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     return(1);
 201     }
 202
 203
 204 static int
 205 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 206         {
 207         DTLS1_RECORD_DATA *rdata;
 208         pitem *item;
 209
 210         /* Limit the size of the queue to prevent DOS attacks */
 211         if (pqueue_size(queue->q) >= 100)
 212                 return 0;
 213
 214         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 215         item = pitem_new(priority, rdata);
 216         if (rdata == NULL || item == NULL)
 217                 {
 218                 if (rdata != NULL) OPENSSL_free(rdata);
 219                 if (item != NULL) pitem_free(item);
 220
 221                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 222                 return(0);
 223                 }
 224
 225         rdata->packet = s->packet;
 226         rdata->packet_length = s->packet_length;
 227         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 228         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 229
 230         item->data = rdata;
 231
 232         /* insert should not fail, since duplicates are dropped */
 233         if (pqueue_insert(queue->q, item) == NULL)
 234                 {
 235                 OPENSSL_free(rdata);
 236                 pitem_free(item);
 237                 return(0);
 238                 }
 239
 240         s->packet = NULL;
 241         s->packet_length = 0;
 242         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 243         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 244
 245         if (!ssl3_setup_buffers(s))
 246                 {
 247                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 248                 OPENSSL_free(rdata);
 249                 pitem_free(item);
 250                 return(0);
 251                 }
 252
 253         return(1);
 254         }
 255
 256
 257 static int
 258 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 259     {
 260     pitem *item;
 261
 262     item = pqueue_pop(queue->q);
 263     if (item)
 264         {
 265         dtls1_copy_record(s, item);
 266
 267         OPENSSL_free(item->data);
 268                 pitem_free(item);
 269
 270         return(1);
 271         }
 272
 273     return(0);
 274     }
 275
 276
 277 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 278  * yet */
 279 #define dtls1_get_unprocessed_record(s) \
 280                    dtls1_retrieve_buffered_record((s), \
 281                    &((s)->d1->unprocessed_rcds))
 282
 283 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 284 #define dtls1_get_processed_record(s) \
 285                    dtls1_retrieve_buffered_record((s), \
 286                    &((s)->d1->processed_rcds))
 287
 288 static int
 289 dtls1_process_buffered_records(SSL *s)
 290     {
 291     pitem *item;
 292
 293     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 294     if (item)
 295         {
 296         DTLS1_RECORD_DATA *rdata;
 297         rdata = (DTLS1_RECORD_DATA *)item->data;
 298
 299         /* Check if epoch is current. */
 300         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 301             return(1);  /* Nothing to do. */
 302
 303         /* Process all the records. */
 304         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 305             {
 306             dtls1_get_unprocessed_record(s);
 307             if ( ! dtls1_process_record(s))
 308                 return(0);
 309             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 310                 s->s3->rrec.seq_num);
 311             }
 312         }
 313
 314     /* sync epoch numbers once all the unprocessed records
 315      * have been processed */
 316     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 317     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 318
 319     return(1);
 320     }
 321
 322
 323 #if 0
 324
 325 static int
 326 dtls1_get_buffered_record(SSL *s)
 327         {
 328         pitem *item;
 329         PQ_64BIT priority =
 330                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 331                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 332
 333         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 334                                                            nothing buffered */
 335                 return 0;
 336
 337
 338         item = pqueue_peek(s->d1->rcvd_records);
 339         if (item && item->priority == priority)
 340                 {
 341                 /* Check if we've received the record of interest.  It must be
 342                  * a handshake record, since data records as passed up without
 343                  * buffering */
 344                 DTLS1_RECORD_DATA *rdata;
 345                 item = pqueue_pop(s->d1->rcvd_records);
 346                 rdata = (DTLS1_RECORD_DATA *)item->data;
 347
 348                 if (s->s3->rbuf.buf != NULL)
 349                         OPENSSL_free(s->s3->rbuf.buf);
 350
 351                 s->packet = rdata->packet;
 352                 s->packet_length = rdata->packet_length;
 353                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 354                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 355
 356                 OPENSSL_free(item->data);
 357                 pitem_free(item);
 358
 359                 /* s->d1->next_expected_seq_num++; */
 360                 return(1);
 361                 }
 362
 363         return 0;
 364         }
 365
 366 #endif
 367
 368 static int
 369 dtls1_process_record(SSL *s)
 370 {
 371         int i,al;
 372         int clear=0;
 373         int enc_err;
 374         SSL_SESSION *sess;
 375         SSL3_RECORD *rr;
 376         unsigned int mac_size;
 377         unsigned char md[EVP_MAX_MD_SIZE];
 378
 379
 380         rr= &(s->s3->rrec);
 381         sess = s->session;
 382
 383         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 384          * and we have that many bytes in s->packet
 385          */
 386         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 387
 388         /* ok, we can now read from 's->packet' data into 'rr'
 389          * rr->input points at rr->length bytes, which
 390          * need to be copied into rr->data by either
 391          * the decryption or by the decompression
 392          * When the data is 'copied' into the rr->data buffer,
 393          * rr->input will be pointed at the new buffer */
 394
 395         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 396          * rr->length bytes of encrypted compressed stuff. */
 397
 398         /* check is not needed I believe */
 399         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 400                 {
 401                 al=SSL_AD_RECORD_OVERFLOW;
 402                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 403                 goto f_err;
 404                 }
 405
 406         /* decrypt in place in 'rr->input' */
 407         rr->data=rr->input;
 408
 409         enc_err = s->method->ssl3_enc->enc(s,0);
 410         if (enc_err <= 0)
 411                 {
 412                 if (enc_err == 0)
 413                         /* SSLerr() and ssl3_send_alert() have been called */
 414                         goto err;
 415
 416                 /* otherwise enc_err == -1 */
 417                 goto decryption_failed_or_bad_record_mac;
 418                 }
 419
 420 #ifdef TLS_DEBUG
 421 printf("dec %d\n",rr->length);
 422 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 423 printf("\n");
 424 #endif
 425
 426         /* r->length is now the compressed data plus mac */
 427         if (    (sess == NULL) ||
 428                 (s->enc_read_ctx == NULL) ||
 429                 (s->read_hash == NULL))
 430                 clear=1;
 431
 432         if (!clear)
 433                 {
 434                 /* !clear => s->read_hash != NULL => mac_size != -1 */
 435                 int t;
 436                 t=EVP_MD_CTX_size(s->read_hash);
 437                 OPENSSL_assert(t >= 0);
 438                 mac_size=t;
 439
 440                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 441                         {
 442 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 443                         al=SSL_AD_RECORD_OVERFLOW;
 444                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 445                         goto f_err;
