /* decrypt in place in 'rr->input' */
 356         rr->data=rr->input;
 357
 358         enc_err = s->method->ssl3_enc->enc(s,0);
 359         if (enc_err <= 0)
 360                 {
 361                 if (enc_err == 0)
 362                         /* SSLerr() and ssl3_send_alert() have been called */
 363                         goto err;
 364
 365                 /* otherwise enc_err == -1 */
 366                 goto decryption_failed_or_bad_record_mac;
 367                 }
 368
 369 #ifdef TLS_DEBUG
 370 printf("dec %d\n",rr->length);
 371 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 372 printf("\n");
 373 #endif
 374
 375         /* r->length is now the compressed data plus mac */
 376 if (    (sess == NULL) ||
 377                 (s->enc_read_ctx == NULL) ||
 378                 (s->read_hash == NULL))
 379     clear=1;
 380
 381         if (!clear)
 382                 {
 383                 mac_size=EVP_MD_size(s->read_hash);
 384
 385                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 386                         {
 387 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 388                         al=SSL_AD_RECORD_OVERFLOW;
 389                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 390                         goto f_err;
 391 #else
 392                         goto decryption_failed_or_bad_record_mac;
 393 #endif
 394                         }
 395                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 396                 if (rr->length < mac_size)
 397                         {
 398 #if 0 /* OK only for stream ciphers */
 399                         al=SSL_AD_DECODE_ERROR;
 400                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 401                         goto f_err;
 402 #else
 403                         goto decryption_failed_or_bad_record_mac;
 404 #endif
 405                         }
 406                 rr->length-=mac_size;
 407                 i=s->method->ssl3_enc->mac(s,md,0);
 408                 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 409                         {
 410                         goto decryption_failed_or_bad_record_mac;
 411                         }
 412                 }
 413
 414         /* r->length is now just compressed */
 415         if (s->expand != NULL)
 416                 {
 417                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 418                         {
 419                         al=SSL_AD_RECORD_OVERFLOW;
 420                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 421                         goto f_err;
 422                         }
 423                 if (!ssl3_do_uncompress(s))
 424                         {
 425                         al=SSL_AD_DECOMPRESSION_FAILURE;
 426                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 427                         goto f_err;
 428                         }
 429                 }
 430
 431         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 432                 {
 433                 al=SSL_AD_RECORD_OVERFLOW;
 434                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 435                 goto f_err;
 436                 }
 437
 438         rr->off=0;
 439         /* So at this point the following is true
 440          * ssl->s3->rrec.type   is the type of record
 441          * ssl->s3->rrec.length == number of bytes in record
 442          * ssl->s3->rrec.off    == offset to first valid byte
 443          * ssl->s3->rrec.data   == where to take bytes from, increment
 444          *                         after use :-).
 445          */
 446
 447         /* we have pulled in a full packet so zero things */
 448         s->packet_length=0;
 449     dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 450     return(1);
 451
 452 decryption_failed_or_bad_record_mac:
 453         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
 454          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 455          * failure is directly visible from the ciphertext anyway,
 456          * we should not reveal which kind of error occured -- this
 457          * might become visible to an attacker (e.g. via logfile) */
 458         al=SSL_AD_BAD_RECORD_MAC;
 459         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 460 f_err:
 461         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 462 err:
 463         return(0);
 464 }
 465
 466
 467 /* Call this to get a new input record.
 468  * It will return <= 0 if more data is needed, normally due to an error
 469  * or non-blocking IO.
 470  * When it finishes, one packet has been decoded and can be found in
 471  * ssl->s3->rrec.type    - is the type of record
 472  * ssl->s3->rrec.data,   - data
 473  * ssl->s3->rrec.length, - number of bytes
 474  */
 475 /* used only by dtls1_read_bytes */
 476 int dtls1_get_record(SSL *s)
 477         {
 478         int ssl_major,ssl_minor,al;
 479         int i,n;
 480         SSL3_RECORD *rr;
 481         SSL_SESSION *sess;
 482         unsigned char *p;
 483         short version;
 484         DTLS1_BITMAP *bitmap;
 485         unsigned long long read_sequence;
 486     unsigned int is_next_epoch;
 487
 488         rr= &(s->s3->rrec);
 489         sess=s->session;
 490
 491     /* The epoch may have changed.  If so, process all the
 492      * pending records.  This is a non-blocking operation. */
 493     if ( ! dtls1_process_buffered_records(s))
 494         return 0;
 495
 496         /* if we're renegotiating, then there may be buffered records */
 497         if (dtls1_get_processed_record(s))
 498                 return 1;
 499
 500         /* get something from the wire */
 501 again:
 502         /* check if we have the header */
 503         if (    (s->rstate != SSL_ST_READ_BODY) ||
 504                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 505                 {
 506                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 507                 /* read timeout is handled by dtls1_read_bytes */
 508                 if (n <= 0) return(n); /* error or non-blocking */
 509
 510                 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
 511
 512                 s->rstate=SSL_ST_READ_BODY;
 513
 514                 p=s->packet;
 515
 516                 /* Pull apart the header into the DTLS1_RECORD */
 517                 rr->type= *(p++);
 518                 ssl_major= *(p++);
 519                 ssl_minor= *(p++);
 520                 version=(ssl_major<<8)|ssl_minor;
 521
 522         /* sequence number is 64 bits, with top 2 bytes = epoch */
 523                 n2s(p,rr->epoch);
 524
 525                 read_sequence = 0;
 526                 n2l6(p, read_sequence);
 527                 long_long_to_bytes(read_sequence, s->s3->read_sequence);
 528                 n2s(p,rr->length);
 529
 530                 /* Lets check version */
 531                 if (s->first_packet)
 532                         {
 533                         s->first_packet=0;
 534                         }
 535                 else
 536                         {
 537                         if (version != s->version)
 538                                 {
 539                                 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 540                                 /* Send back error using their
