ssl/d1_pkt.c

   1 /* ssl/d1_pkt.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <stdio.h>
 117 #include <errno.h>
 118 #define USE_SOCKETS
 119 #include "ssl_locl.h"
 120 #include <openssl/evp.h>
 121 #include <openssl/buffer.h>
 122 #include <openssl/pqueue.h>
 123 #include <openssl/rand.h>
 124
 125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
 126 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
 127 {       int ret,sat,brw,i;
 128
 129         if (sizeof(long) == 8) do
 130         {       const union { long one; char little; } is_endian = {1};
 131                 long l;
 132
 133                 if (is_endian.little)                   break;
 134                 /* not reached on little-endians */
 135                 /* following test is redundant, because input is
 136                  * always aligned, but I take no chances... */
 137                 if (((size_t)v1|(size_t)v2)&0x7)        break;
 138
 139                 l  = *((long *)v1);
 140                 l -= *((long *)v2);
 141                 if (l>128)              return 128;
 142                 else if (l<-128)        return -128;
 143                 else                    return (int)l;
 144         } while (0);
 145
 146         ret = (int)v1[7]-(int)v2[7];
 147         sat = 0;
 148         brw = ret>>8;   /* brw is either 0 or -1 */
 149         if (ret & 0x80)
 150         {       for (i=6;i>=0;i--)
 151                 {       brw += (int)v1[i]-(int)v2[i];
 152                         sat |= ~brw;
 153                         brw >>= 8;
 154                 }
 155         }
 156         else
 157         {       for (i=6;i>=0;i--)
 158                 {       brw += (int)v1[i]-(int)v2[i];
 159                         sat |= brw;
 160                         brw >>= 8;
 161                 }
 162         }
 163         brw <<= 8;      /* brw is either 0 or -256 */
 164
 165         if (sat&0xff)   return brw | 0x80;
 166         else            return brw + (ret&0xFF);
 167 }
 168
 169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
 170         int len, int peek);
 171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
 172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
 173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
 174     unsigned int *is_next_epoch);
 175 #if 0
 176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
 177         unsigned short *priority, unsigned long *offset);
 178 #endif
 179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
 180         unsigned char *priority);
 181 static int dtls1_process_record(SSL *s);
 182
 183 /* copy buffered record into SSL structure */
 184 static int
 185 dtls1_copy_record(SSL *s, pitem *item)
 186     {
 187     DTLS1_RECORD_DATA *rdata;
 188
 189     rdata = (DTLS1_RECORD_DATA *)item->data;
 190
 191     if (s->s3->rbuf.buf != NULL)
 192         OPENSSL_free(s->s3->rbuf.buf);
 193
 194     s->packet = rdata->packet;
 195     s->packet_length = rdata->packet_length;
 196     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 197     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 198
 199         /* Set proper sequence number for mac calculation */
 200         memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
 201
 202     return(1);
 203     }
 204
 205
 206 static int
 207 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 208         {
 209         DTLS1_RECORD_DATA *rdata;
 210         pitem *item;
 211
 212         /* Limit the size of the queue to prevent DOS attacks */
 213         if (pqueue_size(queue->q) >= 100)
 214                 return 0;
 215
 216         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 217         item = pitem_new(priority, rdata);
 218         if (rdata == NULL || item == NULL)
 219                 {
 220                 if (rdata != NULL) OPENSSL_free(rdata);
 221                 if (item != NULL) pitem_free(item);
 222
 223                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 224                 return(0);
 225                 }
 226
 227         rdata->packet = s->packet;
 228         rdata->packet_length = s->packet_length;
 229         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 230         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 231
 232         item->data = rdata;
 233
 234         /* insert should not fail, since duplicates are dropped */
 235         if (pqueue_insert(queue->q, item) == NULL)
 236                 {
 237                 OPENSSL_free(rdata);
 238                 pitem_free(item);
 239                 return(0);
 240                 }
 241
 242         s->packet = NULL;
 243         s->packet_length = 0;
 244         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 245         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 246
 247         if (!ssl3_setup_buffers(s))
 248                 {
 249                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 250                 OPENSSL_free(rdata);
 251                 pitem_free(item);
 252                 return(0);
 253                 }
 254
 255         return(1);
 256         }
 257
 258
 259 static int
 260 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 261     {
 262     pitem *item;
 263
 264     item = pqueue_pop(queue->q);
 265     if (item)
 266         {
 267         dtls1_copy_record(s, item);
 268
 269         OPENSSL_free(item->data);
 270                 pitem_free(item);
 271
 272         return(1);
 273         }
 274
 275     return(0);
 276     }
 277
 278
 279 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 280  * yet */
 281 #define dtls1_get_unprocessed_record(s) \
 282                    dtls1_retrieve_buffered_record((s), \
 283                    &((s)->d1->unprocessed_rcds))
 284
 285 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 286 #define dtls1_get_processed_record(s) \
 287                    dtls1_retrieve_buffered_record((s), \
 288                    &((s)->d1->processed_rcds))
 289
 290 static int
 291 dtls1_process_buffered_records(SSL *s)
 292     {
 293     pitem *item;
 294
 295     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 296     if (item)
 297         {
 298         /* Check if epoch is current. */
 299         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 300             return(1);  /* Nothing to do. */
 301
 302         /* Process all the records. */
 303         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 304             {
 305             dtls1_get_unprocessed_record(s);
 306             if ( ! dtls1_process_record(s))
 307                 return(0);
 308             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 309                 s->s3->rrec.seq_num);
 310             }
 311         }
 312
 313     /* sync epoch numbers once all the unprocessed records
 314      * have been processed */
 315     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 316     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 317
 318     return(1);
 319     }
 320
 321
 322 #if 0
 323
 324 static int
 325 dtls1_get_buffered_record(SSL *s)
 326         {
 327         pitem *item;
 328         PQ_64BIT priority =
 329                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 330                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 331
 332         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 333                                                            nothing buffered */
 334                 return 0;
 335
 336
 337         item = pqueue_peek(s->d1->rcvd_records);
 338         if (item && item->priority == priority)
 339                 {
 340                 /* Check if we've received the record of interest.  It must be
 341                  * a handshake record, since data records as passed up without
