ssl/d1_pkt.c

   1 /* ssl/d1_pkt.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <stdio.h>
 117 #include <errno.h>
 118 #define USE_SOCKETS
 119 #include "ssl_locl.h"
 120 #include <openssl/evp.h>
 121 #include <openssl/buffer.h>
 122 #include <openssl/pqueue.h>
 123 #include <openssl/rand.h>
 124
 125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
 126 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
 127 {       int ret,sat,brw,i;
 128
 129         if (sizeof(long) == 8) do
 130         {       const union { long one; char little; } is_endian = {1};
 131                 long l;
 132
 133                 if (is_endian.little)                   break;
 134                 /* not reached on little-endians */
 135                 /* following test is redundant, because input is
 136                  * always aligned, but I take no chances... */
 137                 if (((size_t)v1|(size_t)v2)&0x7)        break;
 138
 139                 l  = *((long *)v1);
 140                 l -= *((long *)v2);
 141                 if (l>128)              return 128;
 142                 else if (l<-128)        return -128;
 143                 else                    return (int)l;
 144         } while (0);
 145
 146         ret = (int)v1[7]-(int)v2[7];
 147         sat = 0;
 148         brw = ret>>8;   /* brw is either 0 or -1 */
 149         if (ret & 0x80)
 150         {       for (i=6;i>=0;i--)
 151                 {       brw += (int)v1[i]-(int)v2[i];
 152                         sat |= ~brw;
 153                         brw >>= 8;
 154                 }
 155         }
 156         else
 157         {       for (i=6;i>=0;i--)
 158                 {       brw += (int)v1[i]-(int)v2[i];
 159                         sat |= brw;
 160                         brw >>= 8;
 161                 }
 162         }
 163         brw <<= 8;      /* brw is either 0 or -256 */
 164
 165         if (sat&0xff)   return brw | 0x80;
 166         else            return brw + (ret&0xFF);
 167 }
 168
 169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
 170         int len, int peek);
 171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
 172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
 173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
 174     unsigned int *is_next_epoch);
 175 #if 0
 176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
 177         unsigned short *priority, unsigned long *offset);
 178 #endif
 179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
 180         unsigned char *priority);
 181 static int dtls1_process_record(SSL *s);
 182 static void dtls1_clear_timeouts(SSL *s);
 183
 184 /* copy buffered record into SSL structure */
 185 static int
 186 dtls1_copy_record(SSL *s, pitem *item)
 187     {
 188     DTLS1_RECORD_DATA *rdata;
 189
 190     rdata = (DTLS1_RECORD_DATA *)item->data;
 191
 192     if (s->s3->rbuf.buf != NULL)
 193         OPENSSL_free(s->s3->rbuf.buf);
 194
 195     s->packet = rdata->packet;
 196     s->packet_length = rdata->packet_length;
 197     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 198     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 199
 200     return(1);
 201     }
 202
 203
 204 static int
 205 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 206         {
 207         DTLS1_RECORD_DATA *rdata;
 208         pitem *item;
 209
 210         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 211         item = pitem_new(priority, rdata);
 212         if (rdata == NULL || item == NULL)
 213                 {
 214                 if (rdata != NULL) OPENSSL_free(rdata);
 215                 if (item != NULL) pitem_free(item);
 216
 217                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 218                 return(0);
 219                 }
 220
 221         rdata->packet = s->packet;
 222         rdata->packet_length = s->packet_length;
 223         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 224         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 225
 226         item->data = rdata;
 227
 228         /* insert should not fail, since duplicates are dropped */
 229         if (pqueue_insert(queue->q, item) == NULL)
 230                 {
 231                 OPENSSL_free(rdata);
 232                 pitem_free(item);
 233                 return(0);
 234                 }
 235
 236         s->packet = NULL;
 237         s->packet_length = 0;
 238         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 239         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 240
 241         if (!ssl3_setup_buffers(s))
 242                 {
 243                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 244                 OPENSSL_free(rdata);
 245                 pitem_free(item);
 246                 return(0);
 247                 }
 248
 249         return(1);
 250         }
 251
 252
 253 static int
 254 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 255     {
 256     pitem *item;
 257
 258     item = pqueue_pop(queue->q);
 259     if (item)
 260         {
 261         dtls1_copy_record(s, item);
 262
 263         OPENSSL_free(item->data);
 264                 pitem_free(item);
 265
 266         return(1);
 267         }
 268
 269     return(0);
 270     }
 271
 272
 273 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 274  * yet */
 275 #define dtls1_get_unprocessed_record(s) \
 276                    dtls1_retrieve_buffered_record((s), \
 277                    &((s)->d1->unprocessed_rcds))
 278
 279 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 280 #define dtls1_get_processed_record(s) \
 281                    dtls1_retrieve_buffered_record((s), \
 282                    &((s)->d1->processed_rcds))
 283
 284 static int
 285 dtls1_process_buffered_records(SSL *s)
 286     {
 287     pitem *item;
 288
 289     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 290     if (item)
 291         {
 292         DTLS1_RECORD_DATA *rdata;
 293         rdata = (DTLS1_RECORD_DATA *)item->data;
 294
 295         /* Check if epoch is current. */
 296         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 297             return(1);  /* Nothing to do. */
 298
 299         /* Process all the records. */
 300         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 301             {
 302             dtls1_get_unprocessed_record(s);
 303             if ( ! dtls1_process_record(s))
 304                 return(0);
 305             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 306                 s->s3->rrec.seq_num);
 307             }
 308         }
 309
 310     /* sync epoch numbers once all the unprocessed records
 311      * have been processed */
 312     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 313     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 314
 315     return(1);
 316     }
 317
 318
 319 #if 0
 320
 321 static int
 322 dtls1_get_buffered_record(SSL *s)
 323         {
 324         pitem *item;
 325         PQ_64BIT priority =
 326                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 327                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 328
 329         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 330                                                            nothing buffered */
 331                 return 0;
 332
 333
