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 #include <openssl/rand.h>
 124
 125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
 126 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
 127 {       int ret,sat,brw,i;
 128
 129         if (sizeof(long) == 8) do
 130         {       const union { long one; char little; } is_endian = {1};
 131                 long l;
 132
 133                 if (is_endian.little)                   break;
 134                 /* not reached on little-endians */
 135                 /* following test is redundant, because input is
 136                  * always aligned, but I take no chances... */
 137                 if (((size_t)v1|(size_t)v2)&0x7)        break;
 138
 139                 l  = *((long *)v1);
 140                 l -= *((long *)v2);
 141                 if (l>128)              return 128;
 142                 else if (l<-128)        return -128;
 143                 else                    return (int)l;
 144         } while (0);
 145
 146         ret = (int)v1[7]-(int)v2[7];
 147         sat = 0;
 148         brw = ret>>8;   /* brw is either 0 or -1 */
 149         if (ret & 0x80)
 150         {       for (i=6;i>=0;i--)
 151                 {       brw += (int)v1[i]-(int)v2[i];
 152                         sat |= ~brw;
 153                         brw >>= 8;
 154                 }
 155         }
 156         else
 157         {       for (i=6;i>=0;i--)
 158                 {       brw += (int)v1[i]-(int)v2[i];
 159                         sat |= brw;
 160                         brw >>= 8;
 161                 }
 162         }
 163         brw <<= 8;      /* brw is either 0 or -256 */
 164
 165         if (sat&0xff)   return brw | 0x80;
 166         else            return brw + (ret&0xFF);
 167 }
 168
 169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
 170         int len, int peek);
 171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
 172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
 173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
 174     unsigned int *is_next_epoch);
 175 #if 0
 176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
 177         unsigned short *priority, unsigned long *offset);
 178 #endif
 179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
 180         unsigned char *priority);
 181 static int dtls1_process_record(SSL *s);
 182 static void dtls1_clear_timeouts(SSL *s);
 183
 184 /* copy buffered record into SSL structure */
 185 static int
 186 dtls1_copy_record(SSL *s, pitem *item)
 187     {
 188     DTLS1_RECORD_DATA *rdata;
 189
 190     rdata = (DTLS1_RECORD_DATA *)item->data;
 191
 192     if (s->s3->rbuf.buf != NULL)
 193         OPENSSL_free(s->s3->rbuf.buf);
 194
 195     s->packet = rdata->packet;
 196     s->packet_length = rdata->packet_length;
 197     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 198     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 199
 200         /* Set proper sequence number for mac calculation */
 201         memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
 202
 203     return(1);
 204     }
 205
 206
 207 static int
 208 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 209         {
 210         DTLS1_RECORD_DATA *rdata;
 211         pitem *item;
 212
 213         /* Limit the size of the queue to prevent DOS attacks */
 214         if (pqueue_size(queue->q) >= 100)
 215                 return 0;
 216
 217         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 218         item = pitem_new(priority, rdata);
 219         if (rdata == NULL || item == NULL)
 220                 {
 221                 if (rdata != NULL) OPENSSL_free(rdata);
 222                 if (item != NULL) pitem_free(item);
 223
 224                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 225                 return(0);
 226                 }
 227
 228         rdata->packet = s->packet;
 229         rdata->packet_length = s->packet_length;
 230         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 231         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 232
 233         item->data = rdata;
 234
 235         /* insert should not fail, since duplicates are dropped */
 236         if (pqueue_insert(queue->q, item) == NULL)
 237                 {
 238                 OPENSSL_free(rdata);
 239                 pitem_free(item);
 240                 return(0);
 241                 }
 242
 243         s->packet = NULL;
 244         s->packet_length = 0;
 245         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 246         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 247
 248         if (!ssl3_setup_buffers(s))
 249                 {
 250                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 251                 OPENSSL_free(rdata);
 252                 pitem_free(item);
 253                 return(0);
 254                 }
 255
 256         return(1);
 257         }
 258
 259
 260 static int
 261 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 262     {
 263     pitem *item;
 264
 265     item = pqueue_pop(queue->q);
 266     if (item)
 267         {
 268         dtls1_copy_record(s, item);
 269
 270         OPENSSL_free(item->data);
 271                 pitem_free(item);
 272
 273         return(1);
 274         }
 275
 276     return(0);
 277     }
 278
 279
 280 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 281  * yet */
 282 #define dtls1_get_unprocessed_record(s) \
 283                    dtls1_retrieve_buffered_record((s), \
 284                    &((s)->d1->unprocessed_rcds))
 285
 286 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 287 #define dtls1_get_processed_record(s) \
 288                    dtls1_retrieve_buffered_record((s), \
 289                    &((s)->d1->processed_rcds))
 290
 291 static int
 292 dtls1_process_buffered_records(SSL *s)
 293     {
 294     pitem *item;
 295
 296     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 297     if (item)
 298         {
 299         /* Check if epoch is current. */
 300         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 301             return(1);  /* Nothing to do. */
 302
 303         /* Process all the records. */
 304         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 305             {
 306             dtls1_get_unprocessed_record(s);
 307             if ( ! dtls1_process_record(s))
 308                 return(0);
 309             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 310                 s->s3->rrec.seq_num);
 311             }
 312         }
 313
 314     /* sync epoch numbers once all the unprocessed records
 315      * have been processed */
 316     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 317     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 318
 319     return(1);
 320     }
 321
 322
 323 #if 0
 324
 325 static int
 326 dtls1_get_buffered_record(SSL *s)
 327         {
 328         pitem *item;
 329         PQ_64BIT priority =
 330                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 331                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 332
