crypto/openssl/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         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)
 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                         {
 551                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 552                         goto err;
 553                         }
 554
 555                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 556                         {
 557                         al=SSL_AD_RECORD_OVERFLOW;
 558                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 559                         goto f_err;
 560                         }
 561
 562                 /* now s->rstate == SSL_ST_READ_BODY */
 563                 }
 564
 565         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 566
 567         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 568                 {
 569                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 570                 i=rr->length;
 571                 n=ssl3_read_n(s,i,i,1);
 572                 if (n <= 0) return(n); /* error or non-blocking io */
 573
 574                 /* this packet contained a partial record, dump it */
 575                 if ( n != i)
 576                         {
 577                         s->packet_length = 0;
 578                         goto again;
 579                         }
 580
 581                 /* now n == rr->length,
 582                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 583                 }
 584         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 585
 586         /* match epochs.  NULL means the packet is dropped on the floor */
 587         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 588         if ( bitmap == NULL)
 589         {
 590         s->packet_length = 0;  /* dump this record */
 591         goto again;   /* get another record */
 592                 }
 593
 594         /* check whether this is a repeat, or aged record */
 595         if ( ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))
 596                 {
 597                 s->packet_length=0; /* dump this record */
 598                 goto again;     /* get another record */
 599                 }
 600
 601         /* just read a 0 length packet */
 602         if (rr->length == 0) goto again;
 603
 604     /* If this record is from the next epoch (either HM or ALERT), buffer it
 605      * since it cannot be processed at this time.
 606      * Records from the next epoch are marked as received even though they are
 607      * not processed, so as to prevent any potential resource DoS attack */
 608     if (is_next_epoch)
 609         {
 610         dtls1_record_bitmap_update(s, bitmap);
 611         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 612         s->packet_length = 0;
 613         goto again;
 614         }
 615
 616     if ( ! dtls1_process_record(s))
 617         return(0);
 618
 619         dtls1_clear_timeouts(s);  /* done waiting */
 620         return(1);
 621
 622 f_err:
 623         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 624 err:
 625         return(0);
 626         }
 627
 628 /* Return up to 'len' payload bytes received in 'type' records.
 629  * 'type' is one of the following:
 630  *
 631  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 632  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 633  *   -  0 (during a shutdown, no data has to be returned)
 634  *
 635  * If we don't have stored data to work from, read a SSL/TLS record first
 636  * (possibly multiple records if we still don't have anything to return).
 637  *
 638  * This function must handle any surprises the peer may have for us, such as
 639  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 640  * a surprise, but handled as if it were), or renegotiation requests.
 641  * Also if record payloads contain fragments too small to process, we store
 642  * them until there is enough for the respective protocol (the record protocol
 643  * may use arbitrary fragmentation and even interleaving):
 644  *     Change cipher spec protocol
 645  *             just 1 byte needed, no need for keeping anything stored
 646  *     Alert protocol
 647  *             2 bytes needed (AlertLevel, AlertDescription)
 648  *     Handshake protocol
 649  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 650  *             to detect unexpected Client Hello and Hello Request messages
 651  *             here, anything else is handled by higher layers
 652  *     Application data protocol
 653  *             none of our business
 654  */
 655 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 656         {
 657         int al,i,j,ret;
 658         unsigned int n;
 659         SSL3_RECORD *rr;
 660         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 661
 662         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 663                 if (!ssl3_setup_buffers(s))
 664                         return(-1);
 665
 666     /* XXX: check what the second '&& type' is about */
 667         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 668                 (type != SSL3_RT_HANDSHAKE) && type) ||
 669             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 670                 {
 671                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 672                 return -1;
 673                 }
 674
 675         /* check whether there's a handshake message (client hello?) waiting */
 676         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 677                 return ret;
 678
 679         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 680
 681         if (!s->in_handshake && SSL_in_init(s))
 682                 {
 683                 /* type == SSL3_RT_APPLICATION_DATA */
 684                 i=s->handshake_func(s);
 685                 if (i < 0) return(i);
 686                 if (i == 0)
 687                         {
 688                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 689                         return(-1);
 690                         }
 691                 }
 692
 693 start:
 694         s->rwstate=SSL_NOTHING;
 695
 696         /* s->s3->rrec.type         - is the type of record
 697          * s->s3->rrec.data,    - data
 698          * s->s3->rrec.off,     - offset into 'data' for next read
 699          * s->s3->rrec.length,  - number of bytes. */
 700         rr = &(s->s3->rrec);
 701
 702         /* get new packet if necessary */
 703         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 704                 {
 705                 ret=dtls1_get_record(s);
 706                 if (ret <= 0)