 334         item = pqueue_peek(s->d1->rcvd_records);
 335         if (item && item->priority == priority)
 336                 {
 337                 /* Check if we've received the record of interest.  It must be
 338                  * a handshake record, since data records as passed up without
 339                  * buffering */
 340                 DTLS1_RECORD_DATA *rdata;
 341                 item = pqueue_pop(s->d1->rcvd_records);
 342                 rdata = (DTLS1_RECORD_DATA *)item->data;
 343
 344                 if (s->s3->rbuf.buf != NULL)
 345                         OPENSSL_free(s->s3->rbuf.buf);
 346
 347                 s->packet = rdata->packet;
 348                 s->packet_length = rdata->packet_length;
 349                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 350                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 351
 352                 OPENSSL_free(item->data);
 353                 pitem_free(item);
 354
 355                 /* s->d1->next_expected_seq_num++; */
 356                 return(1);
 357                 }
 358
 359         return 0;
 360         }
 361
 362 #endif
 363
 364 static int
 365 dtls1_process_record(SSL *s)
 366 {
 367         int i,al;
 368         int clear=0;
 369         int enc_err;
 370         SSL_SESSION *sess;
 371         SSL3_RECORD *rr;
 372         unsigned int mac_size;
 373         unsigned char md[EVP_MAX_MD_SIZE];
 374
 375
 376         rr= &(s->s3->rrec);
 377         sess = s->session;
 378
 379         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 380          * and we have that many bytes in s->packet
 381          */
 382         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 383
 384         /* ok, we can now read from 's->packet' data into 'rr'
 385          * rr->input points at rr->length bytes, which
 386          * need to be copied into rr->data by either
 387          * the decryption or by the decompression
 388          * When the data is 'copied' into the rr->data buffer,
 389          * rr->input will be pointed at the new buffer */
 390
 391         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 392          * rr->length bytes of encrypted compressed stuff. */
 393
 394         /* check is not needed I believe */
 395         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 396                 {
 397                 al=SSL_AD_RECORD_OVERFLOW;
 398                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 399                 goto f_err;
 400                 }
 401
 402         /* decrypt in place in 'rr->input' */
 403         rr->data=rr->input;
 404
 405         enc_err = s->method->ssl3_enc->enc(s,0);
 406         if (enc_err <= 0)
 407                 {
 408                 if (enc_err == 0)
 409                         /* SSLerr() and ssl3_send_alert() have been called */
 410                         goto err;
 411
 412                 /* otherwise enc_err == -1 */
 413                 goto decryption_failed_or_bad_record_mac;
 414                 }
 415
 416 #ifdef TLS_DEBUG
 417 printf("dec %d\n",rr->length);
 418 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 419 printf("\n");
 420 #endif
 421
 422         /* r->length is now the compressed data plus mac */
 423         if (    (sess == NULL) ||
 424                 (s->enc_read_ctx == NULL) ||
 425                 (s->read_hash == NULL))
 426                 clear=1;
 427
 428         if (!clear)
 429                 {
 430                 /* !clear => s->read_hash != NULL => mac_size != -1 */
 431                 int t;
 432                 t=EVP_MD_CTX_size(s->read_hash);
 433                 OPENSSL_assert(t >= 0);
 434                 mac_size=t;
 435
 436                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 437                         {
 438 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 439                         al=SSL_AD_RECORD_OVERFLOW;
 440                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 441                         goto f_err;
 442 #else
 443                         goto decryption_failed_or_bad_record_mac;
 444 #endif
 445                         }
 446                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 447                 if (rr->length < mac_size)
 448                         {
 449 #if 0 /* OK only for stream ciphers */
 450                         al=SSL_AD_DECODE_ERROR;
 451                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 452                         goto f_err;
 453 #else
 454                         goto decryption_failed_or_bad_record_mac;
 455 #endif
 456                         }
 457                 rr->length-=mac_size;
 458                 i=s->method->ssl3_enc->mac(s,md,0);
 459                 if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 460                         {
 461                         goto decryption_failed_or_bad_record_mac;
 462                         }
 463                 }
 464
 465         /* r->length is now just compressed */
 466         if (s->expand != NULL)
 467                 {
 468                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 469                         {
 470                         al=SSL_AD_RECORD_OVERFLOW;
 471                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 472                         goto f_err;
 473                         }
 474                 if (!ssl3_do_uncompress(s))
 475                         {
 476                         al=SSL_AD_DECOMPRESSION_FAILURE;
 477                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 478                         goto f_err;
 479                         }
 480                 }
 481
 482         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 483                 {
 484                 al=SSL_AD_RECORD_OVERFLOW;
 485                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 486                 goto f_err;
 487                 }
 488
 489         rr->off=0;
 490         /* So at this point the following is true
 491          * ssl->s3->rrec.type   is the type of record
 492          * ssl->s3->rrec.length == number of bytes in record
 493          * ssl->s3->rrec.off    == offset to first valid byte
 494          * ssl->s3->rrec.data   == where to take bytes from, increment
 495          *                         after use :-).
 496          */
 497
 498         /* we have pulled in a full packet so zero things */
 499         s->packet_length=0;
 500         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 501         return(1);
 502
 503 decryption_failed_or_bad_record_mac:
 504         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
 505          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 506          * failure is directly visible from the ciphertext anyway,
 507          * we should not reveal which kind of error occured -- this
 508          * might become visible to an attacker (e.g. via logfile) */
 509         al=SSL_AD_BAD_RECORD_MAC;
 510         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 511 f_err:
 512         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 513 err:
 514         return(0);
 515 }
 516
 517
 518 /* Call this to get a new input record.
 519  * It will return <= 0 if more data is needed, normally due to an error
 520  * or non-blocking IO.
