ssl/d1_pkt.c

   1 /* ssl/d1_pkt.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <stdio.h>
 117 #include <errno.h>
 118 #define USE_SOCKETS
 119 #include "ssl_locl.h"
 120 #include <openssl/evp.h>
 121 #include <openssl/buffer.h>
 122 #include <openssl/pqueue.h>
 123 #include <openssl/rand.h>
 124
 125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
 126 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
 127 {       int ret,sat,brw,i;
 128
 129         if (sizeof(long) == 8) do
 130         {       const union { long one; char little; } is_endian = {1};
 131                 long l;
 132
 133                 if (is_endian.little)                   break;
 134                 /* not reached on little-endians */
 135                 /* following test is redundant, because input is
 136                  * always aligned, but I take no chances... */
 137                 if (((size_t)v1|(size_t)v2)&0x7)        break;
 138
 139                 l  = *((long *)v1);
 140                 l -= *((long *)v2);
 141                 if (l>128)              return 128;
 142                 else if (l<-128)        return -128;
 143                 else                    return (int)l;
 144         } while (0);
 145
 146         ret = (int)v1[7]-(int)v2[7];
 147         sat = 0;
 148         brw = ret>>8;   /* brw is either 0 or -1 */
 149         if (ret & 0x80)
 150         {       for (i=6;i>=0;i--)
 151                 {       brw += (int)v1[i]-(int)v2[i];
 152                         sat |= ~brw;
 153                         brw >>= 8;
 154                 }
 155         }
 156         else
 157         {       for (i=6;i>=0;i--)
 158                 {       brw += (int)v1[i]-(int)v2[i];
 159                         sat |= brw;
 160                         brw >>= 8;
 161                 }
 162         }
 163         brw <<= 8;      /* brw is either 0 or -256 */
 164
 165         if (sat&0xff)   return brw | 0x80;
 166         else            return brw + (ret&0xFF);
 167 }
 168
 169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
 170         int len, int peek);
 171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
 172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
 173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
 174     unsigned int *is_next_epoch);
 175 #if 0
 176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
 177         unsigned short *priority, unsigned long *offset);
 178 #endif
 179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
 180         unsigned char *priority);
 181 static int dtls1_process_record(SSL *s);
 182 static void dtls1_clear_timeouts(SSL *s);
 183
 184 /* copy buffered record into SSL structure */
 185 static int
 186 dtls1_copy_record(SSL *s, pitem *item)
 187     {
 188     DTLS1_RECORD_DATA *rdata;
 189
 190     rdata = (DTLS1_RECORD_DATA *)item->data;
 191
 192     if (s->s3->rbuf.buf != NULL)
 193         OPENSSL_free(s->s3->rbuf.buf);
 194
 195     s->packet = rdata->packet;
 196     s->packet_length = rdata->packet_length;
 197     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 198     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 199
 200         /* Set proper sequence number for mac calculation */
 201         memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
 202
 203     return(1);
 204     }
 205
 206
 207 static int
 208 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 209         {
 210         DTLS1_RECORD_DATA *rdata;
 211         pitem *item;
 212
 213         /* Limit the size of the queue to prevent DOS attacks */
 214         if (pqueue_size(queue->q) >= 100)
 215                 return 0;
 216
 217         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 218         item = pitem_new(priority, rdata);
 219         if (rdata == NULL || item == NULL)
 220                 {
 221                 if (rdata != NULL) OPENSSL_free(rdata);
 222                 if (item != NULL) pitem_free(item);
 223
 224                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 225                 return(0);
 226                 }
 227
 228         rdata->packet = s->packet;
 229         rdata->packet_length = s->packet_length;
 230         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 231         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 232
 233         item->data = rdata;
 234
 235         /* insert should not fail, since duplicates are dropped */
 236         if (pqueue_insert(queue->q, item) == NULL)
 237                 {
 238                 OPENSSL_free(rdata);
 239                 pitem_free(item);
 240                 return(0);
 241                 }
 242
 243         s->packet = NULL;
 244         s->packet_length = 0;
 245         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 246         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 247
 248         if (!ssl3_setup_buffers(s))
 249                 {
 250                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 251                 OPENSSL_free(rdata);
 252                 pitem_free(item);
 253                 return(0);
 254                 }
 255
 256         return(1);
 257         }
 258
 259
 260 static int
 261 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 262     {
 263     pitem *item;
 264
 265     item = pqueue_pop(queue->q);
 266     if (item)
 267         {
 268         dtls1_copy_record(s, item);
 269
 270         OPENSSL_free(item->data);
 271                 pitem_free(item);
 272
 273         return(1);
 274         }
 275
 276     return(0);
 277     }
 278
 279
 280 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 281  * yet */
 282 #define dtls1_get_unprocessed_record(s) \
 283                    dtls1_retrieve_buffered_record((s), \
 284                    &((s)->d1->unprocessed_rcds))
 285
 286 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 287 #define dtls1_get_processed_record(s) \
 288                    dtls1_retrieve_buffered_record((s), \
 289                    &((s)->d1->processed_rcds))
 290
 291 static int
 292 dtls1_process_buffered_records(SSL *s)
 293     {
 294     pitem *item;
 295
 296     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 297     if (item)
 298         {
 299         DTLS1_RECORD_DATA *rdata;
 300         rdata = (DTLS1_RECORD_DATA *)item->data;
 301
 302         /* Check if epoch is current. */
 303         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 304             return(1);  /* Nothing to do. */
 305
 306         /* Process all the records. */
 307         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 308             {
 309             dtls1_get_unprocessed_record(s);
 310             if ( ! dtls1_process_record(s))
 311                 return(0);
 312             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 313                 s->s3->rrec.seq_num);
 314             }
 315         }
 316