 342                  * buffering */
 343                 DTLS1_RECORD_DATA *rdata;
 344                 item = pqueue_pop(s->d1->rcvd_records);
 345                 rdata = (DTLS1_RECORD_DATA *)item->data;
 346
 347                 if (s->s3->rbuf.buf != NULL)
 348                         OPENSSL_free(s->s3->rbuf.buf);
 349
 350                 s->packet = rdata->packet;
 351                 s->packet_length = rdata->packet_length;
 352                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 353                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 354
 355                 OPENSSL_free(item->data);
 356                 pitem_free(item);
 357
 358                 /* s->d1->next_expected_seq_num++; */
 359                 return(1);
 360                 }
 361
 362         return 0;
 363         }
 364
 365 #endif
 366
 367 static int
 368 dtls1_process_record(SSL *s)
 369 {
 370         int i,al;
 371         int enc_err;
 372         SSL_SESSION *sess;
 373         SSL3_RECORD *rr;
 374         unsigned int mac_size;
 375         unsigned char md[EVP_MAX_MD_SIZE];
 376
 377         rr= &(s->s3->rrec);
 378         sess = s->session;
 379
 380         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 381          * and we have that many bytes in s->packet
 382          */
 383         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 384
 385         /* ok, we can now read from 's->packet' data into 'rr'
 386          * rr->input points at rr->length bytes, which
 387          * need to be copied into rr->data by either
 388          * the decryption or by the decompression
 389          * When the data is 'copied' into the rr->data buffer,
 390          * rr->input will be pointed at the new buffer */
 391
 392         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 393          * rr->length bytes of encrypted compressed stuff. */
 394
 395         /* check is not needed I believe */
 396         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 397                 {
 398                 al=SSL_AD_RECORD_OVERFLOW;
 399                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 400                 goto f_err;
 401                 }
 402
 403         /* decrypt in place in 'rr->input' */
 404         rr->data=rr->input;
 405         rr->orig_len=rr->length;
 406
 407         enc_err = s->method->ssl3_enc->enc(s,0);
 408         /* enc_err is:
 409          *    0: (in non-constant time) if the record is publically invalid.
 410          *    1: if the padding is valid
 411          *    -1: if the padding is invalid */
 412         if (enc_err == 0)
 413                 {
 414                 /* For DTLS we simply ignore bad packets. */
 415                 rr->length = 0;
 416                 s->packet_length = 0;
 417                 goto err;
 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             (EVP_MD_CTX_md(s->read_hash) != NULL))
 430                 {
 431                 /* s->read_hash != NULL => mac_size != -1 */
 432                 unsigned char *mac = NULL;
 433                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
 434                 mac_size=EVP_MD_CTX_size(s->read_hash);
 435                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
 436
 437                 /* orig_len is the length of the record before any padding was
 438                  * removed. This is public information, as is the MAC in use,
 439                  * therefore we can safely process the record in a different
 440                  * amount of time if it's too short to possibly contain a MAC.
 441                  */
 442                 if (rr->orig_len < mac_size ||
 443                     /* CBC records must have a padding length byte too. */
 444                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
 445                      rr->orig_len < mac_size+1))
 446                         {
 447                         al=SSL_AD_DECODE_ERROR;
 448                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 449                         goto f_err;
 450                         }
 451
 452                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
 453                         {
 454                         /* We update the length so that the TLS header bytes
 455                          * can be constructed correctly but we need to extract
 456                          * the MAC in constant time from within the record,
 457                          * without leaking the contents of the padding bytes.
 458                          * */
 459                         mac = mac_tmp;
 460                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
 461                         rr->length -= mac_size;
 462                         }
 463                 else
 464                         {
 465                         /* In this case there's no padding, so |rec->orig_len|
 466                          * equals |rec->length| and we checked that there's
 467                          * enough bytes for |mac_size| above. */
 468                         rr->length -= mac_size;
 469                         mac = &rr->data[rr->length];
 470                         }
 471
 472                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
 473                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
 474                         enc_err = -1;
 475                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 476                         enc_err = -1;
 477                 }
 478
 479         if (enc_err < 0)
 480                 {
 481                 /* decryption failed, silently discard message */
 482                 rr->length = 0;
 483                 s->packet_length = 0;
 484                 goto err;
 485                 }
 486
 487         /* r->length is now just compressed */
 488         if (s->expand != NULL)
 489                 {
 490                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 491                         {
 492                         al=SSL_AD_RECORD_OVERFLOW;
 493                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 494                         goto f_err;
 495                         }
 496                 if (!ssl3_do_uncompress(s))
 497                         {
 498                         al=SSL_AD_DECOMPRESSION_FAILURE;
 499                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 500                         goto f_err;
 501                         }
 502                 }
 503
 504         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 505                 {
 506                 al=SSL_AD_RECORD_OVERFLOW;
 507                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 508                 goto f_err;
 509                 }
 510
 511         rr->off=0;
 512         /* So at this point the following is true
 513          * ssl->s3->rrec.type   is the type of record
 514          * ssl->s3->rrec.length == number of bytes in record
 515          * ssl->s3->rrec.off    == offset to first valid byte
 516          * ssl->s3->rrec.data   == where to take bytes from, increment
 517          *                         after use :-).
 518          */
 519
 520         /* we have pulled in a full packet so zero things */
 521         s->packet_length=0;
 522         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 523         return(1);
 524
 525 f_err:
 526         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 527 err:
 528         return(0);
 529 }
 530
 531
 532 /* Call this to get a new input record.
 533  * It will return <= 0 if more data is needed, normally due to an error
 534  * or non-blocking IO.