 707                         {
 708                         ret = dtls1_read_failed(s, ret);
 709                         /* anything other than a timeout is an error */
 710                         if (ret <= 0)
 711                                 return(ret);
 712                         else
 713                                 goto start;
 714                         }
 715                 }
 716
 717         /* we now have a packet which can be read and processed */
 718
 719         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 720                                        * reset by ssl3_get_finished */
 721                 && (rr->type != SSL3_RT_HANDSHAKE))
 722                 {
 723                 al=SSL_AD_UNEXPECTED_MESSAGE;
 724                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
 725                 goto err;
 726                 }
 727
 728         /* If the other end has shut down, throw anything we read away
 729          * (even in 'peek' mode) */
 730         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 731                 {
 732                 rr->length=0;
 733                 s->rwstate=SSL_NOTHING;
 734                 return(0);
 735                 }
 736
 737
 738         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 739                 {
 740                 /* make sure that we are not getting application data when we
 741                  * are doing a handshake for the first time */
 742                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 743                         (s->enc_read_ctx == NULL))
 744                         {
 745                         al=SSL_AD_UNEXPECTED_MESSAGE;
 746                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 747                         goto f_err;
 748                         }
 749
 750                 if (len <= 0) return(len);
 751
 752                 if ((unsigned int)len > rr->length)
 753                         n = rr->length;
 754                 else
 755                         n = (unsigned int)len;
 756
 757                 memcpy(buf,&(rr->data[rr->off]),n);
 758                 if (!peek)
 759                         {
 760                         rr->length-=n;
 761                         rr->off+=n;
 762                         if (rr->length == 0)
 763                                 {
 764                                 s->rstate=SSL_ST_READ_HEADER;
 765                                 rr->off=0;
 766                                 }
 767                         }
 768                 return(n);
 769                 }
 770
 771
 772         /* If we get here, then type != rr->type; if we have a handshake
 773          * message, then it was unexpected (Hello Request or Client Hello). */
 774
 775         /* In case of record types for which we have 'fragment' storage,
 776          * fill that so that we can process the data at a fixed place.
 777          */
 778                 {
 779                 unsigned int k, dest_maxlen = 0;
 780                 unsigned char *dest = NULL;
 781                 unsigned int *dest_len = NULL;
 782
 783                 if (rr->type == SSL3_RT_HANDSHAKE)
 784                         {
 785                         dest_maxlen = sizeof s->d1->handshake_fragment;
 786                         dest = s->d1->handshake_fragment;
 787                         dest_len = &s->d1->handshake_fragment_len;
 788                         }
 789                 else if (rr->type == SSL3_RT_ALERT)
 790                         {
 791                         dest_maxlen = sizeof(s->d1->alert_fragment);
 792                         dest = s->d1->alert_fragment;
 793                         dest_len = &s->d1->alert_fragment_len;
 794                         }
 795                 /* else it's a CCS message, or it's wrong */
 796                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 797                         {
 798                           /* Not certain if this is the right error handling */
 799                           al=SSL_AD_UNEXPECTED_MESSAGE;
 800                           SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 801                           goto f_err;
 802                         }
 803
 804
 805                 if (dest_maxlen > 0)
 806                         {
 807             /* XDTLS:  In a pathalogical case, the Client Hello
 808              *  may be fragmented--don't always expect dest_maxlen bytes */
 809                         if ( rr->length < dest_maxlen)
 810                                 {
 811                                 s->rstate=SSL_ST_READ_HEADER;
 812                                 rr->length = 0;
 813                                 goto start;
 814                                 }
 815
 816                         /* now move 'n' bytes: */
 817                         for ( k = 0; k < dest_maxlen; k++)
 818                                 {
 819                                 dest[k] = rr->data[rr->off++];
 820                                 rr->length--;
 821                                 }
 822                         *dest_len = dest_maxlen;
 823                         }
 824                 }
 825
 826         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 827          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 828          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 829
 830         /* If we are a client, check for an incoming 'Hello Request': */
 831         if ((!s->server) &&
 832                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 833                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 834                 (s->session != NULL) && (s->session->cipher != NULL))
 835                 {
 836                 s->d1->handshake_fragment_len = 0;
 837
 838                 if ((s->d1->handshake_fragment[1] != 0) ||
 839                         (s->d1->handshake_fragment[2] != 0) ||
 840                         (s->d1->handshake_fragment[3] != 0))
 841                         {
 842                         al=SSL_AD_DECODE_ERROR;
 843                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 844                         goto err;
 845                         }
 846
 847                 /* no need to check sequence number on HELLO REQUEST messages */
 848
 849                 if (s->msg_callback)
 850                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 851                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 852
 853                 if (SSL_is_init_finished(s) &&
 854                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 855                         !s->s3->renegotiate)