 521  * When it finishes, one packet has been decoded and can be found in
 522  * ssl->s3->rrec.type    - is the type of record
 523  * ssl->s3->rrec.data,   - data
 524  * ssl->s3->rrec.length, - number of bytes
 525  */
 526 /* used only by dtls1_read_bytes */
 527 int dtls1_get_record(SSL *s)
 528         {
 529         int ssl_major,ssl_minor,al;
 530         int i,n;
 531         SSL3_RECORD *rr;
 532         SSL_SESSION *sess;
 533         unsigned char *p;
 534         unsigned short version;
 535         DTLS1_BITMAP *bitmap;
 536         unsigned int is_next_epoch;
 537
 538         rr= &(s->s3->rrec);
 539         sess=s->session;
 540
 541         /* The epoch may have changed.  If so, process all the
 542          * pending records.  This is a non-blocking operation. */
 543         if ( ! dtls1_process_buffered_records(s))
 544             return 0;
 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                 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
 561
 562                 s->rstate=SSL_ST_READ_BODY;
 563
 564                 p=s->packet;
 565
 566                 /* Pull apart the header into the DTLS1_RECORD */
 567                 rr->type= *(p++);
 568                 ssl_major= *(p++);
 569                 ssl_minor= *(p++);
 570                 version=(ssl_major<<8)|ssl_minor;
 571
 572                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 573                 n2s(p,rr->epoch);
 574
 575                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 576                 p+=6;
 577
 578                 n2s(p,rr->length);
 579
 580                 /* Lets check version */
 581                 if (!s->first_packet)
 582                         {
 583                         if (version != s->version)
 584                                 {
 585                                 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 586                                 /* Send back error using their
 587                                  * version number :-) */
 588                                 s->version=version;
 589                                 al=SSL_AD_PROTOCOL_VERSION;
 590                                 goto f_err;
 591                                 }
 592                         }
 593
 594                 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00))
 595                         {
 596                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 597                         goto err;
 598                         }
 599
 600                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 601                         {
 602                         al=SSL_AD_RECORD_OVERFLOW;
 603                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 604                         goto f_err;
 605                         }
 606
 607                 /* now s->rstate == SSL_ST_READ_BODY */
 608                 }
 609
 610         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 611
 612         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 613                 {
 614                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 615                 i=rr->length;
 616                 n=ssl3_read_n(s,i,i,1);
 617                 if (n <= 0) return(n); /* error or non-blocking io */
 618
 619                 /* this packet contained a partial record, dump it */
 620                 if ( n != i)
 621                         {
 622                         s->packet_length = 0;
 623                         goto again;
 624                         }
 625
 626                 /* now n == rr->length,
 627                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 628                 }
 629         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 630
 631         /* match epochs.  NULL means the packet is dropped on the floor */
 632         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 633         if ( bitmap == NULL)
 634                 {
 635                 s->packet_length = 0;  /* dump this record */
 636                 goto again;   /* get another record */
 637                 }
 638
 639         /* check whether this is a repeat, or aged record */
 640         if ( ! dtls1_record_replay_check(s, bitmap))
 641                 {
 642                 rr->length = 0;
 643                 s->packet_length=0; /* dump this record */
 644                 goto again;     /* get another record */
 645                 }
 646
 647         /* just read a 0 length packet */
 648         if (rr->length == 0) goto again;
 649
 650         /* If this record is from the next epoch (either HM or ALERT),
 651          * buffer it since it cannot be processed at this time. Records
 652          * from the next epoch are marked as received even though they
 653          * are not processed, so as to prevent any potential resource
 654          * DoS attack */
 655         if (is_next_epoch)
 656                 {
 657                 dtls1_record_bitmap_update(s, bitmap);
 658                 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 659                 s->packet_length = 0;
 660                 goto again;
 661                 }
 662
 663         if ( ! dtls1_process_record(s))
 664                 return(0);
 665
 666         dtls1_clear_timeouts(s);  /* done waiting */
 667         return(1);
 668
 669 f_err:
 670         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 671 err:
 672         return(0);
 673         }
 674
 675 /* Return up to 'len' payload bytes received in 'type' records.
 676  * 'type' is one of the following:
 677  *
 678  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 679  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 680  *   -  0 (during a shutdown, no data has to be returned)
 681  *
 682  * If we don't have stored data to work from, read a SSL/TLS record first
 683  * (possibly multiple records if we still don't have anything to return).
 684  *
 685  * This function must handle any surprises the peer may have for us, such as
 686  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 687  * a surprise, but handled as if it were), or renegotiation requests.