 446 #else
 447                         goto decryption_failed_or_bad_record_mac;
 448 #endif
 449                         }
 450                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 451                 if (rr->length < mac_size)
 452                         {
 453 #if 0 /* OK only for stream ciphers */
 454                         al=SSL_AD_DECODE_ERROR;
 455                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 456                         goto f_err;
 457 #else
 458                         goto decryption_failed_or_bad_record_mac;
 459 #endif
 460                         }
 461                 rr->length-=mac_size;
 462                 i=s->method->ssl3_enc->mac(s,md,0);
 463                 if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 464                         {
 465                         goto decryption_failed_or_bad_record_mac;
 466                         }
 467                 }
 468
 469         /* r->length is now just compressed */
 470         if (s->expand != NULL)
 471                 {
 472                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 473                         {
 474                         al=SSL_AD_RECORD_OVERFLOW;
 475                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 476                         goto f_err;
 477                         }
 478                 if (!ssl3_do_uncompress(s))
 479                         {
 480                         al=SSL_AD_DECOMPRESSION_FAILURE;
 481                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 482                         goto f_err;
 483                         }
 484                 }
 485
 486         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 487                 {
 488                 al=SSL_AD_RECORD_OVERFLOW;
 489                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 490                 goto f_err;
 491                 }
 492
 493         rr->off=0;
 494         /* So at this point the following is true
 495          * ssl->s3->rrec.type   is the type of record
 496          * ssl->s3->rrec.length == number of bytes in record
 497          * ssl->s3->rrec.off    == offset to first valid byte
 498          * ssl->s3->rrec.data   == where to take bytes from, increment
 499          *                         after use :-).
 500          */
 501
 502         /* we have pulled in a full packet so zero things */
 503         s->packet_length=0;
 504         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 505         return(1);
 506
 507 decryption_failed_or_bad_record_mac:
 508         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
 509          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 510          * failure is directly visible from the ciphertext anyway,
 511          * we should not reveal which kind of error occured -- this
 512          * might become visible to an attacker (e.g. via logfile) */
 513         al=SSL_AD_BAD_RECORD_MAC;
 514         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 515 f_err:
 516         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 517 err:
 518         return(0);
 519 }
 520
 521
 522 /* Call this to get a new input record.
 523  * It will return <= 0 if more data is needed, normally due to an error
 524  * or non-blocking IO.
 525  * When it finishes, one packet has been decoded and can be found in
 526  * ssl->s3->rrec.type    - is the type of record
 527  * ssl->s3->rrec.data,   - data
 528  * ssl->s3->rrec.length, - number of bytes
 529  */
 530 /* used only by dtls1_read_bytes */
 531 int dtls1_get_record(SSL *s)
 532         {
 533         int ssl_major,ssl_minor;
 534         int i,n;
 535         SSL3_RECORD *rr;
 536         SSL_SESSION *sess;
 537         unsigned char *p = NULL;
 538         unsigned short version;
 539         DTLS1_BITMAP *bitmap;
 540         unsigned int is_next_epoch;
 541
 542         rr= &(s->s3->rrec);
 543         sess=s->session;
 544
 545         /* The epoch may have changed.  If so, process all the
 546          * pending records.  This is a non-blocking operation. */
 547         if ( ! dtls1_process_buffered_records(s))
 548             return 0;
 549
 550         /* if we're renegotiating, then there may be buffered records */
 551         if (dtls1_get_processed_record(s))
 552                 return 1;
 553
 554         /* get something from the wire */
 555 again:
 556         /* check if we have the header */
 557         if (    (s->rstate != SSL_ST_READ_BODY) ||
 558                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 559                 {
 560                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 561                 /* read timeout is handled by dtls1_read_bytes */
 562                 if (n <= 0) return(n); /* error or non-blocking */
 563
 564                 /* this packet contained a partial record, dump it */
 565                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
 566                         {
 567                         s->packet_length = 0;
 568                         goto again;
 569                         }
 570
 571                 s->rstate=SSL_ST_READ_BODY;
 572
 573                 p=s->packet;
 574
 575                 /* Pull apart the header into the DTLS1_RECORD */
 576                 rr->type= *(p++);
 577                 ssl_major= *(p++);
 578                 ssl_minor= *(p++);
 579                 version=(ssl_major<<8)|ssl_minor;
 580
 581                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 582                 n2s(p,rr->epoch);
 583
 584                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 585                 p+=6;
 586
 587                 n2s(p,rr->length);
 588
 589                 /* Lets check version */
 590                 if (!s->first_packet)
 591                         {
 592                         if (version != s->version)
 593                                 {
 594                                 /* unexpected version, silently discard */
 595                                 rr->length = 0;
 596                                 s->packet_length = 0;
 597                                 goto again;
 598                                 }
 599                         }
 600
 601                 if ((version & 0xff00) != (s->version & 0xff00))
 602                         {
 603                         /* wrong version, silently discard record */
 604                         rr->length = 0;
 605                         s->packet_length = 0;
 606                         goto again;
 607                         }
 608
 609                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 610                         {
 611                         /* record too long, silently discard it */
 612                         rr->length = 0;
 613                         s->packet_length = 0;
 614                         goto again;
 615                         }
 616
 617                 /* now s->rstate == SSL_ST_READ_BODY */
 618                 }
 619
 620         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 621
 622         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 623                 {
 624                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 625                 i=rr->length;
 626                 n=ssl3_read_n(s,i,i,1);
 627                 if (n <= 0) return(n); /* error or non-blocking io */
 628
 629                 /* this packet contained a partial record, dump it */
 630                 if ( n != i)
 631                         {
 632                         rr->length = 0;
 633                         s->packet_length = 0;
 634                         goto again;
 635                         }
 636
 637                 /* now n == rr->length,
 638                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 639                 }
 640         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 641
 642         /* match epochs.  NULL means the packet is dropped on the floor */
 643         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 644         if ( bitmap == NULL)
 645                 {
 646                 rr->length = 0;
 647                 s->packet_length = 0;  /* dump this record */
 648                 goto again;   /* get another record */
 649                 }
 650
 651         /* Check whether this is a repeat, or aged record.
