ssl/d1_pkt.c

   1 /* ssl/d1_pkt.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <stdio.h>
 117 #include <errno.h>
 118 #define USE_SOCKETS
 119 #include "ssl_locl.h"
 120 #include <openssl/evp.h>
 121 #include <openssl/buffer.h>
 122 #include <openssl/pqueue.h>
 123 #include <openssl/rand.h>
 124
 125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
 126 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
 127 {       int ret,sat,brw,i;
 128
 129         if (sizeof(long) == 8) do
 130         {       const union { long one; char little; } is_endian = {1};
 131                 long l;
 132
 133                 if (is_endian.little)                   break;
 134                 /* not reached on little-endians */
 135                 /* following test is redundant, because input is
 136                  * always aligned, but I take no chances... */
 137                 if (((size_t)v1|(size_t)v2)&0x7)        break;
 138
 139                 l  = *((long *)v1);
 140                 l -= *((long *)v2);
 141                 if (l>128)              return 128;
 142                 else if (l<-128)        return -128;
 143                 else                    return (int)l;
 144         } while (0);
 145
 146         ret = (int)v1[7]-(int)v2[7];
 147         sat = 0;
 148         brw = ret>>8;   /* brw is either 0 or -1 */
 149         if (ret & 0x80)
 150         {       for (i=6;i>=0;i--)
 151                 {       brw += (int)v1[i]-(int)v2[i];
 152                         sat |= ~brw;
 153                         brw >>= 8;
 154                 }
 155         }
 156         else
 157         {       for (i=6;i>=0;i--)
 158                 {       brw += (int)v1[i]-(int)v2[i];
 159                         sat |= brw;
 160                         brw >>= 8;
 161                 }
 162         }
 163         brw <<= 8;      /* brw is either 0 or -256 */
 164
 165         if (sat&0xff)   return brw | 0x80;
 166         else            return brw + (ret&0xFF);
 167 }
 168
 169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
 170         int len, int peek);
 171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
 172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
 173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
 174     unsigned int *is_next_epoch);
 175 #if 0
 176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
 177         unsigned short *priority, unsigned long *offset);
 178 #endif
 179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
 180         unsigned char *priority);
 181 static int dtls1_process_record(SSL *s);
 182 static void dtls1_clear_timeouts(SSL *s);
 183
 184 /* copy buffered record into SSL structure */
 185 static int
 186 dtls1_copy_record(SSL *s, pitem *item)
 187     {
 188     DTLS1_RECORD_DATA *rdata;
 189
 190     rdata = (DTLS1_RECORD_DATA *)item->data;
 191
 192     if (s->s3->rbuf.buf != NULL)
 193         OPENSSL_free(s->s3->rbuf.buf);
 194
 195     s->packet = rdata->packet;
 196     s->packet_length = rdata->packet_length;
 197     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 198     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 199
 200     return(1);
 201     }
 202
 203
 204 static int
 205 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
 206         {
 207         DTLS1_RECORD_DATA *rdata;
 208         pitem *item;
 209
 210         /* Limit the size of the queue to prevent DOS attacks */
 211         if (pqueue_size(queue->q) >= 100)
 212                 return 0;
 213
 214         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
 215         item = pitem_new(priority, rdata);
 216         if (rdata == NULL || item == NULL)
 217                 {
 218                 if (rdata != NULL) OPENSSL_free(rdata);
 219                 if (item != NULL) pitem_free(item);
 220
 221                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 222                 return(0);
 223                 }
 224
 225         rdata->packet = s->packet;
 226         rdata->packet_length = s->packet_length;
 227         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
 228         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
 229
 230         item->data = rdata;
 231
 232         /* insert should not fail, since duplicates are dropped */
 233         if (pqueue_insert(queue->q, item) == NULL)
 234                 {
 235                 OPENSSL_free(rdata);
 236                 pitem_free(item);
 237                 return(0);
 238                 }
 239
 240         s->packet = NULL;
 241         s->packet_length = 0;
 242         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
 243         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
 244
 245         if (!ssl3_setup_buffers(s))
 246                 {
 247                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
 248                 OPENSSL_free(rdata);
 249                 pitem_free(item);
 250                 return(0);
 251                 }
 252
 253         return(1);
 254         }
 255
 256
 257 static int
 258 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
 259     {
 260     pitem *item;
 261
 262     item = pqueue_pop(queue->q);
 263     if (item)
 264         {
 265         dtls1_copy_record(s, item);
 266
 267         OPENSSL_free(item->data);
 268                 pitem_free(item);
 269
 270         return(1);
 271         }
 272
 273     return(0);
 274     }
 275
 276
 277 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
 278  * yet */
 279 #define dtls1_get_unprocessed_record(s) \
 280                    dtls1_retrieve_buffered_record((s), \
 281                    &((s)->d1->unprocessed_rcds))
 282
 283 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
 284 #define dtls1_get_processed_record(s) \
 285                    dtls1_retrieve_buffered_record((s), \
 286                    &((s)->d1->processed_rcds))
 287
 288 static int
 289 dtls1_process_buffered_records(SSL *s)
 290     {
 291     pitem *item;
 292
 293     item = pqueue_peek(s->d1->unprocessed_rcds.q);
 294     if (item)
 295         {
 296         DTLS1_RECORD_DATA *rdata;
 297         rdata = (DTLS1_RECORD_DATA *)item->data;
 298
 299         /* Check if epoch is current. */
 300         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
 301             return(1);  /* Nothing to do. */
 302
 303         /* Process all the records. */
 304         while (pqueue_peek(s->d1->unprocessed_rcds.q))
 305             {
 306             dtls1_get_unprocessed_record(s);
 307             if ( ! dtls1_process_record(s))
 308                 return(0);
 309             dtls1_buffer_record(s, &(s->d1->processed_rcds),
 310                 s->s3->rrec.seq_num);
 311             }
 312         }
 313
 314     /* sync epoch numbers once all the unprocessed records
 315      * have been processed */
 316     s->d1->processed_rcds.epoch = s->d1->r_epoch;
 317     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
 318
 319     return(1);
 320     }
 321
 322
 323 #if 0
 324
 325 static int
 326 dtls1_get_buffered_record(SSL *s)
 327         {
 328         pitem *item;
 329         PQ_64BIT priority =
 330                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
 331                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
 332
 333         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating,
 334                                                            nothing buffered */