 535  * When it finishes, one packet has been decoded and can be found in
 536  * ssl->s3->rrec.type    - is the type of record
 537  * ssl->s3->rrec.data,   - data
 538  * ssl->s3->rrec.length, - number of bytes
 539  */
 540 /* used only by dtls1_read_bytes */
 541 int dtls1_get_record(SSL *s)
 542         {
 543         int ssl_major,ssl_minor;
 544         int i,n;
 545         SSL3_RECORD *rr;
 546         unsigned char *p = NULL;
 547         unsigned short version;
 548         DTLS1_BITMAP *bitmap;
 549         unsigned int is_next_epoch;
 550
 551         rr= &(s->s3->rrec);
 552
 553         /* The epoch may have changed.  If so, process all the
 554          * pending records.  This is a non-blocking operation. */
 555         dtls1_process_buffered_records(s);
 556
 557         /* if we're renegotiating, then there may be buffered records */
 558         if (dtls1_get_processed_record(s))
 559                 return 1;
 560
 561         /* get something from the wire */
 562 again:
 563         /* check if we have the header */
 564         if (    (s->rstate != SSL_ST_READ_BODY) ||
 565                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 566                 {
 567                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 568                 /* read timeout is handled by dtls1_read_bytes */
 569                 if (n <= 0) return(n); /* error or non-blocking */
 570
 571                 /* this packet contained a partial record, dump it */
 572                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
 573                         {
 574                         s->packet_length = 0;
 575                         goto again;
 576                         }
 577
 578                 s->rstate=SSL_ST_READ_BODY;
 579
 580                 p=s->packet;
 581
 582                 /* Pull apart the header into the DTLS1_RECORD */
 583                 rr->type= *(p++);
 584                 ssl_major= *(p++);
 585                 ssl_minor= *(p++);
 586                 version=(ssl_major<<8)|ssl_minor;
 587
 588                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 589                 n2s(p,rr->epoch);
 590
 591                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 592                 p+=6;
 593
 594                 n2s(p,rr->length);
 595
 596                 /* Lets check version */
 597                 if (!s->first_packet)
 598                         {
 599                         if (version != s->version)
 600                                 {
 601                                 /* unexpected version, silently discard */
 602                                 rr->length = 0;
 603                                 s->packet_length = 0;
 604                                 goto again;
 605                                 }
 606                         }
 607
 608                 if ((version & 0xff00) != (s->version & 0xff00))
 609                         {
 610                         /* wrong version, silently discard record */
 611                         rr->length = 0;
 612                         s->packet_length = 0;
 613                         goto again;
 614                         }
 615
 616                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 617                         {
 618                         /* record too long, silently discard it */
 619                         rr->length = 0;
 620                         s->packet_length = 0;
 621                         goto again;
 622                         }
 623
 624                 /* now s->rstate == SSL_ST_READ_BODY */
 625                 }
 626
 627         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 628
 629         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 630                 {
 631                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 632                 i=rr->length;
 633                 n=ssl3_read_n(s,i,i,1);
 634                 if (n <= 0) return(n); /* error or non-blocking io */
 635
 636                 /* this packet contained a partial record, dump it */
 637                 if ( n != i)
 638                         {
 639                         rr->length = 0;
 640                         s->packet_length = 0;
 641                         goto again;
 642                         }
 643
 644                 /* now n == rr->length,
 645                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 646                 }
 647         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 648
 649         /* match epochs.  NULL means the packet is dropped on the floor */
 650         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 651         if ( bitmap == NULL)
 652                 {
 653                 rr->length = 0;
 654                 s->packet_length = 0;  /* dump this record */
 655                 goto again;   /* get another record */
 656                 }
 657
 658         /* Check whether this is a repeat, or aged record.
 659          * Don't check if we're listening and this message is
 660          * a ClientHello. They can look as if they're replayed,
 661          * since they arrive from different connections and
 662          * would be dropped unnecessarily.
 663          */
 664         if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
 665                 *p == SSL3_MT_CLIENT_HELLO) &&
 666                 !dtls1_record_replay_check(s, bitmap))
 667                 {
 668                 rr->length = 0;
 669                 s->packet_length=0; /* dump this record */
 670                 goto again;     /* get another record */
 671                 }
 672
 673         /* just read a 0 length packet */
 674         if (rr->length == 0) goto again;
 675
 676         /* If this record is from the next epoch (either HM or ALERT),
 677          * and a handshake is currently in progress, buffer it since it
 678          * cannot be processed at this time. However, do not buffer
 679          * anything while listening.
 680          */
 681         if (is_next_epoch)
 682                 {
 683                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
 684                         {
 685                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 686                         }
 687                 rr->length = 0;
 688                 s->packet_length = 0;
 689                 goto again;
 690                 }
 691
 692         if (!dtls1_process_record(s))
 693                 {
 694                 rr->length = 0;
 695                 s->packet_length = 0;  /* dump this record */
 696                 goto again;   /* get another record */
 697                 }
 698
 699         return(1);
 700
 701         }
 702
 703 /* Return up to 'len' payload bytes received in 'type' records.
 704  * 'type' is one of the following:
 705  *
 706  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 707  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 708  *   -  0 (during a shutdown, no data has to be returned)
 709  *
 710  * If we don't have stored data to work from, read a SSL/TLS record first
 711  * (possibly multiple records if we still don't have anything to return).
 712  *
 713  * This function must handle any surprises the peer may have for us, such as
 714  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 715  * a surprise, but handled as if it were), or renegotiation requests.