 652          * Don't check if we're listening and this message is
 653          * a ClientHello. They can look as if they're replayed,
 654          * since they arrive from different connections and
 655          * would be dropped unnecessarily.
 656          */
 657         if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
 658                 *p == SSL3_MT_CLIENT_HELLO) &&
 659                 !dtls1_record_replay_check(s, bitmap))
 660                 {
 661                 rr->length = 0;
 662                 s->packet_length=0; /* dump this record */
 663                 goto again;     /* get another record */
 664                 }
 665
 666         /* just read a 0 length packet */
 667         if (rr->length == 0) goto again;
 668
 669         /* If this record is from the next epoch (either HM or ALERT),
 670          * buffer it since it cannot be processed at this time. Records
 671          * from the next epoch are marked as received even though they
 672          * are not processed, so as to prevent any potential resource
 673          * DoS attack */
 674         if (is_next_epoch)
 675                 {
 676                 dtls1_record_bitmap_update(s, bitmap);
 677                 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 678                 rr->length = 0;
 679                 s->packet_length = 0;
 680                 goto again;
 681                 }
 682
 683         if ( ! dtls1_process_record(s))
 684                 return(0);
 685
 686         dtls1_clear_timeouts(s);  /* done waiting */
 687         return(1);
 688
 689         }
 690
 691 /* Return up to 'len' payload bytes received in 'type' records.
 692  * 'type' is one of the following:
 693  *
 694  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 695  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 696  *   -  0 (during a shutdown, no data has to be returned)
 697  *
 698  * If we don't have stored data to work from, read a SSL/TLS record first
 699  * (possibly multiple records if we still don't have anything to return).
 700  *
 701  * This function must handle any surprises the peer may have for us, such as
 702  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 703  * a surprise, but handled as if it were), or renegotiation requests.
 704  * Also if record payloads contain fragments too small to process, we store
 705  * them until there is enough for the respective protocol (the record protocol
 706  * may use arbitrary fragmentation and even interleaving):
 707  *     Change cipher spec protocol
 708  *             just 1 byte needed, no need for keeping anything stored
 709  *     Alert protocol
 710  *             2 bytes needed (AlertLevel, AlertDescription)
 711  *     Handshake protocol
 712  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 713  *             to detect unexpected Client Hello and Hello Request messages
 714  *             here, anything else is handled by higher layers
 715  *     Application data protocol
 716  *             none of our business
 717  */
 718 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 719         {
 720         int al,i,j,ret;
 721         unsigned int n;
 722         SSL3_RECORD *rr;
 723         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 724
 725         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 726                 if (!ssl3_setup_buffers(s))
 727                         return(-1);
 728
 729     /* XXX: check what the second '&& type' is about */
 730         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 731                 (type != SSL3_RT_HANDSHAKE) && type) ||
 732             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 733                 {
 734                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 735                 return -1;
 736                 }
 737
 738         /* check whether there's a handshake message (client hello?) waiting */
 739         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 740                 return ret;
 741
 742         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 743
 744         if (!s->in_handshake && SSL_in_init(s))
 745                 {
 746                 /* type == SSL3_RT_APPLICATION_DATA */
 747                 i=s->handshake_func(s);
 748                 if (i < 0) return(i);
 749                 if (i == 0)
 750                         {
 751                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 752                         return(-1);
 753                         }
 754                 }
 755
 756 start:
 757         s->rwstate=SSL_NOTHING;
 758
 759         /* s->s3->rrec.type         - is the type of record
 760          * s->s3->rrec.data,    - data
 761          * s->s3->rrec.off,     - offset into 'data' for next read
 762          * s->s3->rrec.length,  - number of bytes. */
 763         rr = &(s->s3->rrec);
 764
 765         /* We are not handshaking and have no data yet,
 766          * so process data buffered during the last handshake
 767          * in advance, if any.
 768          */
 769         if (s->state == SSL_ST_OK && rr->length == 0)
 770                 {
 771                 pitem *item;
 772                 item = pqueue_pop(s->d1->buffered_app_data.q);
 773                 if (item)
 774                         {
 775                         dtls1_copy_record(s, item);
 776
 777                         OPENSSL_free(item->data);
 778                         pitem_free(item);
 779                         }
 780                 }
 781
 782         /* Check for timeout */
 783         if (dtls1_handle_timeout(s) > 0)
 784                 goto start;
 785
 786         /* get new packet if necessary */
 787         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 788                 {
 789                 ret=dtls1_get_record(s);
 790                 if (ret <= 0)
 791                         {
 792                         ret = dtls1_read_failed(s, ret);
 793                         /* anything other than a timeout is an error */
 794                         if (ret <= 0)
 795                                 return(ret);
 796                         else
 797                                 goto start;
 798                         }
 799                 }
 800
 801         /* we now have a packet which can be read and processed */
 802
 803         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 804                                        * reset by ssl3_get_finished */
 805                 && (rr->type != SSL3_RT_HANDSHAKE))
 806                 {
 807                 /* We now have application data between CCS and Finished.