 333         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 334                                                            nothing buffered */
 335                 return 0;
 336
 337
 338         item = pqueue_peek(s->d1->rcvd_records);
 339         if (item && item->priority == priority)
 340                 {
 341                 /* Check if we've received the record of interest.  It must be
 342                  * a handshake record, since data records as passed up without
 343                  * buffering */
 344                 DTLS1_RECORD_DATA *rdata;
 345                 item = pqueue_pop(s->d1->rcvd_records);
 346                 rdata = (DTLS1_RECORD_DATA *)item->data;
 347
 348                 if (s->s3->rbuf.buf != NULL)
 349                         OPENSSL_free(s->s3->rbuf.buf);
 350
 351                 s->packet = rdata->packet;
 352                 s->packet_length = rdata->packet_length;
 353                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 354                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 355
 356                 OPENSSL_free(item->data);
 357                 pitem_free(item);
 358
 359                 /* s->d1->next_expected_seq_num++; */
 360                 return(1);
 361                 }
 362
 363         return 0;
 364         }
 365
 366 #endif
 367
 368 static int
 369 dtls1_process_record(SSL *s)
 370 {
 371         int i,al;
 372         int clear=0;
 373         int enc_err;
 374         SSL_SESSION *sess;
 375         SSL3_RECORD *rr;
 376         unsigned int mac_size;
 377         unsigned char md[EVP_MAX_MD_SIZE];
 378         int decryption_failed_or_bad_record_mac = 0;
 379         unsigned char *mac = NULL;
 380
 381
 382         rr= &(s->s3->rrec);
 383         sess = s->session;
 384
 385         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 386          * and we have that many bytes in s->packet
 387          */
 388         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 389
 390         /* ok, we can now read from 's->packet' data into 'rr'
 391          * rr->input points at rr->length bytes, which
 392          * need to be copied into rr->data by either
 393          * the decryption or by the decompression
 394          * When the data is 'copied' into the rr->data buffer,
 395          * rr->input will be pointed at the new buffer */
 396
 397         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 398          * rr->length bytes of encrypted compressed stuff. */
 399
 400         /* check is not needed I believe */
 401         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 402                 {
 403                 al=SSL_AD_RECORD_OVERFLOW;
 404                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 405                 goto f_err;
 406                 }
 407
 408         /* decrypt in place in 'rr->input' */
 409         rr->data=rr->input;
 410
 411         enc_err = s->method->ssl3_enc->enc(s,0);
 412         if (enc_err <= 0)
 413                 {
 414                 /* To minimize information leaked via timing, we will always
 415                  * perform all computations before discarding the message.
 416                  */
 417                 decryption_failed_or_bad_record_mac = 1;
 418                 }
 419
 420 #ifdef TLS_DEBUG
 421 printf("dec %d\n",rr->length);
 422 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 423 printf("\n");
 424 #endif
 425
 426         /* r->length is now the compressed data plus mac */
 427         if (    (sess == NULL) ||
 428                 (s->enc_read_ctx == NULL) ||
 429                 (s->read_hash == NULL))
 430                 clear=1;
 431
 432         if (!clear)
 433                 {
 434                 /* !clear => s->read_hash != NULL => mac_size != -1 */
 435                 int t;
 436                 t=EVP_MD_CTX_size(s->read_hash);
 437                 OPENSSL_assert(t >= 0);
 438                 mac_size=t;
 439
 440                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 441                         {
 442 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 443                         al=SSL_AD_RECORD_OVERFLOW;
 444                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 445                         goto f_err;
 446 #else
 447                         decryption_failed_or_bad_record_mac = 1;
 448 #endif
 449                         }
 450                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 451                 if (rr->length >= mac_size)
 452                         {
 453                         rr->length -= mac_size;
 454                         mac = &rr->data[rr->length];
 455                         }
 456                 else
 457                         rr->length = 0;
 458                 i=s->method->ssl3_enc->mac(s,md,0);
 459                 if (i < 0 || mac == NULL || memcmp(md, mac, mac_size) != 0)
 460                         {
 461                         decryption_failed_or_bad_record_mac = 1;
 462                         }
 463                 }
 464
 465         if (decryption_failed_or_bad_record_mac)
 466                 {
 467                 /* decryption failed, silently discard message */
 468                 rr->length = 0;
 469                 s->packet_length = 0;
 470                 goto err;
 471                 }
 472
 473         /* r->length is now just compressed */
 474         if (s->expand != NULL)
 475                 {
 476                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 477                         {
 478                         al=SSL_AD_RECORD_OVERFLOW;
 479                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 480                         goto f_err;
 481                         }
 482                 if (!ssl3_do_uncompress(s))
 483                         {
 484                         al=SSL_AD_DECOMPRESSION_FAILURE;
 485                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 486                         goto f_err;
 487                         }
 488                 }
 489
 490         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 491                 {
 492                 al=SSL_AD_RECORD_OVERFLOW;
 493                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 494                 goto f_err;
 495                 }
 496
 497         rr->off=0;
 498         /* So at this point the following is true
 499          * ssl->s3->rrec.type   is the type of record
 500          * ssl->s3->rrec.length == number of bytes in record
 501          * ssl->s3->rrec.off    == offset to first valid byte
 502          * ssl->s3->rrec.data   == where to take bytes from, increment
 503          *                         after use :-).
 504          */
 505
 506         /* we have pulled in a full packet so zero things */
 507         s->packet_length=0;
 508         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 509         return(1);
 510
 511 f_err:
 512         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 513 err:
 514         return(0);
 515 }
 516
 517
 518 /* Call this to get a new input record.
 519  * It will return <= 0 if more data is needed, normally due to an error
 520  * or non-blocking IO.
