crypto/openssl/ssl/d1_pkt.c

   1 /* ssl/d1_pkt.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <stdio.h>
 117 #include <errno.h>
 118 #define USE_SOCKETS
 119 #include "ssl_locl.h"
 120 #include <openssl/evp.h>
 121 #include <openssl/buffer.h>
 122 #include <openssl/pqueue.h>
 123 #include <openssl/rand.h>
 124
 125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
 126 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
 127 {       int ret,sat,brw,i;
 128
 129         if (sizeof(long) == 8) do
 130         {       const union { long one; char little; } is_endian = {1};
 131                 long l;
 132
 133                 if (is_endian.little)                   break;
 134                 /* not reached on little-endians */
 135                 /* following test is redundant, because input is
 136                  * always aligned, but I take no chances... */
 137                 if (((size_t)v1|(size_t)v2)&0x7)        break;
 138
 139                 l  = *((long *)v1);
 140                 l -= *((long *)v2);
 141                 if (l>128)              return 128;
 142                 else if (l<-128)        return -128;
 143                 else                    return (int)l;
 144         } while (0);
 145
 146         ret = (int)v1[7]-(int)v2[7];
 147         sat = 0;
 148         brw = ret>>8;   /* brw is either 0 or -1 */
 149         if (ret & 0x80)
 150         {       for (i=6;i>=0;i--)
 151                 {       brw += (int)v1[i]-(int)v2[i];
 152                         sat |= ~brw;
 153                         brw >>= 8;
 154                 }
 155         }
 156         else
 157         {       for (i=6;i>=0;i--)
 158                 {       brw += (int)v1[i]-(int)v2[i];
 159                         sat |= brw;
 160                         brw >>= 8;
 161                 }
 162         }
 163         brw <<= 8;      /* brw is either 0 or -256 */
 164
 165         if (sat&0xff)   return brw | 0x80;
 166         else            return brw + (ret&0xFF);
 167 }
 168
 169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
 170         int len, int peek);
 171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
 172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
 173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
 174     unsigned int *is_next_epoch);
 175 #if 0
 176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
 177         unsigned short *priority, unsigned long *offset);
 178 #endif
 179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
 180         unsigned char *priority);
 181 static int dtls1_process_record(SSL *s);
 182 static void dtls1_clear_timeouts(SSL *s);
 183
 184 /* copy buffered record into SSL structure */
 185 static int
 186 dtls1_copy_record(SSL *s, pitem *item)
 187     {
 188     DTLS1_RECORD_DATA *rdata;
 189
 190     rdata = (DTLS1_RECORD_DATA *)item->data;
 191
 192     if (s->s3->rbuf.buf != NULL)
 193         OPENSSL_free(s->s3->rbuf.buf);
 194
 195     s->packet = rdata->packet;
 196     s->packet_length = rdata->packet_length;
 197     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 198     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 199
 200         /* Set proper sequence number for mac calculation */
 201         memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
 202
 203     return(1);
 204     }
 205
 206
 207 static int
 208 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 209         {
 210         DTLS1_RECORD_DATA *rdata;
 211         pitem *item;
 212
 213         /* Limit the size of the queue to prevent DOS attacks */
 214         if (pqueue_size(queue->q) >= 100)
 215                 return 0;
 216
 217         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 218         item = pitem_new(priority, rdata);
 219         if (rdata == NULL || item == NULL)
 220                 {
 221                 if (rdata != NULL) OPENSSL_free(rdata);
 222                 if (item != NULL) pitem_free(item);
 223
 224                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 225                 return(0);
 226                 }
 227
 228         rdata->packet = s->packet;
 229         rdata->packet_length = s->packet_length;
 230         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 231         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 232
 233         item->data = rdata;
 234
 235         /* insert should not fail, since duplicates are dropped */
 236         if (pqueue_insert(queue->q, item) == NULL)
 237                 {
 238                 OPENSSL_free(rdata);
 239                 pitem_free(item);
 240                 return(0);
 241                 }
 242
 243         s->packet = NULL;
 244         s->packet_length = 0;
 245         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 246         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 247
 248         if (!ssl3_setup_buffers(s))
 249                 {
 250                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 251                 OPENSSL_free(rdata);
 252                 pitem_free(item);
 253                 return(0);
 254                 }
 255
 256         return(1);
 257         }
 258
 259
 260 static int
 261 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 262     {
 263     pitem *item;
 264
 265     item = pqueue_pop(queue->q);
 266     if (item)
 267         {
 268         dtls1_copy_record(s, item);
 269
 270         OPENSSL_free(item->data);
 271                 pitem_free(item);
 272
 273         return(1);
 274         }
 275
 276     return(0);
 277     }
 278
 279
 280 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 281  * yet */
 282 #define dtls1_get_unprocessed_record(s) \
 283                    dtls1_retrieve_buffered_record((s), \
 284                    &((s)->d1->unprocessed_rcds))
 285
 286 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 287 #define dtls1_get_processed_record(s) \
 288                    dtls1_retrieve_buffered_record((s), \
 289                    &((s)->d1->processed_rcds))
 290
 291 static int
 292 dtls1_process_buffered_records(SSL *s)
 293     {
 294     pitem *item;
 295
 296     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 297     if (item)
 298         {
 299         /* Check if epoch is current. */
 300         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 301             return(1);  /* Nothing to do. */
 302
 303         /* Process all the records. */
 304         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 305             {
 306             dtls1_get_unprocessed_record(s);
 307             if ( ! dtls1_process_record(s))
 308                 return(0);
 309             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 310                 s->s3->rrec.seq_num);
 311             }
 312         }
 313
 314     /* sync epoch numbers once all the unprocessed records
 315      * have been processed */
 316     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 317     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 318
 319     return(1);
 320     }
 321
 322
 323 #if 0
 324
 325 static int
 326 dtls1_get_buffered_record(SSL *s)
 327         {
 328         pitem *item;
 329         PQ_64BIT priority =
 330                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 331                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 332