 808                  * Most likely the packets were reordered on their way, so
 809                  * buffer the application data for later processing rather
 810                  * than dropping the connection.
 811                  */
 812                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), 0);
 813                 rr->length = 0;
 814                 goto start;
 815                 }
 816
 817         /* If the other end has shut down, throw anything we read away
 818          * (even in 'peek' mode) */
 819         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 820                 {
 821                 rr->length=0;
 822                 s->rwstate=SSL_NOTHING;
 823                 return(0);
 824                 }
 825
 826
 827         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 828                 {
 829                 /* make sure that we are not getting application data when we
 830                  * are doing a handshake for the first time */
 831                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 832                         (s->enc_read_ctx == NULL))
 833                         {
 834                         al=SSL_AD_UNEXPECTED_MESSAGE;
 835                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 836                         goto f_err;
 837                         }
 838
 839                 if (len <= 0) return(len);
 840
 841                 if ((unsigned int)len > rr->length)
 842                         n = rr->length;
 843                 else
 844                         n = (unsigned int)len;
 845
 846                 memcpy(buf,&(rr->data[rr->off]),n);
 847                 if (!peek)
 848                         {
 849                         rr->length-=n;
 850                         rr->off+=n;
 851                         if (rr->length == 0)
 852                                 {
 853                                 s->rstate=SSL_ST_READ_HEADER;
 854                                 rr->off=0;
 855                                 }
 856                         }
 857                 return(n);
 858                 }
 859
 860
 861         /* If we get here, then type != rr->type; if we have a handshake
 862          * message, then it was unexpected (Hello Request or Client Hello). */
 863
 864         /* In case of record types for which we have 'fragment' storage,
 865          * fill that so that we can process the data at a fixed place.
 866          */
 867                 {
 868                 unsigned int k, dest_maxlen = 0;
 869                 unsigned char *dest = NULL;
 870                 unsigned int *dest_len = NULL;
 871
 872                 if (rr->type == SSL3_RT_HANDSHAKE)
 873                         {
 874                         dest_maxlen = sizeof s->d1->handshake_fragment;
 875                         dest = s->d1->handshake_fragment;
 876                         dest_len = &s->d1->handshake_fragment_len;
 877                         }
 878                 else if (rr->type == SSL3_RT_ALERT)
 879                         {
 880                         dest_maxlen = sizeof(s->d1->alert_fragment);
 881                         dest = s->d1->alert_fragment;
 882                         dest_len = &s->d1->alert_fragment_len;
 883                         }
 884                 /* else it's a CCS message, or application data or wrong */
 885                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 886                         {
 887                         /* Application data while renegotiating
 888                          * is allowed. Try again reading.
 889                          */
 890                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 891                                 {
 892                                 BIO *bio;
 893                                 s->s3->in_read_app_data=2;
 894                                 bio=SSL_get_rbio(s);
 895                                 s->rwstate=SSL_READING;
 896                                 BIO_clear_retry_flags(bio);
 897                                 BIO_set_retry_read(bio);
 898                                 return(-1);
 899                                 }
 900
 901                         /* Not certain if this is the right error handling */
 902                         al=SSL_AD_UNEXPECTED_MESSAGE;
 903                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 904                         goto f_err;
 905                         }
 906
 907                 if (dest_maxlen > 0)
 908                         {
 909             /* XDTLS:  In a pathalogical case, the Client Hello
 910              *  may be fragmented--don't always expect dest_maxlen bytes */
 911                         if ( rr->length < dest_maxlen)
 912                                 {
 913 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
 914                                 /*
 915                                  * for normal alerts rr->length is 2, while
 916                                  * dest_maxlen is 7 if we were to handle this
 917                                  * non-existing alert...