 688  * Also if record payloads contain fragments too small to process, we store
 689  * them until there is enough for the respective protocol (the record protocol
 690  * may use arbitrary fragmentation and even interleaving):
 691  *     Change cipher spec protocol
 692  *             just 1 byte needed, no need for keeping anything stored
 693  *     Alert protocol
 694  *             2 bytes needed (AlertLevel, AlertDescription)
 695  *     Handshake protocol
 696  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 697  *             to detect unexpected Client Hello and Hello Request messages
 698  *             here, anything else is handled by higher layers
 699  *     Application data protocol
 700  *             none of our business
 701  */
 702 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 703         {
 704         int al,i,j,ret;
 705         unsigned int n;
 706         SSL3_RECORD *rr;
 707         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 708
 709         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 710                 if (!ssl3_setup_buffers(s))
 711                         return(-1);
 712
 713     /* XXX: check what the second '&& type' is about */
 714         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 715                 (type != SSL3_RT_HANDSHAKE) && type) ||
 716             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 717                 {
 718                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 719                 return -1;
 720                 }
 721
 722         /* check whether there's a handshake message (client hello?) waiting */
 723         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 724                 return ret;
 725
 726         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 727
 728         if (!s->in_handshake && SSL_in_init(s))
 729                 {
 730                 /* type == SSL3_RT_APPLICATION_DATA */
 731                 i=s->handshake_func(s);
 732                 if (i < 0) return(i);
 733                 if (i == 0)
 734                         {
 735                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 736                         return(-1);
 737                         }
 738                 }
 739
 740 start:
 741         s->rwstate=SSL_NOTHING;
 742
 743         /* s->s3->rrec.type         - is the type of record
 744          * s->s3->rrec.data,    - data
 745          * s->s3->rrec.off,     - offset into 'data' for next read
 746          * s->s3->rrec.length,  - number of bytes. */
 747         rr = &(s->s3->rrec);
 748
 749         /* get new packet if necessary */
 750         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 751                 {
 752                 ret=dtls1_get_record(s);
 753                 if (ret <= 0)
 754                         {
 755                         ret = dtls1_read_failed(s, ret);
 756                         /* anything other than a timeout is an error */
 757                         if (ret <= 0)
 758                                 return(ret);
 759                         else
 760                                 goto start;
 761                         }
 762                 }
 763
 764         /* we now have a packet which can be read and processed */
 765
 766         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 767                                        * reset by ssl3_get_finished */
 768                 && (rr->type != SSL3_RT_HANDSHAKE))
 769                 {
 770                 al=SSL_AD_UNEXPECTED_MESSAGE;
 771                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
 772                 goto err;
 773                 }
 774
 775         /* If the other end has shut down, throw anything we read away
 776          * (even in 'peek' mode) */
 777         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 778                 {
 779                 rr->length=0;
 780                 s->rwstate=SSL_NOTHING;
 781                 return(0);
 782                 }
 783
 784
 785         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 786                 {
 787                 /* make sure that we are not getting application data when we
 788                  * are doing a handshake for the first time */
 789                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 790                         (s->enc_read_ctx == NULL))
 791                         {
 792                         al=SSL_AD_UNEXPECTED_MESSAGE;
 793                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 794                         goto f_err;
 795                         }
 796
 797                 if (len <= 0) return(len);
 798
 799                 if ((unsigned int)len > rr->length)
 800                         n = rr->length;
 801                 else
 802                         n = (unsigned int)len;
 803
 804                 memcpy(buf,&(rr->data[rr->off]),n);
 805                 if (!peek)
 806                         {
 807                         rr->length-=n;
 808                         rr->off+=n;
 809                         if (rr->length == 0)
 810                                 {
 811                                 s->rstate=SSL_ST_READ_HEADER;
 812                                 rr->off=0;
 813                                 }
 814                         }
 815                 return(n);
 816                 }
 817
 818
 819         /* If we get here, then type != rr->type; if we have a handshake
 820          * message, then it was unexpected (Hello Request or Client Hello). */
 821
 822         /* In case of record types for which we have 'fragment' storage,
 823          * fill that so that we can process the data at a fixed place.
 824          */
 825                 {
 826                 unsigned int k, dest_maxlen = 0;
 827                 unsigned char *dest = NULL;
 828                 unsigned int *dest_len = NULL;
 829
 830                 if (rr->type == SSL3_RT_HANDSHAKE)
 831                         {
 832                         dest_maxlen = sizeof s->d1->handshake_fragment;
 833                         dest = s->d1->handshake_fragment;
 834                         dest_len = &s->d1->handshake_fragment_len;
 835                         }
 836                 else if (rr->type == SSL3_RT_ALERT)
 837                         {
 838                         dest_maxlen = sizeof(s->d1->alert_fragment);
 839                         dest = s->d1->alert_fragment;
 840                         dest_len = &s->d1->alert_fragment_len;
 841                         }
 842                 /* else it's a CCS message, or it's wrong */
 843                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 844                         {
 845                           /* Not certain if this is the right error handling */
 846                           al=SSL_AD_UNEXPECTED_MESSAGE;
 847                           SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 848                           goto f_err;
 849                         }
 850
 851
 852                 if (dest_maxlen > 0)
 853                         {
 854             /* XDTLS:  In a pathalogical case, the Client Hello
 855              *  may be fragmented--don't always expect dest_maxlen bytes */
 856                         if ( rr->length < dest_maxlen)
 857                                 {
 858 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
 859                                 /*
 860                                  * for normal alerts rr->length is 2, while
 861                                  * dest_maxlen is 7 if we were to handle this
 862                                  * non-existing alert...
 863                                  */
 864                                 FIX ME
 865 #endif
 866                                 s->rstate=SSL_ST_READ_HEADER;
 867                                 rr->length = 0;
 868                                 goto start;
 869                                 }
 870
 871                         /* now move 'n' bytes: */
 872                         for ( k = 0; k < dest_maxlen; k++)
 873                                 {
 874                                 dest[k] = rr->data[rr->off++];
 875                                 rr->length--;
 876                                 }
 877                         *dest_len = dest_maxlen;
 878                         }
 879                 }
 880
 881         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 882          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 883          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 884
 885         /* If we are a client, check for an incoming 'Hello Request': */
 886         if ((!s->server) &&
 887                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 888                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 889                 (s->session != NULL) && (s->session->cipher != NULL))
 890                 {
 891                 s->d1->handshake_fragment_len = 0;
 892
 893                 if ((s->d1->handshake_fragment[1] != 0) ||