 333         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 334                                                            nothing buffered */
 335                 return 0;
 336
 337
 338         item = pqueue_peek(s->d1->rcvd_records);
 339         if (item && item->priority == priority)
 340                 {
 341                 /* Check if we've received the record of interest.  It must be
 342                  * a handshake record, since data records as passed up without
 343                  * buffering */
 344                 DTLS1_RECORD_DATA *rdata;
 345                 item = pqueue_pop(s->d1->rcvd_records);
 346                 rdata = (DTLS1_RECORD_DATA *)item->data;
 347
 348                 if (s->s3->rbuf.buf != NULL)
 349                         OPENSSL_free(s->s3->rbuf.buf);
 350
 351                 s->packet = rdata->packet;
 352                 s->packet_length = rdata->packet_length;
 353                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 354                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 355
 356                 OPENSSL_free(item->data);
 357                 pitem_free(item);
 358
 359                 /* s->d1->next_expected_seq_num++; */
 360                 return(1);
 361                 }
 362
 363         return 0;
 364         }
 365
 366 #endif
 367
 368 static int
 369 dtls1_process_record(SSL *s)
 370 {
 371         int i,al;
 372         int clear=0;
 373         int enc_err;
 374         SSL_SESSION *sess;
 375         SSL3_RECORD *rr;
 376         unsigned int mac_size;
 377         unsigned char md[EVP_MAX_MD_SIZE];
 378         int decryption_failed_or_bad_record_mac = 0;
 379
 380
 381         rr= &(s->s3->rrec);
 382         sess = s->session;
 383
 384         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 385          * and we have that many bytes in s->packet
 386          */
 387         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 388
 389         /* ok, we can now read from 's->packet' data into 'rr'
 390          * rr->input points at rr->length bytes, which
 391          * need to be copied into rr->data by either
 392          * the decryption or by the decompression
 393          * When the data is 'copied' into the rr->data buffer,
 394          * rr->input will be pointed at the new buffer */
 395
 396         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 397          * rr->length bytes of encrypted compressed stuff. */
 398
 399         /* check is not needed I believe */
 400         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 401                 {
 402                 al=SSL_AD_RECORD_OVERFLOW;
 403                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 404                 goto f_err;
 405                 }
 406
 407         /* decrypt in place in 'rr->input' */
 408         rr->data=rr->input;
 409
 410         enc_err = s->method->ssl3_enc->enc(s,0);
 411         if (enc_err <= 0)
 412                 {
 413                 /* To minimize information leaked via timing, we will always
 414                  * perform all computations before discarding the message.
 415                  */
 416                 decryption_failed_or_bad_record_mac = 1;
 417                 }
 418
 419 #ifdef TLS_DEBUG
 420 printf("dec %d\n",rr->length);
 421 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 422 printf("\n");
 423 #endif
 424
 425         /* r->length is now the compressed data plus mac */
 426         if (    (sess == NULL) ||
 427                 (s->enc_read_ctx == NULL) ||
 428                 (s->read_hash == NULL))
 429                 clear=1;
 430
 431         if (!clear)
 432                 {
 433                 /* !clear => s->read_hash != NULL => mac_size != -1 */
 434                 int t;
 435                 t=EVP_MD_CTX_size(s->read_hash);
 436                 OPENSSL_assert(t >= 0);
 437                 mac_size=t;
 438
 439                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 440                         {
 441 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 442                         al=SSL_AD_RECORD_OVERFLOW;
 443                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 444                         goto f_err;
 445 #else
 446                         decryption_failed_or_bad_record_mac = 1;
 447 #endif
 448                         }
 449                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 450                 if (rr->length < mac_size)
 451                         {
 452 #if 0 /* OK only for stream ciphers */
 453                         al=SSL_AD_DECODE_ERROR;
 454                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 455                         goto f_err;
 456 #else
 457                         decryption_failed_or_bad_record_mac = 1;
 458 #endif
 459                         }
 460                 rr->length-=mac_size;
 461                 i=s->method->ssl3_enc->mac(s,md,0);
 462                 if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 463                         {
 464                         decryption_failed_or_bad_record_mac = 1;
 465                         }
 466                 }
 467
 468         if (decryption_failed_or_bad_record_mac)
 469                 {
 470                 /* decryption failed, silently discard message */
 471                 rr->length = 0;
 472                 s->packet_length = 0;
 473                 goto err;
 474                 }
 475
 476         /* r->length is now just compressed */
 477         if (s->expand != NULL)
 478                 {
 479                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 480                         {
 481                         al=SSL_AD_RECORD_OVERFLOW;
 482                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 483                         goto f_err;
 484                         }
 485                 if (!ssl3_do_uncompress(s))
 486                         {
 487                         al=SSL_AD_DECOMPRESSION_FAILURE;
 488                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 489                         goto f_err;
 490                         }
 491                 }
 492
 493         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 494                 {
 495                 al=SSL_AD_RECORD_OVERFLOW;
 496                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 497                 goto f_err;
 498                 }
 499
 500         rr->off=0;
 501         /* So at this point the following is true
 502          * ssl->s3->rrec.type   is the type of record
 503          * ssl->s3->rrec.length == number of bytes in record
 504          * ssl->s3->rrec.off    == offset to first valid byte
 505          * ssl->s3->rrec.data   == where to take bytes from, increment
 506          *                         after use :-).
 507          */
 508
 509         /* we have pulled in a full packet so zero things */
 510         s->packet_length=0;
 511         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 512         return(1);
 513
 514 f_err:
 515         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 516 err:
 517         return(0);
 518 }
 519
 520
 521 /* Call this to get a new input record.
 522  * It will return <= 0 if more data is needed, normally due to an error
 523  * or non-blocking IO.
