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
 183 /* copy buffered record into SSL structure */
 184 static int
 185 dtls1_copy_record(SSL *s, pitem *item)
 186     {
 187     DTLS1_RECORD_DATA *rdata;
 188
 189     rdata = (DTLS1_RECORD_DATA *)item->data;
 190
 191     if (s->s3->rbuf.buf != NULL)
 192         OPENSSL_free(s->s3->rbuf.buf);
 193
 194     s->packet = rdata->packet;
 195     s->packet_length = rdata->packet_length;
 196     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 197     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 198
 199         /* Set proper sequence number for mac calculation */
 200         memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
 201
 202     return(1);
 203     }
 204
 205
 206 static int
 207 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 208         {
 209         DTLS1_RECORD_DATA *rdata;
 210         pitem *item;
 211
 212         /* Limit the size of the queue to prevent DOS attacks */
 213         if (pqueue_size(queue->q) >= 100)
 214                 return 0;
 215
 216         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 217         item = pitem_new(priority, rdata);
 218         if (rdata == NULL || item == NULL)
 219                 {
 220                 if (rdata != NULL) OPENSSL_free(rdata);
 221                 if (item != NULL) pitem_free(item);
 222
 223                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 224                 return(0);
 225                 }
 226
 227         rdata->packet = s->packet;
 228         rdata->packet_length = s->packet_length;
 229         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 230         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 231
 232         item->data = rdata;
 233
 234         s->packet = NULL;
 235         s->packet_length = 0;
 236         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 237         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 238
 239         if (!ssl3_setup_buffers(s))
 240                 {
 241                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 242                 if (rdata->rbuf.buf != NULL)
 243                         OPENSSL_free(rdata->rbuf.buf);
 244                 OPENSSL_free(rdata);
 245                 pitem_free(item);
 246                 return(-1);
 247                 }
 248
 249         /* insert should not fail, since duplicates are dropped */
 250         if (pqueue_insert(queue->q, item) == NULL)
 251                 {
 252                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 253                 if (rdata->rbuf.buf != NULL)
 254                         OPENSSL_free(rdata->rbuf.buf);
 255                 OPENSSL_free(rdata);
 256                 pitem_free(item);
 257                 return(-1);
 258                 }
 259
 260         return(1);
 261         }
 262
 263
 264 static int
 265 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 266     {
 267     pitem *item;
 268
 269     item = pqueue_pop(queue->q);
 270     if (item)
 271         {
 272         dtls1_copy_record(s, item);
 273
 274         OPENSSL_free(item->data);
 275                 pitem_free(item);
 276
 277         return(1);
 278         }
 279
 280     return(0);
 281     }
 282
 283
 284 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 285  * yet */
 286 #define dtls1_get_unprocessed_record(s) \
 287                    dtls1_retrieve_buffered_record((s), \
 288                    &((s)->d1->unprocessed_rcds))
 289
 290 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 291 #define dtls1_get_processed_record(s) \
 292                    dtls1_retrieve_buffered_record((s), \
 293                    &((s)->d1->processed_rcds))
 294
 295 static int
 296 dtls1_process_buffered_records(SSL *s)
 297     {
 298     pitem *item;
 299
 300     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 301     if (item)
 302         {
 303         /* Check if epoch is current. */
 304         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 305             return(1);  /* Nothing to do. */
 306
 307         /* Process all the records. */
 308         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 309             {
 310             dtls1_get_unprocessed_record(s);
 311             if ( ! dtls1_process_record(s))
 312                 return(0);
 313             if(dtls1_buffer_record(s, &(s->d1->processed_rcds),
 314                 s->s3->rrec.seq_num)<0)
 315                 return -1;
 316             }
 317         }
 318
 319     /* sync epoch numbers once all the unprocessed records
 320      * have been processed */
 321     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 322     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 323
 324     return(1);
 325     }
 326
 327
 328 #if 0
 329
 330 static int
 331 dtls1_get_buffered_record(SSL *s)
 332         {
 333         pitem *item;
 334         PQ_64BIT priority =
 335                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 336                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 337
 338         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 339                                                            nothing buffered */
 340                 return 0;
 341
 342
 343         item = pqueue_peek(s->d1->rcvd_records);
 344         if (item && item->priority == priority)
 345                 {
 346                 /* Check if we've received the record of interest.  It must be
 347                  * a handshake record, since data records as passed up without
 348                  * buffering */
 349                 DTLS1_RECORD_DATA *rdata;
 350                 item = pqueue_pop(s->d1->rcvd_records);
 351                 rdata = (DTLS1_RECORD_DATA *)item->data;
 352
 353                 if (s->s3->rbuf.buf != NULL)
 354                         OPENSSL_free(s->s3->rbuf.buf);
 355
 356                 s->packet = rdata->packet;
 357                 s->packet_length = rdata->packet_length;
 358                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 359                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 360
 361                 OPENSSL_free(item->data);
 362                 pitem_free(item);
 363
 364                 /* s->d1->next_expected_seq_num++; */
 365                 return(1);
 366                 }
 367
 368         return 0;
 369         }
 370
 371 #endif
 372
 373 static int
 374 dtls1_process_record(SSL *s)
 375 {
 376         int i,al;
 377         int enc_err;
 378         SSL_SESSION *sess;
 379         SSL3_RECORD *rr;
 380         unsigned int mac_size, orig_len;
 381         unsigned char md[EVP_MAX_MD_SIZE];
 382
 383         rr= &(s->s3->rrec);
 384         sess = s->session;
 385
 386         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 387          * and we have that many bytes in s->packet
 388          */
 389         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 390
 391         /* ok, we can now read from 's->packet' data into 'rr'
 392          * rr->input points at rr->length bytes, which
 393          * need to be copied into rr->data by either
 394          * the decryption or by the decompression
 395          * When the data is 'copied' into the rr->data buffer,
 396          * rr->input will be pointed at the new buffer */
 397
 398         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 399          * rr->length bytes of encrypted compressed stuff. */
 400
 401         /* check is not needed I believe */
 402         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 403                 {
 404                 al=SSL_AD_RECORD_OVERFLOW;
 405                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 406                 goto f_err;
 407                 }
 408
 409         /* decrypt in place in 'rr->input' */
 410         rr->data=rr->input;
 411
 412         enc_err = s->method->ssl3_enc->enc(s,0);
 413         /* enc_err is:
 414          *    0: (in non-constant time) if the record is publically invalid.