 521  * When it finishes, one packet has been decoded and can be found in
 522  * ssl->s3->rrec.type    - is the type of record
 523  * ssl->s3->rrec.data,   - data
 524  * ssl->s3->rrec.length, - number of bytes
 525  */
 526 /* used only by dtls1_read_bytes */
 527 int dtls1_get_record(SSL *s)
 528         {
 529         int ssl_major,ssl_minor;
 530         int i,n;
 531         SSL3_RECORD *rr;
 532         unsigned char *p = NULL;
 533         unsigned short version;
 534         DTLS1_BITMAP *bitmap;
 535         unsigned int is_next_epoch;
 536
 537         rr= &(s->s3->rrec);
 538
 539         /* The epoch may have changed.  If so, process all the
 540          * pending records.  This is a non-blocking operation. */
 541         dtls1_process_buffered_records(s);
 542
 543         /* if we're renegotiating, then there may be buffered records */
 544         if (dtls1_get_processed_record(s))
 545                 return 1;
 546
 547         /* get something from the wire */
 548 again:
 549         /* check if we have the header */
 550         if (    (s->rstate != SSL_ST_READ_BODY) ||
 551                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 552                 {
 553                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 554                 /* read timeout is handled by dtls1_read_bytes */
 555                 if (n <= 0) return(n); /* error or non-blocking */
 556
 557                 /* this packet contained a partial record, dump it */
 558                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
 559                         {
 560                         s->packet_length = 0;
 561                         goto again;
 562                         }
 563
 564                 s->rstate=SSL_ST_READ_BODY;
 565
 566                 p=s->packet;
 567
 568                 /* Pull apart the header into the DTLS1_RECORD */
 569                 rr->type= *(p++);
 570                 ssl_major= *(p++);
 571                 ssl_minor= *(p++);
 572                 version=(ssl_major<<8)|ssl_minor;
 573
 574                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 575                 n2s(p,rr->epoch);
 576
 577                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 578                 p+=6;
 579
 580                 n2s(p,rr->length);
 581
 582                 /* Lets check version */
 583                 if (!s->first_packet)
 584                         {
 585                         if (version != s->version)
 586                                 {
 587                                 /* unexpected version, silently discard */
 588                                 rr->length = 0;
 589                                 s->packet_length = 0;
 590                                 goto again;
 591                                 }
 592                         }
 593
 594                 if ((version & 0xff00) != (s->version & 0xff00))
 595                         {
 596                         /* wrong version, silently discard record */
 597                         rr->length = 0;
 598                         s->packet_length = 0;
 599                         goto again;
 600                         }
 601
 602                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 603                         {
 604                         /* record too long, silently discard it */
 605                         rr->length = 0;
 606                         s->packet_length = 0;
 607                         goto again;
 608                         }
 609
 610                 /* now s->rstate == SSL_ST_READ_BODY */
 611                 }
 612
 613         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 614
 615         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 616                 {
 617                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 618                 i=rr->length;
 619                 n=ssl3_read_n(s,i,i,1);
 620                 if (n <= 0) return(n); /* error or non-blocking io */
 621
 622                 /* this packet contained a partial record, dump it */
 623                 if ( n != i)
 624                         {
 625                         rr->length = 0;
 626                         s->packet_length = 0;
 627                         goto again;
 628                         }
 629
 630                 /* now n == rr->length,
 631                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 632                 }
 633         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 634
 635         /* match epochs.  NULL means the packet is dropped on the floor */
 636         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 637         if ( bitmap == NULL)
 638                 {
 639                 rr->length = 0;
 640                 s->packet_length = 0;  /* dump this record */
 641                 goto again;   /* get another record */
 642                 }
 643
 644         /* Check whether this is a repeat, or aged record.
 645          * Don't check if we're listening and this message is
 646          * a ClientHello. They can look as if they're replayed,
 647          * since they arrive from different connections and
 648          * would be dropped unnecessarily.
 649          */
 650         if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
 651                 *p == SSL3_MT_CLIENT_HELLO) &&
 652                 !dtls1_record_replay_check(s, bitmap))
 653                 {
 654                 rr->length = 0;
 655                 s->packet_length=0; /* dump this record */
 656                 goto again;     /* get another record */
 657                 }
 658
 659         /* just read a 0 length packet */
 660         if (rr->length == 0) goto again;
 661
 662         /* If this record is from the next epoch (either HM or ALERT),
 663          * and a handshake is currently in progress, buffer it since it
 664          * cannot be processed at this time. However, do not buffer
 665          * anything while listening.
 666          */
 667         if (is_next_epoch)
 668                 {
 669                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
 670                         {
 671                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 672                         }
 673                 rr->length = 0;
 674                 s->packet_length = 0;
 675                 goto again;
 676                 }
 677
 678         if (!dtls1_process_record(s))
 679                 {
 680                 rr->length = 0;
 681                 s->packet_length = 0;  /* dump this record */
 682                 goto again;   /* get another record */
 683                 }
 684
 685         dtls1_clear_timeouts(s);  /* done waiting */
 686         return(1);
 687
 688         }
 689
 690 /* Return up to 'len' payload bytes received in 'type' records.
 691  * 'type' is one of the following:
 692  *
 693  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 694  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 695  *   -  0 (during a shutdown, no data has to be returned)
 696  *
 697  * If we don't have stored data to work from, read a SSL/TLS record first
 698  * (possibly multiple records if we still don't have anything to return).
 699  *
 700  * This function must handle any surprises the peer may have for us, such as
 701  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 702  * a surprise, but handled as if it were), or renegotiation requests.
 703  * Also if record payloads contain fragments too small to process, we store
 704  * them until there is enough for the respective protocol (the record protocol
 705  * may use arbitrary fragmentation and even interleaving):
 706  *     Change cipher spec protocol
 707  *             just 1 byte needed, no need for keeping anything stored
 708  *     Alert protocol
 709  *             2 bytes needed (AlertLevel, AlertDescription)
 710  *     Handshake protocol
 711  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 712  *             to detect unexpected Client Hello and Hello Request messages
 713  *             here, anything else is handled by higher layers
 714  *     Application data protocol
 715  *             none of our business
 716  */
 717 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 718         {
 719         int al,i,j,ret;
 720         unsigned int n;
 721         SSL3_RECORD *rr;
 722         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 723
 724         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 725                 if (!ssl3_setup_buffers(s))
 726                         return(-1);
 727
 728     /* XXX: check what the second '&& type' is about */
 729         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 730                 (type != SSL3_RT_HANDSHAKE) && type) ||
 731             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 732                 {
 733                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 734                 return -1;
 735                 }
 736
 737         /* check whether there's a handshake message (client hello?) waiting */
 738         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 739                 return ret;
 740
 741         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 742
 743         if (!s->in_handshake && SSL_in_init(s))
 744                 {
 745                 /* type == SSL3_RT_APPLICATION_DATA */
 746                 i=s->handshake_func(s);
 747                 if (i < 0) return(i);
 748                 if (i == 0)
 749                         {
 750                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 751                         return(-1);
 752                         }
 753                 }
 754
 755 start:
 756         s->rwstate=SSL_NOTHING;
 757
 758         /* s->s3->rrec.type         - is the type of record
 759          * s->s3->rrec.data,    - data
 760          * s->s3->rrec.off,     - offset into 'data' for next read
 761          * s->s3->rrec.length,  - number of bytes. */
 762         rr = &(s->s3->rrec);
 763
 764         /* We are not handshaking and have no data yet,
 765          * so process data buffered during the last handshake
 766          * in advance, if any.