 524  * When it finishes, one packet has been decoded and can be found in
 525  * ssl->s3->rrec.type    - is the type of record
 526  * ssl->s3->rrec.data,   - data
 527  * ssl->s3->rrec.length, - number of bytes
 528  */
 529 /* used only by dtls1_read_bytes */
 530 int dtls1_get_record(SSL *s)
 531         {
 532         int ssl_major,ssl_minor;
 533         int i,n;
 534         SSL3_RECORD *rr;
 535         unsigned char *p = NULL;
 536         unsigned short version;
 537         DTLS1_BITMAP *bitmap;
 538         unsigned int is_next_epoch;
 539
 540         rr= &(s->s3->rrec);
 541
 542         /* The epoch may have changed.  If so, process all the
 543          * pending records.  This is a non-blocking operation. */
 544         dtls1_process_buffered_records(s);
 545
 546         /* if we're renegotiating, then there may be buffered records */
 547         if (dtls1_get_processed_record(s))
 548                 return 1;
 549
 550         /* get something from the wire */
 551 again:
 552         /* check if we have the header */
 553         if (    (s->rstate != SSL_ST_READ_BODY) ||
 554                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 555                 {
 556                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 557                 /* read timeout is handled by dtls1_read_bytes */
 558                 if (n <= 0) return(n); /* error or non-blocking */
 559
 560                 /* this packet contained a partial record, dump it */
 561                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
 562                         {
 563                         s->packet_length = 0;
 564                         goto again;
 565                         }
 566
 567                 s->rstate=SSL_ST_READ_BODY;
 568
 569                 p=s->packet;
 570
 571                 /* Pull apart the header into the DTLS1_RECORD */
 572                 rr->type= *(p++);
 573                 ssl_major= *(p++);
 574                 ssl_minor= *(p++);
 575                 version=(ssl_major<<8)|ssl_minor;
 576
 577                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 578                 n2s(p,rr->epoch);
 579
 580                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 581                 p+=6;
 582
 583                 n2s(p,rr->length);
 584
 585                 /* Lets check version */
 586                 if (!s->first_packet)
 587                         {
 588                         if (version != s->version)
 589                                 {
 590                                 /* unexpected version, silently discard */
 591                                 rr->length = 0;
 592                                 s->packet_length = 0;
 593                                 goto again;
 594                                 }
 595                         }
 596
 597                 if ((version & 0xff00) != (s->version & 0xff00))
 598                         {
 599                         /* wrong version, silently discard record */
 600                         rr->length = 0;
 601                         s->packet_length = 0;
 602                         goto again;
 603                         }
 604
 605                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 606                         {
 607                         /* record too long, silently discard it */
 608                         rr->length = 0;
 609                         s->packet_length = 0;
 610                         goto again;
 611                         }
 612
 613                 /* now s->rstate == SSL_ST_READ_BODY */
 614                 }
 615
 616         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 617
 618         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 619                 {
 620                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 621                 i=rr->length;
 622                 n=ssl3_read_n(s,i,i,1);
 623                 if (n <= 0) return(n); /* error or non-blocking io */
 624
 625                 /* this packet contained a partial record, dump it */
 626                 if ( n != i)
 627                         {
 628                         rr->length = 0;
 629                         s->packet_length = 0;
 630                         goto again;
 631                         }
 632
 633                 /* now n == rr->length,
 634                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 635                 }
 636         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 637
 638         /* match epochs.  NULL means the packet is dropped on the floor */
 639         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 640         if ( bitmap == NULL)
 641                 {
 642                 rr->length = 0;
 643                 s->packet_length = 0;  /* dump this record */
 644                 goto again;   /* get another record */
 645                 }
 646
 647         /* Check whether this is a repeat, or aged record.
 648          * Don't check if we're listening and this message is
 649          * a ClientHello. They can look as if they're replayed,
 650          * since they arrive from different connections and
 651          * would be dropped unnecessarily.
 652          */
 653         if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
 654                 *p == SSL3_MT_CLIENT_HELLO) &&
 655                 !dtls1_record_replay_check(s, bitmap))
 656                 {
 657                 rr->length = 0;
 658                 s->packet_length=0; /* dump this record */
 659                 goto again;     /* get another record */
 660                 }
 661
 662         /* just read a 0 length packet */
 663         if (rr->length == 0) goto again;
 664
 665         /* If this record is from the next epoch (either HM or ALERT),
 666          * and a handshake is currently in progress, buffer it since it
 667          * cannot be processed at this time. However, do not buffer
 668          * anything while listening.
 669          */
 670         if (is_next_epoch)
 671                 {
 672                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
 673                         {
 674                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 675                         }
 676                 rr->length = 0;
 677                 s->packet_length = 0;
 678                 goto again;
 679                 }
 680
 681         if (!dtls1_process_record(s))
 682                 {
 683                 rr->length = 0;
 684                 s->packet_length = 0;  /* dump this record */
 685                 goto again;   /* get another record */
 686                 }
 687
 688         dtls1_clear_timeouts(s);  /* done waiting */
 689         return(1);
 690
 691         }
 692
 693 /* Return up to 'len' payload bytes received in 'type' records.
 694  * 'type' is one of the following:
 695  *
 696  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 697  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 698  *   -  0 (during a shutdown, no data has to be returned)
 699  *
 700  * If we don't have stored data to work from, read a SSL/TLS record first
 701  * (possibly multiple records if we still don't have anything to return).
 702  *
 703  * This function must handle any surprises the peer may have for us, such as
 704  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 705  * a surprise, but handled as if it were), or renegotiation requests.
 706  * Also if record payloads contain fragments too small to process, we store
 707  * them until there is enough for the respective protocol (the record protocol
 708  * may use arbitrary fragmentation and even interleaving):
 709  *     Change cipher spec protocol
 710  *             just 1 byte needed, no need for keeping anything stored
 711  *     Alert protocol
 712  *             2 bytes needed (AlertLevel, AlertDescription)
 713  *     Handshake protocol
 714  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 715  *             to detect unexpected Client Hello and Hello Request messages
 716  *             here, anything else is handled by higher layers
 717  *     Application data protocol
 718  *             none of our business
 719  */
 720 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 721         {
 722         int al,i,j,ret;
 723         unsigned int n;
 724         SSL3_RECORD *rr;
 725         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 726
 727         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 728                 if (!ssl3_setup_buffers(s))
 729                         return(-1);
 730
 731     /* XXX: check what the second '&& type' is about */
 732         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 733                 (type != SSL3_RT_HANDSHAKE) && type) ||
 734             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 735                 {
 736                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 737                 return -1;
 738                 }
 739
 740         /* check whether there's a handshake message (client hello?) waiting */
 741         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 742                 return ret;
 743
 744         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 745
 746         if (!s->in_handshake && SSL_in_init(s))
 747                 {
 748                 /* type == SSL3_RT_APPLICATION_DATA */
 749                 i=s->handshake_func(s);
 750                 if (i < 0) return(i);
 751                 if (i == 0)
 752                         {
 753                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 754                         return(-1);
 755                         }
 756                 }
 757
 758 start:
 759         s->rwstate=SSL_NOTHING;
 760
 761         /* s->s3->rrec.type         - is the type of record
 762          * s->s3->rrec.data,    - data
 763          * s->s3->rrec.off,     - offset into 'data' for next read
 764          * s->s3->rrec.length,  - number of bytes. */
 765         rr = &(s->s3->rrec);
 766
 767         /* We are not handshaking and have no data yet,
 768          * so process data buffered during the last handshake
 769          * in advance, if any.