 317     /* sync epoch numbers once all the unprocessed records
 318      * have been processed */
 319     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 320     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 321
 322     return(1);
 323     }
 324
 325
 326 #if 0
 327
 328 static int
 329 dtls1_get_buffered_record(SSL *s)
 330         {
 331         pitem *item;
 332         PQ_64BIT priority =
 333                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 334                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 335
 336         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 337                                                            nothing buffered */
 338                 return 0;
 339
 340
 341         item = pqueue_peek(s->d1->rcvd_records);
 342         if (item && item->priority == priority)
 343                 {
 344                 /* Check if we've received the record of interest.  It must be
 345                  * a handshake record, since data records as passed up without
 346                  * buffering */
 347                 DTLS1_RECORD_DATA *rdata;
 348                 item = pqueue_pop(s->d1->rcvd_records);
 349                 rdata = (DTLS1_RECORD_DATA *)item->data;
 350
 351                 if (s->s3->rbuf.buf != NULL)
 352                         OPENSSL_free(s->s3->rbuf.buf);
 353
 354                 s->packet = rdata->packet;
 355                 s->packet_length = rdata->packet_length;
 356                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 357                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 358
 359                 OPENSSL_free(item->data);
 360                 pitem_free(item);
 361
 362                 /* s->d1->next_expected_seq_num++; */
 363                 return(1);
 364                 }
 365
 366         return 0;
 367         }
 368
 369 #endif
 370
 371 static int
 372 dtls1_process_record(SSL *s)
 373 {
 374         int i,al;
 375         int clear=0;
 376         int enc_err;
 377         SSL_SESSION *sess;
 378         SSL3_RECORD *rr;
 379         unsigned int mac_size;
 380         unsigned char md[EVP_MAX_MD_SIZE];
 381
 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         if (enc_err <= 0)
 414                 {
 415                 if (enc_err == 0)
 416                         /* SSLerr() and ssl3_send_alert() have been called */
 417                         goto err;
 418
 419                 /* otherwise enc_err == -1 */
 420                 goto decryption_failed_or_bad_record_mac;
 421                 }
 422
 423 #ifdef TLS_DEBUG
 424 printf("dec %d\n",rr->length);
 425 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 426 printf("\n");
 427 #endif
 428
 429         /* r->length is now the compressed data plus mac */
 430         if (    (sess == NULL) ||
 431                 (s->enc_read_ctx == NULL) ||
 432                 (s->read_hash == NULL))
 433                 clear=1;
 434
 435         if (!clear)
 436                 {
 437                 /* !clear => s->read_hash != NULL => mac_size != -1 */
 438                 int t;
 439                 t=EVP_MD_CTX_size(s->read_hash);
 440                 OPENSSL_assert(t >= 0);
 441                 mac_size=t;
 442
 443                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 444                         {
 445 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 446                         al=SSL_AD_RECORD_OVERFLOW;
 447                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 448                         goto f_err;
 449 #else
 450                         goto decryption_failed_or_bad_record_mac;
 451 #endif
 452                         }
 453                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 454                 if (rr->length < mac_size)
 455                         {
 456 #if 0 /* OK only for stream ciphers */
 457                         al=SSL_AD_DECODE_ERROR;
 458                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 459                         goto f_err;
 460 #else
 461                         goto decryption_failed_or_bad_record_mac;
 462 #endif
 463                         }
 464                 rr->length-=mac_size;
 465                 i=s->method->ssl3_enc->mac(s,md,0);
 466                 if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 467                         {
 468                         goto decryption_failed_or_bad_record_mac;
 469                         }
 470                 }
 471
 472         /* r->length is now just compressed */
 473         if (s->expand != NULL)
 474                 {
 475                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 476                         {
 477                         al=SSL_AD_RECORD_OVERFLOW;
 478                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 479                         goto f_err;
 480                         }
 481                 if (!ssl3_do_uncompress(s))
 482                         {
 483                         al=SSL_AD_DECOMPRESSION_FAILURE;
 484                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 485                         goto f_err;
 486                         }
 487                 }
 488
 489         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 490                 {
 491                 al=SSL_AD_RECORD_OVERFLOW;
 492                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 493                 goto f_err;
 494                 }
 495
 496         rr->off=0;
 497         /* So at this point the following is true
 498          * ssl->s3->rrec.type   is the type of record
 499          * ssl->s3->rrec.length == number of bytes in record
 500          * ssl->s3->rrec.off    == offset to first valid byte
 501          * ssl->s3->rrec.data   == where to take bytes from, increment
 502          *                         after use :-).
 503          */
 504
 505         /* we have pulled in a full packet so zero things */
 506         s->packet_length=0;
 507         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 508         return(1);
 509
 510 decryption_failed_or_bad_record_mac:
 511         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
 512          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 513          * failure is directly visible from the ciphertext anyway,
 514          * we should not reveal which kind of error occured -- this
 515          * might become visible to an attacker (e.g. via logfile) */
 516         al=SSL_AD_BAD_RECORD_MAC;
 517         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 518 f_err:
 519         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 520 err:
 521         return(0);
 522 }
 523
 524
 525 /* Call this to get a new input record.
 526  * It will return <= 0 if more data is needed, normally due to an error
 527  * or non-blocking IO.