 541                                  * version number :-) */
 542                                 s->version=version;
 543                                 al=SSL_AD_PROTOCOL_VERSION;
 544                                 goto f_err;
 545                                 }
 546                         }
 547
 548                 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00))
 549                         {
 550                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 551                         goto err;
 552                         }
 553
 554                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 555                         {
 556                         al=SSL_AD_RECORD_OVERFLOW;
 557                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 558                         goto f_err;
 559                         }
 560
 561                 /* now s->rstate == SSL_ST_READ_BODY */
 562                 }
 563
 564         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 565
 566         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 567                 {
 568                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 569                 i=rr->length;
 570                 n=ssl3_read_n(s,i,i,1);
 571                 if (n <= 0) return(n); /* error or non-blocking io */
 572
 573                 /* this packet contained a partial record, dump it */
 574                 if ( n != i)
 575                         {
 576                         s->packet_length = 0;
 577                         goto again;
 578                         }
 579
 580                 /* now n == rr->length,
 581                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 582                 }
 583         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 584
 585         /* match epochs.  NULL means the packet is dropped on the floor */
 586         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 587         if ( bitmap == NULL)
 588         {
 589         s->packet_length = 0;  /* dump this record */
 590         goto again;   /* get another record */
 591                 }
 592
 593         /* check whether this is a repeat, or aged record */
 594         if ( ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))
 595                 {
 596                 s->packet_length=0; /* dump this record */
 597                 goto again;     /* get another record */
 598                 }
 599
 600         /* just read a 0 length packet */
 601         if (rr->length == 0) goto again;
 602
 603     /* If this record is from the next epoch (either HM or ALERT), buffer it
 604      * since it cannot be processed at this time.
 605      * Records from the next epoch are marked as received even though they are
 606      * not processed, so as to prevent any potential resource DoS attack */
 607     if (is_next_epoch)
 608         {
 609         dtls1_record_bitmap_update(s, bitmap);
 610         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 611         s->packet_length = 0;
 612         goto again;
 613         }
 614
 615     if ( ! dtls1_process_record(s))
 616         return(0);
 617
 618         dtls1_clear_timeouts(s);  /* done waiting */
 619         return(1);
 620
 621 f_err:
 622         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 623 err:
 624         return(0);
 625         }
 626
 627 /* Return up to 'len' payload bytes received in 'type' records.
 628  * 'type' is one of the following:
 629  *
 630  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 631  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 632  *   -  0 (during a shutdown, no data has to be returned)
 633  *
 634  * If we don't have stored data to work from, read a SSL/TLS record first
 635  * (possibly multiple records if we still don't have anything to return).
 636  *
 637  * This function must handle any surprises the peer may have for us, such as
 638  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 639  * a surprise, but handled as if it were), or renegotiation requests.
 640  * Also if record payloads contain fragments too small to process, we store
 641  * them until there is enough for the respective protocol (the record protocol
 642  * may use arbitrary fragmentation and even interleaving):
 643  *     Change cipher spec protocol
 644  *             just 1 byte needed, no need for keeping anything stored
 645  *     Alert protocol
 646  *             2 bytes needed (AlertLevel, AlertDescription)
 647  *     Handshake protocol
 648  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 649  *             to detect unexpected Client Hello and Hello Request messages
 650  *             here, anything else is handled by higher layers
 651  *     Application data protocol
 652  *             none of our business
 653  */
 654 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 655         {
 656         int al,i,j,ret;
 657         unsigned int n;
 658         SSL3_RECORD *rr;
 659         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 660
 661         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 662                 if (!ssl3_setup_buffers(s))
 663                         return(-1);
 664
 665     /* XXX: check what the second '&& type' is about */
 666         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 667                 (type != SSL3_RT_HANDSHAKE) && type) ||
 668             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 669                 {
 670                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 671                 return -1;
 672                 }
 673
 674         /* check whether there's a handshake message (client hello?) waiting */
 675         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 676                 return ret;
 677
 678         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 679
 680         if (!s->in_handshake && SSL_in_init(s))
 681                 {
 682                 /* type == SSL3_RT_APPLICATION_DATA */
 683                 i=s->handshake_func(s);
 684                 if (i < 0) return(i);
 685                 if (i == 0)
 686                         {
 687                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 688                         return(-1);
 689                         }
 690                 }
 691
 692 start:
 693         s->rwstate=SSL_NOTHING;
 694
 695         /* s->s3->rrec.type         - is the type of record
 696          * s->s3->rrec.data,    - data
 697          * s->s3->rrec.off,     - offset into 'data' for next read
 698          * s->s3->rrec.length,  - number of bytes. */
 699         rr = &(s->s3->rrec);
 700
 701         /* get new packet if necessary */
 702         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 703                 {
 704                 ret=dtls1_get_record(s);
 705                 if (ret <= 0)
 706                         {
 707                         ret = dtls1_read_failed(s, ret);
 708                         /* anything other than a timeout is an error */
 709                         if (ret <= 0)
 710                                 return(ret);
 711                         else
 712                                 goto start;
 713                         }
 714                 }
 715
 716         /* we now have a packet which can be read and processed */
 717