 918                                  */
 919                                 FIX ME
 920 #endif
 921                                 s->rstate=SSL_ST_READ_HEADER;
 922                                 rr->length = 0;
 923                                 goto start;
 924                                 }
 925
 926                         /* now move 'n' bytes: */
 927                         for ( k = 0; k < dest_maxlen; k++)
 928                                 {
 929                                 dest[k] = rr->data[rr->off++];
 930                                 rr->length--;
 931                                 }
 932                         *dest_len = dest_maxlen;
 933                         }
 934                 }
 935
 936         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 937          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 938          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 939
 940         /* If we are a client, check for an incoming 'Hello Request': */
 941         if ((!s->server) &&
 942                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 943                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 944                 (s->session != NULL) && (s->session->cipher != NULL))
 945                 {
 946                 s->d1->handshake_fragment_len = 0;
 947
 948                 if ((s->d1->handshake_fragment[1] != 0) ||
 949                         (s->d1->handshake_fragment[2] != 0) ||
 950                         (s->d1->handshake_fragment[3] != 0))
 951                         {
 952                         al=SSL_AD_DECODE_ERROR;
 953                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 954                         goto err;
 955                         }
 956
 957                 /* no need to check sequence number on HELLO REQUEST messages */
 958
 959                 if (s->msg_callback)
 960                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 961                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 962
 963                 if (SSL_is_init_finished(s) &&
 964                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 965                         !s->s3->renegotiate)
 966                         {
 967                         ssl3_renegotiate(s);
 968                         if (ssl3_renegotiate_check(s))
 969                                 {
 970                                 i=s->handshake_func(s);
 971                                 if (i < 0) return(i);
 972                                 if (i == 0)
 973                                         {
 974                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 975                                         return(-1);
 976                                         }
 977
 978                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 979                                         {
 980                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 981                                                 {
 982                                                 BIO *bio;
 983                                                 /* In the case where we try to read application data,
 984                                                  * but we trigger an SSL handshake, we return -1 with
 985                                                  * the retry option set.  Otherwise renegotiation may
 986                                                  * cause nasty problems in the blocking world */
 987                                                 s->rwstate=SSL_READING;
 988                                                 bio=SSL_get_rbio(s);
 989                                                 BIO_clear_retry_flags(bio);
 990                                                 BIO_set_retry_read(bio);
 991                                                 return(-1);
 992                                                 }
 993                                         }
 994                                 }
 995                         }
 996                 /* we either finished a handshake or ignored the request,
 997                  * now try again to obtain the (application) data we were asked for */
 998                 goto start;
 999                 }
1000
1001         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1002                 {
1003                 int alert_level = s->d1->alert_fragment[0];
1004                 int alert_descr = s->d1->alert_fragment[1];
1005
1006                 s->d1->alert_fragment_len = 0;
1007
1008                 if (s->msg_callback)
1009                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1010                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1011
1012                 if (s->info_callback != NULL)
1013                         cb=s->info_callback;
1014                 else if (s->ctx->info_callback != NULL)
1015                         cb=s->ctx->info_callback;
1016
1017                 if (cb != NULL)
1018                         {
1019                         j = (alert_level << 8) | alert_descr;
1020                         cb(s, SSL_CB_READ_ALERT, j);
1021                         }
1022
1023                 if (alert_level == 1) /* warning */
1024                         {
1025                         s->s3->warn_alert = alert_descr;
1026                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1027                                 {
1028                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1029                                 return(0);
1030                                 }
1031 #if 0
1032             /* XXX: this is a possible improvement in the future */
1033                         /* now check if it's a missing record */
1034                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1035                                 {
1036                                 unsigned short seq;
1037                                 unsigned int frag_off;
1038                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1039
1040                                 n2s(p, seq);
1041                                 n2l3(p, frag_off);
1042
1043                                 dtls1_retransmit_message(s,
1044                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1045                                                                                  frag_off, &found);
1046                                 if ( ! found  && SSL_in_init(s))
1047                                         {
1048                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1049                                         /* requested a message not yet sent,
1050                                            send an alert ourselves */
1051                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1052                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1053                                         }
1054                                 }
1055 #endif
1056                         }
1057                 else if (alert_level == 2) /* fatal */
1058                         {
1059                         char tmp[16];
1060
1061                         s->rwstate=SSL_NOTHING;
1062                         s->s3->fatal_alert = alert_descr;
1063                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1064                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1065                         ERR_add_error_data(2,"SSL alert number ",tmp);
1066                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1067                         SSL_CTX_remove_session(s->ctx,s->session);
1068                         return(0);
1069                         }
1070                 else
1071                         {
1072                         al=SSL_AD_ILLEGAL_PARAMETER;
1073                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1074                         goto f_err;
1075                         }
1076
1077                 goto start;
1078                 }
1079
1080         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1081                 {
1082                 s->rwstate=SSL_NOTHING;
1083                 rr->length=0;
1084                 return(0);
1085                 }
1086
1087         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1088                 {
1089                 struct ccs_header_st ccs_hdr;
1090                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1091
1092                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1093
1094                 if (s->version == DTLS1_BAD_VER)
1095                         ccs_hdr_len = 3;
1096
1097                 /* 'Change Cipher Spec' is just a single byte, so we know
1098                  * exactly what the record payload has to look like */
1099                 /* XDTLS: check that epoch is consistent */
1100                 if (    (rr->length != ccs_hdr_len) ||
1101                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1102                         {
1103                         i=SSL_AD_ILLEGAL_PARAMETER;
1104                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1105                         goto err;
1106                         }
1107
1108                 rr->length=0;
1109
1110                 if (s->msg_callback)
1111                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1112                                 rr->data, 1, s, s->msg_callback_arg);
1113
1114                 /* We can't process a CCS now, because previous handshake
1115                  * messages are still missing, so just drop it.
1116                  */
1117                 if (!s->d1->change_cipher_spec_ok)
1118                         {
1119                         goto start;
1120                         }
1121
1122                 s->d1->change_cipher_spec_ok = 0;
1123
1124                 s->s3->change_cipher_spec=1;
1125                 if (!ssl3_do_change_cipher_spec(s))
1126                         goto err;
1127
1128                 /* do this whenever CCS is processed */
1129                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1130
1131                 if (s->version == DTLS1_BAD_VER)
1132                         s->d1->handshake_read_seq++;
1133
1134                 goto start;
1135                 }
1136
1137         /* Unexpected handshake message (Client Hello, or protocol violation) */
1138         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1139                 !s->in_handshake)
1140                 {
1141                 struct hm_header_st msg_hdr;
1142
1143                 /* this may just be a stale retransmit */
1144                 dtls1_get_message_header(rr->data, &msg_hdr);
1145                 if( rr->epoch != s->d1->r_epoch)
1146                         {
1147                         rr->length = 0;
1148                         goto start;
1149                         }
1150
1151                 /* If we are server, we may have a repeated FINISHED of the
1152                  * client here, then retransmit our CCS and FINISHED.