 415          *    1: if the padding is valid
 416          *    -1: if the padding is invalid */
 417         if (enc_err == 0)
 418                 {
 419                 /* For DTLS we simply ignore bad packets. */
 420                 rr->length = 0;
 421                 s->packet_length = 0;
 422                 goto err;
 423                 }
 424
 425 #ifdef TLS_DEBUG
 426 printf("dec %d\n",rr->length);
 427 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 428 printf("\n");
 429 #endif
 430
 431         /* r->length is now the compressed data plus mac */
 432         if ((sess != NULL) &&
 433             (s->enc_read_ctx != NULL) &&
 434             (EVP_MD_CTX_md(s->read_hash) != NULL))
 435                 {
 436                 /* s->read_hash != NULL => mac_size != -1 */
 437                 unsigned char *mac = NULL;
 438                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
 439                 mac_size=EVP_MD_CTX_size(s->read_hash);
 440                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
 441
 442                 /* kludge: *_cbc_remove_padding passes padding length in rr->type */
 443                 orig_len = rr->length+((unsigned int)rr->type>>8);
 444
 445                 /* orig_len is the length of the record before any padding was
 446                  * removed. This is public information, as is the MAC in use,
 447                  * therefore we can safely process the record in a different
 448                  * amount of time if it's too short to possibly contain a MAC.
 449                  */
 450                 if (orig_len < mac_size ||
 451                     /* CBC records must have a padding length byte too. */
 452                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
 453                      orig_len < mac_size+1))
 454                         {
 455                         al=SSL_AD_DECODE_ERROR;
 456                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 457                         goto f_err;
 458                         }
 459
 460                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
 461                         {
 462                         /* We update the length so that the TLS header bytes
 463                          * can be constructed correctly but we need to extract
 464                          * the MAC in constant time from within the record,
 465                          * without leaking the contents of the padding bytes.
 466                          * */
 467                         mac = mac_tmp;
 468                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
 469                         rr->length -= mac_size;
 470                         }
 471                 else
 472                         {
 473                         /* In this case there's no padding, so |orig_len|
 474                          * equals |rec->length| and we checked that there's
 475                          * enough bytes for |mac_size| above. */
 476                         rr->length -= mac_size;
 477                         mac = &rr->data[rr->length];
 478                         }
 479
 480                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
 481                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
 482                         enc_err = -1;
 483                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 484                         enc_err = -1;
 485                 }
 486
 487         if (enc_err < 0)
 488                 {
 489                 /* decryption failed, silently discard message */
 490                 rr->length = 0;
 491                 s->packet_length = 0;
 492                 goto err;
 493                 }
 494
 495         /* r->length is now just compressed */
 496         if (s->expand != NULL)
 497                 {
 498                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 499                         {
 500                         al=SSL_AD_RECORD_OVERFLOW;
 501                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 502                         goto f_err;
 503                         }
 504                 if (!ssl3_do_uncompress(s))
 505                         {
 506                         al=SSL_AD_DECOMPRESSION_FAILURE;
 507                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 508                         goto f_err;
 509                         }
 510                 }
 511
 512         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 513                 {
 514                 al=SSL_AD_RECORD_OVERFLOW;
 515                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 516                 goto f_err;
 517                 }
 518
 519         rr->off=0;
 520         /* So at this point the following is true
 521          * ssl->s3->rrec.type   is the type of record
 522          * ssl->s3->rrec.length == number of bytes in record
 523          * ssl->s3->rrec.off    == offset to first valid byte
 524          * ssl->s3->rrec.data   == where to take bytes from, increment
 525          *                         after use :-).
 526          */
 527
 528         /* we have pulled in a full packet so zero things */
 529         s->packet_length=0;
 530         return(1);
 531
 532 f_err:
 533         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 534 err:
 535         return(0);
 536 }
 537
 538
 539 /* Call this to get a new input record.
 540  * It will return <= 0 if more data is needed, normally due to an error
 541  * or non-blocking IO.