 716  * Also if record payloads contain fragments too small to process, we store
 717  * them until there is enough for the respective protocol (the record protocol
 718  * may use arbitrary fragmentation and even interleaving):
 719  *     Change cipher spec protocol
 720  *             just 1 byte needed, no need for keeping anything stored
 721  *     Alert protocol
 722  *             2 bytes needed (AlertLevel, AlertDescription)
 723  *     Handshake protocol
 724  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 725  *             to detect unexpected Client Hello and Hello Request messages
 726  *             here, anything else is handled by higher layers
 727  *     Application data protocol
 728  *             none of our business
 729  */
 730 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 731         {
 732         int al,i,j,ret;
 733         unsigned int n;
 734         SSL3_RECORD *rr;
 735         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 736
 737         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 738                 if (!ssl3_setup_buffers(s))
 739                         return(-1);
 740
 741     /* XXX: check what the second '&& type' is about */
 742         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 743                 (type != SSL3_RT_HANDSHAKE) && type) ||
 744             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 745                 {
 746                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 747                 return -1;
 748                 }
 749
 750         /* check whether there's a handshake message (client hello?) waiting */
 751         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 752                 return ret;
 753
 754         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 755
 756         if (!s->in_handshake && SSL_in_init(s))
 757                 {
 758                 /* type == SSL3_RT_APPLICATION_DATA */
 759                 i=s->handshake_func(s);
 760                 if (i < 0) return(i);
 761                 if (i == 0)
 762                         {
 763                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 764                         return(-1);
 765                         }
 766                 }
 767
 768 start:
 769         s->rwstate=SSL_NOTHING;
 770
 771         /* s->s3->rrec.type         - is the type of record
 772          * s->s3->rrec.data,    - data
 773          * s->s3->rrec.off,     - offset into 'data' for next read
 774          * s->s3->rrec.length,  - number of bytes. */
 775         rr = &(s->s3->rrec);
 776
 777         /* We are not handshaking and have no data yet,
 778          * so process data buffered during the last handshake
 779          * in advance, if any.
 780          */
 781         if (s->state == SSL_ST_OK && rr->length == 0)
 782                 {
 783                 pitem *item;
 784                 item = pqueue_pop(s->d1->buffered_app_data.q);
 785                 if (item)
 786                         {
 787                         dtls1_copy_record(s, item);
 788
 789                         OPENSSL_free(item->data);
 790                         pitem_free(item);
 791                         }
 792                 }
 793
 794         /* Check for timeout */
 795         if (dtls1_handle_timeout(s) > 0)
 796                 goto start;
 797
 798         /* get new packet if necessary */
 799         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 800                 {
 801                 ret=dtls1_get_record(s);
 802                 if (ret <= 0)
 803                         {
 804                         ret = dtls1_read_failed(s, ret);
 805                         /* anything other than a timeout is an error */
 806                         if (ret <= 0)
 807                                 return(ret);
 808                         else
 809                                 goto start;
 810                         }
 811                 }
 812
 813         /* we now have a packet which can be read and processed */
 814
 815         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 816                                        * reset by ssl3_get_finished */
 817                 && (rr->type != SSL3_RT_HANDSHAKE))
 818                 {
 819                 /* We now have application data between CCS and Finished.
 820                  * Most likely the packets were reordered on their way, so
 821                  * buffer the application data for later processing rather
 822                  * than dropping the connection.
 823                  */
 824                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
 825                 rr->length = 0;
 826                 goto start;
 827                 }
 828
 829         /* If the other end has shut down, throw anything we read away
 830          * (even in 'peek' mode) */
 831         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 832                 {
 833                 rr->length=0;
 834                 s->rwstate=SSL_NOTHING;
 835                 return(0);
 836                 }
 837
 838
 839         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 840                 {
 841                 /* make sure that we are not getting application data when we
 842                  * are doing a handshake for the first time */
 843                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 844                         (s->enc_read_ctx == NULL))
 845                         {
 846                         al=SSL_AD_UNEXPECTED_MESSAGE;
 847                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 848                         goto f_err;
 849                         }
 850
 851                 if (len <= 0) return(len);
 852
 853                 if ((unsigned int)len > rr->length)
 854                         n = rr->length;
 855                 else
 856                         n = (unsigned int)len;
 857
 858                 memcpy(buf,&(rr->data[rr->off]),n);
 859                 if (!peek)
 860                         {
 861                         rr->length-=n;
 862                         rr->off+=n;
 863                         if (rr->length == 0)
 864                                 {
 865                                 s->rstate=SSL_ST_READ_HEADER;
 866                                 rr->off=0;
 867                                 }
 868                         }
 869                 return(n);
 870                 }
 871
 872
 873         /* If we get here, then type != rr->type; if we have a handshake
 874          * message, then it was unexpected (Hello Request or Client Hello). */
 875
 876         /* In case of record types for which we have 'fragment' storage,
 877          * fill that so that we can process the data at a fixed place.
 878          */
 879                 {
 880                 unsigned int k, dest_maxlen = 0;
 881                 unsigned char *dest = NULL;
 882                 unsigned int *dest_len = NULL;
 883
 884                 if (rr->type == SSL3_RT_HANDSHAKE)
 885                         {
 886                         dest_maxlen = sizeof s->d1->handshake_fragment;
 887                         dest = s->d1->handshake_fragment;
 888                         dest_len = &s->d1->handshake_fragment_len;
 889                         }
 890                 else if (rr->type == SSL3_RT_ALERT)
 891                         {
 892                         dest_maxlen = sizeof(s->d1->alert_fragment);
 893                         dest = s->d1->alert_fragment;
 894                         dest_len = &s->d1->alert_fragment_len;
 895                         }
 896                 /* else it's a CCS message, or application data or wrong */
 897                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 898                         {
 899                         /* Application data while renegotiating
 900                          * is allowed. Try again reading.
 901                          */
 902                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 903                                 {
 904                                 BIO *bio;
 905                                 s->s3->in_read_app_data=2;
 906                                 bio=SSL_get_rbio(s);
 907                                 s->rwstate=SSL_READING;
 908                                 BIO_clear_retry_flags(bio);
 909                                 BIO_set_retry_read(bio);
 910                                 return(-1);
 911                                 }
 912
 913                         /* Not certain if this is the right error handling */
 914                         al=SSL_AD_UNEXPECTED_MESSAGE;
 915                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 916                         goto f_err;
 917                         }
 918
 919                 if (dest_maxlen > 0)
 920                         {
 921             /* XDTLS:  In a pathalogical case, the Client Hello
 922              *  may be fragmented--don't always expect dest_maxlen bytes */
 923                         if ( rr->length < dest_maxlen)
 924                                 {
 925 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
 926                                 /*
 927                                  * for normal alerts rr->length is 2, while
 928                                  * dest_maxlen is 7 if we were to handle this
 929                                  * non-existing alert...