 528  * When it finishes, one packet has been decoded and can be found in
 529  * ssl->s3->rrec.type    - is the type of record
 530  * ssl->s3->rrec.data,   - data
 531  * ssl->s3->rrec.length, - number of bytes
 532  */
 533 /* used only by dtls1_read_bytes */
 534 int dtls1_get_record(SSL *s)
 535         {
 536         int ssl_major,ssl_minor;
 537         int i,n;
 538         SSL3_RECORD *rr;
 539         SSL_SESSION *sess;
 540         unsigned char *p = NULL;
 541         unsigned short version;
 542         DTLS1_BITMAP *bitmap;
 543         unsigned int is_next_epoch;
 544
 545         rr= &(s->s3->rrec);
 546         sess=s->session;
 547
 548         /* The epoch may have changed.  If so, process all the
 549          * pending records.  This is a non-blocking operation. */
 550         if ( ! dtls1_process_buffered_records(s))
 551             return 0;
 552
 553         /* if we're renegotiating, then there may be buffered records */
 554         if (dtls1_get_processed_record(s))
 555                 return 1;
 556
 557         /* get something from the wire */
 558 again:
 559         /* check if we have the header */
 560         if (    (s->rstate != SSL_ST_READ_BODY) ||
 561                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 562                 {
 563                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 564                 /* read timeout is handled by dtls1_read_bytes */
 565                 if (n <= 0) return(n); /* error or non-blocking */
 566
 567                 /* this packet contained a partial record, dump it */
 568                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
 569                         {
 570                         s->packet_length = 0;
 571                         goto again;
 572                         }
 573
 574                 s->rstate=SSL_ST_READ_BODY;
 575
 576                 p=s->packet;
 577
 578                 /* Pull apart the header into the DTLS1_RECORD */
 579                 rr->type= *(p++);
 580                 ssl_major= *(p++);
 581                 ssl_minor= *(p++);
 582                 version=(ssl_major<<8)|ssl_minor;
 583
 584                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 585                 n2s(p,rr->epoch);
 586
 587                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 588                 p+=6;
 589
 590                 n2s(p,rr->length);
 591
 592                 /* Lets check version */
 593                 if (!s->first_packet)
 594                         {
 595                         if (version != s->version)
 596                                 {
 597                                 /* unexpected version, silently discard */
 598                                 rr->length = 0;
 599                                 s->packet_length = 0;
 600                                 goto again;
 601                                 }
 602                         }
 603
 604                 if ((version & 0xff00) != (s->version & 0xff00))
 605                         {
 606                         /* wrong version, silently discard record */
 607                         rr->length = 0;
 608                         s->packet_length = 0;
 609                         goto again;
 610                         }
 611
 612                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 613                         {
 614                         /* record too long, silently discard it */
 615                         rr->length = 0;
 616                         s->packet_length = 0;
 617                         goto again;
 618                         }
 619
 620                 /* now s->rstate == SSL_ST_READ_BODY */
 621                 }
 622
 623         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 624
 625         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 626                 {
 627                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 628                 i=rr->length;
 629                 n=ssl3_read_n(s,i,i,1);
 630                 if (n <= 0) return(n); /* error or non-blocking io */
 631
 632                 /* this packet contained a partial record, dump it */
 633                 if ( n != i)
 634                         {
 635                         rr->length = 0;
 636                         s->packet_length = 0;
 637                         goto again;
 638                         }
 639
 640                 /* now n == rr->length,
 641                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 642                 }
 643         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 644
 645         /* match epochs.  NULL means the packet is dropped on the floor */
 646         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 647         if ( bitmap == NULL)
 648                 {
 649                 rr->length = 0;
 650                 s->packet_length = 0;  /* dump this record */
 651                 goto again;   /* get another record */
 652                 }
 653
 654         /* Check whether this is a repeat, or aged record.
 655          * Don't check if we're listening and this message is
 656          * a ClientHello. They can look as if they're replayed,
 657          * since they arrive from different connections and
 658          * would be dropped unnecessarily.
 659          */
 660         if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
 661                 *p == SSL3_MT_CLIENT_HELLO) &&
 662                 !dtls1_record_replay_check(s, bitmap))
 663                 {
 664                 rr->length = 0;
 665                 s->packet_length=0; /* dump this record */
 666                 goto again;     /* get another record */
 667                 }
 668
 669         /* just read a 0 length packet */
 670         if (rr->length == 0) goto again;
 671
 672         /* If this record is from the next epoch (either HM or ALERT),
 673          * and a handshake is currently in progress, buffer it since it
 674          * cannot be processed at this time. */
 675         if (is_next_epoch)
 676                 {
 677                 if (SSL_in_init(s) || s->in_handshake)
 678                         {
 679                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 680                         }
 681                 rr->length = 0;
 682                 s->packet_length = 0;
 683                 goto again;
 684                 }
 685
 686         if ( ! dtls1_process_record(s))
 687                 return(0);
 688
 689         dtls1_clear_timeouts(s);  /* done waiting */
 690         return(1);
 691
 692         }
 693
 694 /* Return up to 'len' payload bytes received in 'type' records.
 695  * 'type' is one of the following:
 696  *
 697  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 698  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 699  *   -  0 (during a shutdown, no data has to be returned)
 700  *
 701  * If we don't have stored data to work from, read a SSL/TLS record first
 702  * (possibly multiple records if we still don't have anything to return).
 703  *
 704  * This function must handle any surprises the peer may have for us, such as
 705  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 706  * a surprise, but handled as if it were), or renegotiation requests.
 707  * Also if record payloads contain fragments too small to process, we store
 708  * them until there is enough for the respective protocol (the record protocol
 709  * may use arbitrary fragmentation and even interleaving):
 710  *     Change cipher spec protocol
 711  *             just 1 byte needed, no need for keeping anything stored
 712  *     Alert protocol
 713  *             2 bytes needed (AlertLevel, AlertDescription)
 714  *     Handshake protocol
 715  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 716  *             to detect unexpected Client Hello and Hello Request messages
 717  *             here, anything else is handled by higher layers
 718  *     Application data protocol
 719  *             none of our business
 720  */
 721 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 722         {
 723         int al,i,j,ret;
 724         unsigned int n;
 725         SSL3_RECORD *rr;
 726         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 727
 728         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 729                 if (!ssl3_setup_buffers(s))
 730                         return(-1);
 731
 732     /* XXX: check what the second '&& type' is about */
 733         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 734                 (type != SSL3_RT_HANDSHAKE) && type) ||
 735             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 736                 {
 737                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 738                 return -1;
 739                 }
 740
 741         /* check whether there's a handshake message (client hello?) waiting */
 742         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 743                 return ret;
 744
 745         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 746
 747         if (!s->in_handshake && SSL_in_init(s))
 748                 {
 749                 /* type == SSL3_RT_APPLICATION_DATA */
 750                 i=s->handshake_func(s);
 751                 if (i < 0) return(i);
 752                 if (i == 0)
 753                         {
 754                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 755                         return(-1);
 756                         }
 757                 }
 758
 759 start:
 760         s->rwstate=SSL_NOTHING;
 761
 762         /* s->s3->rrec.type         - is the type of record
 763          * s->s3->rrec.data,    - data
 764          * s->s3->rrec.off,     - offset into 'data' for next read
 765          * s->s3->rrec.length,  - number of bytes. */
 766         rr = &(s->s3->rrec);
 767
 768         /* We are not handshaking and have no data yet,
 769          * so process data buffered during the last handshake
 770          * in advance, if any.