 542  * When it finishes, one packet has been decoded and can be found in
 543  * ssl->s3->rrec.type    - is the type of record
 544  * ssl->s3->rrec.data,   - data
 545  * ssl->s3->rrec.length, - number of bytes
 546  */
 547 /* used only by dtls1_read_bytes */
 548 int dtls1_get_record(SSL *s)
 549         {
 550         int ssl_major,ssl_minor;
 551         int i,n;
 552         SSL3_RECORD *rr;
 553         unsigned char *p = NULL;
 554         unsigned short version;
 555         DTLS1_BITMAP *bitmap;
 556         unsigned int is_next_epoch;
 557
 558         rr= &(s->s3->rrec);
 559
 560         /* The epoch may have changed.  If so, process all the
 561          * pending records.  This is a non-blocking operation. */
 562         if(dtls1_process_buffered_records(s)<0)
 563                 return -1;
 564
 565         /* if we're renegotiating, then there may be buffered records */
 566         if (dtls1_get_processed_record(s))
 567                 return 1;
 568
 569         /* get something from the wire */
 570 again:
 571         /* check if we have the header */
 572         if (    (s->rstate != SSL_ST_READ_BODY) ||
 573                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 574                 {
 575                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 576                 /* read timeout is handled by dtls1_read_bytes */
 577                 if (n <= 0) return(n); /* error or non-blocking */
 578
 579                 /* this packet contained a partial record, dump it */
 580                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
 581                         {
 582                         s->packet_length = 0;
 583                         goto again;
 584                         }
 585
 586                 s->rstate=SSL_ST_READ_BODY;
 587
 588                 p=s->packet;
 589
 590                 /* Pull apart the header into the DTLS1_RECORD */
 591                 rr->type= *(p++);
 592                 ssl_major= *(p++);
 593                 ssl_minor= *(p++);
 594                 version=(ssl_major<<8)|ssl_minor;
 595
 596                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 597                 n2s(p,rr->epoch);
 598
 599                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 600                 p+=6;
 601
 602                 n2s(p,rr->length);
 603
 604                 /* Lets check version */
 605                 if (!s->first_packet)
 606                         {
 607                         if (version != s->version)
 608                                 {
 609                                 /* unexpected version, silently discard */
 610                                 rr->length = 0;
 611                                 s->packet_length = 0;
 612                                 goto again;
 613                                 }
 614                         }
 615
 616                 if ((version & 0xff00) != (s->version & 0xff00))
 617                         {
 618                         /* wrong version, silently discard record */
 619                         rr->length = 0;
 620                         s->packet_length = 0;
 621                         goto again;
 622                         }
 623
 624                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 625                         {
 626                         /* record too long, silently discard it */
 627                         rr->length = 0;
 628                         s->packet_length = 0;
 629                         goto again;
 630                         }
 631
 632                 /* now s->rstate == SSL_ST_READ_BODY */
 633                 }
 634
 635         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 636
 637         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 638                 {
 639                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 640                 i=rr->length;
 641                 n=ssl3_read_n(s,i,i,1);
 642                 /* this packet contained a partial record, dump it */
 643                 if ( n != i)
 644                         {
 645                         rr->length = 0;
 646                         s->packet_length = 0;
 647                         goto again;
 648                         }
 649
 650                 /* now n == rr->length,
 651                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 652                 }
 653         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 654
 655         /* match epochs.  NULL means the packet is dropped on the floor */
 656         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 657         if ( bitmap == NULL)
 658                 {
 659                 rr->length = 0;
 660                 s->packet_length = 0;  /* dump this record */
 661                 goto again;   /* get another record */
 662                 }
 663
 664         /* Check whether this is a repeat, or aged record.
 665          * Don't check if we're listening and this message is
 666          * a ClientHello. They can look as if they're replayed,
 667          * since they arrive from different connections and
 668          * would be dropped unnecessarily.
 669          */
 670         if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
 671                 s->packet_length > DTLS1_RT_HEADER_LENGTH &&
 672                 s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) &&
 673                 !dtls1_record_replay_check(s, bitmap))
 674                 {
 675                 rr->length = 0;
 676                 s->packet_length=0; /* dump this record */
 677                 goto again;     /* get another record */
 678                 }
 679
 680         /* just read a 0 length packet */
 681         if (rr->length == 0) goto again;
 682
 683         /* If this record is from the next epoch (either HM or ALERT),
 684          * and a handshake is currently in progress, buffer it since it
 685          * cannot be processed at this time. However, do not buffer
 686          * anything while listening.
 687          */
 688         if (is_next_epoch)
 689                 {
 690                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
 691                         {
 692                         if(dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num)<0)
 693                                 return -1;
 694                         dtls1_record_bitmap_update(s, bitmap);/* Mark receipt of record. */
 695                         }
 696                 rr->length = 0;
 697                 s->packet_length = 0;
 698                 goto again;
 699                 }
 700
 701         if (!dtls1_process_record(s))
 702                 {
 703                 rr->length = 0;
 704                 s->packet_length = 0;  /* dump this record */
 705                 goto again;   /* get another record */
 706                 }
 707         dtls1_record_bitmap_update(s, bitmap);/* Mark receipt of record. */
 708
 709         return(1);
 710
 711         }
 712
 713 /* Return up to 'len' payload bytes received in 'type' records.
 714  * 'type' is one of the following:
 715  *
 716  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 717  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 718  *   -  0 (during a shutdown, no data has to be returned)
 719  *
 720  * If we don't have stored data to work from, read a SSL/TLS record first
 721  * (possibly multiple records if we still don't have anything to return).
 722  *
 723  * This function must handle any surprises the peer may have for us, such as
 724  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 725  * a surprise, but handled as if it were), or renegotiation requests.
 726  * Also if record payloads contain fragments too small to process, we store
 727  * them until there is enough for the respective protocol (the record protocol
 728  * may use arbitrary fragmentation and even interleaving):
 729  *     Change cipher spec protocol
 730  *             just 1 byte needed, no need for keeping anything stored
 731  *     Alert protocol
 732  *             2 bytes needed (AlertLevel, AlertDescription)
 733  *     Handshake protocol
 734  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 735  *             to detect unexpected Client Hello and Hello Request messages
 736  *             here, anything else is handled by higher layers
 737  *     Application data protocol
 738  *             none of our business
 739  */
 740 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 741         {
 742         int al,i,j,ret;
 743         unsigned int n;
 744         SSL3_RECORD *rr;
 745         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 746
 747         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 748                 if (!ssl3_setup_buffers(s))
 749                         return(-1);
 750
 751     /* XXX: check what the second '&& type' is about */
 752         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 753                 (type != SSL3_RT_HANDSHAKE) && type) ||
 754             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 755                 {
 756                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 757                 return -1;
 758                 }
 759
 760         /* check whether there's a handshake message (client hello?) waiting */
 761         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 762                 return ret;
 763
 764         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 765
 766         if (!s->in_handshake && SSL_in_init(s))
 767                 {
 768                 /* type == SSL3_RT_APPLICATION_DATA */
 769                 i=s->handshake_func(s);
 770                 if (i < 0) return(i);
 771                 if (i == 0)
 772                         {
 773                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 774                         return(-1);
 775                         }
 776                 }
 777
 778 start:
 779         s->rwstate=SSL_NOTHING;
 780
 781         /* s->s3->rrec.type         - is the type of record
 782          * s->s3->rrec.data,    - data
 783          * s->s3->rrec.off,     - offset into 'data' for next read
 784          * s->s3->rrec.length,  - number of bytes. */
 785         rr = &(s->s3->rrec);
 786
 787         /* We are not handshaking and have no data yet,
 788          * so process data buffered during the last handshake
 789          * in advance, if any.