 718         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 719                                        * reset by ssl3_get_finished */
 720                 && (rr->type != SSL3_RT_HANDSHAKE))
 721                 {
 722                 al=SSL_AD_UNEXPECTED_MESSAGE;
 723                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
 724                 goto err;
 725                 }
 726
 727         /* If the other end has shut down, throw anything we read away
 728          * (even in 'peek' mode) */
 729         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 730                 {
 731                 rr->length=0;
 732                 s->rwstate=SSL_NOTHING;
 733                 return(0);
 734                 }
 735
 736
 737         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 738                 {
 739                 /* make sure that we are not getting application data when we
 740                  * are doing a handshake for the first time */
 741                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 742                         (s->enc_read_ctx == NULL))
 743                         {
 744                         al=SSL_AD_UNEXPECTED_MESSAGE;
 745                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 746                         goto f_err;
 747                         }
 748
 749                 if (len <= 0) return(len);
 750
 751                 if ((unsigned int)len > rr->length)
 752                         n = rr->length;
 753                 else
 754                         n = (unsigned int)len;
 755
 756                 memcpy(buf,&(rr->data[rr->off]),n);
 757                 if (!peek)
 758                         {
 759                         rr->length-=n;
 760                         rr->off+=n;
 761                         if (rr->length == 0)
 762                                 {
 763                                 s->rstate=SSL_ST_READ_HEADER;
 764                                 rr->off=0;
 765                                 }
 766                         }
 767                 return(n);
 768                 }
 769
 770
 771         /* If we get here, then type != rr->type; if we have a handshake
 772          * message, then it was unexpected (Hello Request or Client Hello). */
 773
 774         /* In case of record types for which we have 'fragment' storage,
 775          * fill that so that we can process the data at a fixed place.
 776          */
 777                 {
 778                 unsigned int k, dest_maxlen = 0;
 779                 unsigned char *dest = NULL;
 780                 unsigned int *dest_len = NULL;
 781
 782                 if (rr->type == SSL3_RT_HANDSHAKE)
 783                         {
 784                         dest_maxlen = sizeof s->d1->handshake_fragment;
 785                         dest = s->d1->handshake_fragment;
 786                         dest_len = &s->d1->handshake_fragment_len;
 787                         }
 788                 else if (rr->type == SSL3_RT_ALERT)
 789                         {
 790                         dest_maxlen = sizeof(s->d1->alert_fragment);
 791                         dest = s->d1->alert_fragment;
 792                         dest_len = &s->d1->alert_fragment_len;
 793                         }
 794                 else    /* else it's a CCS message */
 795                         OPENSSL_assert(rr->type == SSL3_RT_CHANGE_CIPHER_SPEC);
 796
 797
 798                 if (dest_maxlen > 0)
 799                         {
 800             /* XDTLS:  In a pathalogical case, the Client Hello
 801              *  may be fragmented--don't always expect dest_maxlen bytes */
 802                         if ( rr->length < dest_maxlen)
 803                                 {
 804                                 s->rstate=SSL_ST_READ_HEADER;
 805                                 rr->length = 0;
 806                                 goto start;
 807                                 }
 808
 809                         /* now move 'n' bytes: */
 810                         for ( k = 0; k < dest_maxlen; k++)
 811                                 {
 812                                 dest[k] = rr->data[rr->off++];
 813                                 rr->length--;
 814                                 }
 815                         *dest_len = dest_maxlen;
 816                         }
 817                 }
 818
 819         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 820          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 821          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 822
 823         /* If we are a client, check for an incoming 'Hello Request': */
 824         if ((!s->server) &&
 825                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 826                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 827                 (s->session != NULL) && (s->session->cipher != NULL))
 828                 {
 829                 s->d1->handshake_fragment_len = 0;
 830
 831                 if ((s->d1->handshake_fragment[1] != 0) ||
 832                         (s->d1->handshake_fragment[2] != 0) ||
 833                         (s->d1->handshake_fragment[3] != 0))
 834                         {
 835                         al=SSL_AD_DECODE_ERROR;
 836                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 837                         goto err;
 838                         }
 839
 840                 /* no need to check sequence number on HELLO REQUEST messages */
 841
 842                 if (s->msg_callback)
 843                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 844                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 845
 846                 if (SSL_is_init_finished(s) &&
 847                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 848                         !s->s3->renegotiate)
 849                         {
 850                         ssl3_renegotiate(s);
 851                         if (ssl3_renegotiate_check(s))
 852                                 {
 853                                 i=s->handshake_func(s);
 854                                 if (i < 0) return(i);
 855                                 if (i == 0)
 856                                         {
 857                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 858                                         return(-1);
 859                                         }
 860
 861                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 862                                         {
 863                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 864                                                 {
 865                                                 BIO *bio;
 866                                                 /* In the case where we try to read application data,
 867                                                  * but we trigger an SSL handshake, we return -1 with
 868                                                  * the retry option set.  Otherwise renegotiation may
 869                                                  * cause nasty problems in the blocking world */
 870                                                 s->rwstate=SSL_READING;
 871                                                 bio=SSL_get_rbio(s);
 872                                                 BIO_clear_retry_flags(bio);
