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         /*-
 521          * So at this point the following is true
 522          * ssl->s3->rrec.type   is the type of record
 523          * ssl->s3->rrec.length == number of bytes in record
 524          * ssl->s3->rrec.off    == offset to first valid byte
 525          * ssl->s3->rrec.data   == where to take bytes from, increment
 526          *                         after use :-).
 527          */
 528
 529         /* we have pulled in a full packet so zero things */
 530         s->packet_length=0;
 531         return(1);
 532
 533 f_err:
 534         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 535 err:
 536         return(0);
 537 }
 538
 539
 540 /*-
 541  * Call this to get a new input record.
 542  * It will return <= 0 if more data is needed, normally due to an error
 543  * or non-blocking IO.
 544  * When it finishes, one packet has been decoded and can be found in
 545  * ssl->s3->rrec.type    - is the type of record
 546  * ssl->s3->rrec.data,   - data
 547  * ssl->s3->rrec.length, - number of bytes
 548  */
 549 /* used only by dtls1_read_bytes */
 550 int dtls1_get_record(SSL *s)
 551         {
 552         int ssl_major,ssl_minor;
 553         int i,n;
 554         SSL3_RECORD *rr;
 555         unsigned char *p = NULL;
 556         unsigned short version;
 557         DTLS1_BITMAP *bitmap;
 558         unsigned int is_next_epoch;
 559
 560         rr= &(s->s3->rrec);
 561
 562         /* The epoch may have changed.  If so, process all the
 563          * pending records.  This is a non-blocking operation. */
 564         if(dtls1_process_buffered_records(s)<0)
 565                 return -1;
 566
 567         /* if we're renegotiating, then there may be buffered records */
 568         if (dtls1_get_processed_record(s))
 569                 return 1;
 570
 571         /* get something from the wire */
 572 again:
 573         /* check if we have the header */
 574         if (    (s->rstate != SSL_ST_READ_BODY) ||
 575                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 576                 {
 577                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 578                 /* read timeout is handled by dtls1_read_bytes */
 579                 if (n <= 0) return(n); /* error or non-blocking */
 580
 581                 /* this packet contained a partial record, dump it */
 582                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
 583                         {
 584                         s->packet_length = 0;
 585                         goto again;
 586                         }
 587
 588                 s->rstate=SSL_ST_READ_BODY;
 589
 590                 p=s->packet;
 591
 592                 /* Pull apart the header into the DTLS1_RECORD */
 593                 rr->type= *(p++);
 594                 ssl_major= *(p++);
 595                 ssl_minor= *(p++);
 596                 version=(ssl_major<<8)|ssl_minor;
 597
 598                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 599                 n2s(p,rr->epoch);
 600
 601                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 602                 p+=6;
 603
 604                 n2s(p,rr->length);
 605
 606                 /* Lets check version */
 607                 if (!s->first_packet)
 608                         {
 609                         if (version != s->version)
 610                                 {
 611                                 /* unexpected version, silently discard */
 612                                 rr->length = 0;
 613                                 s->packet_length = 0;
 614                                 goto again;
 615                                 }
 616                         }
 617
 618                 if ((version & 0xff00) != (s->version & 0xff00))
 619                         {
 620                         /* wrong version, silently discard record */
 621                         rr->length = 0;
 622                         s->packet_length = 0;
 623                         goto again;
 624                         }
 625
 626                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 627                         {
 628                         /* record too long, silently discard it */
 629                         rr->length = 0;
 630                         s->packet_length = 0;
 631                         goto again;
 632                         }
 633
 634                 /* now s->rstate == SSL_ST_READ_BODY */
 635                 }
 636
 637         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 638
 639         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 640                 {
 641                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 642                 i=rr->length;
 643                 n=ssl3_read_n(s,i,i,1);
 644                 /* this packet contained a partial record, dump it */
 645                 if ( n != i)
 646                         {
 647                         rr->length = 0;
 648                         s->packet_length = 0;
 649                         goto again;
 650                         }
 651
 652                 /* now n == rr->length,
 653                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 654                 }
 655         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 656
 657         /* match epochs.  NULL means the packet is dropped on the floor */
 658         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 659         if ( bitmap == NULL)
 660                 {
 661                 rr->length = 0;
 662                 s->packet_length = 0;  /* dump this record */
 663                 goto again;   /* get another record */
 664                 }
 665
 666         /* Check whether this is a repeat, or aged record.
 667          * Don't check if we're listening and this message is
 668          * a ClientHello. They can look as if they're replayed,
 669          * since they arrive from different connections and
 670          * would be dropped unnecessarily.