 790          */
 791         if (s->state == SSL_ST_OK && rr->length == 0)
 792                 {
 793                 pitem *item;
 794                 item = pqueue_pop(s->d1->buffered_app_data.q);
 795                 if (item)
 796                         {
 797                         dtls1_copy_record(s, item);
 798
 799                         OPENSSL_free(item->data);
 800                         pitem_free(item);
 801                         }
 802                 }
 803
 804         /* Check for timeout */
 805         if (dtls1_handle_timeout(s) > 0)
 806                 goto start;
 807
 808         /* get new packet if necessary */
 809         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 810                 {
 811                 ret=dtls1_get_record(s);
 812                 if (ret <= 0)
 813                         {
 814                         ret = dtls1_read_failed(s, ret);
 815                         /* anything other than a timeout is an error */
 816                         if (ret <= 0)
 817                                 return(ret);
 818                         else
 819                                 goto start;
 820                         }
 821                 }
 822
 823         if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE)
 824                 {
 825                 rr->length = 0;
 826                 goto start;
 827                 }
 828
 829         /* we now have a packet which can be read and processed */
 830
 831         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 832                                        * reset by ssl3_get_finished */
 833                 && (rr->type != SSL3_RT_HANDSHAKE))
 834                 {
 835                 /* We now have application data between CCS and Finished.
 836                  * Most likely the packets were reordered on their way, so
 837                  * buffer the application data for later processing rather
 838                  * than dropping the connection.
 839                  */
 840                 if(dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num)<0)
 841                         {
 842                         SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 843                         return -1;
 844                         }
 845                 rr->length = 0;
 846                 goto start;
 847                 }
 848
 849         /* If the other end has shut down, throw anything we read away
 850          * (even in 'peek' mode) */
 851         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 852                 {
 853                 rr->length=0;
 854                 s->rwstate=SSL_NOTHING;
 855                 return(0);
 856                 }
 857
 858
 859         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 860                 {
 861                 /* make sure that we are not getting application data when we
 862                  * are doing a handshake for the first time */
 863                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 864                         (s->enc_read_ctx == NULL))
 865                         {
 866                         al=SSL_AD_UNEXPECTED_MESSAGE;
 867                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 868                         goto f_err;
 869                         }
 870
 871                 if (len <= 0) return(len);
 872
 873                 if ((unsigned int)len > rr->length)
 874                         n = rr->length;
 875                 else
 876                         n = (unsigned int)len;
 877
 878                 memcpy(buf,&(rr->data[rr->off]),n);
 879                 if (!peek)
 880                         {
 881                         rr->length-=n;
 882                         rr->off+=n;
 883                         if (rr->length == 0)
 884                                 {
 885                                 s->rstate=SSL_ST_READ_HEADER;
 886                                 rr->off=0;
 887                                 }
 888                         }
 889                 return(n);
 890                 }
 891
 892
 893         /* If we get here, then type != rr->type; if we have a handshake
 894          * message, then it was unexpected (Hello Request or Client Hello). */
 895
 896         /* In case of record types for which we have 'fragment' storage,
 897          * fill that so that we can process the data at a fixed place.
 898          */
 899                 {
 900                 unsigned int k, dest_maxlen = 0;
 901                 unsigned char *dest = NULL;
 902                 unsigned int *dest_len = NULL;
 903
 904                 if (rr->type == SSL3_RT_HANDSHAKE)
 905                         {
 906                         dest_maxlen = sizeof s->d1->handshake_fragment;
 907                         dest = s->d1->handshake_fragment;
 908                         dest_len = &s->d1->handshake_fragment_len;
 909                         }
 910                 else if (rr->type == SSL3_RT_ALERT)
 911                         {
 912                         dest_maxlen = sizeof(s->d1->alert_fragment);
 913                         dest = s->d1->alert_fragment;
 914                         dest_len = &s->d1->alert_fragment_len;
 915                         }
 916                 /* else it's a CCS message, or application data or wrong */
 917                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 918                         {
 919                         /* Application data while renegotiating
 920                          * is allowed. Try again reading.
 921                          */
 922                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 923                                 {
 924                                 BIO *bio;
 925                                 s->s3->in_read_app_data=2;
 926                                 bio=SSL_get_rbio(s);
 927                                 s->rwstate=SSL_READING;
 928                                 BIO_clear_retry_flags(bio);
 929                                 BIO_set_retry_read(bio);
 930                                 return(-1);
 931                                 }
 932
 933                         /* Not certain if this is the right error handling */
 934                         al=SSL_AD_UNEXPECTED_MESSAGE;
 935                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 936                         goto f_err;
 937                         }
 938
 939                 if (dest_maxlen > 0)
 940                         {
 941             /* XDTLS:  In a pathalogical case, the Client Hello
 942              *  may be fragmented--don't always expect dest_maxlen bytes */
 943                         if ( rr->length < dest_maxlen)
 944                                 {
 945 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
 946                                 /*
 947                                  * for normal alerts rr->length is 2, while
 948                                  * dest_maxlen is 7 if we were to handle this
 949                                  * non-existing alert...