 856                         {
 857                         ssl3_renegotiate(s);
 858                         if (ssl3_renegotiate_check(s))
 859                                 {
 860                                 i=s->handshake_func(s);
 861                                 if (i < 0) return(i);
 862                                 if (i == 0)
 863                                         {
 864                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 865                                         return(-1);
 866                                         }
 867
 868                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 869                                         {
 870                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 871                                                 {
 872                                                 BIO *bio;
 873                                                 /* In the case where we try to read application data,
 874                                                  * but we trigger an SSL handshake, we return -1 with
 875                                                  * the retry option set.  Otherwise renegotiation may
 876                                                  * cause nasty problems in the blocking world */
 877                                                 s->rwstate=SSL_READING;
 878                                                 bio=SSL_get_rbio(s);
 879                                                 BIO_clear_retry_flags(bio);
 880                                                 BIO_set_retry_read(bio);
 881                                                 return(-1);
 882                                                 }
 883                                         }
 884                                 }
 885                         }
 886                 /* we either finished a handshake or ignored the request,
 887                  * now try again to obtain the (application) data we were asked for */
 888                 goto start;
 889                 }
 890
 891         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
 892                 {
 893                 int alert_level = s->d1->alert_fragment[0];
 894                 int alert_descr = s->d1->alert_fragment[1];
 895
 896                 s->d1->alert_fragment_len = 0;
 897
 898                 if (s->msg_callback)
 899                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
 900                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
 901
 902                 if (s->info_callback != NULL)
 903                         cb=s->info_callback;
 904                 else if (s->ctx->info_callback != NULL)
 905                         cb=s->ctx->info_callback;
 906
 907                 if (cb != NULL)
 908                         {
 909                         j = (alert_level << 8) | alert_descr;
 910                         cb(s, SSL_CB_READ_ALERT, j);
 911                         }
 912
 913                 if (alert_level == 1) /* warning */
 914                         {
 915                         s->s3->warn_alert = alert_descr;
 916                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
 917                                 {
 918                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 919                                 return(0);
 920                                 }
 921 #if 0
 922             /* XXX: this is a possible improvement in the future */
 923                         /* now check if it's a missing record */
 924                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
 925                                 {
 926                                 unsigned short seq;
 927                                 unsigned int frag_off;
 928                                 unsigned char *p = &(s->d1->alert_fragment[2]);
 929
 930                                 n2s(p, seq);
 931                                 n2l3(p, frag_off);
 932
 933                                 dtls1_retransmit_message(s, seq, frag_off, &found);
 934                                 if ( ! found  && SSL_in_init(s))
 935                                         {
 936                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
 937                                         /* requested a message not yet sent,
 938                                            send an alert ourselves */
 939                                         ssl3_send_alert(s,SSL3_AL_WARNING,
 940                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 941                                         }
 942                                 }
 943 #endif
 944                         }
 945                 else if (alert_level == 2) /* fatal */
 946                         {
 947                         char tmp[16];
 948
 949                         s->rwstate=SSL_NOTHING;
 950                         s->s3->fatal_alert = alert_descr;
 951                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
 952                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
 953                         ERR_add_error_data(2,"SSL alert number ",tmp);
 954                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
 955                         SSL_CTX_remove_session(s->ctx,s->session);
 956                         return(0);
 957                         }
 958                 else
 959                         {
 960                         al=SSL_AD_ILLEGAL_PARAMETER;
 961                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
 962                         goto f_err;
 963                         }
 964
 965                 goto start;
 966                 }
 967
 968         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
 969                 {
 970                 s->rwstate=SSL_NOTHING;
 971                 rr->length=0;
 972                 return(0);
 973                 }
 974
 975         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
 976         {
 977         struct ccs_header_st ccs_hdr;
 978
 979                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
 980
 981                 if ( ccs_hdr.seq == s->d1->handshake_read_seq)
 982                         {
 983                         /* 'Change Cipher Spec' is just a single byte, so we know
 984                          * exactly what the record payload has to look like */
 985                         /* XDTLS: check that epoch is consistent */
 986                         if (    (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                 else
1013                         {
1014                         rr->length = 0;