 930                                  */
 931                                 FIX ME
 932 #endif
 933                                 s->rstate=SSL_ST_READ_HEADER;
 934                                 rr->length = 0;
 935                                 goto start;
 936                                 }
 937
 938                         /* now move 'n' bytes: */
 939                         for ( k = 0; k < dest_maxlen; k++)
 940                                 {
 941                                 dest[k] = rr->data[rr->off++];
 942                                 rr->length--;
 943                                 }
 944                         *dest_len = dest_maxlen;
 945                         }
 946                 }
 947
 948         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 949          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 950          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 951
 952         /* If we are a client, check for an incoming 'Hello Request': */
 953         if ((!s->server) &&
 954                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 955                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 956                 (s->session != NULL) && (s->session->cipher != NULL))
 957                 {
 958                 s->d1->handshake_fragment_len = 0;
 959
 960                 if ((s->d1->handshake_fragment[1] != 0) ||
 961                         (s->d1->handshake_fragment[2] != 0) ||
 962                         (s->d1->handshake_fragment[3] != 0))
 963                         {
 964                         al=SSL_AD_DECODE_ERROR;
 965                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 966                         goto err;
 967                         }
 968
 969                 /* no need to check sequence number on HELLO REQUEST messages */
 970
 971                 if (s->msg_callback)
 972                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 973                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 974
 975                 if (SSL_is_init_finished(s) &&
 976                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 977                         !s->s3->renegotiate)
 978                         {
 979                         ssl3_renegotiate(s);
 980                         if (ssl3_renegotiate_check(s))
 981                                 {
 982                                 i=s->handshake_func(s);
 983                                 if (i < 0) return(i);
 984                                 if (i == 0)
 985                                         {
 986                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 987                                         return(-1);
 988                                         }
 989
 990                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 991                                         {
 992                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 993                                                 {
 994                                                 BIO *bio;
 995                                                 /* In the case where we try to read application data,
 996                                                  * but we trigger an SSL handshake, we return -1 with
 997                                                  * the retry option set.  Otherwise renegotiation may
 998                                                  * cause nasty problems in the blocking world */
 999                                                 s->rwstate=SSL_READING;
1000                                                 bio=SSL_get_rbio(s);
1001                                                 BIO_clear_retry_flags(bio);
1002                                                 BIO_set_retry_read(bio);
1003                                                 return(-1);
1004                                                 }
1005                                         }
1006                                 }
1007                         }
1008                 /* we either finished a handshake or ignored the request,
1009                  * now try again to obtain the (application) data we were asked for */
1010                 goto start;
1011                 }
1012
1013         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1014                 {
1015                 int alert_level = s->d1->alert_fragment[0];
1016                 int alert_descr = s->d1->alert_fragment[1];
1017
1018                 s->d1->alert_fragment_len = 0;
1019
1020                 if (s->msg_callback)
1021                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1022                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1023
1024                 if (s->info_callback != NULL)
1025                         cb=s->info_callback;
1026                 else if (s->ctx->info_callback != NULL)
1027                         cb=s->ctx->info_callback;
1028
1029                 if (cb != NULL)
1030                         {
1031                         j = (alert_level << 8) | alert_descr;
1032                         cb(s, SSL_CB_READ_ALERT, j);
1033                         }
1034
1035                 if (alert_level == 1) /* warning */
1036                         {
1037                         s->s3->warn_alert = alert_descr;
1038                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1039                                 {
1040                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1041                                 return(0);
1042                                 }
1043 #if 0
1044             /* XXX: this is a possible improvement in the future */
1045                         /* now check if it's a missing record */
1046                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1047                                 {
1048                                 unsigned short seq;
1049                                 unsigned int frag_off;
1050                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1051
1052                                 n2s(p, seq);
1053                                 n2l3(p, frag_off);
1054
1055                                 dtls1_retransmit_message(s,
1056                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1057                                                                                  frag_off, &found);
1058                                 if ( ! found  && SSL_in_init(s))
1059                                         {
1060                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1061                                         /* requested a message not yet sent,
1062                                            send an alert ourselves */
1063                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1064                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1065                                         }
1066                                 }
1067 #endif
1068                         }
1069                 else if (alert_level == 2) /* fatal */
1070                         {
1071                         char tmp[16];
1072
1073                         s->rwstate=SSL_NOTHING;
1074                         s->s3->fatal_alert = alert_descr;
1075                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1076                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1077                         ERR_add_error_data(2,"SSL alert number ",tmp);
1078                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1079                         SSL_CTX_remove_session(s->ctx,s->session);
1080                         return(0);
1081                         }
1082                 else
1083                         {
1084                         al=SSL_AD_ILLEGAL_PARAMETER;
1085                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1086                         goto f_err;
1087                         }
1088
1089                 goto start;
1090                 }
1091
1092         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1093                 {
1094                 s->rwstate=SSL_NOTHING;
1095                 rr->length=0;
1096                 return(0);
1097                 }
1098
1099         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1100                 {
1101                 struct ccs_header_st ccs_hdr;
1102                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1103
1104                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1105
1106                 if (s->version == DTLS1_BAD_VER)
1107                         ccs_hdr_len = 3;
1108
1109                 /* 'Change Cipher Spec' is just a single byte, so we know
1110                  * exactly what the record payload has to look like */
1111                 /* XDTLS: check that epoch is consistent */
1112                 if (    (rr->length != ccs_hdr_len) ||
1113                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1114                         {
1115                         i=SSL_AD_ILLEGAL_PARAMETER;
1116                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1117                         goto err;
1118                         }
1119
1120                 rr->length=0;
1121
1122                 if (s->msg_callback)
1123                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1124                                 rr->data, 1, s, s->msg_callback_arg);
1125
1126                 /* We can't process a CCS now, because previous handshake
1127                  * messages are still missing, so just drop it.