 950                                  */
 951                                 FIX ME
 952 #endif
 953                                 s->rstate=SSL_ST_READ_HEADER;
 954                                 rr->length = 0;
 955                                 goto start;
 956                                 }
 957
 958                         /* now move 'n' bytes: */
 959                         for ( k = 0; k < dest_maxlen; k++)
 960                                 {
 961                                 dest[k] = rr->data[rr->off++];
 962                                 rr->length--;
 963                                 }
 964                         *dest_len = dest_maxlen;
 965                         }
 966                 }
 967
 968         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 969          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 970          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 971
 972         /* If we are a client, check for an incoming 'Hello Request': */
 973         if ((!s->server) &&
 974                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 975                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 976                 (s->session != NULL) && (s->session->cipher != NULL))
 977                 {
 978                 s->d1->handshake_fragment_len = 0;
 979
 980                 if ((s->d1->handshake_fragment[1] != 0) ||
 981                         (s->d1->handshake_fragment[2] != 0) ||
 982                         (s->d1->handshake_fragment[3] != 0))
 983                         {
 984                         al=SSL_AD_DECODE_ERROR;
 985                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 986                         goto err;
 987                         }
 988
 989                 /* no need to check sequence number on HELLO REQUEST messages */
 990
 991                 if (s->msg_callback)
 992                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 993                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 994
 995                 if (SSL_is_init_finished(s) &&
 996                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 997                         !s->s3->renegotiate)
 998                         {
 999                         s->d1->handshake_read_seq++;
1000                         ssl3_renegotiate(s);
1001                         if (ssl3_renegotiate_check(s))
1002                                 {
1003                                 i=s->handshake_func(s);
1004                                 if (i < 0) return(i);
1005                                 if (i == 0)
1006                                         {
1007                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1008                                         return(-1);
1009                                         }
1010
1011                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1012                                         {
1013                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1014                                                 {
1015                                                 BIO *bio;
1016                                                 /* In the case where we try to read application data,
1017                                                  * but we trigger an SSL handshake, we return -1 with
1018                                                  * the retry option set.  Otherwise renegotiation may
1019                                                  * cause nasty problems in the blocking world */
1020                                                 s->rwstate=SSL_READING;
1021                                                 bio=SSL_get_rbio(s);
1022                                                 BIO_clear_retry_flags(bio);
1023                                                 BIO_set_retry_read(bio);
1024                                                 return(-1);
1025                                                 }
1026                                         }
1027                                 }
1028                         }
1029                 /* we either finished a handshake or ignored the request,
1030                  * now try again to obtain the (application) data we were asked for */
1031                 goto start;
1032                 }
1033
1034         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1035                 {
1036                 int alert_level = s->d1->alert_fragment[0];
1037                 int alert_descr = s->d1->alert_fragment[1];
1038
1039                 s->d1->alert_fragment_len = 0;
1040
1041                 if (s->msg_callback)
1042                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1043                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1044
1045                 if (s->info_callback != NULL)
1046                         cb=s->info_callback;
1047                 else if (s->ctx->info_callback != NULL)
1048                         cb=s->ctx->info_callback;
1049
1050                 if (cb != NULL)
1051                         {
1052                         j = (alert_level << 8) | alert_descr;
1053                         cb(s, SSL_CB_READ_ALERT, j);
1054                         }
1055
1056                 if (alert_level == 1) /* warning */
1057                         {
1058                         s->s3->warn_alert = alert_descr;
1059                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1060                                 {
1061                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1062                                 return(0);
1063                                 }
1064 #if 0
1065             /* XXX: this is a possible improvement in the future */
1066                         /* now check if it's a missing record */
1067                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1068                                 {
1069                                 unsigned short seq;
1070                                 unsigned int frag_off;
1071                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1072
1073                                 n2s(p, seq);
1074                                 n2l3(p, frag_off);
1075
1076                                 dtls1_retransmit_message(s,
1077                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1078                                                                                  frag_off, &found);
1079                                 if ( ! found  && SSL_in_init(s))
1080                                         {
1081                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1082                                         /* requested a message not yet sent,
1083                                            send an alert ourselves */
1084                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1085                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1086                                         }
1087                                 }
1088 #endif
1089                         }
1090                 else if (alert_level == 2) /* fatal */
1091                         {
1092                         char tmp[16];
1093
1094                         s->rwstate=SSL_NOTHING;
1095                         s->s3->fatal_alert = alert_descr;
1096                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1097                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1098                         ERR_add_error_data(2,"SSL alert number ",tmp);
1099                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1100                         SSL_CTX_remove_session(s->ctx,s->session);
1101                         return(0);
1102                         }
1103                 else
1104                         {
1105                         al=SSL_AD_ILLEGAL_PARAMETER;
1106                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1107                         goto f_err;
1108                         }
1109
1110                 goto start;
1111                 }
1112
1113         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1114                 {
1115                 s->rwstate=SSL_NOTHING;
1116                 rr->length=0;
1117                 return(0);
1118                 }
1119
1120         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1121                 {
1122                 struct ccs_header_st ccs_hdr;
1123                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1124
1125                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1126
1127                 if (s->version == DTLS1_BAD_VER)
1128                         ccs_hdr_len = 3;
1129
1130                 /* 'Change Cipher Spec' is just a single byte, so we know
1131                  * exactly what the record payload has to look like */
1132                 /* XDTLS: check that epoch is consistent */
1133                 if (    (rr->length != ccs_hdr_len) ||
1134                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1135                         {
1136                         i=SSL_AD_ILLEGAL_PARAMETER;
1137                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1138                         goto err;
1139                         }
1140
1141                 rr->length=0;
1142
1143                 if (s->msg_callback)
1144                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1145                                 rr->data, 1, s, s->msg_callback_arg);
1146
1147                 /* We can't process a CCS now, because previous handshake
1148                  * messages are still missing, so just drop it.
1149                  */
1150                 if (!s->d1->change_cipher_spec_ok)
1151                         {
1152                         goto start;
1153                         }
1154
1155                 s->d1->change_cipher_spec_ok = 0;
1156
1157                 s->s3->change_cipher_spec=1;
1158                 if (!ssl3_do_change_cipher_spec(s))
1159                         goto err;
1160
1161                 /* do this whenever CCS is processed */
1162                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1163
1164                 if (s->version == DTLS1_BAD_VER)
1165                         s->d1->handshake_read_seq++;
1166
1167                 goto start;
1168                 }
1169
1170         /* Unexpected handshake message (Client Hello, or protocol violation) */
1171         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1172                 !s->in_handshake)
1173                 {
1174                 struct hm_header_st msg_hdr;
1175
1176                 /* this may just be a stale retransmit */
1177                 dtls1_get_message_header(rr->data, &msg_hdr);
1178                 if( rr->epoch != s->d1->r_epoch)
1179                         {
1180                         rr->length = 0;
1181                         goto start;
1182                         }
1183
1184                 /* If we are server, we may have a repeated FINISHED of the
1185                  * client here, then retransmit our CCS and FINISHED.