 767          */
 768         if (s->state == SSL_ST_OK && rr->length == 0)
 769                 {
 770                 pitem *item;
 771                 item = pqueue_pop(s->d1->buffered_app_data.q);
 772                 if (item)
 773                         {
 774                         dtls1_copy_record(s, item);
 775
 776                         OPENSSL_free(item->data);
 777                         pitem_free(item);
 778                         }
 779                 }
 780
 781         /* Check for timeout */
 782         if (dtls1_handle_timeout(s) > 0)
 783                 goto start;
 784
 785         /* get new packet if necessary */
 786         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 787                 {
 788                 ret=dtls1_get_record(s);
 789                 if (ret <= 0)
 790                         {
 791                         ret = dtls1_read_failed(s, ret);
 792                         /* anything other than a timeout is an error */
 793                         if (ret <= 0)
 794                                 return(ret);
 795                         else
 796                                 goto start;
 797                         }
 798                 }
 799
 800         /* we now have a packet which can be read and processed */
 801
 802         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 803                                        * reset by ssl3_get_finished */
 804                 && (rr->type != SSL3_RT_HANDSHAKE))
 805                 {
 806                 /* We now have application data between CCS and Finished.
 807                  * Most likely the packets were reordered on their way, so
 808                  * buffer the application data for later processing rather
 809                  * than dropping the connection.
 810                  */
 811                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
 812                 rr->length = 0;
 813                 goto start;
 814                 }
 815
 816         /* If the other end has shut down, throw anything we read away
 817          * (even in 'peek' mode) */
 818         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 819                 {
 820                 rr->length=0;
 821                 s->rwstate=SSL_NOTHING;
 822                 return(0);
 823                 }
 824
 825
 826         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 827                 {
 828                 /* make sure that we are not getting application data when we
 829                  * are doing a handshake for the first time */
 830                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 831                         (s->enc_read_ctx == NULL))
 832                         {
 833                         al=SSL_AD_UNEXPECTED_MESSAGE;
 834                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 835                         goto f_err;
 836                         }
 837
 838                 if (len <= 0) return(len);
 839
 840                 if ((unsigned int)len > rr->length)
 841                         n = rr->length;
 842                 else
 843                         n = (unsigned int)len;
 844
 845                 memcpy(buf,&(rr->data[rr->off]),n);
 846                 if (!peek)
 847                         {
 848                         rr->length-=n;
 849                         rr->off+=n;
 850                         if (rr->length == 0)
 851                                 {
 852                                 s->rstate=SSL_ST_READ_HEADER;
 853                                 rr->off=0;
 854                                 }
 855                         }
 856                 return(n);
 857                 }
 858
 859
 860         /* If we get here, then type != rr->type; if we have a handshake
 861          * message, then it was unexpected (Hello Request or Client Hello). */
 862
 863         /* In case of record types for which we have 'fragment' storage,
 864          * fill that so that we can process the data at a fixed place.
 865          */
 866                 {
 867                 unsigned int k, dest_maxlen = 0;
 868                 unsigned char *dest = NULL;
 869                 unsigned int *dest_len = NULL;
 870
 871                 if (rr->type == SSL3_RT_HANDSHAKE)
 872                         {
 873                         dest_maxlen = sizeof s->d1->handshake_fragment;
 874                         dest = s->d1->handshake_fragment;
 875                         dest_len = &s->d1->handshake_fragment_len;
 876                         }
 877                 else if (rr->type == SSL3_RT_ALERT)
 878                         {
 879                         dest_maxlen = sizeof(s->d1->alert_fragment);
 880                         dest = s->d1->alert_fragment;
 881                         dest_len = &s->d1->alert_fragment_len;
 882                         }
 883                 /* else it's a CCS message, or application data or wrong */
 884                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 885                         {
 886                         /* Application data while renegotiating
 887                          * is allowed. Try again reading.
 888                          */
 889                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 890                                 {
 891                                 BIO *bio;
 892                                 s->s3->in_read_app_data=2;
 893                                 bio=SSL_get_rbio(s);
 894                                 s->rwstate=SSL_READING;
 895                                 BIO_clear_retry_flags(bio);
 896                                 BIO_set_retry_read(bio);
 897                                 return(-1);
 898                                 }
 899
 900                         /* Not certain if this is the right error handling */
 901                         al=SSL_AD_UNEXPECTED_MESSAGE;
 902                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 903                         goto f_err;
 904                         }
 905
 906                 if (dest_maxlen > 0)
 907                         {
 908             /* XDTLS:  In a pathalogical case, the Client Hello
 909              *  may be fragmented--don't always expect dest_maxlen bytes */
 910                         if ( rr->length < dest_maxlen)
 911                                 {
 912 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
 913                                 /*
 914                                  * for normal alerts rr->length is 2, while
 915                                  * dest_maxlen is 7 if we were to handle this
 916                                  * non-existing alert...