 771          */
 772         if (s->state == SSL_ST_OK && rr->length == 0)
 773                 {
 774                 pitem *item;
 775                 item = pqueue_pop(s->d1->buffered_app_data.q);
 776                 if (item)
 777                         {
 778                         dtls1_copy_record(s, item);
 779
 780                         OPENSSL_free(item->data);
 781                         pitem_free(item);
 782                         }
 783                 }
 784
 785         /* Check for timeout */
 786         if (dtls1_handle_timeout(s) > 0)
 787                 goto start;
 788
 789         /* get new packet if necessary */
 790         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 791                 {
 792                 ret=dtls1_get_record(s);
 793                 if (ret <= 0)
 794                         {
 795                         ret = dtls1_read_failed(s, ret);
 796                         /* anything other than a timeout is an error */
 797                         if (ret <= 0)
 798                                 return(ret);
 799                         else
 800                                 goto start;
 801                         }
 802                 }
 803
 804         /* we now have a packet which can be read and processed */
 805
 806         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 807                                        * reset by ssl3_get_finished */
 808                 && (rr->type != SSL3_RT_HANDSHAKE))
 809                 {
 810                 /* We now have application data between CCS and Finished.
 811                  * Most likely the packets were reordered on their way, so
 812                  * buffer the application data for later processing rather
 813                  * than dropping the connection.
 814                  */
 815                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
 816                 rr->length = 0;
 817                 goto start;
 818                 }
 819
 820         /* If the other end has shut down, throw anything we read away
 821          * (even in 'peek' mode) */
 822         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 823                 {
 824                 rr->length=0;
 825                 s->rwstate=SSL_NOTHING;
 826                 return(0);
 827                 }
 828
 829
 830         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 831                 {
 832                 /* make sure that we are not getting application data when we
 833                  * are doing a handshake for the first time */
 834                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 835                         (s->enc_read_ctx == NULL))
 836                         {
 837                         al=SSL_AD_UNEXPECTED_MESSAGE;
 838                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 839                         goto f_err;
 840                         }
 841
 842                 if (len <= 0) return(len);
 843
 844                 if ((unsigned int)len > rr->length)
 845                         n = rr->length;
 846                 else
 847                         n = (unsigned int)len;
 848
 849                 memcpy(buf,&(rr->data[rr->off]),n);
 850                 if (!peek)
 851                         {
 852                         rr->length-=n;
 853                         rr->off+=n;
 854                         if (rr->length == 0)
 855                                 {
 856                                 s->rstate=SSL_ST_READ_HEADER;
 857                                 rr->off=0;
 858                                 }
 859                         }
 860                 return(n);
 861                 }
 862
 863
 864         /* If we get here, then type != rr->type; if we have a handshake
 865          * message, then it was unexpected (Hello Request or Client Hello). */
 866
 867         /* In case of record types for which we have 'fragment' storage,
 868          * fill that so that we can process the data at a fixed place.
 869          */
 870                 {
 871                 unsigned int k, dest_maxlen = 0;
 872                 unsigned char *dest = NULL;
 873                 unsigned int *dest_len = NULL;
 874
 875                 if (rr->type == SSL3_RT_HANDSHAKE)
 876                         {
 877                         dest_maxlen = sizeof s->d1->handshake_fragment;
 878                         dest = s->d1->handshake_fragment;
 879                         dest_len = &s->d1->handshake_fragment_len;
 880                         }
 881                 else if (rr->type == SSL3_RT_ALERT)
 882                         {
 883                         dest_maxlen = sizeof(s->d1->alert_fragment);
 884                         dest = s->d1->alert_fragment;
 885                         dest_len = &s->d1->alert_fragment_len;
 886                         }
 887                 /* else it's a CCS message, or application data or wrong */
 888                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 889                         {
 890                         /* Application data while renegotiating
 891                          * is allowed. Try again reading.
 892                          */
 893                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 894                                 {
 895                                 BIO *bio;
 896                                 s->s3->in_read_app_data=2;
 897                                 bio=SSL_get_rbio(s);
 898                                 s->rwstate=SSL_READING;
 899                                 BIO_clear_retry_flags(bio);
 900                                 BIO_set_retry_read(bio);
 901                                 return(-1);
 902                                 }
 903
 904                         /* Not certain if this is the right error handling */
 905                         al=SSL_AD_UNEXPECTED_MESSAGE;
 906                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 907                         goto f_err;
 908                         }
 909
 910                 if (dest_maxlen > 0)
 911                         {
 912             /* XDTLS:  In a pathalogical case, the Client Hello
 913              *  may be fragmented--don't always expect dest_maxlen bytes */
 914                         if ( rr->length < dest_maxlen)
 915                                 {
 916 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
 917                                 /*
 918                                  * for normal alerts rr->length is 2, while
 919                                  * dest_maxlen is 7 if we were to handle this
 920                                  * non-existing alert...