 335                 return 0;
 336
 337
 338         item = pqueue_peek(s->d1->rcvd_records);
 339         if (item && item->priority == priority)
 340                 {
 341                 /* Check if we've received the record of interest.  It must be
 342                  * a handshake record, since data records as passed up without
 343                  * buffering */
 344                 DTLS1_RECORD_DATA *rdata;
 345                 item = pqueue_pop(s->d1->rcvd_records);
 346                 rdata = (DTLS1_RECORD_DATA *)item->data;
 347
 348                 if (s->s3->rbuf.buf != NULL)
 349                         OPENSSL_free(s->s3->rbuf.buf);
 350
 351                 s->packet = rdata->packet;
 352                 s->packet_length = rdata->packet_length;
 353                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
 354                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
 355
 356                 OPENSSL_free(item->data);
 357                 pitem_free(item);
 358
 359                 /* s->d1->next_expected_seq_num++; */
 360                 return(1);
 361                 }
 362
 363         return 0;
 364         }
 365
 366 #endif
 367
 368 static int
 369 dtls1_process_record(SSL *s)
 370 {
 371         int i,al;
 372         int clear=0;
 373         int enc_err;
 374         SSL_SESSION *sess;
 375         SSL3_RECORD *rr;
 376         unsigned int mac_size;
 377         unsigned char md[EVP_MAX_MD_SIZE];
 378
 379
 380         rr= &(s->s3->rrec);
 381         sess = s->session;
 382
 383         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
 384          * and we have that many bytes in s->packet
 385          */
 386         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
 387
 388         /* ok, we can now read from 's->packet' data into 'rr'
 389          * rr->input points at rr->length bytes, which
 390          * need to be copied into rr->data by either
 391          * the decryption or by the decompression
 392          * When the data is 'copied' into the rr->data buffer,
 393          * rr->input will be pointed at the new buffer */
 394
 395         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
 396          * rr->length bytes of encrypted compressed stuff. */
 397
 398         /* check is not needed I believe */
 399         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 400                 {
 401                 al=SSL_AD_RECORD_OVERFLOW;
 402                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
 403                 goto f_err;
 404                 }
 405
 406         /* decrypt in place in 'rr->input' */
 407         rr->data=rr->input;
 408
 409         enc_err = s->method->ssl3_enc->enc(s,0);
 410         if (enc_err <= 0)
 411                 {
 412                 if (enc_err == 0)
 413                         /* SSLerr() and ssl3_send_alert() have been called */
 414                         goto err;
 415
 416                 /* otherwise enc_err == -1 */
 417                 goto decryption_failed_or_bad_record_mac;
 418                 }
 419
 420 #ifdef TLS_DEBUG
 421 printf("dec %d\n",rr->length);
 422 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
 423 printf("\n");
 424 #endif
 425
 426         /* r->length is now the compressed data plus mac */
 427         if (    (sess == NULL) ||
 428                 (s->enc_read_ctx == NULL) ||
 429                 (s->read_hash == NULL))
 430                 clear=1;
 431
 432         if (!clear)
 433                 {
 434                 /* !clear => s->read_hash != NULL => mac_size != -1 */
 435                 int t;
 436                 t=EVP_MD_CTX_size(s->read_hash);
 437                 OPENSSL_assert(t >= 0);
 438                 mac_size=t;
 439
 440                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
 441                         {
 442 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
 443                         al=SSL_AD_RECORD_OVERFLOW;
 444                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
 445                         goto f_err;
 446 #else
 447                         goto decryption_failed_or_bad_record_mac;
 448 #endif
 449                         }
 450                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
 451                 if (rr->length < mac_size)
 452                         {
 453 #if 0 /* OK only for stream ciphers */
 454                         al=SSL_AD_DECODE_ERROR;
 455                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
 456                         goto f_err;
 457 #else
 458                         goto decryption_failed_or_bad_record_mac;
 459 #endif
 460                         }
 461                 rr->length-=mac_size;
 462                 i=s->method->ssl3_enc->mac(s,md,0);
 463                 if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
 464                         {
 465                         goto decryption_failed_or_bad_record_mac;
 466                         }
 467                 }
 468
 469         /* r->length is now just compressed */
 470         if (s->expand != NULL)
 471                 {
 472                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
 473                         {
 474                         al=SSL_AD_RECORD_OVERFLOW;
 475                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
 476                         goto f_err;
 477                         }
 478                 if (!ssl3_do_uncompress(s))
 479                         {
 480                         al=SSL_AD_DECOMPRESSION_FAILURE;
 481                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
 482                         goto f_err;
 483                         }
 484                 }
 485
 486         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
 487                 {
 488                 al=SSL_AD_RECORD_OVERFLOW;
 489                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
 490                 goto f_err;
 491                 }
 492
 493         rr->off=0;
 494         /* So at this point the following is true
 495          * ssl->s3->rrec.type   is the type of record
 496          * ssl->s3->rrec.length == number of bytes in record
 497          * ssl->s3->rrec.off    == offset to first valid byte
 498          * ssl->s3->rrec.data   == where to take bytes from, increment
 499          *                         after use :-).
 500          */
 501
 502         /* we have pulled in a full packet so zero things */
 503         s->packet_length=0;
 504         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
 505         return(1);
 506
 507 decryption_failed_or_bad_record_mac:
 508         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
 509          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
 510          * failure is directly visible from the ciphertext anyway,
 511          * we should not reveal which kind of error occured -- this
 512          * might become visible to an attacker (e.g. via logfile) */
 513         al=SSL_AD_BAD_RECORD_MAC;
 514         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
 515 f_err:
 516         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 517 err:
 518         return(0);
 519 }
 520
 521
 522 /* Call this to get a new input record.
 523  * It will return <= 0 if more data is needed, normally due to an error
 524  * or non-blocking IO.