 894                         (s->d1->handshake_fragment[2] != 0) ||
 895                         (s->d1->handshake_fragment[3] != 0))
 896                         {
 897                         al=SSL_AD_DECODE_ERROR;
 898                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 899                         goto err;
 900                         }
 901
 902                 /* no need to check sequence number on HELLO REQUEST messages */
 903
 904                 if (s->msg_callback)
 905                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 906                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 907
 908                 if (SSL_is_init_finished(s) &&
 909                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 910                         !s->s3->renegotiate)
 911                         {
 912                         ssl3_renegotiate(s);
 913                         if (ssl3_renegotiate_check(s))
 914                                 {
 915                                 i=s->handshake_func(s);
 916                                 if (i < 0) return(i);
 917                                 if (i == 0)
 918                                         {
 919                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 920                                         return(-1);
 921                                         }
 922
 923                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 924                                         {
 925                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 926                                                 {
 927                                                 BIO *bio;
 928                                                 /* In the case where we try to read application data,
 929                                                  * but we trigger an SSL handshake, we return -1 with
 930                                                  * the retry option set.  Otherwise renegotiation may
 931                                                  * cause nasty problems in the blocking world */
 932                                                 s->rwstate=SSL_READING;
 933                                                 bio=SSL_get_rbio(s);
 934                                                 BIO_clear_retry_flags(bio);
 935                                                 BIO_set_retry_read(bio);
 936                                                 return(-1);
 937                                                 }
 938                                         }
 939                                 }
 940                         }
 941                 /* we either finished a handshake or ignored the request,
 942                  * now try again to obtain the (application) data we were asked for */
 943                 goto start;
 944                 }
 945
 946         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
 947                 {
 948                 int alert_level = s->d1->alert_fragment[0];
 949                 int alert_descr = s->d1->alert_fragment[1];
 950
 951                 s->d1->alert_fragment_len = 0;
 952
 953                 if (s->msg_callback)
 954                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
 955                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
 956
 957                 if (s->info_callback != NULL)
 958                         cb=s->info_callback;
 959                 else if (s->ctx->info_callback != NULL)
 960                         cb=s->ctx->info_callback;
 961
 962                 if (cb != NULL)
 963                         {
 964                         j = (alert_level << 8) | alert_descr;
 965                         cb(s, SSL_CB_READ_ALERT, j);
 966                         }
 967
 968                 if (alert_level == 1) /* warning */
 969                         {
 970                         s->s3->warn_alert = alert_descr;
 971                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
 972                                 {
 973                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
 974                                 return(0);
 975                                 }
 976 #if 0
 977             /* XXX: this is a possible improvement in the future */
 978                         /* now check if it's a missing record */
 979                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
 980                                 {
 981                                 unsigned short seq;
 982                                 unsigned int frag_off;
 983                                 unsigned char *p = &(s->d1->alert_fragment[2]);
 984
 985                                 n2s(p, seq);
 986                                 n2l3(p, frag_off);
 987
 988                                 dtls1_retransmit_message(s,
 989                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
 990                                                                                  frag_off, &found);
 991                                 if ( ! found  && SSL_in_init(s))
 992                                         {
 993                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
 994                                         /* requested a message not yet sent,
 995                                            send an alert ourselves */
 996                                         ssl3_send_alert(s,SSL3_AL_WARNING,
 997                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 998                                         }
 999                                 }
1000 #endif
1001                         }
1002                 else if (alert_level == 2) /* fatal */
1003                         {
1004                         char tmp[16];
1005
1006                         s->rwstate=SSL_NOTHING;
1007                         s->s3->fatal_alert = alert_descr;
1008                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1009                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1010                         ERR_add_error_data(2,"SSL alert number ",tmp);
1011                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1012                         SSL_CTX_remove_session(s->ctx,s->session);
1013                         return(0);
1014                         }
1015                 else
1016                         {
1017                         al=SSL_AD_ILLEGAL_PARAMETER;
1018                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1019                         goto f_err;
1020                         }
1021
1022                 goto start;
1023                 }
1024
1025         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1026                 {
1027                 s->rwstate=SSL_NOTHING;
1028                 rr->length=0;
1029                 return(0);
1030                 }
1031
1032         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1033                 {
1034                 struct ccs_header_st ccs_hdr;
1035
1036                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1037
1038                 /* 'Change Cipher Spec' is just a single byte, so we know
1039                  * exactly what the record payload has to look like */
1040                 /* XDTLS: check that epoch is consistent */
1041                 if (    (rr->length != DTLS1_CCS_HEADER_LENGTH) ||
1042                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1043                         {
1044                         i=SSL_AD_ILLEGAL_PARAMETER;
1045                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1046                         goto err;
1047                         }
1048
1049                 rr->length=0;
1050
1051                 if (s->msg_callback)
1052                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1053                                 rr->data, 1, s, s->msg_callback_arg);
1054
1055                 s->s3->change_cipher_spec=1;
1056                 if (!ssl3_do_change_cipher_spec(s))
1057                         goto err;
1058
1059                 /* do this whenever CCS is processed */
1060                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1061
1062                 goto start;
1063                 }
1064
1065         /* Unexpected handshake message (Client Hello, or protocol violation) */
1066         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1067                 !s->in_handshake)
1068                 {
1069                 struct hm_header_st msg_hdr;
1070
1071                 /* this may just be a stale retransmit */
1072                 dtls1_get_message_header(rr->data, &msg_hdr);
1073                 if( rr->epoch != s->d1->r_epoch)
1074                         {
1075                         rr->length = 0;
1076                         goto start;
1077                         }
1078
1079                 /* If we are server, we may have a repeated FINISHED of the
1080                  * client here, then retransmit our CCS and FINISHED.