1015                         goto start;
1016                         }
1017                 }
1018
1019         /* Unexpected handshake message (Client Hello, or protocol violation) */
1020         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1021                 !s->in_handshake)
1022                 {
1023                 struct hm_header_st msg_hdr;
1024
1025                 /* this may just be a stale retransmit */
1026                 dtls1_get_message_header(rr->data, &msg_hdr);
1027                 if( rr->epoch != s->d1->r_epoch)
1028                         {
1029                         rr->length = 0;
1030                         goto start;
1031                         }
1032
1033                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1034                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1035                         {
1036 #if 0 /* worked only because C operator preferences are not as expected (and
1037        * because this is not really needed for clients except for detecting
1038        * protocol violations): */
1039                         s->state=SSL_ST_BEFORE|(s->server)
1040                                 ?SSL_ST_ACCEPT
1041                                 :SSL_ST_CONNECT;
1042 #else
1043                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1044 #endif
1045                         s->new_session=1;
1046                         }
1047                 i=s->handshake_func(s);
1048                 if (i < 0) return(i);
1049                 if (i == 0)
1050                         {
1051                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1052                         return(-1);
1053                         }
1054
1055                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1056                         {
1057                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1058                                 {
1059                                 BIO *bio;
1060                                 /* In the case where we try to read application data,
1061                                  * but we trigger an SSL handshake, we return -1 with
1062                                  * the retry option set.  Otherwise renegotiation may
1063                                  * cause nasty problems in the blocking world */
1064                                 s->rwstate=SSL_READING;
1065                                 bio=SSL_get_rbio(s);
1066                                 BIO_clear_retry_flags(bio);
1067                                 BIO_set_retry_read(bio);
1068                                 return(-1);
1069                                 }
1070                         }
1071                 goto start;
1072                 }
1073
1074         switch (rr->type)
1075                 {
1076         default:
1077 #ifndef OPENSSL_NO_TLS
1078                 /* TLS just ignores unknown message types */
1079                 if (s->version == TLS1_VERSION)
1080                         {
1081                         rr->length = 0;
1082                         goto start;
1083                         }
1084 #endif
1085                 al=SSL_AD_UNEXPECTED_MESSAGE;
1086                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1087                 goto f_err;
1088         case SSL3_RT_CHANGE_CIPHER_SPEC:
1089         case SSL3_RT_ALERT:
1090         case SSL3_RT_HANDSHAKE:
1091                 /* we already handled all of these, with the possible exception
1092                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1093                  * should not happen when type != rr->type */
1094                 al=SSL_AD_UNEXPECTED_MESSAGE;
1095                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1096                 goto f_err;
1097         case SSL3_RT_APPLICATION_DATA:
1098                 /* At this point, we were expecting handshake data,
1099                  * but have application data.  If the library was
1100                  * running inside ssl3_read() (i.e. in_read_app_data
1101                  * is set) and it makes sense to read application data
1102                  * at this point (session renegotiation not yet started),
1103                  * we will indulge it.
1104                  */
1105                 if (s->s3->in_read_app_data &&
1106                         (s->s3->total_renegotiations != 0) &&
1107                         ((
1108                                 (s->state & SSL_ST_CONNECT) &&
1109                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1110                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1111                                 ) || (
1112                                         (s->state & SSL_ST_ACCEPT) &&
1113                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1114                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1115                                         )
1116                                 ))
1117                         {
1118                         s->s3->in_read_app_data=2;
1119                         return(-1);
1120                         }
1121                 else
1122                         {
1123                         al=SSL_AD_UNEXPECTED_MESSAGE;
1124                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1125                         goto f_err;
1126                         }
1127                 }
1128         /* not reached */
1129
1130 f_err:
1131         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1132 err:
1133         return(-1);
1134         }
1135
1136 int
1137 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1138         {
1139         unsigned int n,tot;
1140         int i;
1141
1142         if (SSL_in_init(s) && !s->in_handshake)
1143                 {
1144                 i=s->handshake_func(s);
1145                 if (i < 0) return(i);
1146                 if (i == 0)
1147                         {
1148                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1149                         return -1;
1150                         }
1151                 }
1152
1153         tot = s->s3->wnum;
1154         n = len - tot;
1155
1156         while( n)
1157                 {
1158                 /* dtls1_write_bytes sends one record at a time, sized according to
1159                  * the currently known MTU */
1160                 i = dtls1_write_bytes(s, type, buf_, len);
1161                 if (i <= 0) return i;
1162
1163                 if ((i == (int)n) ||
1164                         (type == SSL3_RT_APPLICATION_DATA &&
1165                                 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1166                         {