 525  * When it finishes, one packet has been decoded and can be found in
 526  * ssl->s3->rrec.type    - is the type of record
 527  * ssl->s3->rrec.data,   - data
 528  * ssl->s3->rrec.length, - number of bytes
 529  */
 530 /* used only by dtls1_read_bytes */
 531 int dtls1_get_record(SSL *s)
 532         {
 533         int ssl_major,ssl_minor,al;
 534         int i,n;
 535         SSL3_RECORD *rr;
 536         SSL_SESSION *sess;
 537         unsigned char *p;
 538         unsigned short version;
 539         DTLS1_BITMAP *bitmap;
 540         unsigned int is_next_epoch;
 541
 542         rr= &(s->s3->rrec);
 543         sess=s->session;
 544
 545         /* The epoch may have changed.  If so, process all the
 546          * pending records.  This is a non-blocking operation. */
 547         if ( ! dtls1_process_buffered_records(s))
 548             return 0;
 549
 550         /* if we're renegotiating, then there may be buffered records */
 551         if (dtls1_get_processed_record(s))
 552                 return 1;
 553
 554         /* get something from the wire */
 555 again:
 556         /* check if we have the header */
 557         if (    (s->rstate != SSL_ST_READ_BODY) ||
 558                 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
 559                 {
 560                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
 561                 /* read timeout is handled by dtls1_read_bytes */
 562                 if (n <= 0) return(n); /* error or non-blocking */
 563
 564                 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
 565
 566                 s->rstate=SSL_ST_READ_BODY;
 567
 568                 p=s->packet;
 569
 570                 /* Pull apart the header into the DTLS1_RECORD */
 571                 rr->type= *(p++);
 572                 ssl_major= *(p++);
 573                 ssl_minor= *(p++);
 574                 version=(ssl_major<<8)|ssl_minor;
 575
 576                 /* sequence number is 64 bits, with top 2 bytes = epoch */
 577                 n2s(p,rr->epoch);
 578
 579                 memcpy(&(s->s3->read_sequence[2]), p, 6);
 580                 p+=6;
 581
 582                 n2s(p,rr->length);
 583
 584                 /* Lets check version */
 585                 if (!s->first_packet)
 586                         {
 587                         if (version != s->version)
 588                                 {
 589                                 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 590                                 /* Send back error using their
 591                                  * version number :-) */
 592                                 s->version=version;
 593                                 al=SSL_AD_PROTOCOL_VERSION;
 594                                 goto f_err;
 595                                 }
 596                         }
 597
 598                 if ((version & 0xff00) != (s->version & 0xff00))
 599                         {
 600                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
 601                         goto err;
 602                         }
 603
 604                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 605                         {
 606                         al=SSL_AD_RECORD_OVERFLOW;
 607                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
 608                         goto f_err;
 609                         }
 610
 611                 /* now s->rstate == SSL_ST_READ_BODY */
 612                 }
 613
 614         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 615
 616         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 617                 {
 618                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 619                 i=rr->length;
 620                 n=ssl3_read_n(s,i,i,1);
 621                 if (n <= 0) return(n); /* error or non-blocking io */
 622
 623                 /* this packet contained a partial record, dump it */
 624                 if ( n != i)
 625                         {
 626                         rr->length = 0;
 627                         s->packet_length = 0;
 628                         goto again;
 629                         }
 630
 631                 /* now n == rr->length,
 632                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 633                 }
 634         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 635
 636         /* match epochs.  NULL means the packet is dropped on the floor */
 637         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 638         if ( bitmap == NULL)
 639                 {
 640                 rr->length = 0;
 641                 s->packet_length = 0;  /* dump this record */
 642                 goto again;   /* get another record */
 643                 }
 644
 645         /* check whether this is a repeat, or aged record */
 646         if ( ! dtls1_record_replay_check(s, bitmap))
 647                 {
 648                 rr->length = 0;
 649                 s->packet_length=0; /* dump this record */
 650                 goto again;     /* get another record */
 651                 }
 652
 653         /* just read a 0 length packet */
 654         if (rr->length == 0) goto again;
 655
 656         /* If this record is from the next epoch (either HM or ALERT),
 657          * buffer it since it cannot be processed at this time. Records
 658          * from the next epoch are marked as received even though they
 659          * are not processed, so as to prevent any potential resource
 660          * DoS attack */
 661         if (is_next_epoch)
 662                 {
 663                 dtls1_record_bitmap_update(s, bitmap);
 664                 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 665                 rr->length = 0;
 666                 s->packet_length = 0;
 667                 goto again;
 668                 }
 669
 670         if ( ! dtls1_process_record(s))
 671                 return(0);
 672
 673         dtls1_clear_timeouts(s);  /* done waiting */
 674         return(1);
 675
 676 f_err:
 677         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 678 err:
 679         return(0);
 680         }
 681
 682 /* Return up to 'len' payload bytes received in 'type' records.
 683  * 'type' is one of the following:
 684  *
 685  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 686  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 687  *   -  0 (during a shutdown, no data has to be returned)
 688  *
 689  * If we don't have stored data to work from, read a SSL/TLS record first
 690  * (possibly multiple records if we still don't have anything to return).
 691  *
 692  * This function must handle any surprises the peer may have for us, such as
 693  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 694  * a surprise, but handled as if it were), or renegotiation requests.
 695  * Also if record payloads contain fragments too small to process, we store
 696  * them until there is enough for the respective protocol (the record protocol
 697  * may use arbitrary fragmentation and even interleaving):
 698  *     Change cipher spec protocol
 699  *             just 1 byte needed, no need for keeping anything stored
 700  *     Alert protocol
 701  *             2 bytes needed (AlertLevel, AlertDescription)
 702  *     Handshake protocol
 703  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 704  *             to detect unexpected Client Hello and Hello Request messages
 705  *             here, anything else is handled by higher layers
 706  *     Application data protocol
 707  *             none of our business
 708  */
 709 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 710         {
 711         int al,i,j,ret;
 712         unsigned int n;
 713         SSL3_RECORD *rr;
 714         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 715
 716         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 717                 if (!ssl3_setup_buffers(s))
 718                         return(-1);
 719
 720     /* XXX: check what the second '&& type' is about */
 721         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 722                 (type != SSL3_RT_HANDSHAKE) && type) ||
 723             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 724                 {
 725                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 726                 return -1;
 727                 }
 728
 729         /* check whether there's a handshake message (client hello?) waiting */
 730         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 731                 return ret;
 732
 733         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 734
 735         if (!s->in_handshake && SSL_in_init(s))
 736                 {
 737                 /* type == SSL3_RT_APPLICATION_DATA */
 738                 i=s->handshake_func(s);
 739                 if (i < 0) return(i);
 740                 if (i == 0)
 741                         {
 742                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 743                         return(-1);
 744                         }
 745                 }
 746
 747 start:
 748         s->rwstate=SSL_NOTHING;
 749
 750         /* s->s3->rrec.type         - is the type of record
 751          * s->s3->rrec.data,    - data
 752          * s->s3->rrec.off,     - offset into 'data' for next read
 753          * s->s3->rrec.length,  - number of bytes. */
 754         rr = &(s->s3->rrec);
 755
 756         /* We are not handshaking and have no data yet,
 757          * so process data buffered during the last handshake
 758          * in advance, if any.