 917                                  */
 918                                 FIX ME
 919 #endif
 920                                 s->rstate=SSL_ST_READ_HEADER;
 921                                 rr->length = 0;
 922                                 goto start;
 923                                 }
 924
 925                         /* now move 'n' bytes: */
 926                         for ( k = 0; k < dest_maxlen; k++)
 927                                 {
 928                                 dest[k] = rr->data[rr->off++];
 929                                 rr->length--;
 930                                 }
 931                         *dest_len = dest_maxlen;
 932                         }
 933                 }
 934
 935         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 936          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 937          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 938
 939         /* If we are a client, check for an incoming 'Hello Request': */
 940         if ((!s->server) &&
 941                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 942                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 943                 (s->session != NULL) && (s->session->cipher != NULL))
 944                 {
 945                 s->d1->handshake_fragment_len = 0;
 946
 947                 if ((s->d1->handshake_fragment[1] != 0) ||
 948                         (s->d1->handshake_fragment[2] != 0) ||
 949                         (s->d1->handshake_fragment[3] != 0))
 950                         {
 951                         al=SSL_AD_DECODE_ERROR;
 952                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 953                         goto err;
 954                         }
 955
 956                 /* no need to check sequence number on HELLO REQUEST messages */
 957
 958                 if (s->msg_callback)
 959                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 960                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 961
 962                 if (SSL_is_init_finished(s) &&
 963                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 964                         !s->s3->renegotiate)
 965                         {
 966                         ssl3_renegotiate(s);
 967                         if (ssl3_renegotiate_check(s))
 968                                 {
 969                                 i=s->handshake_func(s);
 970                                 if (i < 0) return(i);
 971                                 if (i == 0)
 972                                         {
 973                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 974                                         return(-1);
 975                                         }
 976
 977                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 978                                         {
 979                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 980                                                 {
 981                                                 BIO *bio;
 982                                                 /* In the case where we try to read application data,
 983                                                  * but we trigger an SSL handshake, we return -1 with
 984                                                  * the retry option set.  Otherwise renegotiation may
 985                                                  * cause nasty problems in the blocking world */
 986                                                 s->rwstate=SSL_READING;
 987                                                 bio=SSL_get_rbio(s);
 988                                                 BIO_clear_retry_flags(bio);
 989                                                 BIO_set_retry_read(bio);
 990                                                 return(-1);
 991                                                 }
 992                                         }
 993                                 }
 994                         }
 995                 /* we either finished a handshake or ignored the request,
 996                  * now try again to obtain the (application) data we were asked for */
 997                 goto start;
 998                 }
 999
1000         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1001                 {
1002                 int alert_level = s->d1->alert_fragment[0];
1003                 int alert_descr = s->d1->alert_fragment[1];
1004
1005                 s->d1->alert_fragment_len = 0;
1006
1007                 if (s->msg_callback)
1008                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1009                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1010
1011                 if (s->info_callback != NULL)
1012                         cb=s->info_callback;
1013                 else if (s->ctx->info_callback != NULL)
1014                         cb=s->ctx->info_callback;
1015
1016                 if (cb != NULL)
1017                         {
1018                         j = (alert_level << 8) | alert_descr;
1019                         cb(s, SSL_CB_READ_ALERT, j);
1020                         }
1021
1022                 if (alert_level == 1) /* warning */
1023                         {
1024                         s->s3->warn_alert = alert_descr;
1025                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1026                                 {
1027                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1028                                 return(0);
1029                                 }
1030 #if 0
1031             /* XXX: this is a possible improvement in the future */
1032                         /* now check if it's a missing record */
1033                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1034                                 {
1035                                 unsigned short seq;
1036                                 unsigned int frag_off;
1037                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1038
1039                                 n2s(p, seq);
1040                                 n2l3(p, frag_off);
1041
1042                                 dtls1_retransmit_message(s,
1043                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1044                                                                                  frag_off, &found);
1045                                 if ( ! found  && SSL_in_init(s))
1046                                         {
1047                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1048                                         /* requested a message not yet sent,
1049                                            send an alert ourselves */
1050                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1051                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1052                                         }
1053                                 }
1054 #endif
1055                         }
1056                 else if (alert_level == 2) /* fatal */
1057                         {
1058                         char tmp[16];
1059
1060                         s->rwstate=SSL_NOTHING;
1061                         s->s3->fatal_alert = alert_descr;
1062                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1063                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1064                         ERR_add_error_data(2,"SSL alert number ",tmp);
1065                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1066                         SSL_CTX_remove_session(s->ctx,s->session);
1067                         return(0);
1068                         }
1069                 else
1070                         {
1071                         al=SSL_AD_ILLEGAL_PARAMETER;
1072                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1073                         goto f_err;
1074                         }
1075
1076                 goto start;
1077                 }
1078
1079         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1080                 {
1081                 s->rwstate=SSL_NOTHING;
1082                 rr->length=0;
1083                 return(0);
1084                 }
1085
1086         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1087                 {
1088                 struct ccs_header_st ccs_hdr;
1089                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1090
1091                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1092
1093                 if (s->version == DTLS1_BAD_VER)
1094                         ccs_hdr_len = 3;
1095
1096                 /* 'Change Cipher Spec' is just a single byte, so we know
1097                  * exactly what the record payload has to look like */
1098                 /* XDTLS: check that epoch is consistent */
1099                 if (    (rr->length != ccs_hdr_len) ||
1100                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1101                         {
1102                         i=SSL_AD_ILLEGAL_PARAMETER;
1103                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1104                         goto err;
1105                         }
1106
1107                 rr->length=0;
1108
1109                 if (s->msg_callback)
1110                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1111                                 rr->data, 1, s, s->msg_callback_arg);
1112
1113                 /* We can't process a CCS now, because previous handshake
1114                  * messages are still missing, so just drop it.
1115                  */
1116                 if (!s->d1->change_cipher_spec_ok)
1117                         {
1118                         goto start;
1119                         }
1120
1121                 s->d1->change_cipher_spec_ok = 0;
1122
1123                 s->s3->change_cipher_spec=1;
1124                 if (!ssl3_do_change_cipher_spec(s))
1125                         goto err;
1126
1127                 /* do this whenever CCS is processed */
1128                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1129
1130                 if (s->version == DTLS1_BAD_VER)
1131                         s->d1->handshake_read_seq++;
1132
1133                 goto start;
1134                 }
1135
1136         /* Unexpected handshake message (Client Hello, or protocol violation) */
1137         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1138                 !s->in_handshake)
1139                 {
1140                 struct hm_header_st msg_hdr;
1141
1142                 /* this may just be a stale retransmit */
1143                 dtls1_get_message_header(rr->data, &msg_hdr);
1144                 if( rr->epoch != s->d1->r_epoch)
1145                         {
1146                         rr->length = 0;
1147                         goto start;
1148                         }
1149
1150                 /* If we are server, we may have a repeated FINISHED of the
1151                  * client here, then retransmit our CCS and FINISHED.