1186                  */
1187                 if (msg_hdr.type == SSL3_MT_FINISHED)
1188                         {
1189                         if (dtls1_check_timeout_num(s) < 0)
1190                                 return -1;
1191
1192                         dtls1_retransmit_buffered_messages(s);
1193                         rr->length = 0;
1194                         goto start;
1195                         }
1196
1197                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1198                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1199                         {
1200 #if 0 /* worked only because C operator preferences are not as expected (and
1201        * because this is not really needed for clients except for detecting
1202        * protocol violations): */
1203                         s->state=SSL_ST_BEFORE|(s->server)
1204                                 ?SSL_ST_ACCEPT
1205                                 :SSL_ST_CONNECT;
1206 #else
1207                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1208 #endif
1209                         s->new_session=1;
1210                         }
1211                 i=s->handshake_func(s);
1212                 if (i < 0) return(i);
1213                 if (i == 0)
1214                         {
1215                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1216                         return(-1);
1217                         }
1218
1219                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1220                         {
1221                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1222                                 {
1223                                 BIO *bio;
1224                                 /* In the case where we try to read application data,
1225                                  * but we trigger an SSL handshake, we return -1 with
1226                                  * the retry option set.  Otherwise renegotiation may
1227                                  * cause nasty problems in the blocking world */
1228                                 s->rwstate=SSL_READING;
1229                                 bio=SSL_get_rbio(s);
1230                                 BIO_clear_retry_flags(bio);
1231                                 BIO_set_retry_read(bio);
1232                                 return(-1);
1233                                 }
1234                         }
1235                 goto start;
1236                 }
1237
1238         switch (rr->type)
1239                 {
1240         default:
1241 #ifndef OPENSSL_NO_TLS
1242                 /* TLS just ignores unknown message types */
1243                 if (s->version == TLS1_VERSION)
1244                         {
1245                         rr->length = 0;
1246                         goto start;
1247                         }
1248 #endif
1249                 al=SSL_AD_UNEXPECTED_MESSAGE;
1250                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1251                 goto f_err;
1252         case SSL3_RT_CHANGE_CIPHER_SPEC:
1253         case SSL3_RT_ALERT:
1254         case SSL3_RT_HANDSHAKE:
1255                 /* we already handled all of these, with the possible exception
1256                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1257                  * should not happen when type != rr->type */
1258                 al=SSL_AD_UNEXPECTED_MESSAGE;
1259                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1260                 goto f_err;
1261         case SSL3_RT_APPLICATION_DATA:
1262                 /* At this point, we were expecting handshake data,
1263                  * but have application data.  If the library was
1264                  * running inside ssl3_read() (i.e. in_read_app_data
1265                  * is set) and it makes sense to read application data
1266                  * at this point (session renegotiation not yet started),
1267                  * we will indulge it.
1268                  */
1269                 if (s->s3->in_read_app_data &&
1270                         (s->s3->total_renegotiations != 0) &&
1271                         ((
1272                                 (s->state & SSL_ST_CONNECT) &&
1273                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1274                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1275                                 ) || (
1276                                         (s->state & SSL_ST_ACCEPT) &&
1277                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1278                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1279                                         )
1280                                 ))
1281                         {
1282                         s->s3->in_read_app_data=2;
1283                         return(-1);
1284                         }
1285                 else
1286                         {
1287                         al=SSL_AD_UNEXPECTED_MESSAGE;
1288                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1289                         goto f_err;
1290                         }
1291                 }
1292         /* not reached */
1293
1294 f_err:
1295         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1296 err:
1297         return(-1);
1298         }
1299
1300 int
1301 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1302         {
1303         int i;
1304
1305         if (SSL_in_init(s) && !s->in_handshake)
1306                 {
1307                 i=s->handshake_func(s);
1308                 if (i < 0) return(i);
1309                 if (i == 0)
1310                         {
1311                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1312                         return -1;
1313                         }
1314                 }
1315
1316         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1317                 {
1318                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1319                         return -1;
1320                 }
1321
1322         i = dtls1_write_bytes(s, type, buf_, len);
1323         return i;
1324         }
1325
1326
1327         /* this only happens when a client hello is received and a handshake
1328          * is started. */
1329 static int
1330 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1331         int len, int peek)
1332         {
1333
1334         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1335                 /* (partially) satisfy request from storage */
1336                 {
1337                 unsigned char *src = s->d1->handshake_fragment;
1338                 unsigned char *dst = buf;
1339                 unsigned int k,n;
1340
1341                 /* peek == 0 */
1342                 n = 0;
1343                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1344                         {
1345                         *dst++ = *src++;
1346                         len--; s->d1->handshake_fragment_len--;
1347                         n++;
1348                         }
1349                 /* move any remaining fragment bytes: */
1350                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1351                         s->d1->handshake_fragment[k] = *src++;
1352                 return n;
1353                 }
1354
1355         return 0;
1356         }
1357
1358
1359
1360
1361 /* Call this to write data in records of type 'type'
1362  * It will return <= 0 if not all data has been sent or non-blocking IO.