 759          */
 760         if (s->state == SSL_ST_OK && rr->length == 0)
 761                 {
 762                 pitem *item;
 763                 item = pqueue_pop(s->d1->buffered_app_data.q);
 764                 if (item)
 765                         {
 766                         dtls1_copy_record(s, item);
 767
 768                         OPENSSL_free(item->data);
 769                         pitem_free(item);
 770                         }
 771                 }
 772
 773         /* Check for timeout */
 774         if (dtls1_is_timer_expired(s))
 775                 {
 776                 if (dtls1_read_failed(s, -1) > 0);
 777                         goto start;
 778                 }
 779
 780         /* get new packet if necessary */
 781         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 782                 {
 783                 ret=dtls1_get_record(s);
 784                 if (ret <= 0)
 785                         {
 786                         ret = dtls1_read_failed(s, ret);
 787                         /* anything other than a timeout is an error */
 788                         if (ret <= 0)
 789                                 return(ret);
 790                         else
 791                                 goto start;
 792                         }
 793                 }
 794
 795         /* we now have a packet which can be read and processed */
 796
 797         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 798                                        * reset by ssl3_get_finished */
 799                 && (rr->type != SSL3_RT_HANDSHAKE))
 800                 {
 801                 /* We now have application data between CCS and Finished.
 802                  * Most likely the packets were reordered on their way, so
 803                  * buffer the application data for later processing rather
 804                  * than dropping the connection.
 805                  */
 806                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), 0);
 807                 rr->length = 0;
 808                 goto start;
 809                 }
 810
 811         /* If the other end has shut down, throw anything we read away
 812          * (even in 'peek' mode) */
 813         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 814                 {
 815                 rr->length=0;
 816                 s->rwstate=SSL_NOTHING;
 817                 return(0);
 818                 }
 819
 820
 821         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 822                 {
 823                 /* make sure that we are not getting application data when we
 824                  * are doing a handshake for the first time */
 825                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 826                         (s->enc_read_ctx == NULL))
 827                         {
 828                         al=SSL_AD_UNEXPECTED_MESSAGE;
 829                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 830                         goto f_err;
 831                         }
 832
 833                 if (len <= 0) return(len);
 834
 835                 if ((unsigned int)len > rr->length)
 836                         n = rr->length;
 837                 else
 838                         n = (unsigned int)len;
 839
 840                 memcpy(buf,&(rr->data[rr->off]),n);
 841                 if (!peek)
 842                         {
 843                         rr->length-=n;
 844                         rr->off+=n;
 845                         if (rr->length == 0)
 846                                 {
 847                                 s->rstate=SSL_ST_READ_HEADER;
 848                                 rr->off=0;
 849                                 }
 850                         }
 851                 return(n);
 852                 }
 853
 854
 855         /* If we get here, then type != rr->type; if we have a handshake
 856          * message, then it was unexpected (Hello Request or Client Hello). */
 857
 858         /* In case of record types for which we have 'fragment' storage,
 859          * fill that so that we can process the data at a fixed place.
 860          */
 861                 {
 862                 unsigned int k, dest_maxlen = 0;
 863                 unsigned char *dest = NULL;
 864                 unsigned int *dest_len = NULL;
 865
 866                 if (rr->type == SSL3_RT_HANDSHAKE)
 867                         {
 868                         dest_maxlen = sizeof s->d1->handshake_fragment;
 869                         dest = s->d1->handshake_fragment;
 870                         dest_len = &s->d1->handshake_fragment_len;
 871                         }
 872                 else if (rr->type == SSL3_RT_ALERT)
 873                         {
 874                         dest_maxlen = sizeof(s->d1->alert_fragment);
 875                         dest = s->d1->alert_fragment;
 876                         dest_len = &s->d1->alert_fragment_len;
 877                         }
 878                 /* else it's a CCS message, or application data or wrong */
 879                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 880                         {
 881                         /* Application data while renegotiating
 882                          * is allowed. Try again reading.
 883                          */
 884                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 885                                 {
 886                                 BIO *bio;
 887                                 s->s3->in_read_app_data=2;
 888                                 bio=SSL_get_rbio(s);
 889                                 s->rwstate=SSL_READING;
 890                                 BIO_clear_retry_flags(bio);
 891                                 BIO_set_retry_read(bio);
 892                                 return(-1);
 893                                 }
 894
 895                         /* Not certain if this is the right error handling */
 896                         al=SSL_AD_UNEXPECTED_MESSAGE;
 897                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 898                         goto f_err;
 899                         }
 900
 901                 if (dest_maxlen > 0)
 902                         {
 903             /* XDTLS:  In a pathalogical case, the Client Hello
 904              *  may be fragmented--don't always expect dest_maxlen bytes */
 905                         if ( rr->length < dest_maxlen)
 906                                 {
 907 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
 908                                 /*
 909                                  * for normal alerts rr->length is 2, while
 910                                  * dest_maxlen is 7 if we were to handle this
 911                                  * non-existing alert...