1152                  */
1153                 if (msg_hdr.type == SSL3_MT_FINISHED)
1154                         {
1155                         dtls1_retransmit_buffered_messages(s);
1156                         rr->length = 0;
1157                         goto start;
1158                         }
1159
1160                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1161                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1162                         {
1163 #if 0 /* worked only because C operator preferences are not as expected (and
1164        * because this is not really needed for clients except for detecting
1165        * protocol violations): */
1166                         s->state=SSL_ST_BEFORE|(s->server)
1167                                 ?SSL_ST_ACCEPT
1168                                 :SSL_ST_CONNECT;
1169 #else
1170                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1171 #endif
1172                         s->new_session=1;
1173                         }
1174                 i=s->handshake_func(s);
1175                 if (i < 0) return(i);
1176                 if (i == 0)
1177                         {
1178                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1179                         return(-1);
1180                         }
1181
1182                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1183                         {
1184                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1185                                 {
1186                                 BIO *bio;
1187                                 /* In the case where we try to read application data,
1188                                  * but we trigger an SSL handshake, we return -1 with
1189                                  * the retry option set.  Otherwise renegotiation may
1190                                  * cause nasty problems in the blocking world */
1191                                 s->rwstate=SSL_READING;
1192                                 bio=SSL_get_rbio(s);
1193                                 BIO_clear_retry_flags(bio);
1194                                 BIO_set_retry_read(bio);
1195                                 return(-1);
1196                                 }
1197                         }
1198                 goto start;
1199                 }
1200
1201         switch (rr->type)
1202                 {
1203         default:
1204 #ifndef OPENSSL_NO_TLS
1205                 /* TLS just ignores unknown message types */
1206                 if (s->version == TLS1_VERSION)
1207                         {
1208                         rr->length = 0;
1209                         goto start;
1210                         }
1211 #endif
1212                 al=SSL_AD_UNEXPECTED_MESSAGE;
1213                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1214                 goto f_err;
1215         case SSL3_RT_CHANGE_CIPHER_SPEC:
1216         case SSL3_RT_ALERT:
1217         case SSL3_RT_HANDSHAKE:
1218                 /* we already handled all of these, with the possible exception
1219                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1220                  * should not happen when type != rr->type */
1221                 al=SSL_AD_UNEXPECTED_MESSAGE;
1222                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1223                 goto f_err;
1224         case SSL3_RT_APPLICATION_DATA:
1225                 /* At this point, we were expecting handshake data,
1226                  * but have application data.  If the library was
1227                  * running inside ssl3_read() (i.e. in_read_app_data
1228                  * is set) and it makes sense to read application data
1229                  * at this point (session renegotiation not yet started),
1230                  * we will indulge it.
1231                  */
1232                 if (s->s3->in_read_app_data &&
1233                         (s->s3->total_renegotiations != 0) &&
1234                         ((
1235                                 (s->state & SSL_ST_CONNECT) &&
1236                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1237                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1238                                 ) || (
1239                                         (s->state & SSL_ST_ACCEPT) &&
1240                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1241                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1242                                         )
1243                                 ))
1244                         {
1245                         s->s3->in_read_app_data=2;
1246                         return(-1);
1247                         }
1248                 else
1249                         {
1250                         al=SSL_AD_UNEXPECTED_MESSAGE;
1251                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1252                         goto f_err;
1253                         }
1254                 }
1255         /* not reached */
1256
1257 f_err:
1258         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1259 err:
1260         return(-1);
1261         }
1262
1263 int
1264 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1265         {
1266         int i;
1267
1268         if (SSL_in_init(s) && !s->in_handshake)
1269                 {
1270                 i=s->handshake_func(s);
1271                 if (i < 0) return(i);
1272                 if (i == 0)
1273                         {
1274                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1275                         return -1;
1276                         }
1277                 }
1278
1279         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1280                 {
1281                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1282                         return -1;
1283                 }
1284
1285         i = dtls1_write_bytes(s, type, buf_, len);
1286         return i;
1287         }
1288
1289
1290         /* this only happens when a client hello is received and a handshake
1291          * is started. */
1292 static int
1293 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1294         int len, int peek)
1295         {
1296
1297         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1298                 /* (partially) satisfy request from storage */
1299                 {
1300                 unsigned char *src = s->d1->handshake_fragment;
1301                 unsigned char *dst = buf;
1302                 unsigned int k,n;
1303
1304                 /* peek == 0 */
1305                 n = 0;
1306                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1307                         {
1308                         *dst++ = *src++;
1309                         len--; s->d1->handshake_fragment_len--;
1310                         n++;
1311                         }
1312                 /* move any remaining fragment bytes: */
1313                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1314                         s->d1->handshake_fragment[k] = *src++;
1315                 return n;
1316                 }
1317
1318         return 0;
1319         }
1320
1321
1322
1323
1324 /* Call this to write data in records of type 'type'
1325  * It will return <= 0 if not all data has been sent or non-blocking IO.