1153                  */
1154                 if (msg_hdr.type == SSL3_MT_FINISHED)
1155                         {
1156                         dtls1_retransmit_buffered_messages(s);
1157                         rr->length = 0;
1158                         goto start;
1159                         }
1160
1161                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1162                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1163                         {
1164 #if 0 /* worked only because C operator preferences are not as expected (and
1165        * because this is not really needed for clients except for detecting
1166        * protocol violations): */
1167                         s->state=SSL_ST_BEFORE|(s->server)
1168                                 ?SSL_ST_ACCEPT
1169                                 :SSL_ST_CONNECT;
1170 #else
1171                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1172 #endif
1173                         s->new_session=1;
1174                         }
1175                 i=s->handshake_func(s);
1176                 if (i < 0) return(i);
1177                 if (i == 0)
1178                         {
1179                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1180                         return(-1);
1181                         }
1182
1183                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1184                         {
1185                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1186                                 {
1187                                 BIO *bio;
1188                                 /* In the case where we try to read application data,
1189                                  * but we trigger an SSL handshake, we return -1 with
1190                                  * the retry option set.  Otherwise renegotiation may
1191                                  * cause nasty problems in the blocking world */
1192                                 s->rwstate=SSL_READING;
1193                                 bio=SSL_get_rbio(s);
1194                                 BIO_clear_retry_flags(bio);
1195                                 BIO_set_retry_read(bio);
1196                                 return(-1);
1197                                 }
1198                         }
1199                 goto start;
1200                 }
1201
1202         switch (rr->type)
1203                 {
1204         default:
1205 #ifndef OPENSSL_NO_TLS
1206                 /* TLS just ignores unknown message types */
1207                 if (s->version == TLS1_VERSION)
1208                         {
1209                         rr->length = 0;
1210                         goto start;
1211                         }
1212 #endif
1213                 al=SSL_AD_UNEXPECTED_MESSAGE;
1214                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1215                 goto f_err;
1216         case SSL3_RT_CHANGE_CIPHER_SPEC:
1217         case SSL3_RT_ALERT:
1218         case SSL3_RT_HANDSHAKE:
1219                 /* we already handled all of these, with the possible exception
1220                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1221                  * should not happen when type != rr->type */
1222                 al=SSL_AD_UNEXPECTED_MESSAGE;
1223                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1224                 goto f_err;
1225         case SSL3_RT_APPLICATION_DATA:
1226                 /* At this point, we were expecting handshake data,
1227                  * but have application data.  If the library was
1228                  * running inside ssl3_read() (i.e. in_read_app_data
1229                  * is set) and it makes sense to read application data
1230                  * at this point (session renegotiation not yet started),
1231                  * we will indulge it.
1232                  */
1233                 if (s->s3->in_read_app_data &&
1234                         (s->s3->total_renegotiations != 0) &&
1235                         ((
1236                                 (s->state & SSL_ST_CONNECT) &&
1237                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1238                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1239                                 ) || (
1240                                         (s->state & SSL_ST_ACCEPT) &&
1241                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1242                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1243                                         )
1244                                 ))
1245                         {
1246                         s->s3->in_read_app_data=2;
1247                         return(-1);
1248                         }
1249                 else
1250                         {
1251                         al=SSL_AD_UNEXPECTED_MESSAGE;
1252                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1253                         goto f_err;
1254                         }
1255                 }
1256         /* not reached */
1257
1258 f_err:
1259         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1260 err:
1261         return(-1);
1262         }
1263
1264 int
1265 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1266         {
1267         int i;
1268
1269         if (SSL_in_init(s) && !s->in_handshake)
1270                 {
1271                 i=s->handshake_func(s);
1272                 if (i < 0) return(i);
1273                 if (i == 0)
1274                         {
1275                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1276                         return -1;
1277                         }
1278                 }
1279
1280         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1281                 {
1282                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1283                         return -1;
1284                 }
1285
1286         i = dtls1_write_bytes(s, type, buf_, len);
1287         return i;
1288         }
1289
1290
1291         /* this only happens when a client hello is received and a handshake
1292          * is started. */
1293 static int
1294 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1295         int len, int peek)
1296         {
1297
1298         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1299                 /* (partially) satisfy request from storage */
1300                 {
1301                 unsigned char *src = s->d1->handshake_fragment;
1302                 unsigned char *dst = buf;
1303                 unsigned int k,n;
1304
1305                 /* peek == 0 */
1306                 n = 0;
1307                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1308                         {
1309                         *dst++ = *src++;
1310                         len--; s->d1->handshake_fragment_len--;
1311                         n++;
1312                         }
1313                 /* move any remaining fragment bytes: */
1314                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1315                         s->d1->handshake_fragment[k] = *src++;
1316                 return n;
1317                 }
1318
1319         return 0;
1320         }
1321
1322
1323
1324
1325 /* Call this to write data in records of type 'type'
1326  * It will return <= 0 if not all data has been sent or non-blocking IO.