 912                                  */
 913                                 FIX ME
 914 #endif
 915                                 s->rstate=SSL_ST_READ_HEADER;
 916                                 rr->length = 0;
 917                                 goto start;
 918                                 }
 919
 920                         /* now move 'n' bytes: */
 921                         for ( k = 0; k < dest_maxlen; k++)
 922                                 {
 923                                 dest[k] = rr->data[rr->off++];
 924                                 rr->length--;
 925                                 }
 926                         *dest_len = dest_maxlen;
 927                         }
 928                 }
 929
 930         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 931          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 932          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 933
 934         /* If we are a client, check for an incoming 'Hello Request': */
 935         if ((!s->server) &&
 936                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 937                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 938                 (s->session != NULL) && (s->session->cipher != NULL))
 939                 {
 940                 s->d1->handshake_fragment_len = 0;
 941
 942                 if ((s->d1->handshake_fragment[1] != 0) ||
 943                         (s->d1->handshake_fragment[2] != 0) ||
 944                         (s->d1->handshake_fragment[3] != 0))
 945                         {
 946                         al=SSL_AD_DECODE_ERROR;
 947                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 948                         goto err;
 949                         }
 950
 951                 /* no need to check sequence number on HELLO REQUEST messages */
 952
 953                 if (s->msg_callback)
 954                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 955                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 956
 957                 if (SSL_is_init_finished(s) &&
 958                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 959                         !s->s3->renegotiate)
 960                         {
 961                         ssl3_renegotiate(s);
 962                         if (ssl3_renegotiate_check(s))
 963                                 {
 964                                 i=s->handshake_func(s);
 965                                 if (i < 0) return(i);
 966                                 if (i == 0)
 967                                         {
 968                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 969                                         return(-1);
 970                                         }
 971
 972                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 973                                         {
 974                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 975                                                 {
 976                                                 BIO *bio;
 977                                                 /* In the case where we try to read application data,
 978                                                  * but we trigger an SSL handshake, we return -1 with
 979                                                  * the retry option set.  Otherwise renegotiation may
 980                                                  * cause nasty problems in the blocking world */
 981                                                 s->rwstate=SSL_READING;
 982                                                 bio=SSL_get_rbio(s);
 983                                                 BIO_clear_retry_flags(bio);
 984                                                 BIO_set_retry_read(bio);
 985                                                 return(-1);
 986                                                 }
 987                                         }
 988                                 }
 989                         }
 990                 /* we either finished a handshake or ignored the request,
 991                  * now try again to obtain the (application) data we were asked for */
 992                 goto start;
 993                 }
 994
 995         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
 996                 {
 997                 int alert_level = s->d1->alert_fragment[0];
 998                 int alert_descr = s->d1->alert_fragment[1];
 999
1000                 s->d1->alert_fragment_len = 0;
1001
1002                 if (s->msg_callback)
1003                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1004                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1005
1006                 if (s->info_callback != NULL)
1007                         cb=s->info_callback;
1008                 else if (s->ctx->info_callback != NULL)
1009                         cb=s->ctx->info_callback;
1010
1011                 if (cb != NULL)
1012                         {
1013                         j = (alert_level << 8) | alert_descr;
1014                         cb(s, SSL_CB_READ_ALERT, j);
1015                         }
1016
1017                 if (alert_level == 1) /* warning */
1018                         {
1019                         s->s3->warn_alert = alert_descr;
1020                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1021                                 {
1022                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1023                                 return(0);
1024                                 }
1025 #if 0
1026             /* XXX: this is a possible improvement in the future */
1027                         /* now check if it's a missing record */
1028                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1029                                 {
1030                                 unsigned short seq;
1031                                 unsigned int frag_off;
1032                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1033
1034                                 n2s(p, seq);
1035                                 n2l3(p, frag_off);
1036
1037                                 dtls1_retransmit_message(s,
1038                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1039                                                                                  frag_off, &found);
1040                                 if ( ! found  && SSL_in_init(s))
1041                                         {
1042                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1043                                         /* requested a message not yet sent,
1044                                            send an alert ourselves */
1045                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1046                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1047                                         }
1048                                 }
1049 #endif
1050                         }
1051                 else if (alert_level == 2) /* fatal */
1052                         {
1053                         char tmp[16];
1054
1055                         s->rwstate=SSL_NOTHING;
1056                         s->s3->fatal_alert = alert_descr;
1057                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1058                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1059                         ERR_add_error_data(2,"SSL alert number ",tmp);
1060                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1061                         SSL_CTX_remove_session(s->ctx,s->session);
1062                         return(0);
1063                         }
1064                 else
1065                         {
1066                         al=SSL_AD_ILLEGAL_PARAMETER;
1067                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1068                         goto f_err;
1069                         }
1070
1071                 goto start;
1072                 }
1073
1074         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1075                 {
1076                 s->rwstate=SSL_NOTHING;
1077                 rr->length=0;
1078                 return(0);
1079                 }
1080
1081         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1082                 {
1083                 struct ccs_header_st ccs_hdr;
1084                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1085
1086                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1087
1088                 if (s->version == DTLS1_BAD_VER)
1089                         ccs_hdr_len = 3;
1090
1091                 /* 'Change Cipher Spec' is just a single byte, so we know
1092                  * exactly what the record payload has to look like */
1093                 /* XDTLS: check that epoch is consistent */
1094                 if (    (rr->length != ccs_hdr_len) ||
1095                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1096                         {
1097                         i=SSL_AD_ILLEGAL_PARAMETER;
1098                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1099                         goto err;
1100                         }
1101
1102                 rr->length=0;
1103
1104                 if (s->msg_callback)
1105                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1106                                 rr->data, 1, s, s->msg_callback_arg);
1107
1108                 /* We can't process a CCS now, because previous handshake
1109                  * messages are still missing, so just drop it.
1110                  */
1111                 if (!s->d1->change_cipher_spec_ok)
1112                         {
1113                         goto start;
1114                         }
1115
1116                 s->d1->change_cipher_spec_ok = 0;
1117
1118                 s->s3->change_cipher_spec=1;
1119                 if (!ssl3_do_change_cipher_spec(s))
1120                         goto err;
1121
1122                 /* do this whenever CCS is processed */
1123                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1124
1125                 if (s->version == DTLS1_BAD_VER)
1126                         s->d1->handshake_read_seq++;
1127
1128                 goto start;
1129                 }
1130
1131         /* Unexpected handshake message (Client Hello, or protocol violation) */
1132         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1133                 !s->in_handshake)
1134                 {
1135                 struct hm_header_st msg_hdr;
1136
1137                 /* this may just be a stale retransmit */
1138                 dtls1_get_message_header(rr->data, &msg_hdr);
1139                 if( rr->epoch != s->d1->r_epoch)
1140                         {
1141                         rr->length = 0;
1142                         goto start;
1143                         }
1144
1145                 /* If we are server, we may have a repeated FINISHED of the
1146                  * client here, then retransmit our CCS and FINISHED.