1128                  */
1129                 if (!s->d1->change_cipher_spec_ok)
1130                         {
1131                         goto start;
1132                         }
1133
1134                 s->d1->change_cipher_spec_ok = 0;
1135
1136                 s->s3->change_cipher_spec=1;
1137                 if (!ssl3_do_change_cipher_spec(s))
1138                         goto err;
1139
1140                 /* do this whenever CCS is processed */
1141                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1142
1143                 if (s->version == DTLS1_BAD_VER)
1144                         s->d1->handshake_read_seq++;
1145
1146                 goto start;
1147                 }
1148
1149         /* Unexpected handshake message (Client Hello, or protocol violation) */
1150         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1151                 !s->in_handshake)
1152                 {
1153                 struct hm_header_st msg_hdr;
1154
1155                 /* this may just be a stale retransmit */
1156                 dtls1_get_message_header(rr->data, &msg_hdr);
1157                 if( rr->epoch != s->d1->r_epoch)
1158                         {
1159                         rr->length = 0;
1160                         goto start;
1161                         }
1162
1163                 /* If we are server, we may have a repeated FINISHED of the
1164                  * client here, then retransmit our CCS and FINISHED.
1165                  */
1166                 if (msg_hdr.type == SSL3_MT_FINISHED)
1167                         {
1168                         if (dtls1_check_timeout_num(s) < 0)
1169                                 return -1;
1170
1171                         dtls1_retransmit_buffered_messages(s);
1172                         rr->length = 0;
1173                         goto start;
1174                         }
1175
1176                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1177                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1178                         {
1179 #if 0 /* worked only because C operator preferences are not as expected (and
1180        * because this is not really needed for clients except for detecting
1181        * protocol violations): */
1182                         s->state=SSL_ST_BEFORE|(s->server)
1183                                 ?SSL_ST_ACCEPT
1184                                 :SSL_ST_CONNECT;
1185 #else
1186                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1187 #endif
1188                         s->new_session=1;
1189                         }
1190                 i=s->handshake_func(s);
1191                 if (i < 0) return(i);
1192                 if (i == 0)
1193                         {
1194                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1195                         return(-1);
1196                         }
1197
1198                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1199                         {
1200                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1201                                 {
1202                                 BIO *bio;
1203                                 /* In the case where we try to read application data,
1204                                  * but we trigger an SSL handshake, we return -1 with
1205                                  * the retry option set.  Otherwise renegotiation may
1206                                  * cause nasty problems in the blocking world */
1207                                 s->rwstate=SSL_READING;
1208                                 bio=SSL_get_rbio(s);
1209                                 BIO_clear_retry_flags(bio);
1210                                 BIO_set_retry_read(bio);
1211                                 return(-1);
1212                                 }
1213                         }
1214                 goto start;
1215                 }
1216
1217         switch (rr->type)
1218                 {
1219         default:
1220 #ifndef OPENSSL_NO_TLS
1221                 /* TLS just ignores unknown message types */
1222                 if (s->version == TLS1_VERSION)
1223                         {
1224                         rr->length = 0;
1225                         goto start;
1226                         }
1227 #endif
1228                 al=SSL_AD_UNEXPECTED_MESSAGE;
1229                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1230                 goto f_err;
1231         case SSL3_RT_CHANGE_CIPHER_SPEC:
1232         case SSL3_RT_ALERT:
1233         case SSL3_RT_HANDSHAKE:
1234                 /* we already handled all of these, with the possible exception
1235                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1236                  * should not happen when type != rr->type */
1237                 al=SSL_AD_UNEXPECTED_MESSAGE;
1238                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1239                 goto f_err;
1240         case SSL3_RT_APPLICATION_DATA:
1241                 /* At this point, we were expecting handshake data,
1242                  * but have application data.  If the library was
1243                  * running inside ssl3_read() (i.e. in_read_app_data
1244                  * is set) and it makes sense to read application data
1245                  * at this point (session renegotiation not yet started),
1246                  * we will indulge it.
1247                  */
1248                 if (s->s3->in_read_app_data &&
1249                         (s->s3->total_renegotiations != 0) &&
1250                         ((
1251                                 (s->state & SSL_ST_CONNECT) &&
1252                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1253                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1254                                 ) || (
1255                                         (s->state & SSL_ST_ACCEPT) &&
1256                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1257                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1258                                         )
1259                                 ))
1260                         {
1261                         s->s3->in_read_app_data=2;
1262                         return(-1);
1263                         }
1264                 else
1265                         {
1266                         al=SSL_AD_UNEXPECTED_MESSAGE;
1267                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1268                         goto f_err;
1269                         }
1270                 }
1271         /* not reached */
1272
1273 f_err:
1274         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1275 err:
1276         return(-1);
1277         }
1278
1279 int
1280 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1281         {
1282         int i;
1283
1284         if (SSL_in_init(s) && !s->in_handshake)
1285                 {
1286                 i=s->handshake_func(s);
1287                 if (i < 0) return(i);
1288                 if (i == 0)
1289                         {
1290                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1291                         return -1;
1292                         }
1293                 }
1294
1295         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1296                 {
1297                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1298                         return -1;
1299                 }
1300
1301         i = dtls1_write_bytes(s, type, buf_, len);
1302         return i;
1303         }
1304
1305
1306         /* this only happens when a client hello is received and a handshake
1307          * is started. */
1308 static int
1309 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1310         int len, int peek)
1311         {
1312
1313         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1314                 /* (partially) satisfy request from storage */
1315                 {
1316                 unsigned char *src = s->d1->handshake_fragment;
1317                 unsigned char *dst = buf;
1318                 unsigned int k,n;
1319
1320                 /* peek == 0 */
1321                 n = 0;
1322                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1323                         {
1324                         *dst++ = *src++;
1325                         len--; s->d1->handshake_fragment_len--;
1326                         n++;
1327                         }
1328                 /* move any remaining fragment bytes: */
1329                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1330                         s->d1->handshake_fragment[k] = *src++;
1331                 return n;
1332                 }
1333
1334         return 0;
1335         }
1336
1337
1338
1339
1340 /* Call this to write data in records of type 'type'
1341  * It will return <= 0 if not all data has been sent or non-blocking IO.