 671          */
 672         if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
 673                 s->packet_length > DTLS1_RT_HEADER_LENGTH &&
 674                 s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) &&
 675                 !dtls1_record_replay_check(s, bitmap))
 676                 {
 677                 rr->length = 0;
 678                 s->packet_length=0; /* dump this record */
 679                 goto again;     /* get another record */
 680                 }
 681
 682         /* just read a 0 length packet */
 683         if (rr->length == 0) goto again;
 684
 685         /* If this record is from the next epoch (either HM or ALERT),
 686          * and a handshake is currently in progress, buffer it since it
 687          * cannot be processed at this time. However, do not buffer
 688          * anything while listening.
 689          */
 690         if (is_next_epoch)
 691                 {
 692                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
 693                         {
 694                         if(dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num)<0)
 695                                 return -1;
 696                         dtls1_record_bitmap_update(s, bitmap);/* Mark receipt of record. */
 697                         }
 698                 rr->length = 0;
 699                 s->packet_length = 0;
 700                 goto again;
 701                 }
 702
 703         if (!dtls1_process_record(s))
 704                 {
 705                 rr->length = 0;
 706                 s->packet_length = 0;  /* dump this record */
 707                 goto again;   /* get another record */
 708                 }
 709         dtls1_record_bitmap_update(s, bitmap);/* Mark receipt of record. */
 710
 711         return(1);
 712
 713         }
 714
 715 /*-
 716  * Return up to 'len' payload bytes received in 'type' records.
 717  * 'type' is one of the following:
 718  *
 719  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 720  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 721  *   -  0 (during a shutdown, no data has to be returned)
 722  *
 723  * If we don't have stored data to work from, read a SSL/TLS record first
 724  * (possibly multiple records if we still don't have anything to return).
 725  *
 726  * This function must handle any surprises the peer may have for us, such as
 727  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 728  * a surprise, but handled as if it were), or renegotiation requests.
 729  * Also if record payloads contain fragments too small to process, we store
 730  * them until there is enough for the respective protocol (the record protocol
 731  * may use arbitrary fragmentation and even interleaving):
 732  *     Change cipher spec protocol
 733  *             just 1 byte needed, no need for keeping anything stored
 734  *     Alert protocol
 735  *             2 bytes needed (AlertLevel, AlertDescription)
 736  *     Handshake protocol
 737  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 738  *             to detect unexpected Client Hello and Hello Request messages
 739  *             here, anything else is handled by higher layers
 740  *     Application data protocol
 741  *             none of our business
 742  */
 743 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 744         {
 745         int al,i,j,ret;
 746         unsigned int n;
 747         SSL3_RECORD *rr;
 748         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 749
 750         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 751                 if (!ssl3_setup_buffers(s))
 752                         return(-1);
 753
 754     /* XXX: check what the second '&& type' is about */
 755         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 756                 (type != SSL3_RT_HANDSHAKE) && type) ||
 757             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 758                 {
 759                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 760                 return -1;
 761                 }
 762
 763         /* check whether there's a handshake message (client hello?) waiting */
 764         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 765                 return ret;
 766
 767         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 768
 769         if (!s->in_handshake && SSL_in_init(s))
 770                 {
 771                 /* type == SSL3_RT_APPLICATION_DATA */
 772                 i=s->handshake_func(s);
 773                 if (i < 0) return(i);
 774                 if (i == 0)
 775                         {
 776                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 777                         return(-1);
 778                         }
 779                 }
 780
 781 start:
 782         s->rwstate=SSL_NOTHING;
 783
 784         /*-
 785          * s->s3->rrec.type         - is the type of record
 786          * s->s3->rrec.data,    - data
 787          * s->s3->rrec.off,     - offset into 'data' for next read
 788          * s->s3->rrec.length,  - number of bytes.
 789          */
 790         rr = &(s->s3->rrec);
 791
 792         /* We are not handshaking and have no data yet,
 793          * so process data buffered during the last handshake
 794          * in advance, if any.
 795          */
 796         if (s->state == SSL_ST_OK && rr->length == 0)
 797                 {
 798                 pitem *item;
 799                 item = pqueue_pop(s->d1->buffered_app_data.q);
 800                 if (item)
 801                         {
 802                         dtls1_copy_record(s, item);
 803
 804                         OPENSSL_free(item->data);
 805                         pitem_free(item);
 806                         }
 807                 }
 808
 809         /* Check for timeout */
 810         if (dtls1_handle_timeout(s) > 0)
 811                 goto start;
 812
 813         /* get new packet if necessary */
 814         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 815                 {
 816                 ret=dtls1_get_record(s);
 817                 if (ret <= 0)
 818                         {
 819                         ret = dtls1_read_failed(s, ret);
 820                         /* anything other than a timeout is an error */
 821                         if (ret <= 0)
 822                                 return(ret);
 823                         else
 824                                 goto start;
 825                         }
 826                 }
 827
 828         if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE)
 829                 {
 830                 rr->length = 0;
 831                 goto start;
 832                 }
 833
 834         /* we now have a packet which can be read and processed */
 835
 836         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 837                                        * reset by ssl3_get_finished */
 838                 && (rr->type != SSL3_RT_HANDSHAKE))
 839                 {
 840                 /* We now have application data between CCS and Finished.