 873                                                 BIO_set_retry_read(bio);
 874                                                 return(-1);
 875                                                 }
 876                                         }
 877                                 }
 878                         }
 879                 /* we either finished a handshake or ignored the request,
 880                  * now try again to obtain the (application) data we were asked for */
 881                 goto start;
 882                 }
 883
 884         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
 885                 {
 886                 int alert_level = s->d1->alert_fragment[0];
 887                 int alert_descr = s->d1->alert_fragment[1];
 888
 889                 s->d1->alert_fragment_len = 0;
 890
 891                 if (s->msg_callback)
 892                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
 893                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
 894
 895                 if (s->info_callback != NULL)
 896                         cb=s->info_callback;
 897                 else if (s->ctx->info_callback != NULL)
 898                         cb=s->ctx->info_callback;
 899
 900                 if (cb != NULL)
 901                         {
 902                         j = (alert_level << 8) | alert_descr;
 903                         cb(s, SSL_CB_READ_ALERT, j);
 904                         }
 905
 906                 if (alert_level == 1) /* warning */
 907                         {
 908                         s->s3->warn_alert = alert_descr;
 909                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
 910                                 {
 911                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 912                                 return(0);
 913                                 }
 914 #if 0
 915             /* XXX: this is a possible improvement in the future */
 916                         /* now check if it's a missing record */
 917                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
 918                                 {
 919                                 unsigned short seq;
 920                                 unsigned int frag_off;
 921                                 unsigned char *p = &(s->d1->alert_fragment[2]);
 922
 923                                 n2s(p, seq);
 924                                 n2l3(p, frag_off);
 925
 926                                 dtls1_retransmit_message(s, seq, frag_off, &found);
 927                                 if ( ! found  && SSL_in_init(s))
 928                                         {
 929                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
 930                                         /* requested a message not yet sent,
 931                                            send an alert ourselves */
 932                                         ssl3_send_alert(s,SSL3_AL_WARNING,
 933                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 934                                         }
 935                                 }
 936 #endif
 937                         }
 938                 else if (alert_level == 2) /* fatal */
 939                         {
 940                         char tmp[16];
 941
 942                         s->rwstate=SSL_NOTHING;
 943                         s->s3->fatal_alert = alert_descr;
 944                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
 945                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
 946                         ERR_add_error_data(2,"SSL alert number ",tmp);
 947                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
 948                         SSL_CTX_remove_session(s->ctx,s->session);
 949                         return(0);
 950                         }
 951                 else
 952                         {
 953                         al=SSL_AD_ILLEGAL_PARAMETER;
 954                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
 955                         goto f_err;
 956                         }
 957
 958                 goto start;
 959                 }
 960
 961         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
 962                 {
 963                 s->rwstate=SSL_NOTHING;
 964                 rr->length=0;
 965                 return(0);
 966                 }
 967
 968         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
 969         {
 970         struct ccs_header_st ccs_hdr;
 971
 972                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
 973
 974                 if ( ccs_hdr.seq == s->d1->handshake_read_seq)
 975                         {
 976                         /* 'Change Cipher Spec' is just a single byte, so we know
 977                          * exactly what the record payload has to look like */
 978                         /* XDTLS: check that epoch is consistent */
 979                         if (    (rr->length != DTLS1_CCS_HEADER_LENGTH) ||
 980                                 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
 981                                 {
 982                                 i=SSL_AD_ILLEGAL_PARAMETER;
 983                                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
 984                                 goto err;
 985                                 }
 986
 987                         rr->length=0;
 988
 989                         if (s->msg_callback)
 990                                 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
 991                                         rr->data, 1, s, s->msg_callback_arg);
 992
 993                         s->s3->change_cipher_spec=1;
 994                         if (!ssl3_do_change_cipher_spec(s))
 995                                 goto err;
 996
 997                         /* do this whenever CCS is processed */
 998                         dtls1_reset_seq_numbers(s, SSL3_CC_READ);
 999
1000                         /* handshake read seq is reset upon handshake completion */
1001                         s->d1->handshake_read_seq++;
1002
1003                         goto start;
1004                         }
1005                 else
1006                         {
1007                         rr->length = 0;
1008                         goto start;
1009                         }
1010                 }
1011
1012         /* Unexpected handshake message (Client Hello, or protocol violation) */
1013         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1014                 !s->in_handshake)
1015                 {
1016                 struct hm_header_st msg_hdr;
1017
1018                 /* this may just be a stale retransmit */
1019                 dtls1_get_message_header(rr->data, &msg_hdr);
1020                 if( rr->epoch != s->d1->r_epoch)
1021                         {
1022                         rr->length = 0;
1023                         goto start;
1024                         }
1025
1026                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1027                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1028                         {
1029 #if 0 /* worked only because C operator preferences are not as expected (and
1030        * because this is not really needed for clients except for detecting
1031        * protocol violations): */