 770          */
 771         if (s->state == SSL_ST_OK && rr->length == 0)
 772                 {
 773                 pitem *item;
 774                 item = pqueue_pop(s->d1->buffered_app_data.q);
 775                 if (item)
 776                         {
 777                         dtls1_copy_record(s, item);
 778
 779                         OPENSSL_free(item->data);
 780                         pitem_free(item);
 781                         }
 782                 }
 783
 784         /* Check for timeout */
 785         if (dtls1_handle_timeout(s) > 0)
 786                 goto start;
 787
 788         /* get new packet if necessary */
 789         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 790                 {
 791                 ret=dtls1_get_record(s);
 792                 if (ret <= 0)
 793                         {
 794                         ret = dtls1_read_failed(s, ret);
 795                         /* anything other than a timeout is an error */
 796                         if (ret <= 0)
 797                                 return(ret);
 798                         else
 799                                 goto start;
 800                         }
 801                 }
 802
 803         /* we now have a packet which can be read and processed */
 804
 805         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 806                                        * reset by ssl3_get_finished */
 807                 && (rr->type != SSL3_RT_HANDSHAKE))
 808                 {
 809                 /* We now have application data between CCS and Finished.
 810                  * Most likely the packets were reordered on their way, so
 811                  * buffer the application data for later processing rather
 812                  * than dropping the connection.
 813                  */
 814                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
 815                 rr->length = 0;
 816                 goto start;
 817                 }
 818
 819         /* If the other end has shut down, throw anything we read away
 820          * (even in 'peek' mode) */
 821         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 822                 {
 823                 rr->length=0;
 824                 s->rwstate=SSL_NOTHING;
 825                 return(0);
 826                 }
 827
 828
 829         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 830                 {
 831                 /* make sure that we are not getting application data when we
 832                  * are doing a handshake for the first time */
 833                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 834                         (s->enc_read_ctx == NULL))
 835                         {
 836                         al=SSL_AD_UNEXPECTED_MESSAGE;
 837                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 838                         goto f_err;
 839                         }
 840
 841                 if (len <= 0) return(len);
 842
 843                 if ((unsigned int)len > rr->length)
 844                         n = rr->length;
 845                 else
 846                         n = (unsigned int)len;
 847
 848                 memcpy(buf,&(rr->data[rr->off]),n);
 849                 if (!peek)
 850                         {
 851                         rr->length-=n;
 852                         rr->off+=n;
 853                         if (rr->length == 0)
 854                                 {
 855                                 s->rstate=SSL_ST_READ_HEADER;
 856                                 rr->off=0;
 857                                 }
 858                         }
 859                 return(n);
 860                 }
 861
 862
 863         /* If we get here, then type != rr->type; if we have a handshake
 864          * message, then it was unexpected (Hello Request or Client Hello). */
 865
 866         /* In case of record types for which we have 'fragment' storage,
 867          * fill that so that we can process the data at a fixed place.
 868          */
 869                 {
 870                 unsigned int k, dest_maxlen = 0;
 871                 unsigned char *dest = NULL;
 872                 unsigned int *dest_len = NULL;
 873
 874                 if (rr->type == SSL3_RT_HANDSHAKE)
 875                         {
 876                         dest_maxlen = sizeof s->d1->handshake_fragment;
 877                         dest = s->d1->handshake_fragment;
 878                         dest_len = &s->d1->handshake_fragment_len;
 879                         }
 880                 else if (rr->type == SSL3_RT_ALERT)
 881                         {
 882                         dest_maxlen = sizeof(s->d1->alert_fragment);
 883                         dest = s->d1->alert_fragment;
 884                         dest_len = &s->d1->alert_fragment_len;
 885                         }
 886                 /* else it's a CCS message, or application data or wrong */
 887                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 888                         {
 889                         /* Application data while renegotiating
 890                          * is allowed. Try again reading.
 891                          */
 892                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 893                                 {
 894                                 BIO *bio;
 895                                 s->s3->in_read_app_data=2;
 896                                 bio=SSL_get_rbio(s);
 897                                 s->rwstate=SSL_READING;
 898                                 BIO_clear_retry_flags(bio);
 899                                 BIO_set_retry_read(bio);
 900                                 return(-1);
 901                                 }
 902
 903                         /* Not certain if this is the right error handling */
 904                         al=SSL_AD_UNEXPECTED_MESSAGE;
 905                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 906                         goto f_err;
 907                         }
 908
 909                 if (dest_maxlen > 0)
 910                         {
 911             /* XDTLS:  In a pathalogical case, the Client Hello
 912              *  may be fragmented--don't always expect dest_maxlen bytes */
 913                         if ( rr->length < dest_maxlen)
 914                                 {
 915 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
 916                                 /*
 917                                  * for normal alerts rr->length is 2, while
 918                                  * dest_maxlen is 7 if we were to handle this
 919                                  * non-existing alert...