 841                  * Most likely the packets were reordered on their way, so
 842                  * buffer the application data for later processing rather
 843                  * than dropping the connection.
 844                  */
 845                 if(dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num)<0)
 846                         {
 847                         SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 848                         return -1;
 849                         }
 850                 rr->length = 0;
 851                 goto start;
 852                 }
 853
 854         /* If the other end has shut down, throw anything we read away
 855          * (even in 'peek' mode) */
 856         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 857                 {
 858                 rr->length=0;
 859                 s->rwstate=SSL_NOTHING;
 860                 return(0);
 861                 }
 862
 863
 864         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 865                 {
 866                 /* make sure that we are not getting application data when we
 867                  * are doing a handshake for the first time */
 868                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 869                         (s->enc_read_ctx == NULL))
 870                         {
 871                         al=SSL_AD_UNEXPECTED_MESSAGE;
 872                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 873                         goto f_err;
 874                         }
 875
 876                 if (len <= 0) return(len);
 877
 878                 if ((unsigned int)len > rr->length)
 879                         n = rr->length;
 880                 else
 881                         n = (unsigned int)len;
 882
 883                 memcpy(buf,&(rr->data[rr->off]),n);
 884                 if (!peek)
 885                         {
 886                         rr->length-=n;
 887                         rr->off+=n;
 888                         if (rr->length == 0)
 889                                 {
 890                                 s->rstate=SSL_ST_READ_HEADER;
 891                                 rr->off=0;
 892                                 }
 893                         }
 894                 return(n);
 895                 }
 896
 897
 898         /* If we get here, then type != rr->type; if we have a handshake
 899          * message, then it was unexpected (Hello Request or Client Hello). */
 900
 901         /* In case of record types for which we have 'fragment' storage,
 902          * fill that so that we can process the data at a fixed place.
 903          */
 904                 {
 905                 unsigned int k, dest_maxlen = 0;
 906                 unsigned char *dest = NULL;
 907                 unsigned int *dest_len = NULL;
 908
 909                 if (rr->type == SSL3_RT_HANDSHAKE)
 910                         {
 911                         dest_maxlen = sizeof s->d1->handshake_fragment;
 912                         dest = s->d1->handshake_fragment;
 913                         dest_len = &s->d1->handshake_fragment_len;
 914                         }
 915                 else if (rr->type == SSL3_RT_ALERT)
 916                         {
 917                         dest_maxlen = sizeof(s->d1->alert_fragment);
 918                         dest = s->d1->alert_fragment;
 919                         dest_len = &s->d1->alert_fragment_len;
 920                         }
 921                 /* else it's a CCS message, or application data or wrong */
 922                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 923                         {
 924                         /* Application data while renegotiating
 925                          * is allowed. Try again reading.
 926                          */
 927                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 928                                 {
 929                                 BIO *bio;
 930                                 s->s3->in_read_app_data=2;
 931                                 bio=SSL_get_rbio(s);
 932                                 s->rwstate=SSL_READING;
 933                                 BIO_clear_retry_flags(bio);
 934                                 BIO_set_retry_read(bio);
 935                                 return(-1);
 936                                 }
 937
 938                         /* Not certain if this is the right error handling */
 939                         al=SSL_AD_UNEXPECTED_MESSAGE;
 940                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 941                         goto f_err;
 942                         }
 943
 944                 if (dest_maxlen > 0)
 945                         {
 946             /* XDTLS:  In a pathalogical case, the Client Hello
 947              *  may be fragmented--don't always expect dest_maxlen bytes */
 948                         if ( rr->length < dest_maxlen)
 949                                 {
 950 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
 951                                 /*
 952                                  * for normal alerts rr->length is 2, while
 953                                  * dest_maxlen is 7 if we were to handle this
 954                                  * non-existing alert...
