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                                 /* unexpected version, silently discard */
 590                                 rr->length = 0;
 591                                 s->packet_length = 0;
 592                                 goto again;
 593                                 }
 594                         }
 595
 596                 if ((version & 0xff00) != (s->version & 0xff00))
 597                         {
 598                         /* wrong version, silently discard record */
 599                         rr->length = 0;
 600                         s->packet_length = 0;
 601                         goto again;
 602                         }
 603
 604                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
 605                         {
 606                         /* record too long, silently discard it */
 607                         rr->length = 0;
 608                         s->packet_length = 0;
 609                         goto again;
 610                         }
 611
 612                 /* now s->rstate == SSL_ST_READ_BODY */
 613                 }
 614
 615         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
 616
 617         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
 618                 {
 619                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
 620                 i=rr->length;
 621                 n=ssl3_read_n(s,i,i,1);
 622                 if (n <= 0) return(n); /* error or non-blocking io */
 623
 624                 /* this packet contained a partial record, dump it */
 625                 if ( n != i)
 626                         {
 627                         rr->length = 0;
 628                         s->packet_length = 0;
 629                         goto again;
 630                         }
 631
 632                 /* now n == rr->length,
 633                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
 634                 }
 635         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
 636
 637         /* match epochs.  NULL means the packet is dropped on the floor */
 638         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
 639         if ( bitmap == NULL)
 640                 {
 641                 rr->length = 0;
 642                 s->packet_length = 0;  /* dump this record */
 643                 goto again;   /* get another record */
 644                 }
 645
 646         /* check whether this is a repeat, or aged record */
 647         if ( ! dtls1_record_replay_check(s, bitmap))
 648                 {
 649                 rr->length = 0;
 650                 s->packet_length=0; /* dump this record */
 651                 goto again;     /* get another record */
 652                 }
 653
 654         /* just read a 0 length packet */
 655         if (rr->length == 0) goto again;
 656
 657         /* If this record is from the next epoch (either HM or ALERT),
 658          * buffer it since it cannot be processed at this time. Records
 659          * from the next epoch are marked as received even though they
 660          * are not processed, so as to prevent any potential resource
 661          * DoS attack */
 662         if (is_next_epoch)
 663                 {
 664                 dtls1_record_bitmap_update(s, bitmap);
 665                 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
 666                 rr->length = 0;
 667                 s->packet_length = 0;
 668                 goto again;
 669                 }
 670
 671         if ( ! dtls1_process_record(s))
 672                 return(0);
 673
 674         dtls1_clear_timeouts(s);  /* done waiting */
 675         return(1);
 676
 677 f_err:
 678         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 679 err:
 680         return(0);
 681         }
 682
 683 /* Return up to 'len' payload bytes received in 'type' records.
 684  * 'type' is one of the following:
 685  *
 686  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 687  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 688  *   -  0 (during a shutdown, no data has to be returned)
 689  *
 690  * If we don't have stored data to work from, read a SSL/TLS record first
 691  * (possibly multiple records if we still don't have anything to return).
 692  *
 693  * This function must handle any surprises the peer may have for us, such as
 694  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 695  * a surprise, but handled as if it were), or renegotiation requests.
 696  * Also if record payloads contain fragments too small to process, we store
 697  * them until there is enough for the respective protocol (the record protocol
 698  * may use arbitrary fragmentation and even interleaving):
 699  *     Change cipher spec protocol
 700  *             just 1 byte needed, no need for keeping anything stored
 701  *     Alert protocol
 702  *             2 bytes needed (AlertLevel, AlertDescription)
 703  *     Handshake protocol
 704  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 705  *             to detect unexpected Client Hello and Hello Request messages
 706  *             here, anything else is handled by higher layers
 707  *     Application data protocol
 708  *             none of our business
 709  */
 710 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
 711         {
 712         int al,i,j,ret;
 713         unsigned int n;
 714         SSL3_RECORD *rr;
 715         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
 716
 717         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
 718                 if (!ssl3_setup_buffers(s))
 719                         return(-1);
 720
 721     /* XXX: check what the second '&& type' is about */
 722         if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
 723                 (type != SSL3_RT_HANDSHAKE) && type) ||
 724             (peek && (type != SSL3_RT_APPLICATION_DATA)))
 725                 {
 726                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
 727                 return -1;
 728                 }
 729
 730         /* check whether there's a handshake message (client hello?) waiting */
 731         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
 732                 return ret;
 733
 734         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
 735
 736         if (!s->in_handshake && SSL_in_init(s))
 737                 {
 738                 /* type == SSL3_RT_APPLICATION_DATA */
 739                 i=s->handshake_func(s);
 740                 if (i < 0) return(i);
 741                 if (i == 0)
 742                         {
 743                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 744                         return(-1);
 745                         }
 746                 }
 747
 748 start:
 749         s->rwstate=SSL_NOTHING;
 750
 751         /* s->s3->rrec.type         - is the type of record
 752          * s->s3->rrec.data,    - data
 753          * s->s3->rrec.off,     - offset into 'data' for next read
 754          * s->s3->rrec.length,  - number of bytes. */
 755         rr = &(s->s3->rrec);
 756
 757         /* We are not handshaking and have no data yet,
 758          * so process data buffered during the last handshake
 759          * in advance, if any.