1147                  */
1148                 if (msg_hdr.type == SSL3_MT_FINISHED)
1149                         {
1150                         dtls1_retransmit_buffered_messages(s);
1151                         rr->length = 0;
1152                         goto start;
1153                         }
1154
1155                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1156                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1157                         {
1158 #if 0 /* worked only because C operator preferences are not as expected (and
1159        * because this is not really needed for clients except for detecting
1160        * protocol violations): */
1161                         s->state=SSL_ST_BEFORE|(s->server)
1162                                 ?SSL_ST_ACCEPT
1163                                 :SSL_ST_CONNECT;
1164 #else
1165                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1166 #endif
1167                         s->new_session=1;
1168                         }
1169                 i=s->handshake_func(s);
1170                 if (i < 0) return(i);
1171                 if (i == 0)
1172                         {
1173                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1174                         return(-1);
1175                         }
1176
1177                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1178                         {
1179                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1180                                 {
1181                                 BIO *bio;
1182                                 /* In the case where we try to read application data,
1183                                  * but we trigger an SSL handshake, we return -1 with
1184                                  * the retry option set.  Otherwise renegotiation may
1185                                  * cause nasty problems in the blocking world */
1186                                 s->rwstate=SSL_READING;
1187                                 bio=SSL_get_rbio(s);
1188                                 BIO_clear_retry_flags(bio);
1189                                 BIO_set_retry_read(bio);
1190                                 return(-1);
1191                                 }
1192                         }
1193                 goto start;
1194                 }
1195
1196         switch (rr->type)
1197                 {
1198         default:
1199 #ifndef OPENSSL_NO_TLS
1200                 /* TLS just ignores unknown message types */
1201                 if (s->version == TLS1_VERSION)
1202                         {
1203                         rr->length = 0;
1204                         goto start;
1205                         }
1206 #endif
1207                 al=SSL_AD_UNEXPECTED_MESSAGE;
1208                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1209                 goto f_err;
1210         case SSL3_RT_CHANGE_CIPHER_SPEC:
1211         case SSL3_RT_ALERT:
1212         case SSL3_RT_HANDSHAKE:
1213                 /* we already handled all of these, with the possible exception
1214                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1215                  * should not happen when type != rr->type */
1216                 al=SSL_AD_UNEXPECTED_MESSAGE;
1217                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1218                 goto f_err;
1219         case SSL3_RT_APPLICATION_DATA:
1220                 /* At this point, we were expecting handshake data,
1221                  * but have application data.  If the library was
1222                  * running inside ssl3_read() (i.e. in_read_app_data
1223                  * is set) and it makes sense to read application data
1224                  * at this point (session renegotiation not yet started),
1225                  * we will indulge it.
1226                  */
1227                 if (s->s3->in_read_app_data &&
1228                         (s->s3->total_renegotiations != 0) &&
1229                         ((
1230                                 (s->state & SSL_ST_CONNECT) &&
1231                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1232                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1233                                 ) || (
1234                                         (s->state & SSL_ST_ACCEPT) &&
1235                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1236                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1237                                         )
1238                                 ))
1239                         {
1240                         s->s3->in_read_app_data=2;
1241                         return(-1);
1242                         }
1243                 else
1244                         {
1245                         al=SSL_AD_UNEXPECTED_MESSAGE;
1246                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1247                         goto f_err;
1248                         }
1249                 }
1250         /* not reached */
1251
1252 f_err:
1253         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1254 err:
1255         return(-1);
1256         }
1257
1258 int
1259 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1260         {
1261         unsigned int n,tot;
1262         int i;
1263
1264         if (SSL_in_init(s) && !s->in_handshake)
1265                 {
1266                 i=s->handshake_func(s);
1267                 if (i < 0) return(i);
1268                 if (i == 0)
1269                         {
1270                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1271                         return -1;
1272                         }
1273                 }
1274
1275         tot = s->s3->wnum;
1276         n = len - tot;
1277
1278         while( n)
1279                 {
1280                 /* dtls1_write_bytes sends one record at a time, sized according to
1281                  * the currently known MTU */
1282                 i = dtls1_write_bytes(s, type, buf_, len);
1283                 if (i <= 0) return i;
1284
1285                 if ((i == (int)n) ||
1286                         (type == SSL3_RT_APPLICATION_DATA &&
1287                                 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1288                         {
1289                         /* next chunk of data should get another prepended empty fragment
1290                          * in ciphersuites with known-IV weakness: */
1291                         s->s3->empty_fragment_done = 0;
1292                         return tot+i;
1293                         }
1294
1295                 tot += i;
1296                 n-=i;
1297                 }
1298
1299         return tot;
1300         }
1301
1302
1303         /* this only happens when a client hello is received and a handshake
1304          * is started. */
1305 static int
1306 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1307         int len, int peek)
1308         {
1309
1310         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1311                 /* (partially) satisfy request from storage */
1312                 {
1313                 unsigned char *src = s->d1->handshake_fragment;
1314                 unsigned char *dst = buf;
1315                 unsigned int k,n;
1316
1317                 /* peek == 0 */
1318                 n = 0;
1319                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1320                         {
1321                         *dst++ = *src++;
1322                         len--; s->d1->handshake_fragment_len--;
1323                         n++;
1324                         }
1325                 /* move any remaining fragment bytes: */
1326                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1327                         s->d1->handshake_fragment[k] = *src++;
1328                 return n;
1329                 }
1330
1331         return 0;
1332         }
1333
1334
1335
1336
1337 /* Call this to write data in records of type 'type'
1338  * It will return <= 0 if not all data has been sent or non-blocking IO.