1326  */
1327 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1328         {
1329         int i;
1330
1331         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1332         s->rwstate=SSL_NOTHING;
1333         i=do_dtls1_write(s, type, buf, len, 0);
1334         return i;
1335         }
1336
1337 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1338         {
1339         unsigned char *p,*pseq;
1340         int i,mac_size,clear=0;
1341         int prefix_len = 0;
1342         SSL3_RECORD *wr;
1343         SSL3_BUFFER *wb;
1344         SSL_SESSION *sess;
1345         int bs;
1346
1347         /* first check if there is a SSL3_BUFFER still being written
1348          * out.  This will happen with non blocking IO */
1349         if (s->s3->wbuf.left != 0)
1350                 {
1351                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1352                 return(ssl3_write_pending(s,type,buf,len));
1353                 }
1354
1355         /* If we have an alert to send, lets send it */
1356         if (s->s3->alert_dispatch)
1357                 {
1358                 i=s->method->ssl_dispatch_alert(s);
1359                 if (i <= 0)
1360                         return(i);
1361                 /* if it went, fall through and send more stuff */
1362                 }
1363
1364         if (len == 0 && !create_empty_fragment)
1365                 return 0;
1366
1367         wr= &(s->s3->wrec);
1368         wb= &(s->s3->wbuf);
1369         sess=s->session;
1370
1371         if (    (sess == NULL) ||
1372                 (s->enc_write_ctx == NULL) ||
1373                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1374                 clear=1;
1375
1376         if (clear)
1377                 mac_size=0;
1378         else
1379                 {
1380                 mac_size=EVP_MD_CTX_size(s->write_hash);
1381                 if (mac_size < 0)
1382                         goto err;
1383                 }
1384
1385         /* DTLS implements explicit IV, so no need for empty fragments */
1386 #if 0
1387         /* 'create_empty_fragment' is true only when this function calls itself */
1388         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1389             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1390                 {
1391                 /* countermeasure against known-IV weakness in CBC ciphersuites
1392                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1393                  */
1394
1395                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1396                         {
1397                         /* recursive function call with 'create_empty_fragment' set;
1398                          * this prepares and buffers the data for an empty fragment
1399                          * (these 'prefix_len' bytes are sent out later
1400                          * together with the actual payload) */
1401                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1402                         if (prefix_len <= 0)
1403                                 goto err;
1404
1405                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1406                                 {
1407                                 /* insufficient space */
1408                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1409                                 goto err;
1410                                 }
1411                         }
1412
1413                 s->s3->empty_fragment_done = 1;
1414                 }
1415 #endif
1416         p = wb->buf + prefix_len;
1417
1418         /* write the header */
1419
1420         *(p++)=type&0xff;
1421         wr->type=type;
1422
1423         *(p++)=(s->version>>8);
1424         *(p++)=s->version&0xff;
1425
1426         /* field where we are to write out packet epoch, seq num and len */
1427         pseq=p;
1428         p+=10;
1429
1430         /* lets setup the record stuff. */
1431
1432         /* Make space for the explicit IV in case of CBC.
1433          * (this is a bit of a boundary violation, but what the heck).
1434          */
1435         if ( s->enc_write_ctx &&
1436                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1437                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1438         else
1439                 bs = 0;
1440
1441         wr->data=p + bs;  /* make room for IV in case of CBC */
1442         wr->length=(int)len;
1443         wr->input=(unsigned char *)buf;
1444
1445         /* we now 'read' from wr->input, wr->length bytes into
1446          * wr->data */
1447
1448         /* first we compress */
1449         if (s->compress != NULL)
1450                 {
1451                 if (!ssl3_do_compress(s))
1452                         {
1453                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1454                         goto err;
1455                         }
1456                 }
1457         else
1458                 {
1459                 memcpy(wr->data,wr->input,wr->length);
1460                 wr->input=wr->data;
1461                 }
1462
1463         /* we should still have the output to wr->data and the input
1464          * from wr->input.  Length should be wr->length.
1465          * wr->data still points in the wb->buf */
1466
1467         if (mac_size != 0)
1468                 {
1469                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1470                         goto err;
1471                 wr->length+=mac_size;
1472                 }
1473
1474         /* this is true regardless of mac size */
1475         wr->input=p;
1476         wr->data=p;
1477
1478
1479         /* ssl3_enc can only have an error on read */
1480         if (bs) /* bs != 0 in case of CBC */
1481                 {
1482                 RAND_pseudo_bytes(p,bs);
1483                 /* master IV and last CBC residue stand for
1484                  * the rest of randomness */
1485                 wr->length += bs;
1486                 }
1487
1488         s->method->ssl3_enc->enc(s,1);
1489
1490         /* record length after mac and block padding */
1491 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1492         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1493
1494         /* there's only one epoch between handshake and app data */
1495
1496         s2n(s->d1->w_epoch, pseq);
1497
1498         /* XDTLS: ?? */
1499 /*      else
1500         s2n(s->d1->handshake_epoch, pseq); */
1501
1502         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1503         pseq+=6;
1504         s2n(wr->length,pseq);
1505
1506         /* we should now have
1507          * wr->data pointing to the encrypted data, which is
1508          * wr->length long */
1509         wr->type=type; /* not needed but helps for debugging */
1510         wr->length+=DTLS1_RT_HEADER_LENGTH;
1511
1512 #if 0  /* this is now done at the message layer */
1513         /* buffer the record, making it easy to handle retransmits */
1514         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1515                 dtls1_buffer_record(s, wr->data, wr->length,
1516                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1517 #endif
1518
1519         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1520
1521         if (create_empty_fragment)
1522                 {
1523                 /* we are in a recursive call;
1524                  * just return the length, don't write out anything here
1525                  */
1526                 return wr->length;
1527                 }
1528
1529         /* now let's set up wb */
1530         wb->left = prefix_len + wr->length;
1531         wb->offset = 0;
1532
1533         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1534         s->s3->wpend_tot=len;
1535         s->s3->wpend_buf=buf;
1536         s->s3->wpend_type=type;
1537         s->s3->wpend_ret=len;
1538
1539         /* we now just need to write the buffer */
1540         return ssl3_write_pending(s,type,buf,len);
1541 err:
1542         return -1;
1543         }
1544
1545
1546
1547 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1548         {
1549         int cmp;
1550         unsigned int shift;
1551         const unsigned char *seq = s->s3->read_sequence;
1552
1553         cmp = satsub64be(seq,bitmap->max_seq_num);