1032                         s->state=SSL_ST_BEFORE|(s->server)
1033                                 ?SSL_ST_ACCEPT
1034                                 :SSL_ST_CONNECT;
1035 #else
1036                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1037 #endif
1038                         s->new_session=1;
1039                         }
1040                 i=s->handshake_func(s);
1041                 if (i < 0) return(i);
1042                 if (i == 0)
1043                         {
1044                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1045                         return(-1);
1046                         }
1047
1048                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1049                         {
1050                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1051                                 {
1052                                 BIO *bio;
1053                                 /* In the case where we try to read application data,
1054                                  * but we trigger an SSL handshake, we return -1 with
1055                                  * the retry option set.  Otherwise renegotiation may
1056                                  * cause nasty problems in the blocking world */
1057                                 s->rwstate=SSL_READING;
1058                                 bio=SSL_get_rbio(s);
1059                                 BIO_clear_retry_flags(bio);
1060                                 BIO_set_retry_read(bio);
1061                                 return(-1);
1062                                 }
1063                         }
1064                 goto start;
1065                 }
1066
1067         switch (rr->type)
1068                 {
1069         default:
1070 #ifndef OPENSSL_NO_TLS
1071                 /* TLS just ignores unknown message types */
1072                 if (s->version == TLS1_VERSION)
1073                         {
1074                         rr->length = 0;
1075                         goto start;
1076                         }
1077 #endif
1078                 al=SSL_AD_UNEXPECTED_MESSAGE;
1079                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1080                 goto f_err;
1081         case SSL3_RT_CHANGE_CIPHER_SPEC:
1082         case SSL3_RT_ALERT:
1083         case SSL3_RT_HANDSHAKE:
1084                 /* we already handled all of these, with the possible exception
1085                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1086                  * should not happen when type != rr->type */
1087                 al=SSL_AD_UNEXPECTED_MESSAGE;
1088                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1089                 goto f_err;
1090         case SSL3_RT_APPLICATION_DATA:
1091                 /* At this point, we were expecting handshake data,
1092                  * but have application data.  If the library was
1093                  * running inside ssl3_read() (i.e. in_read_app_data
1094                  * is set) and it makes sense to read application data
1095                  * at this point (session renegotiation not yet started),
1096                  * we will indulge it.
1097                  */
1098                 if (s->s3->in_read_app_data &&
1099                         (s->s3->total_renegotiations != 0) &&
1100                         ((
1101                                 (s->state & SSL_ST_CONNECT) &&
1102                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1103                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1104                                 ) || (
1105                                         (s->state & SSL_ST_ACCEPT) &&
1106                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1107                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1108                                         )
1109                                 ))
1110                         {
1111                         s->s3->in_read_app_data=2;
1112                         return(-1);
1113                         }
1114                 else
1115                         {
1116                         al=SSL_AD_UNEXPECTED_MESSAGE;
1117                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1118                         goto f_err;
1119                         }
1120                 }
1121         /* not reached */
1122
1123 f_err:
1124         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1125 err:
1126         return(-1);
1127         }
1128
1129 int
1130 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1131         {
1132         unsigned int n,tot;
1133         int i;
1134
1135         if (SSL_in_init(s) && !s->in_handshake)
1136                 {
1137                 i=s->handshake_func(s);
1138                 if (i < 0) return(i);
1139                 if (i == 0)
1140                         {
1141                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1142                         return -1;
1143                         }
1144                 }
1145
1146         tot = s->s3->wnum;
1147         n = len - tot;
1148
1149         while( n)
1150                 {
1151                 /* dtls1_write_bytes sends one record at a time, sized according to
1152                  * the currently known MTU */
1153                 i = dtls1_write_bytes(s, type, buf_, len);
1154                 if (i <= 0) return i;
1155
1156                 if ((i == (int)n) ||
1157                         (type == SSL3_RT_APPLICATION_DATA &&
1158                                 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1159                         {
1160                         /* next chunk of data should get another prepended empty fragment
1161                          * in ciphersuites with known-IV weakness: */
1162                         s->s3->empty_fragment_done = 0;
1163                         return tot+i;
1164                         }
1165
1166                 tot += i;
1167                 n-=i;
1168                 }
1169
1170         return tot;
1171         }
1172
1173
1174         /* this only happens when a client hello is received and a handshake
1175          * is started. */
1176 static int
1177 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1178         int len, int peek)
1179         {
1180
1181         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1182                 /* (partially) satisfy request from storage */
1183                 {
1184                 unsigned char *src = s->d1->handshake_fragment;
1185                 unsigned char *dst = buf;
1186                 unsigned int k,n;
1187
1188                 /* peek == 0 */
1189                 n = 0;
1190                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1191                         {
1192                         *dst++ = *src++;
1193                         len--; s->d1->handshake_fragment_len--;
1194                         n++;
1195                         }
1196                 /* move any remaining fragment bytes: */
1197                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1198                         s->d1->handshake_fragment[k] = *src++;
1199                 return n;
1200                 }
1201
1202         return 0;
1203         }
1204
1205
1206
1207
1208 /* Call this to write data in records of type 'type'
1209  * It will return <= 0 if not all data has been sent or non-blocking IO.