 921                                  */
 922                                 FIX ME
 923 #endif
 924                                 s->rstate=SSL_ST_READ_HEADER;
 925                                 rr->length = 0;
 926                                 goto start;
 927                                 }
 928
 929                         /* now move 'n' bytes: */
 930                         for ( k = 0; k < dest_maxlen; k++)
 931                                 {
 932                                 dest[k] = rr->data[rr->off++];
 933                                 rr->length--;
 934                                 }
 935                         *dest_len = dest_maxlen;
 936                         }
 937                 }
 938
 939         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 940          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 941          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 942
 943         /* If we are a client, check for an incoming 'Hello Request': */
 944         if ((!s->server) &&
 945                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 946                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 947                 (s->session != NULL) && (s->session->cipher != NULL))
 948                 {
 949                 s->d1->handshake_fragment_len = 0;
 950
 951                 if ((s->d1->handshake_fragment[1] != 0) ||
 952                         (s->d1->handshake_fragment[2] != 0) ||
 953                         (s->d1->handshake_fragment[3] != 0))
 954                         {
 955                         al=SSL_AD_DECODE_ERROR;
 956                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 957                         goto err;
 958                         }
 959
 960                 /* no need to check sequence number on HELLO REQUEST messages */
 961
 962                 if (s->msg_callback)
 963                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 964                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 965
 966                 if (SSL_is_init_finished(s) &&
 967                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 968                         !s->s3->renegotiate)
 969                         {
 970                         ssl3_renegotiate(s);
 971                         if (ssl3_renegotiate_check(s))
 972                                 {
 973                                 i=s->handshake_func(s);
 974                                 if (i < 0) return(i);
 975                                 if (i == 0)
 976                                         {
 977                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 978                                         return(-1);
 979                                         }
 980
 981                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 982                                         {
 983                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 984                                                 {
 985                                                 BIO *bio;
 986                                                 /* In the case where we try to read application data,
 987                                                  * but we trigger an SSL handshake, we return -1 with
 988                                                  * the retry option set.  Otherwise renegotiation may
 989                                                  * cause nasty problems in the blocking world */
 990                                                 s->rwstate=SSL_READING;
 991                                                 bio=SSL_get_rbio(s);
 992                                                 BIO_clear_retry_flags(bio);
 993                                                 BIO_set_retry_read(bio);
 994                                                 return(-1);
 995                                                 }
 996                                         }
 997                                 }
 998                         }
 999                 /* we either finished a handshake or ignored the request,
1000                  * now try again to obtain the (application) data we were asked for */
1001                 goto start;
1002                 }
1003
1004         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1005                 {
1006                 int alert_level = s->d1->alert_fragment[0];
1007                 int alert_descr = s->d1->alert_fragment[1];
1008
1009                 s->d1->alert_fragment_len = 0;
1010
1011                 if (s->msg_callback)
1012                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1013                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1014
1015                 if (s->info_callback != NULL)
1016                         cb=s->info_callback;
1017                 else if (s->ctx->info_callback != NULL)
1018                         cb=s->ctx->info_callback;
1019
1020                 if (cb != NULL)
1021                         {
1022                         j = (alert_level << 8) | alert_descr;
1023                         cb(s, SSL_CB_READ_ALERT, j);
1024                         }
1025
1026                 if (alert_level == 1) /* warning */
1027                         {
1028                         s->s3->warn_alert = alert_descr;
1029                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1030                                 {
1031                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1032                                 return(0);
1033                                 }
1034 #if 0
1035             /* XXX: this is a possible improvement in the future */
1036                         /* now check if it's a missing record */
1037                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1038                                 {
1039                                 unsigned short seq;
1040                                 unsigned int frag_off;
1041                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1042
1043                                 n2s(p, seq);
1044                                 n2l3(p, frag_off);
1045
1046                                 dtls1_retransmit_message(s,
1047                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1048                                                                                  frag_off, &found);
1049                                 if ( ! found  && SSL_in_init(s))
1050                                         {
1051                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1052                                         /* requested a message not yet sent,
1053                                            send an alert ourselves */
1054                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1055                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1056                                         }
1057                                 }
1058 #endif
1059                         }
1060                 else if (alert_level == 2) /* fatal */
1061                         {
1062                         char tmp[16];
1063
1064                         s->rwstate=SSL_NOTHING;
1065                         s->s3->fatal_alert = alert_descr;
1066                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1067                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1068                         ERR_add_error_data(2,"SSL alert number ",tmp);
1069                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1070                         SSL_CTX_remove_session(s->ctx,s->session);
1071                         return(0);
1072                         }
1073                 else
1074                         {
1075                         al=SSL_AD_ILLEGAL_PARAMETER;
1076                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1077                         goto f_err;
1078                         }
1079
1080                 goto start;
1081                 }
1082
1083         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1084                 {
1085                 s->rwstate=SSL_NOTHING;
1086                 rr->length=0;
1087                 return(0);
1088                 }
1089
1090         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1091                 {
1092                 struct ccs_header_st ccs_hdr;
1093                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1094
1095                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1096
1097                 if (s->version == DTLS1_BAD_VER)
1098                         ccs_hdr_len = 3;
1099
1100                 /* 'Change Cipher Spec' is just a single byte, so we know
1101                  * exactly what the record payload has to look like */
1102                 /* XDTLS: check that epoch is consistent */
1103                 if (    (rr->length != ccs_hdr_len) ||
1104                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1105                         {
1106                         i=SSL_AD_ILLEGAL_PARAMETER;
1107                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1108                         goto err;
1109                         }
1110
1111                 rr->length=0;
1112
1113                 if (s->msg_callback)
1114                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1115                                 rr->data, 1, s, s->msg_callback_arg);
1116
1117                 /* We can't process a CCS now, because previous handshake
1118                  * messages are still missing, so just drop it.
1119                  */
1120                 if (!s->d1->change_cipher_spec_ok)
1121                         {
1122                         goto start;
1123                         }
1124
1125                 s->d1->change_cipher_spec_ok = 0;
1126
1127                 s->s3->change_cipher_spec=1;
1128                 if (!ssl3_do_change_cipher_spec(s))
1129                         goto err;
1130
1131                 /* do this whenever CCS is processed */
1132                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1133
1134                 if (s->version == DTLS1_BAD_VER)
1135                         s->d1->handshake_read_seq++;
1136
1137                 goto start;
1138                 }
1139
1140         /* Unexpected handshake message (Client Hello, or protocol violation) */
1141         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1142                 !s->in_handshake)
1143                 {
1144                 struct hm_header_st msg_hdr;
1145
1146                 /* this may just be a stale retransmit */
1147                 dtls1_get_message_header(rr->data, &msg_hdr);
1148                 if( rr->epoch != s->d1->r_epoch)
1149                         {
1150                         rr->length = 0;
1151                         goto start;
1152                         }
1153
1154                 /* If we are server, we may have a repeated FINISHED of the
1155                  * client here, then retransmit our CCS and FINISHED.