 955                                  */
 956                                 FIX ME
 957 #endif
 958                                 s->rstate=SSL_ST_READ_HEADER;
 959                                 rr->length = 0;
 960                                 goto start;
 961                                 }
 962
 963                         /* now move 'n' bytes: */
 964                         for ( k = 0; k < dest_maxlen; k++)
 965                                 {
 966                                 dest[k] = rr->data[rr->off++];
 967                                 rr->length--;
 968                                 }
 969                         *dest_len = dest_maxlen;
 970                         }
 971                 }
 972
 973         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 974          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 975          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 976
 977         /* If we are a client, check for an incoming 'Hello Request': */
 978         if ((!s->server) &&
 979                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 980                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 981                 (s->session != NULL) && (s->session->cipher != NULL))
 982                 {
 983                 s->d1->handshake_fragment_len = 0;
 984
 985                 if ((s->d1->handshake_fragment[1] != 0) ||
 986                         (s->d1->handshake_fragment[2] != 0) ||
 987                         (s->d1->handshake_fragment[3] != 0))
 988                         {
 989                         al=SSL_AD_DECODE_ERROR;
 990                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 991                         goto err;
 992                         }
 993
 994                 /* no need to check sequence number on HELLO REQUEST messages */
 995
 996                 if (s->msg_callback)
 997                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 998                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 999
1000                 if (SSL_is_init_finished(s) &&
1001                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1002                         !s->s3->renegotiate)
1003                         {
1004                         s->d1->handshake_read_seq++;
1005                         ssl3_renegotiate(s);
1006                         if (ssl3_renegotiate_check(s))
1007                                 {
1008                                 i=s->handshake_func(s);
1009                                 if (i < 0) return(i);
1010                                 if (i == 0)
1011                                         {
1012                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1013                                         return(-1);
1014                                         }
1015
1016                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1017                                         {
1018                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1019                                                 {
1020                                                 BIO *bio;
1021                                                 /* In the case where we try to read application data,
1022                                                  * but we trigger an SSL handshake, we return -1 with
1023                                                  * the retry option set.  Otherwise renegotiation may
1024                                                  * cause nasty problems in the blocking world */
1025                                                 s->rwstate=SSL_READING;
1026                                                 bio=SSL_get_rbio(s);
1027                                                 BIO_clear_retry_flags(bio);
1028                                                 BIO_set_retry_read(bio);
1029                                                 return(-1);
1030                                                 }
1031                                         }
1032                                 }
1033                         }
1034                 /* we either finished a handshake or ignored the request,
1035                  * now try again to obtain the (application) data we were asked for */
1036                 goto start;
1037                 }
1038
1039         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1040                 {
1041                 int alert_level = s->d1->alert_fragment[0];
1042                 int alert_descr = s->d1->alert_fragment[1];
1043
1044                 s->d1->alert_fragment_len = 0;
1045
1046                 if (s->msg_callback)
1047                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1048                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1049
1050                 if (s->info_callback != NULL)
1051                         cb=s->info_callback;
1052                 else if (s->ctx->info_callback != NULL)
1053                         cb=s->ctx->info_callback;
1054
1055                 if (cb != NULL)
1056                         {
1057                         j = (alert_level << 8) | alert_descr;
1058                         cb(s, SSL_CB_READ_ALERT, j);
1059                         }
1060
1061                 if (alert_level == 1) /* warning */
1062                         {
1063                         s->s3->warn_alert = alert_descr;
1064                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1065                                 {
1066                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1067                                 return(0);
1068                                 }
1069 #if 0
1070             /* XXX: this is a possible improvement in the future */
1071                         /* now check if it's a missing record */
1072                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1073                                 {
1074                                 unsigned short seq;
1075                                 unsigned int frag_off;
1076                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1077
1078                                 n2s(p, seq);
1079                                 n2l3(p, frag_off);
1080
1081                                 dtls1_retransmit_message(s,
1082                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1083                                                                                  frag_off, &found);
1084                                 if ( ! found  && SSL_in_init(s))
1085                                         {
1086                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1087                                         /* requested a message not yet sent,
1088                                            send an alert ourselves */
1089                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1090                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1091                                         }
1092                                 }
1093 #endif
1094                         }
1095                 else if (alert_level == 2) /* fatal */
1096                         {
1097                         char tmp[16];
1098
1099                         s->rwstate=SSL_NOTHING;
1100                         s->s3->fatal_alert = alert_descr;
1101                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1102                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1103                         ERR_add_error_data(2,"SSL alert number ",tmp);
1104                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1105                         SSL_CTX_remove_session(s->ctx,s->session);
1106                         return(0);
1107                         }
1108                 else
1109                         {
1110                         al=SSL_AD_ILLEGAL_PARAMETER;
1111                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1112                         goto f_err;
1113                         }
1114
1115                 goto start;
1116                 }
1117
1118         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1119                 {
1120                 s->rwstate=SSL_NOTHING;
1121                 rr->length=0;
1122                 return(0);
1123                 }
1124
1125         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1126                 {
1127                 struct ccs_header_st ccs_hdr;
1128                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1129
1130                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1131
1132                 if (s->version == DTLS1_BAD_VER)
1133                         ccs_hdr_len = 3;
1134
1135                 /* 'Change Cipher Spec' is just a single byte, so we know
1136                  * exactly what the record payload has to look like */
1137                 /* XDTLS: check that epoch is consistent */
1138                 if (    (rr->length != ccs_hdr_len) ||
1139                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1140                         {
1141                         i=SSL_AD_ILLEGAL_PARAMETER;
1142                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1143                         goto err;
1144                         }
1145
1146                 rr->length=0;
1147
1148                 if (s->msg_callback)
1149                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1150                                 rr->data, 1, s, s->msg_callback_arg);
1151
1152                 /* We can't process a CCS now, because previous handshake
1153                  * messages are still missing, so just drop it.