 920                                  */
 921                                 FIX ME
 922 #endif
 923                                 s->rstate=SSL_ST_READ_HEADER;
 924                                 rr->length = 0;
 925                                 goto start;
 926                                 }
 927
 928                         /* now move 'n' bytes: */
 929                         for ( k = 0; k < dest_maxlen; k++)
 930                                 {
 931                                 dest[k] = rr->data[rr->off++];
 932                                 rr->length--;
 933                                 }
 934                         *dest_len = dest_maxlen;
 935                         }
 936                 }
 937
 938         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 939          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 940          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 941
 942         /* If we are a client, check for an incoming 'Hello Request': */
 943         if ((!s->server) &&
 944                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 945                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 946                 (s->session != NULL) && (s->session->cipher != NULL))
 947                 {
 948                 s->d1->handshake_fragment_len = 0;
 949
 950                 if ((s->d1->handshake_fragment[1] != 0) ||
 951                         (s->d1->handshake_fragment[2] != 0) ||
 952                         (s->d1->handshake_fragment[3] != 0))
 953                         {
 954                         al=SSL_AD_DECODE_ERROR;
 955                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 956                         goto err;
 957                         }
 958
 959                 /* no need to check sequence number on HELLO REQUEST messages */
 960
 961                 if (s->msg_callback)
 962                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 963                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 964
 965                 if (SSL_is_init_finished(s) &&
 966                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 967                         !s->s3->renegotiate)
 968                         {
 969                         ssl3_renegotiate(s);
 970                         if (ssl3_renegotiate_check(s))
 971                                 {
 972                                 i=s->handshake_func(s);
 973                                 if (i < 0) return(i);
 974                                 if (i == 0)
 975                                         {
 976                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 977                                         return(-1);
 978                                         }
 979
 980                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 981                                         {
 982                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 983                                                 {
 984                                                 BIO *bio;
 985                                                 /* In the case where we try to read application data,
 986                                                  * but we trigger an SSL handshake, we return -1 with
 987                                                  * the retry option set.  Otherwise renegotiation may
 988                                                  * cause nasty problems in the blocking world */
 989                                                 s->rwstate=SSL_READING;
 990                                                 bio=SSL_get_rbio(s);
 991                                                 BIO_clear_retry_flags(bio);
 992                                                 BIO_set_retry_read(bio);
 993                                                 return(-1);
 994                                                 }
 995                                         }
 996                                 }
 997                         }
 998                 /* we either finished a handshake or ignored the request,
 999                  * now try again to obtain the (application) data we were asked for */
1000                 goto start;
1001                 }
1002
1003         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1004                 {
1005                 int alert_level = s->d1->alert_fragment[0];
1006                 int alert_descr = s->d1->alert_fragment[1];
1007
1008                 s->d1->alert_fragment_len = 0;
1009
1010                 if (s->msg_callback)
1011                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1012                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1013
1014                 if (s->info_callback != NULL)
1015                         cb=s->info_callback;
1016                 else if (s->ctx->info_callback != NULL)
1017                         cb=s->ctx->info_callback;
1018
1019                 if (cb != NULL)
1020                         {
1021                         j = (alert_level << 8) | alert_descr;
1022                         cb(s, SSL_CB_READ_ALERT, j);
1023                         }
1024
1025                 if (alert_level == 1) /* warning */
1026                         {
1027                         s->s3->warn_alert = alert_descr;
1028                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1029                                 {
1030                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1031                                 return(0);
1032                                 }
1033 #if 0
1034             /* XXX: this is a possible improvement in the future */
1035                         /* now check if it's a missing record */
1036                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1037                                 {
1038                                 unsigned short seq;
1039                                 unsigned int frag_off;
1040                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1041
1042                                 n2s(p, seq);
1043                                 n2l3(p, frag_off);
1044
1045                                 dtls1_retransmit_message(s,
1046                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1047                                                                                  frag_off, &found);
1048                                 if ( ! found  && SSL_in_init(s))
1049                                         {
1050                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1051                                         /* requested a message not yet sent,
1052                                            send an alert ourselves */
1053                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1054                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1055                                         }
1056                                 }
1057 #endif
1058                         }
1059                 else if (alert_level == 2) /* fatal */
1060                         {
1061                         char tmp[16];
1062
1063                         s->rwstate=SSL_NOTHING;
1064                         s->s3->fatal_alert = alert_descr;
1065                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1066                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1067                         ERR_add_error_data(2,"SSL alert number ",tmp);
1068                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1069                         SSL_CTX_remove_session(s->ctx,s->session);
1070                         return(0);
1071                         }
1072                 else
1073                         {
1074                         al=SSL_AD_ILLEGAL_PARAMETER;
1075                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1076                         goto f_err;
1077                         }
1078
1079                 goto start;
1080                 }
1081
1082         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1083                 {
1084                 s->rwstate=SSL_NOTHING;
1085                 rr->length=0;
1086                 return(0);
1087                 }
1088
1089         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1090                 {
1091                 struct ccs_header_st ccs_hdr;
1092                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1093
1094                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1095
1096                 if (s->version == DTLS1_BAD_VER)
1097                         ccs_hdr_len = 3;
1098
1099                 /* 'Change Cipher Spec' is just a single byte, so we know
1100                  * exactly what the record payload has to look like */
1101                 /* XDTLS: check that epoch is consistent */
1102                 if (    (rr->length != ccs_hdr_len) ||
1103                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1104                         {
1105                         i=SSL_AD_ILLEGAL_PARAMETER;
1106                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1107                         goto err;
1108                         }
1109
1110                 rr->length=0;
1111
1112                 if (s->msg_callback)
1113                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1114                                 rr->data, 1, s, s->msg_callback_arg);
1115
1116                 /* We can't process a CCS now, because previous handshake
1117                  * messages are still missing, so just drop it.