 760          */
 761         if (s->state == SSL_ST_OK && rr->length == 0)
 762                 {
 763                 pitem *item;
 764                 item = pqueue_pop(s->d1->buffered_app_data.q);
 765                 if (item)
 766                         {
 767                         dtls1_copy_record(s, item);
 768
 769                         OPENSSL_free(item->data);
 770                         pitem_free(item);
 771                         }
 772                 }
 773
 774         /* Check for timeout */
 775         if (dtls1_is_timer_expired(s))
 776                 {
 777                 if (dtls1_read_failed(s, -1) > 0);
 778                         goto start;
 779                 }
 780
 781         /* get new packet if necessary */
 782         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
 783                 {
 784                 ret=dtls1_get_record(s);
 785                 if (ret <= 0)
 786                         {
 787                         ret = dtls1_read_failed(s, ret);
 788                         /* anything other than a timeout is an error */
 789                         if (ret <= 0)
 790                                 return(ret);
 791                         else
 792                                 goto start;
 793                         }
 794                 }
 795
 796         /* we now have a packet which can be read and processed */
 797
 798         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
 799                                        * reset by ssl3_get_finished */
 800                 && (rr->type != SSL3_RT_HANDSHAKE))
 801                 {
 802                 /* We now have application data between CCS and Finished.
 803                  * Most likely the packets were reordered on their way, so
 804                  * buffer the application data for later processing rather
 805                  * than dropping the connection.
 806                  */
 807                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), 0);
 808                 rr->length = 0;
 809                 goto start;
 810                 }
 811
 812         /* If the other end has shut down, throw anything we read away
 813          * (even in 'peek' mode) */
 814         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
 815                 {
 816                 rr->length=0;
 817                 s->rwstate=SSL_NOTHING;
 818                 return(0);
 819                 }
 820
 821
 822         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
 823                 {
 824                 /* make sure that we are not getting application data when we
 825                  * are doing a handshake for the first time */
 826                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
 827                         (s->enc_read_ctx == NULL))
 828                         {
 829                         al=SSL_AD_UNEXPECTED_MESSAGE;
 830                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
 831                         goto f_err;
 832                         }
 833
 834                 if (len <= 0) return(len);
 835
 836                 if ((unsigned int)len > rr->length)
 837                         n = rr->length;
 838                 else
 839                         n = (unsigned int)len;
 840
 841                 memcpy(buf,&(rr->data[rr->off]),n);
 842                 if (!peek)
 843                         {
 844                         rr->length-=n;
 845                         rr->off+=n;
 846                         if (rr->length == 0)
 847                                 {
 848                                 s->rstate=SSL_ST_READ_HEADER;
 849                                 rr->off=0;
 850                                 }
 851                         }
 852                 return(n);
 853                 }
 854
 855
 856         /* If we get here, then type != rr->type; if we have a handshake
 857          * message, then it was unexpected (Hello Request or Client Hello). */
 858
 859         /* In case of record types for which we have 'fragment' storage,
 860          * fill that so that we can process the data at a fixed place.