1167                         /* next chunk of data should get another prepended empty fragment
1168                          * in ciphersuites with known-IV weakness: */
1169                         s->s3->empty_fragment_done = 0;
1170                         return tot+i;
1171                         }
1172
1173                 tot += i;
1174                 n-=i;
1175                 }
1176
1177         return tot;
1178         }
1179
1180
1181         /* this only happens when a client hello is received and a handshake
1182          * is started. */
1183 static int
1184 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1185         int len, int peek)
1186         {
1187
1188         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1189                 /* (partially) satisfy request from storage */
1190                 {
1191                 unsigned char *src = s->d1->handshake_fragment;
1192                 unsigned char *dst = buf;
1193                 unsigned int k,n;
1194
1195                 /* peek == 0 */
1196                 n = 0;
1197                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1198                         {
1199                         *dst++ = *src++;
1200                         len--; s->d1->handshake_fragment_len--;
1201                         n++;
1202                         }
1203                 /* move any remaining fragment bytes: */
1204                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1205                         s->d1->handshake_fragment[k] = *src++;
1206                 return n;
1207                 }
1208
1209         return 0;
1210         }
1211
1212
1213
1214
1215 /* Call this to write data in records of type 'type'
1216  * It will return <= 0 if not all data has been sent or non-blocking IO.
1217  */
1218 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1219         {
1220         const unsigned char *buf=buf_;
1221         unsigned int tot,n,nw;
1222         int i;
1223         unsigned int mtu;
1224
1225         s->rwstate=SSL_NOTHING;
1226         tot=s->s3->wnum;
1227
1228         n=(len-tot);
1229
1230         /* handshake layer figures out MTU for itself, but data records
1231          * are also sent through this interface, so need to figure out MTU */
1232 #if 0
1233         mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1234         mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
1235 #endif
1236         mtu = s->d1->mtu;
1237
1238         if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1239                 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1240
1241         if (n > mtu)
1242                 nw=mtu;
1243         else
1244                 nw=n;
1245
1246         i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1247         if (i <= 0)
1248                 {
1249                 s->s3->wnum=tot;
1250                 return i;
1251                 }
1252
1253         if ( (int)s->s3->wnum + i == len)
1254                 s->s3->wnum = 0;
1255         else
1256                 s->s3->wnum += i;
1257
1258         return tot + i;
1259         }
1260
1261 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1262         {
1263         unsigned char *p,*pseq;
1264         int i,mac_size,clear=0;
1265         int prefix_len = 0;
1266         SSL3_RECORD *wr;
1267         SSL3_BUFFER *wb;
1268         SSL_SESSION *sess;
1269         int bs;
1270
1271         /* first check if there is a SSL3_BUFFER still being written
1272          * out.  This will happen with non blocking IO */
1273         if (s->s3->wbuf.left != 0)
1274                 {
1275                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1276                 return(ssl3_write_pending(s,type,buf,len));
1277                 }
1278
1279         /* If we have an alert to send, lets send it */
1280         if (s->s3->alert_dispatch)
1281                 {
1282                 i=s->method->ssl_dispatch_alert(s);
1283                 if (i <= 0)
1284                         return(i);
1285                 /* if it went, fall through and send more stuff */
1286                 }
1287
1288         if (len == 0 && !create_empty_fragment)
1289                 return 0;
1290
1291         wr= &(s->s3->wrec);
1292         wb= &(s->s3->wbuf);
1293         sess=s->session;
1294
1295         if (    (sess == NULL) ||
1296                 (s->enc_write_ctx == NULL) ||
1297                 (s->write_hash == NULL))
1298                 clear=1;
1299
1300         if (clear)
1301                 mac_size=0;
1302         else
1303                 mac_size=EVP_MD_size(s->write_hash);
1304
1305         /* DTLS implements explicit IV, so no need for empty fragments */
1306 #if 0
1307         /* 'create_empty_fragment' is true only when this function calls itself */
1308         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1309                 && SSL_version(s) != DTLS1_VERSION)
1310                 {
1311                 /* countermeasure against known-IV weakness in CBC ciphersuites
1312                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1313                  */
1314
1315                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1316                         {
1317                         /* recursive function call with 'create_empty_fragment' set;
1318                          * this prepares and buffers the data for an empty fragment
1319                          * (these 'prefix_len' bytes are sent out later
1320                          * together with the actual payload) */
1321                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1322                         if (prefix_len <= 0)
1323                                 goto err;
1324
1325                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1326                                 {
1327                                 /* insufficient space */
1328                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1329                                 goto err;
1330                                 }
1331                         }
1332
1333                 s->s3->empty_fragment_done = 1;
1334                 }
1335 #endif
1336
1337         p = wb->buf + prefix_len;
1338
1339         /* write the header */
1340
1341         *(p++)=type&0xff;
1342         wr->type=type;
1343
1344         *(p++)=(s->version>>8);
1345         *(p++)=s->version&0xff;
1346
1347         /* field where we are to write out packet epoch, seq num and len */
1348         pseq=p;
1349         p+=10;
1350
1351         /* lets setup the record stuff. */
1352
1353         /* Make space for the explicit IV in case of CBC.