1081                  */
1082                 if (msg_hdr.type == SSL3_MT_FINISHED)
1083                         {
1084                         dtls1_retransmit_buffered_messages(s);
1085                         rr->length = 0;
1086                         goto start;
1087                         }
1088
1089                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1090                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1091                         {
1092 #if 0 /* worked only because C operator preferences are not as expected (and
1093        * because this is not really needed for clients except for detecting
1094        * protocol violations): */
1095                         s->state=SSL_ST_BEFORE|(s->server)
1096                                 ?SSL_ST_ACCEPT
1097                                 :SSL_ST_CONNECT;
1098 #else
1099                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1100 #endif
1101                         s->new_session=1;
1102                         }
1103                 i=s->handshake_func(s);
1104                 if (i < 0) return(i);
1105                 if (i == 0)
1106                         {
1107                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1108                         return(-1);
1109                         }
1110
1111                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1112                         {
1113                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1114                                 {
1115                                 BIO *bio;
1116                                 /* In the case where we try to read application data,
1117                                  * but we trigger an SSL handshake, we return -1 with
1118                                  * the retry option set.  Otherwise renegotiation may
1119                                  * cause nasty problems in the blocking world */
1120                                 s->rwstate=SSL_READING;
1121                                 bio=SSL_get_rbio(s);
1122                                 BIO_clear_retry_flags(bio);
1123                                 BIO_set_retry_read(bio);
1124                                 return(-1);
1125                                 }
1126                         }
1127                 goto start;
1128                 }
1129
1130         switch (rr->type)
1131                 {
1132         default:
1133 #ifndef OPENSSL_NO_TLS
1134                 /* TLS just ignores unknown message types */
1135                 if (s->version == TLS1_VERSION)
1136                         {
1137                         rr->length = 0;
1138                         goto start;
1139                         }
1140 #endif
1141                 al=SSL_AD_UNEXPECTED_MESSAGE;
1142                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1143                 goto f_err;
1144         case SSL3_RT_CHANGE_CIPHER_SPEC:
1145         case SSL3_RT_ALERT:
1146         case SSL3_RT_HANDSHAKE:
1147                 /* we already handled all of these, with the possible exception
1148                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1149                  * should not happen when type != rr->type */
1150                 al=SSL_AD_UNEXPECTED_MESSAGE;
1151                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1152                 goto f_err;
1153         case SSL3_RT_APPLICATION_DATA:
1154                 /* At this point, we were expecting handshake data,
1155                  * but have application data.  If the library was
1156                  * running inside ssl3_read() (i.e. in_read_app_data
1157                  * is set) and it makes sense to read application data
1158                  * at this point (session renegotiation not yet started),
1159                  * we will indulge it.
1160                  */
1161                 if (s->s3->in_read_app_data &&
1162                         (s->s3->total_renegotiations != 0) &&
1163                         ((
1164                                 (s->state & SSL_ST_CONNECT) &&
1165                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1166                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1167                                 ) || (
1168                                         (s->state & SSL_ST_ACCEPT) &&
1169                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1170                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1171                                         )
1172                                 ))
1173                         {
1174                         s->s3->in_read_app_data=2;
1175                         return(-1);
1176                         }
1177                 else
1178                         {
1179                         al=SSL_AD_UNEXPECTED_MESSAGE;
1180                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1181                         goto f_err;
1182                         }
1183                 }
1184         /* not reached */
1185
1186 f_err:
1187         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1188 err:
1189         return(-1);
1190         }
1191
1192 int
1193 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1194         {
1195         unsigned int n,tot;
1196         int i;
1197
1198         if (SSL_in_init(s) && !s->in_handshake)
1199                 {
1200                 i=s->handshake_func(s);
1201                 if (i < 0) return(i);
1202                 if (i == 0)
1203                         {
1204                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1205                         return -1;
1206                         }
1207                 }
1208
1209         tot = s->s3->wnum;
1210         n = len - tot;
1211
1212         while( n)
1213                 {
1214                 /* dtls1_write_bytes sends one record at a time, sized according to
1215                  * the currently known MTU */
1216                 i = dtls1_write_bytes(s, type, buf_, len);
1217                 if (i <= 0) return i;
1218
1219                 if ((i == (int)n) ||
1220                         (type == SSL3_RT_APPLICATION_DATA &&
1221                                 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1222                         {
1223                         /* next chunk of data should get another prepended empty fragment
1224                          * in ciphersuites with known-IV weakness: */
1225                         s->s3->empty_fragment_done = 0;
1226                         return tot+i;
1227                         }
1228
1229                 tot += i;
1230                 n-=i;
1231                 }
1232
1233         return tot;
1234         }
1235
1236
1237         /* this only happens when a client hello is received and a handshake
1238          * is started. */
1239 static int
1240 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1241         int len, int peek)
1242         {
1243
1244         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1245                 /* (partially) satisfy request from storage */
1246                 {
1247                 unsigned char *src = s->d1->handshake_fragment;
1248                 unsigned char *dst = buf;
1249                 unsigned int k,n;
1250
1251                 /* peek == 0 */
1252                 n = 0;
1253                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1254                         {
1255                         *dst++ = *src++;
1256                         len--; s->d1->handshake_fragment_len--;
1257                         n++;
1258                         }
1259                 /* move any remaining fragment bytes: */
1260                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1261                         s->d1->handshake_fragment[k] = *src++;
1262                 return n;
1263                 }
1264
1265         return 0;
1266         }
1267
1268
1269
1270
1271 /* Call this to write data in records of type 'type'
1272  * It will return <= 0 if not all data has been sent or non-blocking IO.