1342  */
1343 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1344         {
1345         int i;
1346
1347         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1348         s->rwstate=SSL_NOTHING;
1349         i=do_dtls1_write(s, type, buf, len, 0);
1350         return i;
1351         }
1352
1353 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1354         {
1355         unsigned char *p,*pseq;
1356         int i,mac_size,clear=0;
1357         int prefix_len = 0;
1358         SSL3_RECORD *wr;
1359         SSL3_BUFFER *wb;
1360         SSL_SESSION *sess;
1361         int bs;
1362
1363         /* first check if there is a SSL3_BUFFER still being written
1364          * out.  This will happen with non blocking IO */
1365         if (s->s3->wbuf.left != 0)
1366                 {
1367                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1368                 return(ssl3_write_pending(s,type,buf,len));
1369                 }
1370
1371         /* If we have an alert to send, lets send it */
1372         if (s->s3->alert_dispatch)
1373                 {
1374                 i=s->method->ssl_dispatch_alert(s);
1375                 if (i <= 0)
1376                         return(i);
1377                 /* if it went, fall through and send more stuff */
1378                 }
1379
1380         if (len == 0 && !create_empty_fragment)
1381                 return 0;
1382
1383         wr= &(s->s3->wrec);
1384         wb= &(s->s3->wbuf);
1385         sess=s->session;
1386
1387         if (    (sess == NULL) ||
1388                 (s->enc_write_ctx == NULL) ||
1389                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1390                 clear=1;
1391
1392         if (clear)
1393                 mac_size=0;
1394         else
1395                 {
1396                 mac_size=EVP_MD_CTX_size(s->write_hash);
1397                 if (mac_size < 0)
1398                         goto err;
1399                 }
1400
1401         /* DTLS implements explicit IV, so no need for empty fragments */
1402 #if 0
1403         /* 'create_empty_fragment' is true only when this function calls itself */
1404         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1405             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1406                 {
1407                 /* countermeasure against known-IV weakness in CBC ciphersuites
1408                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1409                  */
1410
1411                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1412                         {
1413                         /* recursive function call with 'create_empty_fragment' set;
1414                          * this prepares and buffers the data for an empty fragment
1415                          * (these 'prefix_len' bytes are sent out later
1416                          * together with the actual payload) */
1417                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1418                         if (prefix_len <= 0)
1419                                 goto err;
1420
1421                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1422                                 {
1423                                 /* insufficient space */
1424                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1425                                 goto err;
1426                                 }
1427                         }
1428
1429                 s->s3->empty_fragment_done = 1;
1430                 }
1431 #endif
1432         p = wb->buf + prefix_len;
1433
1434         /* write the header */
1435
1436         *(p++)=type&0xff;
1437         wr->type=type;
1438
1439         *(p++)=(s->version>>8);
1440         *(p++)=s->version&0xff;
1441
1442         /* field where we are to write out packet epoch, seq num and len */
1443         pseq=p;
1444         p+=10;
1445
1446         /* lets setup the record stuff. */
1447
1448         /* Make space for the explicit IV in case of CBC.
1449          * (this is a bit of a boundary violation, but what the heck).
1450          */
1451         if ( s->enc_write_ctx &&
1452                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1453                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1454         else
1455                 bs = 0;
1456
1457         wr->data=p + bs;  /* make room for IV in case of CBC */
1458         wr->length=(int)len;
1459         wr->input=(unsigned char *)buf;
1460
1461         /* we now 'read' from wr->input, wr->length bytes into
1462          * wr->data */
1463
1464         /* first we compress */
1465         if (s->compress != NULL)
1466                 {
1467                 if (!ssl3_do_compress(s))
1468                         {
1469                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1470                         goto err;
1471                         }
1472                 }
1473         else
1474                 {
1475                 memcpy(wr->data,wr->input,wr->length);
1476                 wr->input=wr->data;
1477                 }
1478
1479         /* we should still have the output to wr->data and the input
1480          * from wr->input.  Length should be wr->length.
1481          * wr->data still points in the wb->buf */
1482
1483         if (mac_size != 0)
1484                 {
1485                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1486                         goto err;
1487                 wr->length+=mac_size;
1488                 }
1489
1490         /* this is true regardless of mac size */
1491         wr->input=p;
1492         wr->data=p;
1493
1494
1495         /* ssl3_enc can only have an error on read */
1496         if (bs) /* bs != 0 in case of CBC */
1497                 {
1498                 RAND_pseudo_bytes(p,bs);
1499                 /* master IV and last CBC residue stand for
1500                  * the rest of randomness */
1501                 wr->length += bs;
1502                 }
1503
1504         s->method->ssl3_enc->enc(s,1);
1505
1506         /* record length after mac and block padding */
1507 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1508         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1509
1510         /* there's only one epoch between handshake and app data */
1511
1512         s2n(s->d1->w_epoch, pseq);
1513
1514         /* XDTLS: ?? */
1515 /*      else
1516         s2n(s->d1->handshake_epoch, pseq); */
1517
1518         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1519         pseq+=6;
1520         s2n(wr->length,pseq);
1521
1522         /* we should now have
1523          * wr->data pointing to the encrypted data, which is
1524          * wr->length long */
1525         wr->type=type; /* not needed but helps for debugging */
1526         wr->length+=DTLS1_RT_HEADER_LENGTH;
1527
1528 #if 0  /* this is now done at the message layer */
1529         /* buffer the record, making it easy to handle retransmits */
1530         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1531                 dtls1_buffer_record(s, wr->data, wr->length,
1532                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1533 #endif
1534
1535         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1536
1537         if (create_empty_fragment)
1538                 {
1539                 /* we are in a recursive call;
1540                  * just return the length, don't write out anything here
1541                  */
1542                 return wr->length;
1543                 }
1544
1545         /* now let's set up wb */
1546         wb->left = prefix_len + wr->length;
1547         wb->offset = 0;
1548
1549         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1550         s->s3->wpend_tot=len;
1551         s->s3->wpend_buf=buf;
1552         s->s3->wpend_type=type;
1553         s->s3->wpend_ret=len;
1554
1555         /* we now just need to write the buffer */
1556         return ssl3_write_pending(s,type,buf,len);
1557 err:
1558         return -1;
1559         }
1560
1561
1562
1563 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1564         {
1565         int cmp;
1566         unsigned int shift;
1567         const unsigned char *seq = s->s3->read_sequence;