1156                  */
1157                 if (msg_hdr.type == SSL3_MT_FINISHED)
1158                         {
1159                         dtls1_retransmit_buffered_messages(s);
1160                         rr->length = 0;
1161                         goto start;
1162                         }
1163
1164                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1165                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1166                         {
1167 #if 0 /* worked only because C operator preferences are not as expected (and
1168        * because this is not really needed for clients except for detecting
1169        * protocol violations): */
1170                         s->state=SSL_ST_BEFORE|(s->server)
1171                                 ?SSL_ST_ACCEPT
1172                                 :SSL_ST_CONNECT;
1173 #else
1174                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1175 #endif
1176                         s->new_session=1;
1177                         }
1178                 i=s->handshake_func(s);
1179                 if (i < 0) return(i);
1180                 if (i == 0)
1181                         {
1182                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1183                         return(-1);
1184                         }
1185
1186                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1187                         {
1188                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1189                                 {
1190                                 BIO *bio;
1191                                 /* In the case where we try to read application data,
1192                                  * but we trigger an SSL handshake, we return -1 with
1193                                  * the retry option set.  Otherwise renegotiation may
1194                                  * cause nasty problems in the blocking world */
1195                                 s->rwstate=SSL_READING;
1196                                 bio=SSL_get_rbio(s);
1197                                 BIO_clear_retry_flags(bio);
1198                                 BIO_set_retry_read(bio);
1199                                 return(-1);
1200                                 }
1201                         }
1202                 goto start;
1203                 }
1204
1205         switch (rr->type)
1206                 {
1207         default:
1208 #ifndef OPENSSL_NO_TLS
1209                 /* TLS just ignores unknown message types */
1210                 if (s->version == TLS1_VERSION)
1211                         {
1212                         rr->length = 0;
1213                         goto start;
1214                         }
1215 #endif
1216                 al=SSL_AD_UNEXPECTED_MESSAGE;
1217                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1218                 goto f_err;
1219         case SSL3_RT_CHANGE_CIPHER_SPEC:
1220         case SSL3_RT_ALERT:
1221         case SSL3_RT_HANDSHAKE:
1222                 /* we already handled all of these, with the possible exception
1223                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1224                  * should not happen when type != rr->type */
1225                 al=SSL_AD_UNEXPECTED_MESSAGE;
1226                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1227                 goto f_err;
1228         case SSL3_RT_APPLICATION_DATA:
1229                 /* At this point, we were expecting handshake data,
1230                  * but have application data.  If the library was
1231                  * running inside ssl3_read() (i.e. in_read_app_data
1232                  * is set) and it makes sense to read application data
1233                  * at this point (session renegotiation not yet started),
1234                  * we will indulge it.
1235                  */
1236                 if (s->s3->in_read_app_data &&
1237                         (s->s3->total_renegotiations != 0) &&
1238                         ((
1239                                 (s->state & SSL_ST_CONNECT) &&
1240                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1241                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1242                                 ) || (
1243                                         (s->state & SSL_ST_ACCEPT) &&
1244                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1245                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1246                                         )
1247                                 ))
1248                         {
1249                         s->s3->in_read_app_data=2;
1250                         return(-1);
1251                         }
1252                 else
1253                         {
1254                         al=SSL_AD_UNEXPECTED_MESSAGE;
1255                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1256                         goto f_err;
1257                         }
1258                 }
1259         /* not reached */
1260
1261 f_err:
1262         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1263 err:
1264         return(-1);
1265         }
1266
1267 int
1268 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1269         {
1270         int i;
1271
1272         if (SSL_in_init(s) && !s->in_handshake)
1273                 {
1274                 i=s->handshake_func(s);
1275                 if (i < 0) return(i);
1276                 if (i == 0)
1277                         {
1278                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1279                         return -1;
1280                         }
1281                 }
1282
1283         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1284                 {
1285                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1286                         return -1;
1287                 }
1288
1289         i = dtls1_write_bytes(s, type, buf_, len);
1290         return i;
1291         }
1292
1293
1294         /* this only happens when a client hello is received and a handshake
1295          * is started. */
1296 static int
1297 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1298         int len, int peek)
1299         {
1300
1301         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1302                 /* (partially) satisfy request from storage */
1303                 {
1304                 unsigned char *src = s->d1->handshake_fragment;
1305                 unsigned char *dst = buf;
1306                 unsigned int k,n;
1307
1308                 /* peek == 0 */
1309                 n = 0;
1310                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1311                         {
1312                         *dst++ = *src++;
1313                         len--; s->d1->handshake_fragment_len--;
1314                         n++;
1315                         }
1316                 /* move any remaining fragment bytes: */
1317                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1318                         s->d1->handshake_fragment[k] = *src++;
1319                 return n;
1320                 }
1321
1322         return 0;
1323         }
1324
1325
1326
1327
1328 /* Call this to write data in records of type 'type'
1329  * It will return <= 0 if not all data has been sent or non-blocking IO.