1327  */
1328 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1329         {
1330         int i;
1331
1332         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1333         s->rwstate=SSL_NOTHING;
1334         i=do_dtls1_write(s, type, buf, len, 0);
1335         return i;
1336         }
1337
1338 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1339         {
1340         unsigned char *p,*pseq;
1341         int i,mac_size,clear=0;
1342         int prefix_len = 0;
1343         SSL3_RECORD *wr;
1344         SSL3_BUFFER *wb;
1345         SSL_SESSION *sess;
1346         int bs;
1347
1348         /* first check if there is a SSL3_BUFFER still being written
1349          * out.  This will happen with non blocking IO */
1350         if (s->s3->wbuf.left != 0)
1351                 {
1352                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1353                 return(ssl3_write_pending(s,type,buf,len));
1354                 }
1355
1356         /* If we have an alert to send, lets send it */
1357         if (s->s3->alert_dispatch)
1358                 {
1359                 i=s->method->ssl_dispatch_alert(s);
1360                 if (i <= 0)
1361                         return(i);
1362                 /* if it went, fall through and send more stuff */
1363                 }
1364
1365         if (len == 0 && !create_empty_fragment)
1366                 return 0;
1367
1368         wr= &(s->s3->wrec);
1369         wb= &(s->s3->wbuf);
1370         sess=s->session;
1371
1372         if (    (sess == NULL) ||
1373                 (s->enc_write_ctx == NULL) ||
1374                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1375                 clear=1;
1376
1377         if (clear)
1378                 mac_size=0;
1379         else
1380                 {
1381                 mac_size=EVP_MD_CTX_size(s->write_hash);
1382                 if (mac_size < 0)
1383                         goto err;
1384                 }
1385
1386         /* DTLS implements explicit IV, so no need for empty fragments */
1387 #if 0
1388         /* 'create_empty_fragment' is true only when this function calls itself */
1389         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1390             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1391                 {
1392                 /* countermeasure against known-IV weakness in CBC ciphersuites
1393                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1394                  */
1395
1396                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1397                         {
1398                         /* recursive function call with 'create_empty_fragment' set;
1399                          * this prepares and buffers the data for an empty fragment
1400                          * (these 'prefix_len' bytes are sent out later
1401                          * together with the actual payload) */
1402                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1403                         if (prefix_len <= 0)
1404                                 goto err;
1405
1406                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1407                                 {
1408                                 /* insufficient space */
1409                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1410                                 goto err;
1411                                 }
1412                         }
1413
1414                 s->s3->empty_fragment_done = 1;
1415                 }
1416 #endif
1417         p = wb->buf + prefix_len;
1418
1419         /* write the header */
1420
1421         *(p++)=type&0xff;
1422         wr->type=type;
1423
1424         *(p++)=(s->version>>8);
1425         *(p++)=s->version&0xff;
1426
1427         /* field where we are to write out packet epoch, seq num and len */
1428         pseq=p;
1429         p+=10;
1430
1431         /* lets setup the record stuff. */
1432
1433         /* Make space for the explicit IV in case of CBC.
1434          * (this is a bit of a boundary violation, but what the heck).
1435          */
1436         if ( s->enc_write_ctx &&
1437                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1438                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1439         else
1440                 bs = 0;
1441
1442         wr->data=p + bs;  /* make room for IV in case of CBC */
1443         wr->length=(int)len;
1444         wr->input=(unsigned char *)buf;
1445
1446         /* we now 'read' from wr->input, wr->length bytes into
1447          * wr->data */
1448
1449         /* first we compress */
1450         if (s->compress != NULL)
1451                 {
1452                 if (!ssl3_do_compress(s))
1453                         {
1454                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1455                         goto err;
1456                         }
1457                 }
1458         else
1459                 {
1460                 memcpy(wr->data,wr->input,wr->length);
1461                 wr->input=wr->data;
1462                 }
1463
1464         /* we should still have the output to wr->data and the input
1465          * from wr->input.  Length should be wr->length.
1466          * wr->data still points in the wb->buf */
1467
1468         if (mac_size != 0)
1469                 {
1470                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1471                         goto err;
1472                 wr->length+=mac_size;
1473                 }
1474
1475         /* this is true regardless of mac size */
1476         wr->input=p;
1477         wr->data=p;
1478
1479
1480         /* ssl3_enc can only have an error on read */
1481         if (bs) /* bs != 0 in case of CBC */
1482                 {
1483                 RAND_pseudo_bytes(p,bs);
1484                 /* master IV and last CBC residue stand for
1485                  * the rest of randomness */
1486                 wr->length += bs;
1487                 }
1488
1489         s->method->ssl3_enc->enc(s,1);
1490
1491         /* record length after mac and block padding */
1492 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1493         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1494
1495         /* there's only one epoch between handshake and app data */
1496
1497         s2n(s->d1->w_epoch, pseq);
1498
1499         /* XDTLS: ?? */
1500 /*      else
1501         s2n(s->d1->handshake_epoch, pseq); */
1502
1503         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1504         pseq+=6;
1505         s2n(wr->length,pseq);
1506
1507         /* we should now have
1508          * wr->data pointing to the encrypted data, which is
1509          * wr->length long */
1510         wr->type=type; /* not needed but helps for debugging */
1511         wr->length+=DTLS1_RT_HEADER_LENGTH;
1512
1513 #if 0  /* this is now done at the message layer */
1514         /* buffer the record, making it easy to handle retransmits */
1515         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1516                 dtls1_buffer_record(s, wr->data, wr->length,
1517                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1518 #endif
1519
1520         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1521
1522         if (create_empty_fragment)
1523                 {
1524                 /* we are in a recursive call;
1525                  * just return the length, don't write out anything here
1526                  */
1527                 return wr->length;
1528                 }
1529
1530         /* now let's set up wb */
1531         wb->left = prefix_len + wr->length;
1532         wb->offset = 0;
1533
1534         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1535         s->s3->wpend_tot=len;
1536         s->s3->wpend_buf=buf;
1537         s->s3->wpend_type=type;
1538         s->s3->wpend_ret=len;
1539
1540         /* we now just need to write the buffer */
1541         return ssl3_write_pending(s,type,buf,len);
1542 err:
1543         return -1;
1544         }
1545
1546
1547
1548 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1549         {
1550         int cmp;
1551         unsigned int shift;
1552         const unsigned char *seq = s->s3->read_sequence;
1553
1554         cmp = satsub64be(seq,bitmap->max_seq_num);