1210  */
1211 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1212         {
1213         const unsigned char *buf=buf_;
1214         unsigned int tot,n,nw;
1215         int i;
1216         unsigned int mtu;
1217
1218         s->rwstate=SSL_NOTHING;
1219         tot=s->s3->wnum;
1220
1221         n=(len-tot);
1222
1223         /* handshake layer figures out MTU for itself, but data records
1224          * are also sent through this interface, so need to figure out MTU */
1225 #if 0
1226         mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1227         mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
1228 #endif
1229         mtu = s->d1->mtu;
1230
1231         if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1232                 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1233
1234         if (n > mtu)
1235                 nw=mtu;
1236         else
1237                 nw=n;
1238
1239         i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1240         if (i <= 0)
1241                 {
1242                 s->s3->wnum=tot;
1243                 return i;
1244                 }
1245
1246         if ( s->s3->wnum + i == len)
1247                 s->s3->wnum = 0;
1248         else
1249                 s->s3->wnum += i;
1250
1251         return tot + i;
1252         }
1253
1254 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1255         {
1256         unsigned char *p,*pseq;
1257         int i,mac_size,clear=0;
1258         int prefix_len = 0;
1259         SSL3_RECORD *wr;
1260         SSL3_BUFFER *wb;
1261         SSL_SESSION *sess;
1262         int bs;
1263
1264         /* first check if there is a SSL3_BUFFER still being written
1265          * out.  This will happen with non blocking IO */
1266         if (s->s3->wbuf.left != 0)
1267                 {
1268                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1269                 return(ssl3_write_pending(s,type,buf,len));
1270                 }
1271
1272         /* If we have an alert to send, lets send it */
1273         if (s->s3->alert_dispatch)
1274                 {
1275                 i=s->method->ssl_dispatch_alert(s);
1276                 if (i <= 0)
1277                         return(i);
1278                 /* if it went, fall through and send more stuff */
1279                 }
1280
1281         if (len == 0 && !create_empty_fragment)
1282                 return 0;
1283
1284         wr= &(s->s3->wrec);
1285         wb= &(s->s3->wbuf);
1286         sess=s->session;
1287
1288         if (    (sess == NULL) ||
1289                 (s->enc_write_ctx == NULL) ||
1290                 (s->write_hash == NULL))
1291                 clear=1;
1292
1293         if (clear)
1294                 mac_size=0;
1295         else
1296                 mac_size=EVP_MD_size(s->write_hash);
1297
1298         /* DTLS implements explicit IV, so no need for empty fragments */
1299 #if 0
1300         /* 'create_empty_fragment' is true only when this function calls itself */
1301         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1302                 && SSL_version(s) != DTLS1_VERSION)
1303                 {
1304                 /* countermeasure against known-IV weakness in CBC ciphersuites
1305                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1306                  */
1307
1308                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1309                         {
1310                         /* recursive function call with 'create_empty_fragment' set;
1311                          * this prepares and buffers the data for an empty fragment
1312                          * (these 'prefix_len' bytes are sent out later
1313                          * together with the actual payload) */
1314                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1315                         if (prefix_len <= 0)
1316                                 goto err;
1317
1318                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1319                                 {
1320                                 /* insufficient space */
1321                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1322                                 goto err;
1323                                 }
1324                         }
1325
1326                 s->s3->empty_fragment_done = 1;
1327                 }
1328 #endif
1329
1330         p = wb->buf + prefix_len;
1331
1332         /* write the header */
1333
1334         *(p++)=type&0xff;
1335         wr->type=type;
1336
1337         *(p++)=(s->version>>8);
1338         *(p++)=s->version&0xff;
1339
1340         /* field where we are to write out packet epoch, seq num and len */
1341         pseq=p;
1342         p+=10;
1343
1344         /* lets setup the record stuff. */
1345
1346         /* Make space for the explicit IV in case of CBC.
1347          * (this is a bit of a boundary violation, but what the heck).
1348          */
1349         if ( s->enc_write_ctx &&
1350                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1351                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1352         else
1353                 bs = 0;
1354
1355         wr->data=p + bs;  /* make room for IV in case of CBC */
1356         wr->length=(int)len;
1357         wr->input=(unsigned char *)buf;
1358
1359         /* we now 'read' from wr->input, wr->length bytes into
1360          * wr->data */
1361
1362         /* first we compress */
1363         if (s->compress != NULL)
1364                 {
1365                 if (!ssl3_do_compress(s))
1366                         {
1367                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1368                         goto err;
1369                         }
1370                 }
1371         else
1372                 {
1373                 memcpy(wr->data,wr->input,wr->length);
1374                 wr->input=wr->data;
1375                 }
1376
1377         /* we should still have the output to wr->data and the input
1378          * from wr->input.  Length should be wr->length.