1554         if (cmp > 0)
1555                 {
1556                 memcpy (s->s3->rrec.seq_num,seq,8);
1557                 return 1; /* this record in new */
1558                 }
1559         shift = -cmp;
1560         if (shift >= sizeof(bitmap->map)*8)
1561                 return 0; /* stale, outside the window */
1562         else if (bitmap->map & (1UL<<shift))
1563                 return 0; /* record previously received */
1564
1565         memcpy (s->s3->rrec.seq_num,seq,8);
1566         return 1;
1567         }
1568
1569
1570 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1571         {
1572         int cmp;
1573         unsigned int shift;
1574         const unsigned char *seq = s->s3->read_sequence;
1575
1576         cmp = satsub64be(seq,bitmap->max_seq_num);
1577         if (cmp > 0)
1578                 {
1579                 shift = cmp;
1580                 if (shift < sizeof(bitmap->map)*8)
1581                         bitmap->map <<= shift, bitmap->map |= 1UL;
1582                 else
1583                         bitmap->map = 1UL;
1584                 memcpy(bitmap->max_seq_num,seq,8);
1585                 }
1586         else    {
1587                 shift = -cmp;
1588                 if (shift < sizeof(bitmap->map)*8)
1589                         bitmap->map |= 1UL<<shift;
1590                 }
1591         }
1592
1593
1594 int dtls1_dispatch_alert(SSL *s)
1595         {
1596         int i,j;
1597         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1598         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1599         unsigned char *ptr = &buf[0];
1600
1601         s->s3->alert_dispatch=0;
1602
1603         memset(buf, 0x00, sizeof(buf));
1604         *ptr++ = s->s3->send_alert[0];
1605         *ptr++ = s->s3->send_alert[1];
1606
1607 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1608         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1609                 {
1610                 s2n(s->d1->handshake_read_seq, ptr);
1611 #if 0
1612                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1613
1614                 else
1615                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1616 #endif
1617
1618 #if 0
1619                 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);
1620 #endif
1621                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1622                 }
1623 #endif
1624
1625         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1626         if (i <= 0)
1627                 {
1628                 s->s3->alert_dispatch=1;
1629                 /* fprintf( stderr, "not done with alert\n" ); */
1630                 }
1631         else
1632                 {
1633                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1634 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1635                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1636 #endif
1637                     )
1638                         (void)BIO_flush(s->wbio);
1639
1640                 if (s->msg_callback)
1641                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1642                                 2, s, s->msg_callback_arg);
1643
1644                 if (s->info_callback != NULL)
1645                         cb=s->info_callback;
1646                 else if (s->ctx->info_callback != NULL)
1647                         cb=s->ctx->info_callback;
1648
1649                 if (cb != NULL)
1650                         {
1651                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1652                         cb(s,SSL_CB_WRITE_ALERT,j);
1653                         }
1654                 }
1655         return(i);
1656         }
1657
1658
1659 static DTLS1_BITMAP *
1660 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1661     {
1662
1663     *is_next_epoch = 0;
1664
1665     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1666     if (rr->epoch == s->d1->r_epoch)
1667         return &s->d1->bitmap;
1668
1669     /* Only HM and ALERT messages can be from the next epoch */
1670     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1671         (rr->type == SSL3_RT_HANDSHAKE ||
1672             rr->type == SSL3_RT_ALERT))
1673         {
1674         *is_next_epoch = 1;
1675         return &s->d1->next_bitmap;
1676         }
1677
1678     return NULL;
1679     }
1680
1681 #if 0
1682 static int
1683 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1684         unsigned long *offset)
1685         {
1686
1687         /* alerts are passed up immediately */
1688         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1689                 rr->type == SSL3_RT_ALERT)
1690                 return 0;
1691
1692         /* Only need to buffer if a handshake is underway.
1693          * (this implies that Hello Request and Client Hello are passed up
1694          * immediately) */
1695         if ( SSL_in_init(s))
1696                 {
1697                 unsigned char *data = rr->data;
1698                 /* need to extract the HM/CCS sequence number here */
1699                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1700                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1701                         {
1702                         unsigned short seq_num;
1703                         struct hm_header_st msg_hdr;
1704                         struct ccs_header_st ccs_hdr;
1705
1706                         if ( rr->type == SSL3_RT_HANDSHAKE)
1707                                 {
1708                                 dtls1_get_message_header(data, &msg_hdr);
1709                                 seq_num = msg_hdr.seq;
1710                                 *offset = msg_hdr.frag_off;
1711                                 }
1712                         else
1713                                 {
1714                                 dtls1_get_ccs_header(data, &ccs_hdr);
1715                                 seq_num = ccs_hdr.seq;
1716                                 *offset = 0;
1717                                 }
1718
1719                         /* this is either a record we're waiting for, or a
1720                          * retransmit of something we happened to previously
1721                          * receive (higher layers will drop the repeat silently */
1722                         if ( seq_num < s->d1->handshake_read_seq)
1723                                 return 0;
1724                         if (rr->type == SSL3_RT_HANDSHAKE &&
1725                                 seq_num == s->d1->handshake_read_seq &&
1726                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1727                                 return 0;
1728                         else if ( seq_num == s->d1->handshake_read_seq &&
1729                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1730                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1731                                 return 0;
1732                         else
1733                                 {
1734                                 *priority = seq_num;
1735                                 return 1;
1736                                 }
1737                         }
1738                 else /* unknown record type */
1739                         return 0;
1740                 }
1741
1742         return 0;
1743         }
1744 #endif
1745
1746 void
1747 dtls1_reset_seq_numbers(SSL *s, int rw)
1748         {
1749         unsigned char *seq;
1750         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1751
1752         if ( rw & SSL3_CC_READ)
1753                 {
1754                 seq = s->s3->read_sequence;
1755                 s->d1->r_epoch++;
1756                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1757                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1758                 }
1759         else
1760                 {
1761                 seq = s->s3->write_sequence;
1762                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1763                 s->d1->w_epoch++;
1764                 }
1765
1766         memset(seq, 0x00, seq_bytes);
1767         }
1768
1769
1770 static void
1771 dtls1_clear_timeouts(SSL *s)
1772         {
1773         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1774         }