1273  */
1274 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1275         {
1276         const unsigned char *buf=buf_;
1277         unsigned int tot,n,nw;
1278         int i;
1279         unsigned int mtu;
1280
1281         s->rwstate=SSL_NOTHING;
1282         tot=s->s3->wnum;
1283
1284         n=(len-tot);
1285
1286         /* handshake layer figures out MTU for itself, but data records
1287          * are also sent through this interface, so need to figure out MTU */
1288 #if 0
1289         mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1290         mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
1291 #endif
1292         mtu = s->d1->mtu;
1293
1294         if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1295                 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1296
1297         if (n > mtu)
1298                 nw=mtu;
1299         else
1300                 nw=n;
1301
1302         i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1303         if (i <= 0)
1304                 {
1305                 s->s3->wnum=tot;
1306                 return i;
1307                 }
1308
1309         if ( (int)s->s3->wnum + i == len)
1310                 s->s3->wnum = 0;
1311         else
1312                 s->s3->wnum += i;
1313
1314         return i;
1315         }
1316
1317 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1318         {
1319         unsigned char *p,*pseq;
1320         int i,mac_size,clear=0;
1321         int prefix_len = 0;
1322         SSL3_RECORD *wr;
1323         SSL3_BUFFER *wb;
1324         SSL_SESSION *sess;
1325         int bs;
1326
1327         /* first check if there is a SSL3_BUFFER still being written
1328          * out.  This will happen with non blocking IO */
1329         if (s->s3->wbuf.left != 0)
1330                 {
1331                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1332                 return(ssl3_write_pending(s,type,buf,len));
1333                 }
1334
1335         /* If we have an alert to send, lets send it */
1336         if (s->s3->alert_dispatch)
1337                 {
1338                 i=s->method->ssl_dispatch_alert(s);
1339                 if (i <= 0)
1340                         return(i);
1341                 /* if it went, fall through and send more stuff */
1342                 }
1343
1344         if (len == 0 && !create_empty_fragment)
1345                 return 0;
1346
1347         wr= &(s->s3->wrec);
1348         wb= &(s->s3->wbuf);
1349         sess=s->session;
1350
1351         if (    (sess == NULL) ||
1352                 (s->enc_write_ctx == NULL) ||
1353                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1354                 clear=1;
1355
1356         if (clear)
1357                 mac_size=0;
1358         else
1359                 {
1360                 mac_size=EVP_MD_CTX_size(s->write_hash);
1361                 if (mac_size < 0)
1362                         goto err;
1363                 }
1364
1365         /* DTLS implements explicit IV, so no need for empty fragments */
1366 #if 0
1367         /* 'create_empty_fragment' is true only when this function calls itself */
1368         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1369                 && SSL_version(s) != DTLS1_VERSION)
1370                 {
1371                 /* countermeasure against known-IV weakness in CBC ciphersuites
1372                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1373                  */
1374
1375                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1376                         {
1377                         /* recursive function call with 'create_empty_fragment' set;
1378                          * this prepares and buffers the data for an empty fragment
1379                          * (these 'prefix_len' bytes are sent out later
1380                          * together with the actual payload) */
1381                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1382                         if (prefix_len <= 0)
1383                                 goto err;
1384
1385                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1386                                 {
1387                                 /* insufficient space */
1388                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1389                                 goto err;
1390                                 }
1391                         }
1392
1393                 s->s3->empty_fragment_done = 1;
1394                 }
1395 #endif
1396
1397         p = wb->buf + prefix_len;
1398
1399         /* write the header */
1400
1401         *(p++)=type&0xff;
1402         wr->type=type;
1403
1404         *(p++)=(s->version>>8);
1405         *(p++)=s->version&0xff;
1406
1407         /* field where we are to write out packet epoch, seq num and len */
1408         pseq=p;
1409         p+=10;
1410
1411         /* lets setup the record stuff. */
1412
1413         /* Make space for the explicit IV in case of CBC.
1414          * (this is a bit of a boundary violation, but what the heck).
1415          */
1416         if ( s->enc_write_ctx &&
1417                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1418                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1419         else
1420                 bs = 0;
1421
1422         wr->data=p + bs;  /* make room for IV in case of CBC */
1423         wr->length=(int)len;
1424         wr->input=(unsigned char *)buf;
1425
1426         /* we now 'read' from wr->input, wr->length bytes into
1427          * wr->data */
1428
1429         /* first we compress */
1430         if (s->compress != NULL)
1431                 {
1432                 if (!ssl3_do_compress(s))
1433                         {
1434                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1435                         goto err;
1436                         }
1437                 }
1438         else
1439                 {
1440                 memcpy(wr->data,wr->input,wr->length);
1441                 wr->input=wr->data;
1442                 }
1443
1444         /* we should still have the output to wr->data and the input
1445          * from wr->input.  Length should be wr->length.
1446          * wr->data still points in the wb->buf */
1447
1448         if (mac_size != 0)
1449                 {
1450                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1451                         goto err;
1452                 wr->length+=mac_size;
1453                 }
1454
1455         /* this is true regardless of mac size */
1456         wr->input=p;
1457         wr->data=p;
1458
1459
1460         /* ssl3_enc can only have an error on read */
1461         if (bs) /* bs != 0 in case of CBC */
1462                 {
1463                 RAND_pseudo_bytes(p,bs);
1464                 /* master IV and last CBC residue stand for
1465                  * the rest of randomness */
1466                 wr->length += bs;
1467                 }
1468
1469         s->method->ssl3_enc->enc(s,1);
1470
1471         /* record length after mac and block padding */
1472 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1473         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1474
1475         /* there's only one epoch between handshake and app data */
1476
1477         s2n(s->d1->w_epoch, pseq);
1478
1479         /* XDTLS: ?? */
1480 /*      else
1481         s2n(s->d1->handshake_epoch, pseq); */
1482
1483         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1484         pseq+=6;
1485         s2n(wr->length,pseq);
1486
1487         /* we should now have
1488          * wr->data pointing to the encrypted data, which is
1489          * wr->length long */
1490         wr->type=type; /* not needed but helps for debugging */
1491         wr->length+=DTLS1_RT_HEADER_LENGTH;
1492
1493 #if 0  /* this is now done at the message layer */
1494         /* buffer the record, making it easy to handle retransmits */
1495         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1496                 dtls1_buffer_record(s, wr->data, wr->length,
1497                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1498 #endif
1499
1500         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1501
1502         if (create_empty_fragment)
1503                 {
1504                 /* we are in a recursive call;
1505                  * just return the length, don't write out anything here
1506                  */
1507                 return wr->length;
1508                 }
1509
1510         /* now let's set up wb */
1511         wb->left = prefix_len + wr->length;
1512         wb->offset = 0;
1513
1514         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1515         s->s3->wpend_tot=len;
1516         s->s3->wpend_buf=buf;