1354          * (this is a bit of a boundary violation, but what the heck).
1355          */
1356         if ( s->enc_write_ctx &&
1357                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1358                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1359         else
1360                 bs = 0;
1361
1362         wr->data=p + bs;  /* make room for IV in case of CBC */
1363         wr->length=(int)len;
1364         wr->input=(unsigned char *)buf;
1365
1366         /* we now 'read' from wr->input, wr->length bytes into
1367          * wr->data */
1368
1369         /* first we compress */
1370         if (s->compress != NULL)
1371                 {
1372                 if (!ssl3_do_compress(s))
1373                         {
1374                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1375                         goto err;
1376                         }
1377                 }
1378         else
1379                 {
1380                 memcpy(wr->data,wr->input,wr->length);
1381                 wr->input=wr->data;
1382                 }
1383
1384         /* we should still have the output to wr->data and the input
1385          * from wr->input.  Length should be wr->length.
1386          * wr->data still points in the wb->buf */
1387
1388         if (mac_size != 0)
1389                 {
1390                 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1391                 wr->length+=mac_size;
1392                 }
1393
1394         /* this is true regardless of mac size */
1395         wr->input=p;
1396         wr->data=p;
1397
1398
1399         /* ssl3_enc can only have an error on read */
1400         wr->length += bs;  /* bs != 0 in case of CBC.  The enc fn provides
1401                                                 * the randomness */
1402         s->method->ssl3_enc->enc(s,1);
1403
1404         /* record length after mac and block padding */
1405 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1406         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1407
1408         /* there's only one epoch between handshake and app data */
1409
1410         s2n(s->d1->w_epoch, pseq);
1411
1412         /* XDTLS: ?? */
1413 /*      else
1414         s2n(s->d1->handshake_epoch, pseq); */
1415
1416         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1417         pseq+=6;
1418         s2n(wr->length,pseq);
1419
1420         /* we should now have
1421          * wr->data pointing to the encrypted data, which is
1422          * wr->length long */
1423         wr->type=type; /* not needed but helps for debugging */
1424         wr->length+=DTLS1_RT_HEADER_LENGTH;
1425
1426 #if 0  /* this is now done at the message layer */
1427         /* buffer the record, making it easy to handle retransmits */
1428         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1429                 dtls1_buffer_record(s, wr->data, wr->length,
1430                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1431 #endif
1432
1433         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1434
1435         if (create_empty_fragment)
1436                 {
1437                 /* we are in a recursive call;
1438                  * just return the length, don't write out anything here
1439                  */
1440                 return wr->length;
1441                 }
1442
1443         /* now let's set up wb */
1444         wb->left = prefix_len + wr->length;
1445         wb->offset = 0;
1446
1447         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1448         s->s3->wpend_tot=len;
1449         s->s3->wpend_buf=buf;
1450         s->s3->wpend_type=type;
1451         s->s3->wpend_ret=len;
1452
1453         /* we now just need to write the buffer */
1454         return ssl3_write_pending(s,type,buf,len);
1455 err:
1456         return -1;
1457         }
1458
1459
1460
1461 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
1462         PQ_64BIT *seq_num)
1463         {
1464 #if PQ_64BIT_IS_INTEGER
1465         PQ_64BIT mask = 0x0000000000000001L;
1466 #endif
1467         PQ_64BIT rcd_num, tmp;
1468
1469         pq_64bit_init(&rcd_num);
1470         pq_64bit_init(&tmp);
1471
1472         /* this is the sequence number for the record just read */
1473         pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1474
1475
1476         if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1477                 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1478                 {
1479                 pq_64bit_assign(seq_num, &rcd_num);
1480                 pq_64bit_free(&rcd_num);
1481                 pq_64bit_free(&tmp);
1482                 return 1;  /* this record is new */
1483                 }
1484
1485         pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1486
1487         if ( pq_64bit_get_word(&tmp) > bitmap->length)
1488                 {
1489                 pq_64bit_free(&rcd_num);
1490                 pq_64bit_free(&tmp);
1491                 return 0;  /* stale, outside the window */
1492                 }
1493
1494 #if PQ_64BIT_IS_BIGNUM
1495         {
1496         int offset;
1497         pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1498         pq_64bit_sub_word(&tmp, 1);
1499         offset = pq_64bit_get_word(&tmp);
1500         if ( pq_64bit_is_bit_set(&(bitmap->map), offset))
1501                 {
1502                 pq_64bit_free(&rcd_num);
1503                 pq_64bit_free(&tmp);
1504                 return 0;
1505                 }