1330  */
1331 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1332         {
1333         int i;
1334
1335         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1336         s->rwstate=SSL_NOTHING;
1337         i=do_dtls1_write(s, type, buf, len, 0);
1338         return i;
1339         }
1340
1341 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1342         {
1343         unsigned char *p,*pseq;
1344         int i,mac_size,clear=0;
1345         int prefix_len = 0;
1346         SSL3_RECORD *wr;
1347         SSL3_BUFFER *wb;
1348         SSL_SESSION *sess;
1349         int bs;
1350
1351         /* first check if there is a SSL3_BUFFER still being written
1352          * out.  This will happen with non blocking IO */
1353         if (s->s3->wbuf.left != 0)
1354                 {
1355                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1356                 return(ssl3_write_pending(s,type,buf,len));
1357                 }
1358
1359         /* If we have an alert to send, lets send it */
1360         if (s->s3->alert_dispatch)
1361                 {
1362                 i=s->method->ssl_dispatch_alert(s);
1363                 if (i <= 0)
1364                         return(i);
1365                 /* if it went, fall through and send more stuff */
1366                 }
1367
1368         if (len == 0 && !create_empty_fragment)
1369                 return 0;
1370
1371         wr= &(s->s3->wrec);
1372         wb= &(s->s3->wbuf);
1373         sess=s->session;
1374
1375         if (    (sess == NULL) ||
1376                 (s->enc_write_ctx == NULL) ||
1377                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1378                 clear=1;
1379
1380         if (clear)
1381                 mac_size=0;
1382         else
1383                 {
1384                 mac_size=EVP_MD_CTX_size(s->write_hash);
1385                 if (mac_size < 0)
1386                         goto err;
1387                 }
1388
1389         /* DTLS implements explicit IV, so no need for empty fragments */
1390 #if 0
1391         /* 'create_empty_fragment' is true only when this function calls itself */
1392         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1393             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1394                 {
1395                 /* countermeasure against known-IV weakness in CBC ciphersuites
1396                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1397                  */
1398
1399                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1400                         {
1401                         /* recursive function call with 'create_empty_fragment' set;
1402                          * this prepares and buffers the data for an empty fragment
1403                          * (these 'prefix_len' bytes are sent out later
1404                          * together with the actual payload) */
1405                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1406                         if (prefix_len <= 0)
1407                                 goto err;
1408
1409                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1410                                 {
1411                                 /* insufficient space */
1412                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1413                                 goto err;
1414                                 }
1415                         }
1416
1417                 s->s3->empty_fragment_done = 1;
1418                 }
1419 #endif
1420         p = wb->buf + prefix_len;
1421
1422         /* write the header */
1423
1424         *(p++)=type&0xff;
1425         wr->type=type;
1426
1427         *(p++)=(s->version>>8);
1428         *(p++)=s->version&0xff;
1429
1430         /* field where we are to write out packet epoch, seq num and len */
1431         pseq=p;
1432         p+=10;
1433
1434         /* lets setup the record stuff. */
1435
1436         /* Make space for the explicit IV in case of CBC.
1437          * (this is a bit of a boundary violation, but what the heck).
1438          */
1439         if ( s->enc_write_ctx &&
1440                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1441                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1442         else
1443                 bs = 0;
1444
1445         wr->data=p + bs;  /* make room for IV in case of CBC */
1446         wr->length=(int)len;
1447         wr->input=(unsigned char *)buf;
1448
1449         /* we now 'read' from wr->input, wr->length bytes into
1450          * wr->data */
1451
1452         /* first we compress */
1453         if (s->compress != NULL)
1454                 {
1455                 if (!ssl3_do_compress(s))
1456                         {
1457                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1458                         goto err;
1459                         }
1460                 }
1461         else
1462                 {
1463                 memcpy(wr->data,wr->input,wr->length);
1464                 wr->input=wr->data;
1465                 }
1466
1467         /* we should still have the output to wr->data and the input
1468          * from wr->input.  Length should be wr->length.
1469          * wr->data still points in the wb->buf */
1470
1471         if (mac_size != 0)
1472                 {
1473                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1474                         goto err;
1475                 wr->length+=mac_size;
1476                 }
1477
1478         /* this is true regardless of mac size */
1479         wr->input=p;
1480         wr->data=p;
1481
1482
1483         /* ssl3_enc can only have an error on read */
1484         if (bs) /* bs != 0 in case of CBC */
1485                 {
1486                 RAND_pseudo_bytes(p,bs);
1487                 /* master IV and last CBC residue stand for
1488                  * the rest of randomness */
1489                 wr->length += bs;
1490                 }
1491
1492         s->method->ssl3_enc->enc(s,1);
1493
1494         /* record length after mac and block padding */
1495 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1496         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1497
1498         /* there's only one epoch between handshake and app data */
1499
1500         s2n(s->d1->w_epoch, pseq);
1501
1502         /* XDTLS: ?? */
1503 /*      else
1504         s2n(s->d1->handshake_epoch, pseq); */
1505
1506         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1507         pseq+=6;
1508         s2n(wr->length,pseq);
1509
1510         /* we should now have
1511          * wr->data pointing to the encrypted data, which is
1512          * wr->length long */
1513         wr->type=type; /* not needed but helps for debugging */
1514         wr->length+=DTLS1_RT_HEADER_LENGTH;
1515
1516 #if 0  /* this is now done at the message layer */
1517         /* buffer the record, making it easy to handle retransmits */
1518         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1519                 dtls1_buffer_record(s, wr->data, wr->length,
1520                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1521 #endif
1522
1523         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1524
1525         if (create_empty_fragment)
1526                 {
1527                 /* we are in a recursive call;
1528                  * just return the length, don't write out anything here
1529                  */
1530                 return wr->length;
1531                 }
1532
1533         /* now let's set up wb */
1534         wb->left = prefix_len + wr->length;
1535         wb->offset = 0;
1536
1537         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1538         s->s3->wpend_tot=len;
1539         s->s3->wpend_buf=buf;
1540         s->s3->wpend_type=type;
1541         s->s3->wpend_ret=len;
1542
1543         /* we now just need to write the buffer */
1544         return ssl3_write_pending(s,type,buf,len);
1545 err:
1546         return -1;
1547         }
1548
1549
1550
1551 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1552         {
1553         int cmp;
1554         unsigned int shift;
1555         const unsigned char *seq = s->s3->read_sequence;
1556
1557         cmp = satsub64be(seq,bitmap->max_seq_num);