1154                  */
1155                 if (!s->d1->change_cipher_spec_ok)
1156                         {
1157                         goto start;
1158                         }
1159
1160                 s->d1->change_cipher_spec_ok = 0;
1161
1162                 s->s3->change_cipher_spec=1;
1163                 if (!ssl3_do_change_cipher_spec(s))
1164                         goto err;
1165
1166                 /* do this whenever CCS is processed */
1167                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1168
1169                 if (s->version == DTLS1_BAD_VER)
1170                         s->d1->handshake_read_seq++;
1171
1172                 goto start;
1173                 }
1174
1175         /* Unexpected handshake message (Client Hello, or protocol violation) */
1176         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1177                 !s->in_handshake)
1178                 {
1179                 struct hm_header_st msg_hdr;
1180
1181                 /* this may just be a stale retransmit */
1182                 dtls1_get_message_header(rr->data, &msg_hdr);
1183                 if( rr->epoch != s->d1->r_epoch)
1184                         {
1185                         rr->length = 0;
1186                         goto start;
1187                         }
1188
1189                 /* If we are server, we may have a repeated FINISHED of the
1190                  * client here, then retransmit our CCS and FINISHED.
1191                  */
1192                 if (msg_hdr.type == SSL3_MT_FINISHED)
1193                         {
1194                         if (dtls1_check_timeout_num(s) < 0)
1195                                 return -1;
1196
1197                         dtls1_retransmit_buffered_messages(s);
1198                         rr->length = 0;
1199                         goto start;
1200                         }
1201
1202                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1203                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1204                         {
1205 #if 0 /* worked only because C operator preferences are not as expected (and
1206        * because this is not really needed for clients except for detecting
1207        * protocol violations): */
1208                         s->state=SSL_ST_BEFORE|(s->server)
1209                                 ?SSL_ST_ACCEPT
1210                                 :SSL_ST_CONNECT;
1211 #else
1212                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1213 #endif
1214                         s->new_session=1;
1215                         }
1216                 i=s->handshake_func(s);
1217                 if (i < 0) return(i);
1218                 if (i == 0)
1219                         {
1220                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1221                         return(-1);
1222                         }
1223
1224                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1225                         {
1226                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1227                                 {
1228                                 BIO *bio;
1229                                 /* In the case where we try to read application data,
1230                                  * but we trigger an SSL handshake, we return -1 with
1231                                  * the retry option set.  Otherwise renegotiation may
1232                                  * cause nasty problems in the blocking world */
1233                                 s->rwstate=SSL_READING;
1234                                 bio=SSL_get_rbio(s);
1235                                 BIO_clear_retry_flags(bio);
1236                                 BIO_set_retry_read(bio);
1237                                 return(-1);
1238                                 }
1239                         }
1240                 goto start;
1241                 }
1242
1243         switch (rr->type)
1244                 {
1245         default:
1246 #ifndef OPENSSL_NO_TLS
1247                 /* TLS just ignores unknown message types */
1248                 if (s->version == TLS1_VERSION)
1249                         {
1250                         rr->length = 0;
1251                         goto start;
1252                         }
1253 #endif
1254                 al=SSL_AD_UNEXPECTED_MESSAGE;
1255                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1256                 goto f_err;
1257         case SSL3_RT_CHANGE_CIPHER_SPEC:
1258         case SSL3_RT_ALERT:
1259         case SSL3_RT_HANDSHAKE:
1260                 /* we already handled all of these, with the possible exception
1261                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1262                  * should not happen when type != rr->type */
1263                 al=SSL_AD_UNEXPECTED_MESSAGE;
1264                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1265                 goto f_err;
1266         case SSL3_RT_APPLICATION_DATA:
1267                 /* At this point, we were expecting handshake data,
1268                  * but have application data.  If the library was
1269                  * running inside ssl3_read() (i.e. in_read_app_data
1270                  * is set) and it makes sense to read application data
1271                  * at this point (session renegotiation not yet started),
1272                  * we will indulge it.