1568
1569         cmp = satsub64be(seq,bitmap->max_seq_num);
1570         if (cmp > 0)
1571                 {
1572                 memcpy (s->s3->rrec.seq_num,seq,8);
1573                 return 1; /* this record in new */
1574                 }
1575         shift = -cmp;
1576         if (shift >= sizeof(bitmap->map)*8)
1577                 return 0; /* stale, outside the window */
1578         else if (bitmap->map & (1UL<<shift))
1579                 return 0; /* record previously received */
1580
1581         memcpy (s->s3->rrec.seq_num,seq,8);
1582         return 1;
1583         }
1584
1585
1586 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1587         {
1588         int cmp;
1589         unsigned int shift;
1590         const unsigned char *seq = s->s3->read_sequence;
1591
1592         cmp = satsub64be(seq,bitmap->max_seq_num);
1593         if (cmp > 0)
1594                 {
1595                 shift = cmp;
1596                 if (shift < sizeof(bitmap->map)*8)
1597                         bitmap->map <<= shift, bitmap->map |= 1UL;
1598                 else
1599                         bitmap->map = 1UL;
1600                 memcpy(bitmap->max_seq_num,seq,8);
1601                 }
1602         else    {
1603                 shift = -cmp;
1604                 if (shift < sizeof(bitmap->map)*8)
1605                         bitmap->map |= 1UL<<shift;
1606                 }
1607         }
1608
1609
1610 int dtls1_dispatch_alert(SSL *s)
1611         {
1612         int i,j;
1613         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1614         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1615         unsigned char *ptr = &buf[0];
1616
1617         s->s3->alert_dispatch=0;
1618
1619         memset(buf, 0x00, sizeof(buf));
1620         *ptr++ = s->s3->send_alert[0];
1621         *ptr++ = s->s3->send_alert[1];
1622
1623 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1624         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1625                 {
1626                 s2n(s->d1->handshake_read_seq, ptr);
1627 #if 0
1628                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1629
1630                 else
1631                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1632 #endif
1633
1634 #if 0
1635                 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);
1636 #endif
1637                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1638                 }
1639 #endif
1640
1641         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1642         if (i <= 0)
1643                 {
1644                 s->s3->alert_dispatch=1;
1645                 /* fprintf( stderr, "not done with alert\n" ); */
1646                 }
1647         else
1648                 {
1649                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1650 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1651                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1652 #endif
1653                     )
1654                         (void)BIO_flush(s->wbio);
1655
1656                 if (s->msg_callback)
1657                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1658                                 2, s, s->msg_callback_arg);
1659
1660                 if (s->info_callback != NULL)
1661                         cb=s->info_callback;
1662                 else if (s->ctx->info_callback != NULL)
1663                         cb=s->ctx->info_callback;
1664
1665                 if (cb != NULL)
1666                         {
1667                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1668                         cb(s,SSL_CB_WRITE_ALERT,j);
1669                         }
1670                 }
1671         return(i);
1672         }
1673
1674
1675 static DTLS1_BITMAP *
1676 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1677     {
1678
1679     *is_next_epoch = 0;
1680
1681     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1682     if (rr->epoch == s->d1->r_epoch)
1683         return &s->d1->bitmap;
1684
1685     /* Only HM and ALERT messages can be from the next epoch */
1686     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1687         (rr->type == SSL3_RT_HANDSHAKE ||
1688             rr->type == SSL3_RT_ALERT))
1689         {
1690         *is_next_epoch = 1;
1691         return &s->d1->next_bitmap;
1692         }
1693
1694     return NULL;
1695     }
1696
1697 #if 0
1698 static int
1699 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1700         unsigned long *offset)
1701         {
1702
1703         /* alerts are passed up immediately */
1704         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1705                 rr->type == SSL3_RT_ALERT)
1706                 return 0;
1707
1708         /* Only need to buffer if a handshake is underway.
1709          * (this implies that Hello Request and Client Hello are passed up
1710          * immediately) */
1711         if ( SSL_in_init(s))
1712                 {
1713                 unsigned char *data = rr->data;
1714                 /* need to extract the HM/CCS sequence number here */
1715                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1716                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1717                         {
1718                         unsigned short seq_num;
1719                         struct hm_header_st msg_hdr;
1720                         struct ccs_header_st ccs_hdr;
1721
1722                         if ( rr->type == SSL3_RT_HANDSHAKE)
1723                                 {
1724                                 dtls1_get_message_header(data, &msg_hdr);
1725                                 seq_num = msg_hdr.seq;
1726                                 *offset = msg_hdr.frag_off;
1727                                 }
1728                         else
1729                                 {
1730                                 dtls1_get_ccs_header(data, &ccs_hdr);
1731                                 seq_num = ccs_hdr.seq;
1732                                 *offset = 0;
1733                                 }
1734
1735                         /* this is either a record we're waiting for, or a
1736                          * retransmit of something we happened to previously
1737                          * receive (higher layers will drop the repeat silently */
1738                         if ( seq_num < s->d1->handshake_read_seq)
1739                                 return 0;
1740                         if (rr->type == SSL3_RT_HANDSHAKE &&
1741                                 seq_num == s->d1->handshake_read_seq &&
1742                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1743                                 return 0;
1744                         else if ( seq_num == s->d1->handshake_read_seq &&
1745                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1746                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1747                                 return 0;
1748                         else
1749                                 {
1750                                 *priority = seq_num;
1751                                 return 1;
1752                                 }
1753                         }
1754                 else /* unknown record type */
1755                         return 0;
1756                 }
1757
1758         return 0;
1759         }
1760 #endif
1761
1762 void
1763 dtls1_reset_seq_numbers(SSL *s, int rw)
1764         {
1765         unsigned char *seq;
1766         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1767
1768         if ( rw & SSL3_CC_READ)
1769                 {
1770                 seq = s->s3->read_sequence;
1771                 s->d1->r_epoch++;
1772                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1773                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1774                 }
1775         else
1776                 {
1777                 seq = s->s3->write_sequence;
1778                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1779                 s->d1->w_epoch++;
1780                 }
1781
1782         memset(seq, 0x00, seq_bytes);
1783         }