1118                  */
1119                 if (!s->d1->change_cipher_spec_ok)
1120                         {
1121                         goto start;
1122                         }
1123
1124                 s->d1->change_cipher_spec_ok = 0;
1125
1126                 s->s3->change_cipher_spec=1;
1127                 if (!ssl3_do_change_cipher_spec(s))
1128                         goto err;
1129
1130                 /* do this whenever CCS is processed */
1131                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1132
1133                 if (s->version == DTLS1_BAD_VER)
1134                         s->d1->handshake_read_seq++;
1135
1136                 goto start;
1137                 }
1138
1139         /* Unexpected handshake message (Client Hello, or protocol violation) */
1140         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1141                 !s->in_handshake)
1142                 {
1143                 struct hm_header_st msg_hdr;
1144
1145                 /* this may just be a stale retransmit */
1146                 dtls1_get_message_header(rr->data, &msg_hdr);
1147                 if( rr->epoch != s->d1->r_epoch)
1148                         {
1149                         rr->length = 0;
1150                         goto start;
1151                         }
1152
1153                 /* If we are server, we may have a repeated FINISHED of the
1154                  * client here, then retransmit our CCS and FINISHED.
1155                  */
1156                 if (msg_hdr.type == SSL3_MT_FINISHED)
1157                         {
1158                         dtls1_retransmit_buffered_messages(s);
1159                         rr->length = 0;
1160                         goto start;
1161                         }
1162
1163                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1164                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1165                         {
1166 #if 0 /* worked only because C operator preferences are not as expected (and
1167        * because this is not really needed for clients except for detecting
1168        * protocol violations): */
1169                         s->state=SSL_ST_BEFORE|(s->server)
1170                                 ?SSL_ST_ACCEPT
1171                                 :SSL_ST_CONNECT;
1172 #else
1173                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1174 #endif
1175                         s->new_session=1;
1176                         }
1177                 i=s->handshake_func(s);
1178                 if (i < 0) return(i);
1179                 if (i == 0)
1180                         {
1181                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1182                         return(-1);
1183                         }
1184
1185                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1186                         {
1187                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1188                                 {
1189                                 BIO *bio;
1190                                 /* In the case where we try to read application data,
1191                                  * but we trigger an SSL handshake, we return -1 with
1192                                  * the retry option set.  Otherwise renegotiation may
1193                                  * cause nasty problems in the blocking world */
1194                                 s->rwstate=SSL_READING;
1195                                 bio=SSL_get_rbio(s);
1196                                 BIO_clear_retry_flags(bio);
1197                                 BIO_set_retry_read(bio);
1198                                 return(-1);
1199                                 }
1200                         }
1201                 goto start;
1202                 }
1203
1204         switch (rr->type)
1205                 {
1206         default:
1207 #ifndef OPENSSL_NO_TLS
1208                 /* TLS just ignores unknown message types */
1209                 if (s->version == TLS1_VERSION)
1210                         {
1211                         rr->length = 0;
1212                         goto start;
1213                         }
1214 #endif
1215                 al=SSL_AD_UNEXPECTED_MESSAGE;
1216                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1217                 goto f_err;
1218         case SSL3_RT_CHANGE_CIPHER_SPEC:
1219         case SSL3_RT_ALERT:
1220         case SSL3_RT_HANDSHAKE:
1221                 /* we already handled all of these, with the possible exception
1222                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1223                  * should not happen when type != rr->type */
1224                 al=SSL_AD_UNEXPECTED_MESSAGE;
1225                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1226                 goto f_err;
1227         case SSL3_RT_APPLICATION_DATA:
1228                 /* At this point, we were expecting handshake data,
1229                  * but have application data.  If the library was
1230                  * running inside ssl3_read() (i.e. in_read_app_data
1231                  * is set) and it makes sense to read application data
1232                  * at this point (session renegotiation not yet started),
1233                  * we will indulge it.
1234                  */
1235                 if (s->s3->in_read_app_data &&
1236                         (s->s3->total_renegotiations != 0) &&
1237                         ((
1238                                 (s->state & SSL_ST_CONNECT) &&
1239                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1240                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1241                                 ) || (
1242                                         (s->state & SSL_ST_ACCEPT) &&
1243                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1244                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1245                                         )
1246                                 ))
1247                         {
1248                         s->s3->in_read_app_data=2;
1249                         return(-1);
1250                         }
1251                 else
1252                         {
1253                         al=SSL_AD_UNEXPECTED_MESSAGE;
1254                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1255                         goto f_err;
1256                         }
1257                 }
1258         /* not reached */
1259
1260 f_err:
1261         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1262 err:
1263         return(-1);
1264         }
1265
1266 int
1267 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1268         {
1269         int i;
1270
1271         if (SSL_in_init(s) && !s->in_handshake)
1272                 {
1273                 i=s->handshake_func(s);
1274                 if (i < 0) return(i);
1275                 if (i == 0)
1276                         {
1277                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1278                         return -1;
1279                         }
1280                 }
1281
1282         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1283                 {
1284                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1285                         return -1;
1286                 }
1287
1288         i = dtls1_write_bytes(s, type, buf_, len);
1289         return i;
1290         }
1291
1292
1293         /* this only happens when a client hello is received and a handshake
1294          * is started. */
1295 static int
1296 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1297         int len, int peek)
1298         {
1299
1300         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1301                 /* (partially) satisfy request from storage */
1302                 {
1303                 unsigned char *src = s->d1->handshake_fragment;
1304                 unsigned char *dst = buf;
1305                 unsigned int k,n;
1306
1307                 /* peek == 0 */
1308                 n = 0;
1309                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1310                         {
1311                         *dst++ = *src++;
1312                         len--; s->d1->handshake_fragment_len--;
1313                         n++;
1314                         }
1315                 /* move any remaining fragment bytes: */
1316                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1317                         s->d1->handshake_fragment[k] = *src++;
1318                 return n;
1319                 }
1320
1321         return 0;
1322         }
1323
1324
1325
1326
1327 /* Call this to write data in records of type 'type'
1328  * It will return <= 0 if not all data has been sent or non-blocking IO.