1363  */
1364 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1365         {
1366         int i;
1367
1368         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1369         s->rwstate=SSL_NOTHING;
1370         i=do_dtls1_write(s, type, buf, len, 0);
1371         return i;
1372         }
1373
1374 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1375         {
1376         unsigned char *p,*pseq;
1377         int i,mac_size,clear=0;
1378         int prefix_len = 0;
1379         SSL3_RECORD *wr;
1380         SSL3_BUFFER *wb;
1381         SSL_SESSION *sess;
1382         int bs;
1383
1384         /* first check if there is a SSL3_BUFFER still being written
1385          * out.  This will happen with non blocking IO */
1386         if (s->s3->wbuf.left != 0)
1387                 {
1388                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1389                 return(ssl3_write_pending(s,type,buf,len));
1390                 }
1391
1392         /* If we have an alert to send, lets send it */
1393         if (s->s3->alert_dispatch)
1394                 {
1395                 i=s->method->ssl_dispatch_alert(s);
1396                 if (i <= 0)
1397                         return(i);
1398                 /* if it went, fall through and send more stuff */
1399                 }
1400
1401         if (len == 0 && !create_empty_fragment)
1402                 return 0;
1403
1404         wr= &(s->s3->wrec);
1405         wb= &(s->s3->wbuf);
1406         sess=s->session;
1407
1408         if (    (sess == NULL) ||
1409                 (s->enc_write_ctx == NULL) ||
1410                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1411                 clear=1;
1412
1413         if (clear)
1414                 mac_size=0;
1415         else
1416                 {
1417                 mac_size=EVP_MD_CTX_size(s->write_hash);
1418                 if (mac_size < 0)
1419                         goto err;
1420                 }
1421
1422         /* DTLS implements explicit IV, so no need for empty fragments */
1423 #if 0
1424         /* 'create_empty_fragment' is true only when this function calls itself */
1425         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1426             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1427                 {
1428                 /* countermeasure against known-IV weakness in CBC ciphersuites
1429                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1430                  */
1431
1432                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1433                         {
1434                         /* recursive function call with 'create_empty_fragment' set;
1435                          * this prepares and buffers the data for an empty fragment
1436                          * (these 'prefix_len' bytes are sent out later
1437                          * together with the actual payload) */
1438                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1439                         if (prefix_len <= 0)
1440                                 goto err;
1441
1442                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1443                                 {
1444                                 /* insufficient space */
1445                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1446                                 goto err;
1447                                 }
1448                         }
1449
1450                 s->s3->empty_fragment_done = 1;
1451                 }
1452 #endif
1453         p = wb->buf + prefix_len;
1454
1455         /* write the header */
1456
1457         *(p++)=type&0xff;
1458         wr->type=type;
1459
1460         *(p++)=(s->version>>8);
1461         *(p++)=s->version&0xff;
1462
1463         /* field where we are to write out packet epoch, seq num and len */
1464         pseq=p;
1465         p+=10;
1466
1467         /* lets setup the record stuff. */
1468
1469         /* Make space for the explicit IV in case of CBC.
1470          * (this is a bit of a boundary violation, but what the heck).
1471          */
1472         if ( s->enc_write_ctx &&
1473                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1474                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1475         else
1476                 bs = 0;
1477
1478         wr->data=p + bs;  /* make room for IV in case of CBC */
1479         wr->length=(int)len;
1480         wr->input=(unsigned char *)buf;
1481
1482         /* we now 'read' from wr->input, wr->length bytes into
1483          * wr->data */
1484
1485         /* first we compress */
1486         if (s->compress != NULL)
1487                 {
1488                 if (!ssl3_do_compress(s))
1489                         {
1490                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1491                         goto err;
1492                         }
1493                 }
1494         else
1495                 {
1496                 memcpy(wr->data,wr->input,wr->length);
1497                 wr->input=wr->data;
1498                 }
1499
1500         /* we should still have the output to wr->data and the input
1501          * from wr->input.  Length should be wr->length.
1502          * wr->data still points in the wb->buf */
1503
1504         if (mac_size != 0)
1505                 {
1506                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1507                         goto err;
1508                 wr->length+=mac_size;
1509                 }
1510
1511         /* this is true regardless of mac size */
1512         wr->input=p;
1513         wr->data=p;
1514
1515
1516         /* ssl3_enc can only have an error on read */
1517         if (bs) /* bs != 0 in case of CBC */
1518                 {
1519                 RAND_pseudo_bytes(p,bs);
1520                 /* master IV and last CBC residue stand for
1521                  * the rest of randomness */
1522                 wr->length += bs;
1523                 }
1524
1525         if(s->method->ssl3_enc->enc(s,1) < 1) goto err;
1526
1527         /* record length after mac and block padding */
1528 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1529         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1530
1531         /* there's only one epoch between handshake and app data */
1532
1533         s2n(s->d1->w_epoch, pseq);
1534
1535         /* XDTLS: ?? */
1536 /*      else
1537         s2n(s->d1->handshake_epoch, pseq); */
1538
1539         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1540         pseq+=6;
1541         s2n(wr->length,pseq);
1542
1543         /* we should now have
1544          * wr->data pointing to the encrypted data, which is
1545          * wr->length long */
1546         wr->type=type; /* not needed but helps for debugging */
1547         wr->length+=DTLS1_RT_HEADER_LENGTH;
1548
1549 #if 0  /* this is now done at the message layer */
1550         /* buffer the record, making it easy to handle retransmits */
1551         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1552                 dtls1_buffer_record(s, wr->data, wr->length,
1553                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1554 #endif
1555
1556         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1557
1558         if (create_empty_fragment)
1559                 {
1560                 /* we are in a recursive call;
1561                  * just return the length, don't write out anything here
1562                  */
1563                 return wr->length;
1564                 }
1565
1566         /* now let's set up wb */
1567         wb->left = prefix_len + wr->length;
1568         wb->offset = 0;
1569
1570         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1571         s->s3->wpend_tot=len;
1572         s->s3->wpend_buf=buf;
1573         s->s3->wpend_type=type;
1574         s->s3->wpend_ret=len;
1575
1576         /* we now just need to write the buffer */
1577         return ssl3_write_pending(s,type,buf,len);
1578 err:
1579         return -1;
1580         }
1581
1582
1583
1584 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1585         {
1586         int cmp;
1587         unsigned int shift;