1506         }
1507 #else
1508         mask <<= (bitmap->max_seq_num - rcd_num - 1);
1509         if (bitmap->map & mask)
1510                 return 0; /* record previously received */
1511 #endif
1512
1513         pq_64bit_assign(seq_num, &rcd_num);
1514         pq_64bit_free(&rcd_num);
1515         pq_64bit_free(&tmp);
1516         return 1;
1517         }
1518
1519
1520 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1521         {
1522         unsigned int shift;
1523         PQ_64BIT rcd_num;
1524         PQ_64BIT tmp;
1525         PQ_64BIT_CTX *ctx;
1526
1527         pq_64bit_init(&rcd_num);
1528         pq_64bit_init(&tmp);
1529
1530         pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1531
1532         /* unfortunate code complexity due to 64-bit manipulation support
1533          * on 32-bit machines */
1534         if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1535                 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1536                 {
1537                 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num));
1538                 pq_64bit_add_word(&tmp, 1);
1539
1540                 shift = (unsigned int)pq_64bit_get_word(&tmp);
1541
1542                 pq_64bit_lshift(&(tmp), &(bitmap->map), shift);
1543                 pq_64bit_assign(&(bitmap->map), &tmp);
1544
1545                 pq_64bit_set_bit(&(bitmap->map), 0);
1546                 pq_64bit_add_word(&rcd_num, 1);
1547                 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num);
1548
1549                 pq_64bit_assign_word(&tmp, 1);
1550                 pq_64bit_lshift(&tmp, &tmp, bitmap->length);
1551                 ctx = pq_64bit_ctx_new(&ctx);
1552                 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx);
1553                 pq_64bit_ctx_free(ctx);
1554                 }
1555         else
1556                 {
1557                 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1558                 pq_64bit_sub_word(&tmp, 1);
1559                 shift = (unsigned int)pq_64bit_get_word(&tmp);
1560
1561                 pq_64bit_set_bit(&(bitmap->map), shift);
1562                 }
1563
1564         pq_64bit_free(&rcd_num);
1565         pq_64bit_free(&tmp);
1566         }
1567
1568
1569 int dtls1_dispatch_alert(SSL *s)
1570         {
1571         int i,j;
1572         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1573         unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */
1574         unsigned char *ptr = &buf[0];
1575
1576         s->s3->alert_dispatch=0;
1577
1578         memset(buf, 0x00, sizeof(buf));
1579         *ptr++ = s->s3->send_alert[0];
1580         *ptr++ = s->s3->send_alert[1];
1581
1582         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1583                 {
1584                 s2n(s->d1->handshake_read_seq, ptr);
1585 #if 0
1586                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1587
1588                 else
1589                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1590 #endif
1591
1592 #if 0
1593                 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);
1594 #endif
1595                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1596                 }
1597
1598         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1599         if (i <= 0)
1600                 {
1601                 s->s3->alert_dispatch=1;
1602                 /* fprintf( stderr, "not done with alert\n" ); */
1603                 }
1604         else
1605                 {
1606                 if ( s->s3->send_alert[0] == SSL3_AL_FATAL ||
1607                         s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1608                         (void)BIO_flush(s->wbio);
1609
1610                 if (s->msg_callback)
1611                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1612                                 2, s, s->msg_callback_arg);
1613
1614                 if (s->info_callback != NULL)
1615                         cb=s->info_callback;
1616                 else if (s->ctx->info_callback != NULL)
1617                         cb=s->ctx->info_callback;
1618
1619                 if (cb != NULL)
1620                         {
1621                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1622                         cb(s,SSL_CB_WRITE_ALERT,j);
1623                         }
1624                 }
1625         return(i);
1626         }
1627
1628
1629 static DTLS1_BITMAP *
1630 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1631     {
1632
1633     *is_next_epoch = 0;
1634
1635     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1636     if (rr->epoch == s->d1->r_epoch)
1637         return &s->d1->bitmap;
1638
1639     /* Only HM and ALERT messages can be from the next epoch */
1640     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1641         (rr->type == SSL3_RT_HANDSHAKE ||
1642             rr->type == SSL3_RT_ALERT))
1643         {
1644         *is_next_epoch = 1;
1645         return &s->d1->next_bitmap;
1646         }
1647
1648     return NULL;
1649     }
1650
1651 #if 0
1652 static int
1653 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1654         unsigned long *offset)
1655         {
1656
1657         /* alerts are passed up immediately */
1658         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1659                 rr->type == SSL3_RT_ALERT)
1660                 return 0;
1661
1662         /* Only need to buffer if a handshake is underway.