1517         s->s3->wpend_type=type;
1518         s->s3->wpend_ret=len;
1519
1520         /* we now just need to write the buffer */
1521         return ssl3_write_pending(s,type,buf,len);
1522 err:
1523         return -1;
1524         }
1525
1526
1527
1528 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1529         {
1530         int cmp;
1531         unsigned int shift;
1532         const unsigned char *seq = s->s3->read_sequence;
1533
1534         cmp = satsub64be(seq,bitmap->max_seq_num);
1535         if (cmp > 0)
1536                 {
1537                 memcpy (s->s3->rrec.seq_num,seq,8);
1538                 return 1; /* this record in new */
1539                 }
1540         shift = -cmp;
1541         if (shift >= sizeof(bitmap->map)*8)
1542                 return 0; /* stale, outside the window */
1543         else if (bitmap->map & (1UL<<shift))
1544                 return 0; /* record previously received */
1545
1546         memcpy (s->s3->rrec.seq_num,seq,8);
1547         return 1;
1548         }
1549
1550
1551 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1552         {
1553         int cmp;
1554         unsigned int shift;
1555         const unsigned char *seq = s->s3->read_sequence;
1556
1557         cmp = satsub64be(seq,bitmap->max_seq_num);
1558         if (cmp > 0)
1559                 {
1560                 shift = cmp;
1561                 if (shift < sizeof(bitmap->map)*8)
1562                         bitmap->map <<= shift, bitmap->map |= 1UL;
1563                 else
1564                         bitmap->map = 1UL;
1565                 memcpy(bitmap->max_seq_num,seq,8);
1566                 }
1567         else    {
1568                 shift = -cmp;
1569                 if (shift < sizeof(bitmap->map)*8)
1570                         bitmap->map |= 1UL<<shift;
1571                 }
1572         }
1573
1574
1575 int dtls1_dispatch_alert(SSL *s)
1576         {
1577         int i,j;
1578         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1579         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1580         unsigned char *ptr = &buf[0];
1581
1582         s->s3->alert_dispatch=0;
1583
1584         memset(buf, 0x00, sizeof(buf));
1585         *ptr++ = s->s3->send_alert[0];
1586         *ptr++ = s->s3->send_alert[1];
1587
1588 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1589         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1590                 {
1591                 s2n(s->d1->handshake_read_seq, ptr);
1592 #if 0
1593                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1594
1595                 else
1596                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1597 #endif
1598
1599 #if 0
1600                 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);
1601 #endif
1602                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1603                 }
1604 #endif
1605
1606         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1607         if (i <= 0)
1608                 {
1609                 s->s3->alert_dispatch=1;
1610                 /* fprintf( stderr, "not done with alert\n" ); */
1611                 }
1612         else
1613                 {
1614                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1615 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1616                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1617 #endif
1618                     )
1619                         (void)BIO_flush(s->wbio);
1620
1621                 if (s->msg_callback)
1622                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1623                                 2, s, s->msg_callback_arg);
1624
1625                 if (s->info_callback != NULL)
1626                         cb=s->info_callback;
1627                 else if (s->ctx->info_callback != NULL)
1628                         cb=s->ctx->info_callback;
1629
1630                 if (cb != NULL)
1631                         {
1632                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1633                         cb(s,SSL_CB_WRITE_ALERT,j);
1634                         }
1635                 }
1636         return(i);
1637         }
1638
1639
1640 static DTLS1_BITMAP *
1641 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1642     {
1643
1644     *is_next_epoch = 0;
1645
1646     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1647     if (rr->epoch == s->d1->r_epoch)
1648         return &s->d1->bitmap;
1649
1650     /* Only HM and ALERT messages can be from the next epoch */
1651     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1652         (rr->type == SSL3_RT_HANDSHAKE ||
1653             rr->type == SSL3_RT_ALERT))
1654         {
1655         *is_next_epoch = 1;
1656         return &s->d1->next_bitmap;
1657         }
1658
1659     return NULL;
1660     }
1661
1662 #if 0
1663 static int
1664 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1665         unsigned long *offset)
1666         {
1667
1668         /* alerts are passed up immediately */
1669         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1670                 rr->type == SSL3_RT_ALERT)
1671                 return 0;
1672
1673         /* Only need to buffer if a handshake is underway.
1674          * (this implies that Hello Request and Client Hello are passed up
1675          * immediately) */
1676         if ( SSL_in_init(s))
1677                 {
1678                 unsigned char *data = rr->data;
1679                 /* need to extract the HM/CCS sequence number here */
1680                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1681                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1682                         {
1683                         unsigned short seq_num;
1684                         struct hm_header_st msg_hdr;
1685                         struct ccs_header_st ccs_hdr;
1686
1687                         if ( rr->type == SSL3_RT_HANDSHAKE)
1688                                 {
1689                                 dtls1_get_message_header(data, &msg_hdr);
1690                                 seq_num = msg_hdr.seq;
1691                                 *offset = msg_hdr.frag_off;
1692                                 }
1693                         else
1694                                 {
1695                                 dtls1_get_ccs_header(data, &ccs_hdr);
1696                                 seq_num = ccs_hdr.seq;
1697                                 *offset = 0;
1698                                 }
1699
1700                         /* this is either a record we're waiting for, or a
1701                          * retransmit of something we happened to previously
1702                          * receive (higher layers will drop the repeat silently */
1703                         if ( seq_num < s->d1->handshake_read_seq)
1704                                 return 0;
1705                         if (rr->type == SSL3_RT_HANDSHAKE &&
1706                                 seq_num == s->d1->handshake_read_seq &&
1707                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1708                                 return 0;
1709                         else if ( seq_num == s->d1->handshake_read_seq &&
1710                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1711                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1712                                 return 0;
1713                         else
1714                                 {
1715                                 *priority = seq_num;
1716                                 return 1;
1717                                 }
1718                         }
1719                 else /* unknown record type */
1720                         return 0;
1721                 }
1722
1723         return 0;
1724         }
1725 #endif
1726
1727 void
1728 dtls1_reset_seq_numbers(SSL *s, int rw)
1729         {
1730         unsigned char *seq;
1731         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1732
1733         if ( rw & SSL3_CC_READ)
1734                 {
1735                 seq = s->s3->read_sequence;
1736                 s->d1->r_epoch++;
1737                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1738                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1739                 }
1740         else
1741                 {
1742                 seq = s->s3->write_sequence;
1743                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1744                 s->d1->w_epoch++;
1745                 }
1746
1747         memset(seq, 0x00, seq_bytes);
1748         }
1749
1750
1751 static void
1752 dtls1_clear_timeouts(SSL *s)
1753         {
1754         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1755         }