1555         if (cmp > 0)
1556                 {
1557                 memcpy (s->s3->rrec.seq_num,seq,8);
1558                 return 1; /* this record in new */
1559                 }
1560         shift = -cmp;
1561         if (shift >= sizeof(bitmap->map)*8)
1562                 return 0; /* stale, outside the window */
1563         else if (bitmap->map & (1UL<<shift))
1564                 return 0; /* record previously received */
1565
1566         memcpy (s->s3->rrec.seq_num,seq,8);
1567         return 1;
1568         }
1569
1570
1571 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1572         {
1573         int cmp;
1574         unsigned int shift;
1575         const unsigned char *seq = s->s3->read_sequence;
1576
1577         cmp = satsub64be(seq,bitmap->max_seq_num);
1578         if (cmp > 0)
1579                 {
1580                 shift = cmp;
1581                 if (shift < sizeof(bitmap->map)*8)
1582                         bitmap->map <<= shift, bitmap->map |= 1UL;
1583                 else
1584                         bitmap->map = 1UL;
1585                 memcpy(bitmap->max_seq_num,seq,8);
1586                 }
1587         else    {
1588                 shift = -cmp;
1589                 if (shift < sizeof(bitmap->map)*8)
1590                         bitmap->map |= 1UL<<shift;
1591                 }
1592         }
1593
1594
1595 int dtls1_dispatch_alert(SSL *s)
1596         {
1597         int i,j;
1598         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1599         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1600         unsigned char *ptr = &buf[0];
1601
1602         s->s3->alert_dispatch=0;
1603
1604         memset(buf, 0x00, sizeof(buf));
1605         *ptr++ = s->s3->send_alert[0];
1606         *ptr++ = s->s3->send_alert[1];
1607
1608 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1609         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1610                 {
1611                 s2n(s->d1->handshake_read_seq, ptr);
1612 #if 0
1613                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1614
1615                 else
1616                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1617 #endif
1618
1619 #if 0
1620                 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);
1621 #endif
1622                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1623                 }
1624 #endif
1625
1626         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1627         if (i <= 0)
1628                 {
1629                 s->s3->alert_dispatch=1;
1630                 /* fprintf( stderr, "not done with alert\n" ); */
1631                 }
1632         else
1633                 {
1634                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1635 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1636                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1637 #endif
1638                     )
1639                         (void)BIO_flush(s->wbio);
1640
1641                 if (s->msg_callback)
1642                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1643                                 2, s, s->msg_callback_arg);
1644
1645                 if (s->info_callback != NULL)
1646                         cb=s->info_callback;
1647                 else if (s->ctx->info_callback != NULL)
1648                         cb=s->ctx->info_callback;
1649
1650                 if (cb != NULL)
1651                         {
1652                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1653                         cb(s,SSL_CB_WRITE_ALERT,j);
1654                         }
1655                 }
1656         return(i);
1657         }
1658
1659
1660 static DTLS1_BITMAP *
1661 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1662     {
1663
1664     *is_next_epoch = 0;
1665
1666     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1667     if (rr->epoch == s->d1->r_epoch)
1668         return &s->d1->bitmap;
1669
1670     /* Only HM and ALERT messages can be from the next epoch */
1671     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1672         (rr->type == SSL3_RT_HANDSHAKE ||
1673             rr->type == SSL3_RT_ALERT))
1674         {
1675         *is_next_epoch = 1;
1676         return &s->d1->next_bitmap;
1677         }
1678
1679     return NULL;
1680     }
1681
1682 #if 0
1683 static int
1684 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1685         unsigned long *offset)
1686         {
1687
1688         /* alerts are passed up immediately */
1689         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1690                 rr->type == SSL3_RT_ALERT)
1691                 return 0;
1692
1693         /* Only need to buffer if a handshake is underway.
1694          * (this implies that Hello Request and Client Hello are passed up
1695          * immediately) */
1696         if ( SSL_in_init(s))
1697                 {
1698                 unsigned char *data = rr->data;
1699                 /* need to extract the HM/CCS sequence number here */
1700                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1701                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1702                         {
1703                         unsigned short seq_num;
1704                         struct hm_header_st msg_hdr;
1705                         struct ccs_header_st ccs_hdr;
1706
1707                         if ( rr->type == SSL3_RT_HANDSHAKE)
1708                                 {
1709                                 dtls1_get_message_header(data, &msg_hdr);
1710                                 seq_num = msg_hdr.seq;
1711                                 *offset = msg_hdr.frag_off;
1712                                 }
1713                         else
1714                                 {
1715                                 dtls1_get_ccs_header(data, &ccs_hdr);
1716                                 seq_num = ccs_hdr.seq;
1717                                 *offset = 0;
1718                                 }
1719
1720                         /* this is either a record we're waiting for, or a
1721                          * retransmit of something we happened to previously
1722                          * receive (higher layers will drop the repeat silently */
1723                         if ( seq_num < s->d1->handshake_read_seq)
1724                                 return 0;
1725                         if (rr->type == SSL3_RT_HANDSHAKE &&
1726                                 seq_num == s->d1->handshake_read_seq &&
1727                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1728                                 return 0;
1729                         else if ( seq_num == s->d1->handshake_read_seq &&
1730                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1731                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1732                                 return 0;
1733                         else
1734                                 {
1735                                 *priority = seq_num;
1736                                 return 1;
1737                                 }
1738                         }
1739                 else /* unknown record type */
1740                         return 0;
1741                 }
1742
1743         return 0;
1744         }
1745 #endif
1746
1747 void
1748 dtls1_reset_seq_numbers(SSL *s, int rw)
1749         {
1750         unsigned char *seq;
1751         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1752
1753         if ( rw & SSL3_CC_READ)
1754                 {
1755                 seq = s->s3->read_sequence;
1756                 s->d1->r_epoch++;
1757                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1758                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1759                 }
1760         else
1761                 {
1762                 seq = s->s3->write_sequence;
1763                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1764                 s->d1->w_epoch++;
1765                 }
1766
1767         memset(seq, 0x00, seq_bytes);
1768         }
1769
1770
1771 static void
1772 dtls1_clear_timeouts(SSL *s)
1773         {
1774         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1775         }