1379          * wr->data still points in the wb->buf */
1380
1381         if (mac_size != 0)
1382                 {
1383                 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1384                 wr->length+=mac_size;
1385                 }
1386
1387         /* this is true regardless of mac size */
1388         wr->input=p;
1389         wr->data=p;
1390
1391
1392         /* ssl3_enc can only have an error on read */
1393         wr->length += bs;  /* bs != 0 in case of CBC.  The enc fn provides
1394                                                 * the randomness */
1395         s->method->ssl3_enc->enc(s,1);
1396
1397         /* record length after mac and block padding */
1398 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1399         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1400
1401         /* there's only one epoch between handshake and app data */
1402
1403         s2n(s->d1->w_epoch, pseq);
1404
1405         /* XDTLS: ?? */
1406 /*      else
1407         s2n(s->d1->handshake_epoch, pseq); */
1408
1409         l2n6(bytes_to_long_long(s->s3->write_sequence), pseq);
1410         s2n(wr->length,pseq);
1411
1412         /* we should now have
1413          * wr->data pointing to the encrypted data, which is
1414          * wr->length long */
1415         wr->type=type; /* not needed but helps for debugging */
1416         wr->length+=DTLS1_RT_HEADER_LENGTH;
1417
1418 #if 0  /* this is now done at the message layer */
1419         /* buffer the record, making it easy to handle retransmits */
1420         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1421                 dtls1_buffer_record(s, wr->data, wr->length,
1422                         *((unsigned long long *)&(s->s3->write_sequence[0])));
1423 #endif
1424
1425         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1426
1427         if (create_empty_fragment)
1428                 {
1429                 /* we are in a recursive call;
1430                  * just return the length, don't write out anything here
1431                  */
1432                 return wr->length;
1433                 }
1434
1435         /* now let's set up wb */
1436         wb->left = prefix_len + wr->length;
1437         wb->offset = 0;
1438
1439         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1440         s->s3->wpend_tot=len;
1441         s->s3->wpend_buf=buf;
1442         s->s3->wpend_type=type;
1443         s->s3->wpend_ret=len;
1444
1445         /* we now just need to write the buffer */
1446         return ssl3_write_pending(s,type,buf,len);
1447 err:
1448         return -1;
1449         }
1450
1451
1452
1453 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
1454         unsigned long long *seq_num)
1455         {
1456         unsigned long long mask = 0x0000000000000001LL;
1457         unsigned long long rcd_num;
1458
1459         rcd_num = bytes_to_long_long(s->s3->read_sequence);
1460
1461         if (rcd_num >= bitmap->max_seq_num)
1462                 {
1463                 *seq_num = rcd_num;
1464                 return 1;  /* this record is new */
1465                 }
1466
1467         if (bitmap->max_seq_num - rcd_num > bitmap->length)
1468                 return 0;  /* stale, outside the window */
1469
1470         mask <<= (bitmap->max_seq_num - rcd_num - 1);
1471         if (bitmap->map & mask)
1472                 return 0; /* record previously received */
1473
1474         *seq_num = rcd_num;
1475         return 1;
1476         }
1477
1478
1479 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1480         {
1481         unsigned int shift;
1482         unsigned long long mask = 0x0000000000000001L;
1483         unsigned long long rcd_num;
1484
1485         rcd_num = bytes_to_long_long(s->s3->read_sequence);
1486
1487         if (rcd_num >= bitmap->max_seq_num)
1488                 {
1489                 shift = rcd_num - bitmap->max_seq_num + 1;
1490                 bitmap->max_seq_num = rcd_num + 1;
1491                 bitmap->map <<= shift;
1492                 bitmap->map |= 0x0000000000000001LL;
1493                 }
1494         else
1495                 {
1496                 mask <<= (bitmap->max_seq_num - rcd_num - 1);
1497                 bitmap->map |= mask;
1498                 }
1499         }
1500
1501
1502 int dtls1_dispatch_alert(SSL *s)
1503         {
1504         int i,j;
1505         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1506         unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */
1507         unsigned char *ptr = &buf[0];
1508
1509         s->s3->alert_dispatch=0;
1510
1511         memset(buf, 0x00, sizeof(buf));
1512         *ptr++ = s->s3->send_alert[0];
1513         *ptr++ = s->s3->send_alert[1];
1514
1515         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1516                 {
1517                 s2n(s->d1->handshake_read_seq, ptr);
1518 #if 0
1519                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1520
1521                 else
1522                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1523 #endif
1524
1525 #if 0
1526                 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);
1527 #endif
1528                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1529                 }
1530
1531         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1532         if (i <= 0)
1533                 {
1534                 s->s3->alert_dispatch=1;
1535                 /* fprintf( stderr, "not done with alert\n" ); */
1536                 }
1537         else
1538                 {
1539                 if ( s->s3->send_alert[0] == SSL3_AL_FATAL ||
1540                         s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1541                         (void)BIO_flush(s->wbio);
1542
1543                 if (s->msg_callback)
1544                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1545                                 2, s, s->msg_callback_arg);
1546
1547                 if (s->info_callback != NULL)
1548                         cb=s->info_callback;
1549                 else if (s->ctx->info_callback != NULL)
1550                         cb=s->ctx->info_callback;
1551
1552                 if (cb != NULL)
1553                         {
1554                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1555                         cb(s,SSL_CB_WRITE_ALERT,j);
1556                         }
1557                 }
1558         return(i);
1559         }
1560
1561
1562 static DTLS1_BITMAP *
1563 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1564     {
1565
1566     *is_next_epoch = 0;
1567
1568     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1569     if (rr->epoch == s->d1->r_epoch)
1570         return &s->d1->bitmap;
1571
1572     /* Only HM and ALERT messages can be from the next epoch */
1573     else if (rr->epoch == s->d1->r_epoch + 1 &&
1574         (rr->type == SSL3_RT_HANDSHAKE ||
1575             rr->type == SSL3_RT_ALERT))
1576         {
1577         *is_next_epoch = 1;
1578         return &s->d1->next_bitmap;
1579         }
1580
1581     return NULL;
1582     }
1583
1584 #if 0
1585 static int
1586 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1587         unsigned long *offset)
1588         {
1589
1590         /* alerts are passed up immediately */
1591         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1592                 rr->type == SSL3_RT_ALERT)
1593                 return 0;
1594
1595         /* Only need to buffer if a handshake is underway.