1558         if (cmp > 0)
1559                 {
1560                 memcpy (s->s3->rrec.seq_num,seq,8);
1561                 return 1; /* this record in new */
1562                 }
1563         shift = -cmp;
1564         if (shift >= sizeof(bitmap->map)*8)
1565                 return 0; /* stale, outside the window */
1566         else if (bitmap->map & (1UL<<shift))
1567                 return 0; /* record previously received */
1568
1569         memcpy (s->s3->rrec.seq_num,seq,8);
1570         return 1;
1571         }
1572
1573
1574 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1575         {
1576         int cmp;
1577         unsigned int shift;
1578         const unsigned char *seq = s->s3->read_sequence;
1579
1580         cmp = satsub64be(seq,bitmap->max_seq_num);
1581         if (cmp > 0)
1582                 {
1583                 shift = cmp;
1584                 if (shift < sizeof(bitmap->map)*8)
1585                         bitmap->map <<= shift, bitmap->map |= 1UL;
1586                 else
1587                         bitmap->map = 1UL;
1588                 memcpy(bitmap->max_seq_num,seq,8);
1589                 }
1590         else    {
1591                 shift = -cmp;
1592                 if (shift < sizeof(bitmap->map)*8)
1593                         bitmap->map |= 1UL<<shift;
1594                 }
1595         }
1596
1597
1598 int dtls1_dispatch_alert(SSL *s)
1599         {
1600         int i,j;
1601         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1602         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1603         unsigned char *ptr = &buf[0];
1604
1605         s->s3->alert_dispatch=0;
1606
1607         memset(buf, 0x00, sizeof(buf));
1608         *ptr++ = s->s3->send_alert[0];
1609         *ptr++ = s->s3->send_alert[1];
1610
1611 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1612         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1613                 {
1614                 s2n(s->d1->handshake_read_seq, ptr);
1615 #if 0
1616                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1617
1618                 else
1619                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1620 #endif
1621
1622 #if 0
1623                 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);
1624 #endif
1625                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1626                 }
1627 #endif
1628
1629         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1630         if (i <= 0)
1631                 {
1632                 s->s3->alert_dispatch=1;
1633                 /* fprintf( stderr, "not done with alert\n" ); */
1634                 }
1635         else
1636                 {
1637                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1638 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1639                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1640 #endif
1641                     )
1642                         (void)BIO_flush(s->wbio);
1643
1644                 if (s->msg_callback)
1645                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1646                                 2, s, s->msg_callback_arg);
1647
1648                 if (s->info_callback != NULL)
1649                         cb=s->info_callback;
1650                 else if (s->ctx->info_callback != NULL)
1651                         cb=s->ctx->info_callback;
1652
1653                 if (cb != NULL)
1654                         {
1655                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1656                         cb(s,SSL_CB_WRITE_ALERT,j);
1657                         }
1658                 }
1659         return(i);
1660         }
1661
1662
1663 static DTLS1_BITMAP *
1664 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1665     {
1666
1667     *is_next_epoch = 0;
1668
1669     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1670     if (rr->epoch == s->d1->r_epoch)
1671         return &s->d1->bitmap;
1672
1673     /* Only HM and ALERT messages can be from the next epoch */
1674     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1675         (rr->type == SSL3_RT_HANDSHAKE ||
1676             rr->type == SSL3_RT_ALERT))
1677         {
1678         *is_next_epoch = 1;
1679         return &s->d1->next_bitmap;
1680         }
1681
1682     return NULL;
1683     }
1684
1685 #if 0
1686 static int
1687 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1688         unsigned long *offset)
1689         {
1690
1691         /* alerts are passed up immediately */
1692         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1693                 rr->type == SSL3_RT_ALERT)
1694                 return 0;
1695
1696         /* Only need to buffer if a handshake is underway.
1697          * (this implies that Hello Request and Client Hello are passed up
1698          * immediately) */
1699         if ( SSL_in_init(s))
1700                 {
1701                 unsigned char *data = rr->data;
1702                 /* need to extract the HM/CCS sequence number here */
1703                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1704                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1705                         {
1706                         unsigned short seq_num;
1707                         struct hm_header_st msg_hdr;
1708                         struct ccs_header_st ccs_hdr;
1709
1710                         if ( rr->type == SSL3_RT_HANDSHAKE)
1711                                 {
1712                                 dtls1_get_message_header(data, &msg_hdr);
1713                                 seq_num = msg_hdr.seq;
1714                                 *offset = msg_hdr.frag_off;
1715                                 }
1716                         else
1717                                 {
1718                                 dtls1_get_ccs_header(data, &ccs_hdr);
1719                                 seq_num = ccs_hdr.seq;
1720                                 *offset = 0;
1721                                 }
1722
1723                         /* this is either a record we're waiting for, or a
1724                          * retransmit of something we happened to previously
1725                          * receive (higher layers will drop the repeat silently */
1726                         if ( seq_num < s->d1->handshake_read_seq)
1727                                 return 0;
1728                         if (rr->type == SSL3_RT_HANDSHAKE &&
1729                                 seq_num == s->d1->handshake_read_seq &&
1730                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1731                                 return 0;
1732                         else if ( seq_num == s->d1->handshake_read_seq &&
1733                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1734                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1735                                 return 0;
1736                         else
1737                                 {
1738                                 *priority = seq_num;
1739                                 return 1;
1740                                 }
1741                         }
1742                 else /* unknown record type */
1743                         return 0;
1744                 }
1745
1746         return 0;
1747         }
1748 #endif
1749
1750 void
1751 dtls1_reset_seq_numbers(SSL *s, int rw)
1752         {
1753         unsigned char *seq;
1754         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1755
1756         if ( rw & SSL3_CC_READ)
1757                 {
1758                 seq = s->s3->read_sequence;
1759                 s->d1->r_epoch++;
1760                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1761                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1762                 }
1763         else
1764                 {
1765                 seq = s->s3->write_sequence;
1766                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1767                 s->d1->w_epoch++;
1768                 }
1769
1770         memset(seq, 0x00, seq_bytes);
1771         }
1772
1773
1774 static void
1775 dtls1_clear_timeouts(SSL *s)
1776         {
1777         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1778         }