 861          */
 862                 {
 863                 unsigned int k, dest_maxlen = 0;
 864                 unsigned char *dest = NULL;
 865                 unsigned int *dest_len = NULL;
 866
 867                 if (rr->type == SSL3_RT_HANDSHAKE)
 868                         {
 869                         dest_maxlen = sizeof s->d1->handshake_fragment;
 870                         dest = s->d1->handshake_fragment;
 871                         dest_len = &s->d1->handshake_fragment_len;
 872                         }
 873                 else if (rr->type == SSL3_RT_ALERT)
 874                         {
 875                         dest_maxlen = sizeof(s->d1->alert_fragment);
 876                         dest = s->d1->alert_fragment;
 877                         dest_len = &s->d1->alert_fragment_len;
 878                         }
 879                 /* else it's a CCS message, or application data or wrong */
 880                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
 881                         {
 882                         /* Application data while renegotiating
 883                          * is allowed. Try again reading.
 884                          */
 885                         if (rr->type == SSL3_RT_APPLICATION_DATA)
 886                                 {
 887                                 BIO *bio;
 888                                 s->s3->in_read_app_data=2;
 889                                 bio=SSL_get_rbio(s);
 890                                 s->rwstate=SSL_READING;
 891                                 BIO_clear_retry_flags(bio);
 892                                 BIO_set_retry_read(bio);
 893                                 return(-1);
 894                                 }
 895
 896                         /* Not certain if this is the right error handling */
 897                         al=SSL_AD_UNEXPECTED_MESSAGE;
 898                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
 899                         goto f_err;
 900                         }
 901
 902                 if (dest_maxlen > 0)
 903                         {
 904             /* XDTLS:  In a pathalogical case, the Client Hello
 905              *  may be fragmented--don't always expect dest_maxlen bytes */
 906                         if ( rr->length < dest_maxlen)
 907                                 {
 908 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
 909                                 /*
 910                                  * for normal alerts rr->length is 2, while
 911                                  * dest_maxlen is 7 if we were to handle this
 912                                  * non-existing alert...
 913                                  */
 914                                 FIX ME
 915 #endif
 916                                 s->rstate=SSL_ST_READ_HEADER;
 917                                 rr->length = 0;
 918                                 goto start;
 919                                 }
 920
 921                         /* now move 'n' bytes: */
 922                         for ( k = 0; k < dest_maxlen; k++)
 923                                 {
 924                                 dest[k] = rr->data[rr->off++];
 925                                 rr->length--;
 926                                 }
 927                         *dest_len = dest_maxlen;
 928                         }
 929                 }
 930
 931         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
 932          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
 933          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
 934
 935         /* If we are a client, check for an incoming 'Hello Request': */
 936         if ((!s->server) &&
 937                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
 938                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
 939                 (s->session != NULL) && (s->session->cipher != NULL))
 940                 {
 941                 s->d1->handshake_fragment_len = 0;
 942
 943                 if ((s->d1->handshake_fragment[1] != 0) ||
 944                         (s->d1->handshake_fragment[2] != 0) ||
 945                         (s->d1->handshake_fragment[3] != 0))
 946                         {
 947                         al=SSL_AD_DECODE_ERROR;
 948                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
 949                         goto err;
 950                         }
 951
 952                 /* no need to check sequence number on HELLO REQUEST messages */
 953
 954                 if (s->msg_callback)
 955                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 956                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
 957
 958                 if (SSL_is_init_finished(s) &&
 959                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
 960                         !s->s3->renegotiate)
 961                         {
 962                         ssl3_renegotiate(s);
 963                         if (ssl3_renegotiate_check(s))
 964                                 {
 965                                 i=s->handshake_func(s);
 966                                 if (i < 0) return(i);
 967                                 if (i == 0)
 968                                         {
 969                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
 970                                         return(-1);
 971                                         }
 972
 973                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
 974                                         {
 975                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
 976                                                 {
 977                                                 BIO *bio;
 978                                                 /* In the case where we try to read application data,
 979                                                  * but we trigger an SSL handshake, we return -1 with
 980                                                  * the retry option set.  Otherwise renegotiation may
 981                                                  * cause nasty problems in the blocking world */
 982                                                 s->rwstate=SSL_READING;
 983                                                 bio=SSL_get_rbio(s);
 984                                                 BIO_clear_retry_flags(bio);
 985                                                 BIO_set_retry_read(bio);
 986                                                 return(-1);
 987                                                 }
 988                                         }
 989                                 }
 990                         }