1596          * (this implies that Hello Request and Client Hello are passed up
1597          * immediately) */
1598         if ( SSL_in_init(s))
1599                 {
1600                 unsigned char *data = rr->data;
1601                 /* need to extract the HM/CCS sequence number here */
1602                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1603                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1604                         {
1605                         unsigned short seq_num;
1606                         struct hm_header_st msg_hdr;
1607                         struct ccs_header_st ccs_hdr;
1608
1609                         if ( rr->type == SSL3_RT_HANDSHAKE)
1610                                 {
1611                                 dtls1_get_message_header(data, &msg_hdr);
1612                                 seq_num = msg_hdr.seq;
1613                                 *offset = msg_hdr.frag_off;
1614                                 }
1615                         else
1616                                 {
1617                                 dtls1_get_ccs_header(data, &ccs_hdr);
1618                                 seq_num = ccs_hdr.seq;
1619                                 *offset = 0;
1620                                 }
1621
1622                         /* this is either a record we're waiting for, or a
1623                          * retransmit of something we happened to previously
1624                          * receive (higher layers will drop the repeat silently */
1625                         if ( seq_num < s->d1->handshake_read_seq)
1626                                 return 0;
1627                         if (rr->type == SSL3_RT_HANDSHAKE &&
1628                                 seq_num == s->d1->handshake_read_seq &&
1629                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1630                                 return 0;
1631                         else if ( seq_num == s->d1->handshake_read_seq &&
1632                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1633                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1634                                 return 0;
1635                         else
1636                                 {
1637                                 *priority = seq_num;
1638                                 return 1;
1639                                 }
1640                         }
1641                 else /* unknown record type */
1642                         return 0;
1643                 }
1644
1645         return 0;
1646         }
1647 #endif
1648
1649 void
1650 dtls1_reset_seq_numbers(SSL *s, int rw)
1651         {
1652         unsigned char *seq;
1653         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1654
1655         if ( rw & SSL3_CC_READ)
1656                 {
1657                 seq = s->s3->read_sequence;
1658                 s->d1->r_epoch++;
1659                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1660                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1661                 }
1662         else
1663                 {
1664                 seq = s->s3->write_sequence;
1665                 s->d1->w_epoch++;
1666                 }
1667
1668         memset(seq, 0x00, seq_bytes);
1669         }
1670
1671
1672 static unsigned long long
1673 bytes_to_long_long(unsigned char *bytes)
1674         {
1675         unsigned long long num;
1676
1677         num = (((unsigned long long)bytes[0]) << 56) |
1678                 (((unsigned long long)bytes[1]) << 48) |
1679                 (((unsigned long long)bytes[2]) << 40) |
1680                 (((unsigned long long)bytes[3]) << 32) |
1681                 (((unsigned long long)bytes[4]) << 24) |
1682                 (((unsigned long long)bytes[5]) << 16) |
1683                 (((unsigned long long)bytes[6]) <<  8) |
1684                 (((unsigned long long)bytes[7])      );
1685
1686         return num;
1687         }
1688
1689 static void
1690 long_long_to_bytes(unsigned long long num, unsigned char *bytes)
1691         {
1692         bytes[0] = (unsigned char)((num >> 56)&0xff);
1693         bytes[1] = (unsigned char)((num >> 48)&0xff);
1694         bytes[2] = (unsigned char)((num >> 40)&0xff);
1695         bytes[3] = (unsigned char)((num >> 32)&0xff);
1696         bytes[4] = (unsigned char)((num >> 24)&0xff);
1697         bytes[5] = (unsigned char)((num >> 16)&0xff);
1698         bytes[6] = (unsigned char)((num >>  8)&0xff);
1699         bytes[7] = (unsigned char)((num      )&0xff);
1700         }
1701
1702 static void
1703 dtls1_clear_timeouts(SSL *s)
1704         {
1705         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1706         }