1663          * (this implies that Hello Request and Client Hello are passed up
1664          * immediately) */
1665         if ( SSL_in_init(s))
1666                 {
1667                 unsigned char *data = rr->data;
1668                 /* need to extract the HM/CCS sequence number here */
1669                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1670                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1671                         {
1672                         unsigned short seq_num;
1673                         struct hm_header_st msg_hdr;
1674                         struct ccs_header_st ccs_hdr;
1675
1676                         if ( rr->type == SSL3_RT_HANDSHAKE)
1677                                 {
1678                                 dtls1_get_message_header(data, &msg_hdr);
1679                                 seq_num = msg_hdr.seq;
1680                                 *offset = msg_hdr.frag_off;
1681                                 }
1682                         else
1683                                 {
1684                                 dtls1_get_ccs_header(data, &ccs_hdr);
1685                                 seq_num = ccs_hdr.seq;
1686                                 *offset = 0;
1687                                 }
1688
1689                         /* this is either a record we're waiting for, or a
1690                          * retransmit of something we happened to previously
1691                          * receive (higher layers will drop the repeat silently */
1692                         if ( seq_num < s->d1->handshake_read_seq)
1693                                 return 0;
1694                         if (rr->type == SSL3_RT_HANDSHAKE &&
1695                                 seq_num == s->d1->handshake_read_seq &&
1696                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1697                                 return 0;
1698                         else if ( seq_num == s->d1->handshake_read_seq &&
1699                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1700                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1701                                 return 0;
1702                         else
1703                                 {
1704                                 *priority = seq_num;
1705                                 return 1;
1706                                 }
1707                         }
1708                 else /* unknown record type */
1709                         return 0;
1710                 }
1711
1712         return 0;
1713         }
1714 #endif
1715
1716 void
1717 dtls1_reset_seq_numbers(SSL *s, int rw)
1718         {
1719         unsigned char *seq;
1720         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1721
1722         if ( rw & SSL3_CC_READ)
1723                 {
1724                 seq = s->s3->read_sequence;
1725                 s->d1->r_epoch++;
1726
1727                 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map));
1728                 s->d1->bitmap.length = s->d1->next_bitmap.length;
1729                 pq_64bit_assign(&(s->d1->bitmap.max_seq_num),
1730                         &(s->d1->next_bitmap.max_seq_num));
1731
1732                 pq_64bit_free(&(s->d1->next_bitmap.map));
1733                 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
1734                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1735                 pq_64bit_init(&(s->d1->next_bitmap.map));
1736                 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
1737                 }
1738         else
1739                 {
1740                 seq = s->s3->write_sequence;
1741                 s->d1->w_epoch++;
1742                 }
1743
1744         memset(seq, 0x00, seq_bytes);
1745         }
1746
1747 #if PQ_64BIT_IS_INTEGER
1748 static PQ_64BIT
1749 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
1750        {
1751        PQ_64BIT _num;
1752
1753        _num = (((PQ_64BIT)bytes[0]) << 56) |
1754                (((PQ_64BIT)bytes[1]) << 48) |
1755                (((PQ_64BIT)bytes[2]) << 40) |
1756                (((PQ_64BIT)bytes[3]) << 32) |
1757                (((PQ_64BIT)bytes[4]) << 24) |
1758                (((PQ_64BIT)bytes[5]) << 16) |
1759                (((PQ_64BIT)bytes[6]) <<  8) |
1760                (((PQ_64BIT)bytes[7])      );
1761
1762            *num = _num ;
1763        return _num;
1764        }
1765 #endif
1766
1767
1768 static void
1769 dtls1_clear_timeouts(SSL *s)
1770         {
1771         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1772         }