1339  */
1340 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1341         {
1342         const unsigned char *buf=buf_;
1343         unsigned int tot,n,nw;
1344         int i;
1345         unsigned int mtu;
1346
1347         s->rwstate=SSL_NOTHING;
1348         tot=s->s3->wnum;
1349
1350         n=(len-tot);
1351
1352         /* handshake layer figures out MTU for itself, but data records
1353          * are also sent through this interface, so need to figure out MTU */
1354 #if 0
1355         mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1356         mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
1357 #endif
1358         mtu = s->d1->mtu;
1359
1360         if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1361                 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1362
1363         if (n > mtu)
1364                 nw=mtu;
1365         else
1366                 nw=n;
1367
1368         i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1369         if (i <= 0)
1370                 {
1371                 s->s3->wnum=tot;
1372                 return i;
1373                 }
1374
1375         if ( (int)s->s3->wnum + i == len)
1376                 s->s3->wnum = 0;
1377         else
1378                 s->s3->wnum += i;
1379
1380         return i;
1381         }
1382
1383 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1384         {
1385         unsigned char *p,*pseq;
1386         int i,mac_size,clear=0;
1387         int prefix_len = 0;
1388         SSL3_RECORD *wr;
1389         SSL3_BUFFER *wb;
1390         SSL_SESSION *sess;
1391         int bs;
1392
1393         /* first check if there is a SSL3_BUFFER still being written
1394          * out.  This will happen with non blocking IO */
1395         if (s->s3->wbuf.left != 0)
1396                 {
1397                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1398                 return(ssl3_write_pending(s,type,buf,len));
1399                 }
1400
1401         /* If we have an alert to send, lets send it */
1402         if (s->s3->alert_dispatch)
1403                 {
1404                 i=s->method->ssl_dispatch_alert(s);
1405                 if (i <= 0)
1406                         return(i);
1407                 /* if it went, fall through and send more stuff */
1408                 }
1409
1410         if (len == 0 && !create_empty_fragment)
1411                 return 0;
1412
1413         wr= &(s->s3->wrec);
1414         wb= &(s->s3->wbuf);
1415         sess=s->session;
1416
1417         if (    (sess == NULL) ||
1418                 (s->enc_write_ctx == NULL) ||
1419                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1420                 clear=1;
1421
1422         if (clear)
1423                 mac_size=0;
1424         else
1425                 {
1426                 mac_size=EVP_MD_CTX_size(s->write_hash);
1427                 if (mac_size < 0)
1428                         goto err;
1429                 }
1430
1431         /* DTLS implements explicit IV, so no need for empty fragments */
1432 #if 0
1433         /* 'create_empty_fragment' is true only when this function calls itself */
1434         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1435             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1436                 {
1437                 /* countermeasure against known-IV weakness in CBC ciphersuites
1438                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1439                  */
1440
1441                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1442                         {
1443                         /* recursive function call with 'create_empty_fragment' set;
1444                          * this prepares and buffers the data for an empty fragment
1445                          * (these 'prefix_len' bytes are sent out later
1446                          * together with the actual payload) */
1447                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1448                         if (prefix_len <= 0)
1449                                 goto err;
1450
1451                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1452                                 {
1453                                 /* insufficient space */
1454                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1455                                 goto err;
1456                                 }
1457                         }
1458
1459                 s->s3->empty_fragment_done = 1;
1460                 }
1461 #endif
1462         p = wb->buf + prefix_len;
1463
1464         /* write the header */
1465
1466         *(p++)=type&0xff;
1467         wr->type=type;
1468
1469         *(p++)=(s->version>>8);
1470         *(p++)=s->version&0xff;
1471
1472         /* field where we are to write out packet epoch, seq num and len */
1473         pseq=p;
1474         p+=10;
1475
1476         /* lets setup the record stuff. */
1477
1478         /* Make space for the explicit IV in case of CBC.
1479          * (this is a bit of a boundary violation, but what the heck).
1480          */
1481         if ( s->enc_write_ctx &&
1482                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1483                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1484         else
1485                 bs = 0;
1486
1487         wr->data=p + bs;  /* make room for IV in case of CBC */
1488         wr->length=(int)len;
1489         wr->input=(unsigned char *)buf;
1490
1491         /* we now 'read' from wr->input, wr->length bytes into
1492          * wr->data */
1493
1494         /* first we compress */
1495         if (s->compress != NULL)
1496                 {
1497                 if (!ssl3_do_compress(s))
1498                         {
1499                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1500                         goto err;
1501                         }
1502                 }
1503         else
1504                 {
1505                 memcpy(wr->data,wr->input,wr->length);
1506                 wr->input=wr->data;
1507                 }
1508
1509         /* we should still have the output to wr->data and the input
1510          * from wr->input.  Length should be wr->length.
1511          * wr->data still points in the wb->buf */
1512
1513         if (mac_size != 0)
1514                 {
1515                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1516                         goto err;
1517                 wr->length+=mac_size;
1518                 }
1519
1520         /* this is true regardless of mac size */
1521         wr->input=p;
1522         wr->data=p;
1523
1524
1525         /* ssl3_enc can only have an error on read */
1526         if (bs) /* bs != 0 in case of CBC */
1527                 {
1528                 RAND_pseudo_bytes(p,bs);
1529                 /* master IV and last CBC residue stand for
1530                  * the rest of randomness */
1531                 wr->length += bs;
1532                 }
1533
1534         s->method->ssl3_enc->enc(s,1);
1535
1536         /* record length after mac and block padding */
1537 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1538         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1539
1540         /* there's only one epoch between handshake and app data */
1541
1542         s2n(s->d1->w_epoch, pseq);
1543
1544         /* XDTLS: ?? */
1545 /*      else
1546         s2n(s->d1->handshake_epoch, pseq); */
1547
1548         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1549         pseq+=6;
1550         s2n(wr->length,pseq);
1551
1552         /* we should now have
1553          * wr->data pointing to the encrypted data, which is
1554          * wr->length long */
1555         wr->type=type; /* not needed but helps for debugging */
1556         wr->length+=DTLS1_RT_HEADER_LENGTH;
1557
1558 #if 0  /* this is now done at the message layer */
1559         /* buffer the record, making it easy to handle retransmits */
1560         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1561                 dtls1_buffer_record(s, wr->data, wr->length,
1562                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1563 #endif
1564
1565         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1566
1567         if (create_empty_fragment)
1568                 {
1569                 /* we are in a recursive call;
1570                  * just return the length, don't write out anything here
1571                  */
1572                 return wr->length;
1573                 }
1574
1575         /* now let's set up wb */
1576         wb->left = prefix_len + wr->length;
1577         wb->offset = 0;
1578
1579         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1580         s->s3->wpend_tot=len;
1581         s->s3->wpend_buf=buf;