1273                  */
1274                 if (s->s3->in_read_app_data &&
1275                         (s->s3->total_renegotiations != 0) &&
1276                         ((
1277                                 (s->state & SSL_ST_CONNECT) &&
1278                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1279                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1280                                 ) || (
1281                                         (s->state & SSL_ST_ACCEPT) &&
1282                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1283                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1284                                         )
1285                                 ))
1286                         {
1287                         s->s3->in_read_app_data=2;
1288                         return(-1);
1289                         }
1290                 else
1291                         {
1292                         al=SSL_AD_UNEXPECTED_MESSAGE;
1293                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1294                         goto f_err;
1295                         }
1296                 }
1297         /* not reached */
1298
1299 f_err:
1300         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1301 err:
1302         return(-1);
1303         }
1304
1305 int
1306 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1307         {
1308         int i;
1309
1310         if (SSL_in_init(s) && !s->in_handshake)
1311                 {
1312                 i=s->handshake_func(s);
1313                 if (i < 0) return(i);
1314                 if (i == 0)
1315                         {
1316                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1317                         return -1;
1318                         }
1319                 }
1320
1321         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1322                 {
1323                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1324                         return -1;
1325                 }
1326
1327         i = dtls1_write_bytes(s, type, buf_, len);
1328         return i;
1329         }
1330
1331
1332         /* this only happens when a client hello is received and a handshake
1333          * is started. */
1334 static int
1335 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1336         int len, int peek)
1337         {
1338
1339         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1340                 /* (partially) satisfy request from storage */
1341                 {
1342                 unsigned char *src = s->d1->handshake_fragment;
1343                 unsigned char *dst = buf;
1344                 unsigned int k,n;
1345
1346                 /* peek == 0 */
1347                 n = 0;
1348                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1349                         {
1350                         *dst++ = *src++;
1351                         len--; s->d1->handshake_fragment_len--;
1352                         n++;
1353                         }
1354                 /* move any remaining fragment bytes: */
1355                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1356                         s->d1->handshake_fragment[k] = *src++;
1357                 return n;
1358                 }
1359
1360         return 0;
1361         }
1362
1363
1364
1365
1366 /* Call this to write data in records of type 'type'
1367  * It will return <= 0 if not all data has been sent or non-blocking IO.
1368  */
1369 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1370         {
1371         int i;
1372
1373         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1374         s->rwstate=SSL_NOTHING;
1375         i=do_dtls1_write(s, type, buf, len, 0);
1376         return i;
1377         }
1378
1379 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1380         {
1381         unsigned char *p,*pseq;
1382         int i,mac_size,clear=0;
1383         int prefix_len = 0;
1384         SSL3_RECORD *wr;
1385         SSL3_BUFFER *wb;
1386         SSL_SESSION *sess;
1387         int bs;
1388
1389         /* first check if there is a SSL3_BUFFER still being written
1390          * out.  This will happen with non blocking IO */
1391         if (s->s3->wbuf.left != 0)
1392                 {
1393                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1394                 return(ssl3_write_pending(s,type,buf,len));
1395                 }
1396
1397         /* If we have an alert to send, lets send it */
1398         if (s->s3->alert_dispatch)
1399                 {
1400                 i=s->method->ssl_dispatch_alert(s);
1401                 if (i <= 0)
1402                         return(i);
1403                 /* if it went, fall through and send more stuff */
1404                 }
1405
1406         if (len == 0 && !create_empty_fragment)
1407                 return 0;
1408
1409         wr= &(s->s3->wrec);
1410         wb= &(s->s3->wbuf);
1411         sess=s->session;
1412
1413         if (    (sess == NULL) ||
1414                 (s->enc_write_ctx == NULL) ||
1415                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1416                 clear=1;
1417
1418         if (clear)
1419                 mac_size=0;
1420         else
1421                 {
1422                 mac_size=EVP_MD_CTX_size(s->write_hash);
1423                 if (mac_size < 0)
1424                         goto err;
1425                 }
1426
1427         /* DTLS implements explicit IV, so no need for empty fragments */
1428 #if 0
1429         /* 'create_empty_fragment' is true only when this function calls itself */
1430         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1431             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1432                 {
1433                 /* countermeasure against known-IV weakness in CBC ciphersuites
1434                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1435                  */
1436
1437                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1438                         {
1439                         /* recursive function call with 'create_empty_fragment' set;
1440                          * this prepares and buffers the data for an empty fragment
1441                          * (these 'prefix_len' bytes are sent out later
1442                          * together with the actual payload) */
1443                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1444                         if (prefix_len <= 0)
1445                                 goto err;
1446
1447                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1448                                 {
1449                                 /* insufficient space */
1450                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1451                                 goto err;
1452                                 }
1453                         }
1454
1455                 s->s3->empty_fragment_done = 1;
1456                 }
1457 #endif
1458         p = wb->buf + prefix_len;
1459
1460         /* write the header */
1461
1462         *(p++)=type&0xff;
1463         wr->type=type;
1464
1465         *(p++)=(s->version>>8);
1466         *(p++)=s->version&0xff;
1467
1468         /* field where we are to write out packet epoch, seq num and len */
1469         pseq=p;
1470         p+=10;
1471
1472         /* lets setup the record stuff. */
1473
1474         /* Make space for the explicit IV in case of CBC.