1329  */
1330 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1331         {
1332         int i;
1333
1334         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1335         s->rwstate=SSL_NOTHING;
1336         i=do_dtls1_write(s, type, buf, len, 0);
1337         return i;
1338         }
1339
1340 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1341         {
1342         unsigned char *p,*pseq;
1343         int i,mac_size,clear=0;
1344         int prefix_len = 0;
1345         SSL3_RECORD *wr;
1346         SSL3_BUFFER *wb;
1347         SSL_SESSION *sess;
1348         int bs;
1349
1350         /* first check if there is a SSL3_BUFFER still being written
1351          * out.  This will happen with non blocking IO */
1352         if (s->s3->wbuf.left != 0)
1353                 {
1354                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1355                 return(ssl3_write_pending(s,type,buf,len));
1356                 }
1357
1358         /* If we have an alert to send, lets send it */
1359         if (s->s3->alert_dispatch)
1360                 {
1361                 i=s->method->ssl_dispatch_alert(s);
1362                 if (i <= 0)
1363                         return(i);
1364                 /* if it went, fall through and send more stuff */
1365                 }
1366
1367         if (len == 0 && !create_empty_fragment)
1368                 return 0;
1369
1370         wr= &(s->s3->wrec);
1371         wb= &(s->s3->wbuf);
1372         sess=s->session;
1373
1374         if (    (sess == NULL) ||
1375                 (s->enc_write_ctx == NULL) ||
1376                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1377                 clear=1;
1378
1379         if (clear)
1380                 mac_size=0;
1381         else
1382                 {
1383                 mac_size=EVP_MD_CTX_size(s->write_hash);
1384                 if (mac_size < 0)
1385                         goto err;
1386                 }
1387
1388         /* DTLS implements explicit IV, so no need for empty fragments */
1389 #if 0
1390         /* 'create_empty_fragment' is true only when this function calls itself */
1391         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1392             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1393                 {
1394                 /* countermeasure against known-IV weakness in CBC ciphersuites
1395                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1396                  */
1397
1398                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1399                         {
1400                         /* recursive function call with 'create_empty_fragment' set;
1401                          * this prepares and buffers the data for an empty fragment
1402                          * (these 'prefix_len' bytes are sent out later
1403                          * together with the actual payload) */
1404                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1405                         if (prefix_len <= 0)
1406                                 goto err;
1407
1408                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1409                                 {
1410                                 /* insufficient space */
1411                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1412                                 goto err;
1413                                 }
1414                         }
1415
1416                 s->s3->empty_fragment_done = 1;
1417                 }
1418 #endif
1419         p = wb->buf + prefix_len;
1420
1421         /* write the header */
1422
1423         *(p++)=type&0xff;
1424         wr->type=type;
1425
1426         *(p++)=(s->version>>8);
1427         *(p++)=s->version&0xff;
1428
1429         /* field where we are to write out packet epoch, seq num and len */
1430         pseq=p;
1431         p+=10;
1432
1433         /* lets setup the record stuff. */
1434
1435         /* Make space for the explicit IV in case of CBC.
1436          * (this is a bit of a boundary violation, but what the heck).
1437          */
1438         if ( s->enc_write_ctx &&
1439                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1440                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1441         else
1442                 bs = 0;
1443
1444         wr->data=p + bs;  /* make room for IV in case of CBC */
1445         wr->length=(int)len;
1446         wr->input=(unsigned char *)buf;
1447
1448         /* we now 'read' from wr->input, wr->length bytes into
1449          * wr->data */
1450
1451         /* first we compress */
1452         if (s->compress != NULL)
1453                 {
1454                 if (!ssl3_do_compress(s))
1455                         {
1456                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1457                         goto err;
1458                         }
1459                 }
1460         else
1461                 {
1462                 memcpy(wr->data,wr->input,wr->length);
1463                 wr->input=wr->data;
1464                 }
1465
1466         /* we should still have the output to wr->data and the input
1467          * from wr->input.  Length should be wr->length.
1468          * wr->data still points in the wb->buf */
1469
1470         if (mac_size != 0)
1471                 {
1472                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1473                         goto err;
1474                 wr->length+=mac_size;
1475                 }
1476
1477         /* this is true regardless of mac size */
1478         wr->input=p;
1479         wr->data=p;
1480
1481
1482         /* ssl3_enc can only have an error on read */
1483         if (bs) /* bs != 0 in case of CBC */
1484                 {
1485                 RAND_pseudo_bytes(p,bs);
1486                 /* master IV and last CBC residue stand for
1487                  * the rest of randomness */
1488                 wr->length += bs;
1489                 }
1490
1491         s->method->ssl3_enc->enc(s,1);
1492
1493         /* record length after mac and block padding */
1494 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1495         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1496
1497         /* there's only one epoch between handshake and app data */
1498
1499         s2n(s->d1->w_epoch, pseq);
1500
1501         /* XDTLS: ?? */
1502 /*      else
1503         s2n(s->d1->handshake_epoch, pseq); */
1504
1505         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1506         pseq+=6;
1507         s2n(wr->length,pseq);
1508
1509         /* we should now have
1510          * wr->data pointing to the encrypted data, which is
1511          * wr->length long */
1512         wr->type=type; /* not needed but helps for debugging */
1513         wr->length+=DTLS1_RT_HEADER_LENGTH;
1514
1515 #if 0  /* this is now done at the message layer */
1516         /* buffer the record, making it easy to handle retransmits */
1517         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1518                 dtls1_buffer_record(s, wr->data, wr->length,
1519                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1520 #endif
1521
1522         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1523
1524         if (create_empty_fragment)
1525                 {
1526                 /* we are in a recursive call;
1527                  * just return the length, don't write out anything here
1528                  */
1529                 return wr->length;
1530                 }
1531
1532         /* now let's set up wb */
1533         wb->left = prefix_len + wr->length;
1534         wb->offset = 0;
1535
1536         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1537         s->s3->wpend_tot=len;
1538         s->s3->wpend_buf=buf;
1539         s->s3->wpend_type=type;
1540         s->s3->wpend_ret=len;
1541
1542         /* we now just need to write the buffer */
1543         return ssl3_write_pending(s,type,buf,len);
1544 err:
1545         return -1;
1546         }
1547
1548
1549
1550 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1551         {
1552         int cmp;
1553         unsigned int shift;
1554         const unsigned char *seq = s->s3->read_sequence;
1555
1556         cmp = satsub64be(seq,bitmap->max_seq_num);