1582         s->s3->wpend_type=type;
1583         s->s3->wpend_ret=len;
1584
1585         /* we now just need to write the buffer */
1586         return ssl3_write_pending(s,type,buf,len);
1587 err:
1588         return -1;
1589         }
1590
1591
1592
1593 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1594         {
1595         int cmp;
1596         unsigned int shift;
1597         const unsigned char *seq = s->s3->read_sequence;
1598
1599         cmp = satsub64be(seq,bitmap->max_seq_num);
1600         if (cmp > 0)
1601                 {
1602                 memcpy (s->s3->rrec.seq_num,seq,8);
1603                 return 1; /* this record in new */
1604                 }
1605         shift = -cmp;
1606         if (shift >= sizeof(bitmap->map)*8)
1607                 return 0; /* stale, outside the window */
1608         else if (bitmap->map & (1UL<<shift))
1609                 return 0; /* record previously received */
1610
1611         memcpy (s->s3->rrec.seq_num,seq,8);
1612         return 1;
1613         }
1614
1615
1616 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1617         {
1618         int cmp;
1619         unsigned int shift;
1620         const unsigned char *seq = s->s3->read_sequence;
1621
1622         cmp = satsub64be(seq,bitmap->max_seq_num);
1623         if (cmp > 0)
1624                 {
1625                 shift = cmp;
1626                 if (shift < sizeof(bitmap->map)*8)
1627                         bitmap->map <<= shift, bitmap->map |= 1UL;
1628                 else
1629                         bitmap->map = 1UL;
1630                 memcpy(bitmap->max_seq_num,seq,8);
1631                 }
1632         else    {
1633                 shift = -cmp;
1634                 if (shift < sizeof(bitmap->map)*8)
1635                         bitmap->map |= 1UL<<shift;
1636                 }
1637         }
1638
1639
1640 int dtls1_dispatch_alert(SSL *s)
1641         {
1642         int i,j;
1643         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1644         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1645         unsigned char *ptr = &buf[0];
1646
1647         s->s3->alert_dispatch=0;
1648
1649         memset(buf, 0x00, sizeof(buf));
1650         *ptr++ = s->s3->send_alert[0];
1651         *ptr++ = s->s3->send_alert[1];
1652
1653 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1654         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1655                 {
1656                 s2n(s->d1->handshake_read_seq, ptr);
1657 #if 0
1658                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1659
1660                 else
1661                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1662 #endif
1663
1664 #if 0
1665                 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);
1666 #endif
1667                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1668                 }
1669 #endif
1670
1671         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1672         if (i <= 0)
1673                 {
1674                 s->s3->alert_dispatch=1;
1675                 /* fprintf( stderr, "not done with alert\n" ); */
1676                 }
1677         else
1678                 {
1679                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1680 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1681                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1682 #endif
1683                     )
1684                         (void)BIO_flush(s->wbio);
1685
1686                 if (s->msg_callback)
1687                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1688                                 2, s, s->msg_callback_arg);
1689
1690                 if (s->info_callback != NULL)
1691                         cb=s->info_callback;
1692                 else if (s->ctx->info_callback != NULL)
1693                         cb=s->ctx->info_callback;
1694
1695                 if (cb != NULL)
1696                         {
1697                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1698                         cb(s,SSL_CB_WRITE_ALERT,j);
1699                         }
1700                 }
1701         return(i);
1702         }
1703
1704
1705 static DTLS1_BITMAP *
1706 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1707     {
1708
1709     *is_next_epoch = 0;
1710
1711     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1712     if (rr->epoch == s->d1->r_epoch)
1713         return &s->d1->bitmap;
1714
1715     /* Only HM and ALERT messages can be from the next epoch */
1716     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1717         (rr->type == SSL3_RT_HANDSHAKE ||
1718             rr->type == SSL3_RT_ALERT))
1719         {
1720         *is_next_epoch = 1;
1721         return &s->d1->next_bitmap;
1722         }
1723
1724     return NULL;
1725     }
1726
1727 #if 0
1728 static int
1729 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1730         unsigned long *offset)
1731         {
1732
1733         /* alerts are passed up immediately */
1734         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1735                 rr->type == SSL3_RT_ALERT)
1736                 return 0;
1737
1738         /* Only need to buffer if a handshake is underway.
1739          * (this implies that Hello Request and Client Hello are passed up
1740          * immediately) */
1741         if ( SSL_in_init(s))
1742                 {
1743                 unsigned char *data = rr->data;
1744                 /* need to extract the HM/CCS sequence number here */
1745                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1746                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1747                         {
1748                         unsigned short seq_num;
1749                         struct hm_header_st msg_hdr;
1750                         struct ccs_header_st ccs_hdr;
1751
1752                         if ( rr->type == SSL3_RT_HANDSHAKE)
1753                                 {
1754                                 dtls1_get_message_header(data, &msg_hdr);
1755                                 seq_num = msg_hdr.seq;
1756                                 *offset = msg_hdr.frag_off;
1757                                 }
1758                         else
1759                                 {
1760                                 dtls1_get_ccs_header(data, &ccs_hdr);
1761                                 seq_num = ccs_hdr.seq;
1762                                 *offset = 0;
1763                                 }
1764
1765                         /* this is either a record we're waiting for, or a
1766                          * retransmit of something we happened to previously
1767                          * receive (higher layers will drop the repeat silently */
1768                         if ( seq_num < s->d1->handshake_read_seq)
1769                                 return 0;
1770                         if (rr->type == SSL3_RT_HANDSHAKE &&
1771                                 seq_num == s->d1->handshake_read_seq &&
1772                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1773                                 return 0;
1774                         else if ( seq_num == s->d1->handshake_read_seq &&
1775                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1776                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1777                                 return 0;
1778                         else
1779                                 {
1780                                 *priority = seq_num;
1781                                 return 1;
1782                                 }
1783                         }
1784                 else /* unknown record type */
1785                         return 0;
1786                 }
1787
1788         return 0;
1789         }
1790 #endif
1791
1792 void
1793 dtls1_reset_seq_numbers(SSL *s, int rw)
1794         {
1795         unsigned char *seq;
1796         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1797
1798         if ( rw & SSL3_CC_READ)
1799                 {
1800                 seq = s->s3->read_sequence;
1801                 s->d1->r_epoch++;
1802                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1803                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1804                 }
1805         else
1806                 {
1807                 seq = s->s3->write_sequence;
1808                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1809                 s->d1->w_epoch++;
1810                 }
1811
1812         memset(seq, 0x00, seq_bytes);
1813         }
1814
1815
1816 static void
1817 dtls1_clear_timeouts(SSL *s)
1818         {
1819         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1820         }