1588         const unsigned char *seq = s->s3->read_sequence;
1589
1590         cmp = satsub64be(seq,bitmap->max_seq_num);
1591         if (cmp > 0)
1592                 {
1593                 memcpy (s->s3->rrec.seq_num,seq,8);
1594                 return 1; /* this record in new */
1595                 }
1596         shift = -cmp;
1597         if (shift >= sizeof(bitmap->map)*8)
1598                 return 0; /* stale, outside the window */
1599         else if (bitmap->map & (1UL<<shift))
1600                 return 0; /* record previously received */
1601
1602         memcpy (s->s3->rrec.seq_num,seq,8);
1603         return 1;
1604         }
1605
1606
1607 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1608         {
1609         int cmp;
1610         unsigned int shift;
1611         const unsigned char *seq = s->s3->read_sequence;
1612
1613         cmp = satsub64be(seq,bitmap->max_seq_num);
1614         if (cmp > 0)
1615                 {
1616                 shift = cmp;
1617                 if (shift < sizeof(bitmap->map)*8)
1618                         bitmap->map <<= shift, bitmap->map |= 1UL;
1619                 else
1620                         bitmap->map = 1UL;
1621                 memcpy(bitmap->max_seq_num,seq,8);
1622                 }
1623         else    {
1624                 shift = -cmp;
1625                 if (shift < sizeof(bitmap->map)*8)
1626                         bitmap->map |= 1UL<<shift;
1627                 }
1628         }
1629
1630
1631 int dtls1_dispatch_alert(SSL *s)
1632         {
1633         int i,j;
1634         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1635         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1636         unsigned char *ptr = &buf[0];
1637
1638         s->s3->alert_dispatch=0;
1639
1640         memset(buf, 0x00, sizeof(buf));
1641         *ptr++ = s->s3->send_alert[0];
1642         *ptr++ = s->s3->send_alert[1];
1643
1644 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1645         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1646                 {
1647                 s2n(s->d1->handshake_read_seq, ptr);
1648 #if 0
1649                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1650
1651                 else
1652                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1653 #endif
1654
1655 #if 0
1656                 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);
1657 #endif
1658                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1659                 }
1660 #endif
1661
1662         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1663         if (i <= 0)
1664                 {
1665                 s->s3->alert_dispatch=1;
1666                 /* fprintf( stderr, "not done with alert\n" ); */
1667                 }
1668         else
1669                 {
1670                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1671 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1672                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1673 #endif
1674                     )
1675                         (void)BIO_flush(s->wbio);
1676
1677                 if (s->msg_callback)
1678                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1679                                 2, s, s->msg_callback_arg);
1680
1681                 if (s->info_callback != NULL)
1682                         cb=s->info_callback;
1683                 else if (s->ctx->info_callback != NULL)
1684                         cb=s->ctx->info_callback;
1685
1686                 if (cb != NULL)
1687                         {
1688                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1689                         cb(s,SSL_CB_WRITE_ALERT,j);
1690                         }
1691                 }
1692         return(i);
1693         }
1694
1695
1696 static DTLS1_BITMAP *
1697 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1698     {
1699
1700     *is_next_epoch = 0;
1701
1702     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1703     if (rr->epoch == s->d1->r_epoch)
1704         return &s->d1->bitmap;
1705
1706     /* Only HM and ALERT messages can be from the next epoch */
1707     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1708         (rr->type == SSL3_RT_HANDSHAKE ||
1709             rr->type == SSL3_RT_ALERT))
1710         {
1711         *is_next_epoch = 1;
1712         return &s->d1->next_bitmap;
1713         }
1714
1715     return NULL;
1716     }
1717
1718 #if 0
1719 static int
1720 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1721         unsigned long *offset)
1722         {
1723
1724         /* alerts are passed up immediately */
1725         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1726                 rr->type == SSL3_RT_ALERT)
1727                 return 0;
1728
1729         /* Only need to buffer if a handshake is underway.
1730          * (this implies that Hello Request and Client Hello are passed up
1731          * immediately) */
1732         if ( SSL_in_init(s))
1733                 {
1734                 unsigned char *data = rr->data;
1735                 /* need to extract the HM/CCS sequence number here */
1736                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1737                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1738                         {
1739                         unsigned short seq_num;
1740                         struct hm_header_st msg_hdr;
1741                         struct ccs_header_st ccs_hdr;
1742
1743                         if ( rr->type == SSL3_RT_HANDSHAKE)
1744                                 {
1745                                 dtls1_get_message_header(data, &msg_hdr);
1746                                 seq_num = msg_hdr.seq;
1747                                 *offset = msg_hdr.frag_off;
1748                                 }
1749                         else
1750                                 {
1751                                 dtls1_get_ccs_header(data, &ccs_hdr);
1752                                 seq_num = ccs_hdr.seq;
1753                                 *offset = 0;
1754                                 }
1755
1756                         /* this is either a record we're waiting for, or a
1757                          * retransmit of something we happened to previously
1758                          * receive (higher layers will drop the repeat silently */
1759                         if ( seq_num < s->d1->handshake_read_seq)
1760                                 return 0;
1761                         if (rr->type == SSL3_RT_HANDSHAKE &&
1762                                 seq_num == s->d1->handshake_read_seq &&
1763                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1764                                 return 0;
1765                         else if ( seq_num == s->d1->handshake_read_seq &&
1766                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1767                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1768                                 return 0;
1769                         else
1770                                 {
1771                                 *priority = seq_num;
1772                                 return 1;
1773                                 }
1774                         }
1775                 else /* unknown record type */
1776                         return 0;
1777                 }
1778
1779         return 0;
1780         }
1781 #endif
1782
1783 void
1784 dtls1_reset_seq_numbers(SSL *s, int rw)
1785         {
1786         unsigned char *seq;
1787         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1788
1789         if ( rw & SSL3_CC_READ)
1790                 {
1791                 seq = s->s3->read_sequence;
1792                 s->d1->r_epoch++;
1793                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1794                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1795                 }
1796         else
1797                 {
1798                 seq = s->s3->write_sequence;
1799                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1800                 s->d1->w_epoch++;
1801                 }
1802
1803         memset(seq, 0x00, seq_bytes);
1804         }