1557         if (cmp > 0)
1558                 {
1559                 memcpy (s->s3->rrec.seq_num,seq,8);
1560                 return 1; /* this record in new */
1561                 }
1562         shift = -cmp;
1563         if (shift >= sizeof(bitmap->map)*8)
1564                 return 0; /* stale, outside the window */
1565         else if (bitmap->map & (1UL<<shift))
1566                 return 0; /* record previously received */
1567
1568         memcpy (s->s3->rrec.seq_num,seq,8);
1569         return 1;
1570         }
1571
1572
1573 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1574         {
1575         int cmp;
1576         unsigned int shift;
1577         const unsigned char *seq = s->s3->read_sequence;
1578
1579         cmp = satsub64be(seq,bitmap->max_seq_num);
1580         if (cmp > 0)
1581                 {
1582                 shift = cmp;
1583                 if (shift < sizeof(bitmap->map)*8)
1584                         bitmap->map <<= shift, bitmap->map |= 1UL;
1585                 else
1586                         bitmap->map = 1UL;
1587                 memcpy(bitmap->max_seq_num,seq,8);
1588                 }
1589         else    {
1590                 shift = -cmp;
1591                 if (shift < sizeof(bitmap->map)*8)
1592                         bitmap->map |= 1UL<<shift;
1593                 }
1594         }
1595
1596
1597 int dtls1_dispatch_alert(SSL *s)
1598         {
1599         int i,j;
1600         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1601         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1602         unsigned char *ptr = &buf[0];
1603
1604         s->s3->alert_dispatch=0;
1605
1606         memset(buf, 0x00, sizeof(buf));
1607         *ptr++ = s->s3->send_alert[0];
1608         *ptr++ = s->s3->send_alert[1];
1609
1610 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1611         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1612                 {
1613                 s2n(s->d1->handshake_read_seq, ptr);
1614 #if 0
1615                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1616
1617                 else
1618                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1619 #endif
1620
1621 #if 0
1622                 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);
1623 #endif
1624                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1625                 }
1626 #endif
1627
1628         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1629         if (i <= 0)
1630                 {
1631                 s->s3->alert_dispatch=1;
1632                 /* fprintf( stderr, "not done with alert\n" ); */
1633                 }
1634         else
1635                 {
1636                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1637 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1638                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1639 #endif
1640                     )
1641                         (void)BIO_flush(s->wbio);
1642
1643                 if (s->msg_callback)
1644                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1645                                 2, s, s->msg_callback_arg);
1646
1647                 if (s->info_callback != NULL)
1648                         cb=s->info_callback;
1649                 else if (s->ctx->info_callback != NULL)
1650                         cb=s->ctx->info_callback;
1651
1652                 if (cb != NULL)
1653                         {
1654                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1655                         cb(s,SSL_CB_WRITE_ALERT,j);
1656                         }
1657                 }
1658         return(i);
1659         }
1660
1661
1662 static DTLS1_BITMAP *
1663 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1664     {
1665
1666     *is_next_epoch = 0;
1667
1668     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1669     if (rr->epoch == s->d1->r_epoch)
1670         return &s->d1->bitmap;
1671
1672     /* Only HM and ALERT messages can be from the next epoch */
1673     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1674         (rr->type == SSL3_RT_HANDSHAKE ||
1675             rr->type == SSL3_RT_ALERT))
1676         {
1677         *is_next_epoch = 1;
1678         return &s->d1->next_bitmap;
1679         }
1680
1681     return NULL;
1682     }
1683
1684 #if 0
1685 static int
1686 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1687         unsigned long *offset)
1688         {
1689
1690         /* alerts are passed up immediately */
1691         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1692                 rr->type == SSL3_RT_ALERT)
1693                 return 0;
1694
1695         /* Only need to buffer if a handshake is underway.
1696          * (this implies that Hello Request and Client Hello are passed up
1697          * immediately) */
1698         if ( SSL_in_init(s))
1699                 {
1700                 unsigned char *data = rr->data;
1701                 /* need to extract the HM/CCS sequence number here */
1702                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1703                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1704                         {
1705                         unsigned short seq_num;
1706                         struct hm_header_st msg_hdr;
1707                         struct ccs_header_st ccs_hdr;
1708
1709                         if ( rr->type == SSL3_RT_HANDSHAKE)
1710                                 {
1711                                 dtls1_get_message_header(data, &msg_hdr);
1712                                 seq_num = msg_hdr.seq;
1713                                 *offset = msg_hdr.frag_off;
1714                                 }
1715                         else
1716                                 {
1717                                 dtls1_get_ccs_header(data, &ccs_hdr);
1718                                 seq_num = ccs_hdr.seq;
1719                                 *offset = 0;
1720                                 }
1721
1722                         /* this is either a record we're waiting for, or a
1723                          * retransmit of something we happened to previously
1724                          * receive (higher layers will drop the repeat silently */
1725                         if ( seq_num < s->d1->handshake_read_seq)
1726                                 return 0;
1727                         if (rr->type == SSL3_RT_HANDSHAKE &&
1728                                 seq_num == s->d1->handshake_read_seq &&
1729                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1730                                 return 0;
1731                         else if ( seq_num == s->d1->handshake_read_seq &&
1732                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1733                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1734                                 return 0;
1735                         else
1736                                 {
1737                                 *priority = seq_num;
1738                                 return 1;
1739                                 }
1740                         }
1741                 else /* unknown record type */
1742                         return 0;
1743                 }
1744
1745         return 0;
1746         }
1747 #endif
1748
1749 void
1750 dtls1_reset_seq_numbers(SSL *s, int rw)
1751         {
1752         unsigned char *seq;
1753         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1754
1755         if ( rw & SSL3_CC_READ)
1756                 {
1757                 seq = s->s3->read_sequence;
1758                 s->d1->r_epoch++;
1759                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1760                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1761                 }
1762         else
1763                 {
1764                 seq = s->s3->write_sequence;
1765                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1766                 s->d1->w_epoch++;
1767                 }
1768
1769         memset(seq, 0x00, seq_bytes);
1770         }
1771
1772
1773 static void
1774 dtls1_clear_timeouts(SSL *s)
1775         {
1776         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1777         }