1475          * (this is a bit of a boundary violation, but what the heck).
1476          */
1477         if ( s->enc_write_ctx &&
1478                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1479                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1480         else
1481                 bs = 0;
1482
1483         wr->data=p + bs;  /* make room for IV in case of CBC */
1484         wr->length=(int)len;
1485         wr->input=(unsigned char *)buf;
1486
1487         /* we now 'read' from wr->input, wr->length bytes into
1488          * wr->data */
1489
1490         /* first we compress */
1491         if (s->compress != NULL)
1492                 {
1493                 if (!ssl3_do_compress(s))
1494                         {
1495                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1496                         goto err;
1497                         }
1498                 }
1499         else
1500                 {
1501                 memcpy(wr->data,wr->input,wr->length);
1502                 wr->input=wr->data;
1503                 }
1504
1505         /* we should still have the output to wr->data and the input
1506          * from wr->input.  Length should be wr->length.
1507          * wr->data still points in the wb->buf */
1508
1509         if (mac_size != 0)
1510                 {
1511                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1512                         goto err;
1513                 wr->length+=mac_size;
1514                 }
1515
1516         /* this is true regardless of mac size */
1517         wr->input=p;
1518         wr->data=p;
1519
1520
1521         /* ssl3_enc can only have an error on read */
1522         if (bs) /* bs != 0 in case of CBC */
1523                 {
1524                 RAND_pseudo_bytes(p,bs);
1525                 /* master IV and last CBC residue stand for
1526                  * the rest of randomness */
1527                 wr->length += bs;
1528                 }
1529
1530         if(s->method->ssl3_enc->enc(s,1) < 1) goto err;
1531
1532         /* record length after mac and block padding */
1533 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1534         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1535
1536         /* there's only one epoch between handshake and app data */
1537
1538         s2n(s->d1->w_epoch, pseq);
1539
1540         /* XDTLS: ?? */
1541 /*      else
1542         s2n(s->d1->handshake_epoch, pseq); */
1543
1544         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1545         pseq+=6;
1546         s2n(wr->length,pseq);
1547
1548         /* we should now have
1549          * wr->data pointing to the encrypted data, which is
1550          * wr->length long */
1551         wr->type=type; /* not needed but helps for debugging */
1552         wr->length+=DTLS1_RT_HEADER_LENGTH;
1553
1554 #if 0  /* this is now done at the message layer */
1555         /* buffer the record, making it easy to handle retransmits */
1556         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1557                 dtls1_buffer_record(s, wr->data, wr->length,
1558                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1559 #endif
1560
1561         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1562
1563         if (create_empty_fragment)
1564                 {
1565                 /* we are in a recursive call;
1566                  * just return the length, don't write out anything here
1567                  */
1568                 return wr->length;
1569                 }
1570
1571         /* now let's set up wb */
1572         wb->left = prefix_len + wr->length;
1573         wb->offset = 0;
1574
1575         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1576         s->s3->wpend_tot=len;
1577         s->s3->wpend_buf=buf;
1578         s->s3->wpend_type=type;
1579         s->s3->wpend_ret=len;
1580
1581         /* we now just need to write the buffer */
1582         return ssl3_write_pending(s,type,buf,len);
1583 err:
1584         return -1;
1585         }
1586
1587
1588
1589 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1590         {
1591         int cmp;
1592         unsigned int shift;
1593         const unsigned char *seq = s->s3->read_sequence;
1594
1595         cmp = satsub64be(seq,bitmap->max_seq_num);
1596         if (cmp > 0)
1597                 {
1598                 memcpy (s->s3->rrec.seq_num,seq,8);
1599                 return 1; /* this record in new */
1600                 }
1601         shift = -cmp;
1602         if (shift >= sizeof(bitmap->map)*8)
1603                 return 0; /* stale, outside the window */
1604         else if (bitmap->map & (1UL<<shift))
1605                 return 0; /* record previously received */
1606
1607         memcpy (s->s3->rrec.seq_num,seq,8);
1608         return 1;
1609         }
1610
1611
1612 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1613         {
1614         int cmp;
1615         unsigned int shift;
1616         const unsigned char *seq = s->s3->read_sequence;
1617
1618         cmp = satsub64be(seq,bitmap->max_seq_num);
1619         if (cmp > 0)
1620                 {
1621                 shift = cmp;
1622                 if (shift < sizeof(bitmap->map)*8)
1623                         bitmap->map <<= shift, bitmap->map |= 1UL;
1624                 else
1625                         bitmap->map = 1UL;
1626                 memcpy(bitmap->max_seq_num,seq,8);
1627                 }
1628         else    {
1629                 shift = -cmp;
1630                 if (shift < sizeof(bitmap->map)*8)
1631                         bitmap->map |= 1UL<<shift;
1632                 }
1633         }
1634
1635
1636 int dtls1_dispatch_alert(SSL *s)
1637         {
1638         int i,j;
1639         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1640         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1641         unsigned char *ptr = &buf[0];
1642
1643         s->s3->alert_dispatch=0;
1644
1645         memset(buf, 0x00, sizeof(buf));
1646         *ptr++ = s->s3->send_alert[0];
1647         *ptr++ = s->s3->send_alert[1];
1648
1649 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1650         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1651                 {
1652                 s2n(s->d1->handshake_read_seq, ptr);
1653 #if 0
1654                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1655
1656                 else
1657                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1658 #endif
1659
1660 #if 0
1661                 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);
1662 #endif
1663                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1664                 }
1665 #endif
1666
1667         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1668         if (i <= 0)
1669                 {
1670                 s->s3->alert_dispatch=1;
1671                 /* fprintf( stderr, "not done with alert\n" ); */
1672                 }
1673         else
1674                 {
1675                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1676 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1677                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1678 #endif
1679                     )
1680                         (void)BIO_flush(s->wbio);
1681
1682                 if (s->msg_callback)
1683                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1684                                 2, s, s->msg_callback_arg);
1685
1686                 if (s->info_callback != NULL)
1687                         cb=s->info_callback;
1688                 else if (s->ctx->info_callback != NULL)
1689                         cb=s->ctx->info_callback;
1690
1691                 if (cb != NULL)
1692                         {
1693                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1694                         cb(s,SSL_CB_WRITE_ALERT,j);
1695                         }
1696                 }
1697         return(i);
1698         }
1699
1700
1701 static DTLS1_BITMAP *
1702 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1703     {
1704
1705     *is_next_epoch = 0;
1706
1707     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1708     if (rr->epoch == s->d1->r_epoch)
1709         return &s->d1->bitmap;
1710
1711     /* Only HM and ALERT messages can be from the next epoch */
1712     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1713         (rr->type == SSL3_RT_HANDSHAKE ||
1714             rr->type == SSL3_RT_ALERT))
1715         {
1716         *is_next_epoch = 1;
1717         return &s->d1->next_bitmap;
1718         }
1719
1720     return NULL;
1721     }
1722
1723 #if 0
1724 static int
1725 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1726         unsigned long *offset)
1727         {
1728
1729         /* alerts are passed up immediately */
1730         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1731                 rr->type == SSL3_RT_ALERT)
1732                 return 0;
1733
1734         /* Only need to buffer if a handshake is underway.
1735          * (this implies that Hello Request and Client Hello are passed up
1736          * immediately) */
1737         if ( SSL_in_init(s))
1738                 {
1739                 unsigned char *data = rr->data;
1740                 /* need to extract the HM/CCS sequence number here */
1741                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1742                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1743                         {
1744                         unsigned short seq_num;
1745                         struct hm_header_st msg_hdr;
1746                         struct ccs_header_st ccs_hdr;
1747
1748                         if ( rr->type == SSL3_RT_HANDSHAKE)
1749                                 {
1750                                 dtls1_get_message_header(data, &msg_hdr);
1751                                 seq_num = msg_hdr.seq;
1752                                 *offset = msg_hdr.frag_off;
1753                                 }
1754                         else
1755                                 {
1756                                 dtls1_get_ccs_header(data, &ccs_hdr);
1757                                 seq_num = ccs_hdr.seq;
1758                                 *offset = 0;
1759                                 }
1760
1761                         /* this is either a record we're waiting for, or a
1762                          * retransmit of something we happened to previously
1763                          * receive (higher layers will drop the repeat silently */
1764                         if ( seq_num < s->d1->handshake_read_seq)
1765                                 return 0;
1766                         if (rr->type == SSL3_RT_HANDSHAKE &&
1767                                 seq_num == s->d1->handshake_read_seq &&
1768                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1769                                 return 0;
1770                         else if ( seq_num == s->d1->handshake_read_seq &&
1771                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1772                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1773                                 return 0;
1774                         else
1775                                 {
1776                                 *priority = seq_num;
1777                                 return 1;
1778                                 }
1779                         }
1780                 else /* unknown record type */
1781                         return 0;
1782                 }
1783
1784         return 0;
1785         }
1786 #endif
1787
1788 void
1789 dtls1_reset_seq_numbers(SSL *s, int rw)
1790         {
1791         unsigned char *seq;
1792         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1793
1794         if ( rw & SSL3_CC_READ)
1795                 {
1796                 seq = s->s3->read_sequence;
1797                 s->d1->r_epoch++;
1798                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1799                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1800                 }
1801         else
1802                 {
1803                 seq = s->s3->write_sequence;
1804                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1805                 s->d1->w_epoch++;
1806                 }
1807
1808         memset(seq, 0x00, seq_bytes);
1809         }