 991                 /* we either finished a handshake or ignored the request,
 992                  * now try again to obtain the (application) data we were asked for */
 993                 goto start;
 994                 }
 995
 996         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
 997                 {
 998                 int alert_level = s->d1->alert_fragment[0];
 999                 int alert_descr = s->d1->alert_fragment[1];
1000
1001                 s->d1->alert_fragment_len = 0;
1002
1003                 if (s->msg_callback)
1004                         s->msg_callback(0, s->version, SSL3_RT_ALERT,
1005                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1006
1007                 if (s->info_callback != NULL)
1008                         cb=s->info_callback;
1009                 else if (s->ctx->info_callback != NULL)
1010                         cb=s->ctx->info_callback;
1011
1012                 if (cb != NULL)
1013                         {
1014                         j = (alert_level << 8) | alert_descr;
1015                         cb(s, SSL_CB_READ_ALERT, j);
1016                         }
1017
1018                 if (alert_level == 1) /* warning */
1019                         {
1020                         s->s3->warn_alert = alert_descr;
1021                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1022                                 {
1023                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1024                                 return(0);
1025                                 }
1026 #if 0
1027             /* XXX: this is a possible improvement in the future */
1028                         /* now check if it's a missing record */
1029                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1030                                 {
1031                                 unsigned short seq;
1032                                 unsigned int frag_off;
1033                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1034
1035                                 n2s(p, seq);
1036                                 n2l3(p, frag_off);
1037
1038                                 dtls1_retransmit_message(s,
1039                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1040                                                                                  frag_off, &found);
1041                                 if ( ! found  && SSL_in_init(s))
1042                                         {
1043                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1044                                         /* requested a message not yet sent,
1045                                            send an alert ourselves */
1046                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1047                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1048                                         }
1049                                 }
1050 #endif
1051                         }
1052                 else if (alert_level == 2) /* fatal */
1053                         {
1054                         char tmp[16];
1055
1056                         s->rwstate=SSL_NOTHING;
1057                         s->s3->fatal_alert = alert_descr;
1058                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1059                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1060                         ERR_add_error_data(2,"SSL alert number ",tmp);
1061                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1062                         SSL_CTX_remove_session(s->ctx,s->session);
1063                         return(0);
1064                         }
1065                 else
1066                         {
1067                         al=SSL_AD_ILLEGAL_PARAMETER;
1068                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1069                         goto f_err;
1070                         }
1071
1072                 goto start;
1073                 }
1074
1075         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1076                 {
1077                 s->rwstate=SSL_NOTHING;
1078                 rr->length=0;
1079                 return(0);
1080                 }
1081
1082         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1083                 {
1084                 struct ccs_header_st ccs_hdr;
1085                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1086
1087                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1088
1089                 if (s->version == DTLS1_BAD_VER)
1090                         ccs_hdr_len = 3;
1091
1092                 /* 'Change Cipher Spec' is just a single byte, so we know
1093                  * exactly what the record payload has to look like */
1094                 /* XDTLS: check that epoch is consistent */
1095                 if (    (rr->length != ccs_hdr_len) ||
1096                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1097                         {
1098                         i=SSL_AD_ILLEGAL_PARAMETER;
1099                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1100                         goto err;
1101                         }
1102
1103                 rr->length=0;
1104
1105                 if (s->msg_callback)
1106                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1107                                 rr->data, 1, s, s->msg_callback_arg);
1108
1109                 /* We can't process a CCS now, because previous handshake
1110                  * messages are still missing, so just drop it.
1111                  */
1112                 if (!s->d1->change_cipher_spec_ok)
1113                         {
1114                         goto start;
1115                         }
1116
1117                 s->d1->change_cipher_spec_ok = 0;
1118
1119                 s->s3->change_cipher_spec=1;
1120                 if (!ssl3_do_change_cipher_spec(s))
1121                         goto err;
1122
1123                 /* do this whenever CCS is processed */
1124                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1125
1126                 if (s->version == DTLS1_BAD_VER)
1127                         s->d1->handshake_read_seq++;
1128
1129                 goto start;
1130                 }
1131
1132         /* Unexpected handshake message (Client Hello, or protocol violation) */
1133         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1134                 !s->in_handshake)
1135                 {
1136                 struct hm_header_st msg_hdr;
1137
1138                 /* this may just be a stale retransmit */
1139                 dtls1_get_message_header(rr->data, &msg_hdr);
1140                 if( rr->epoch != s->d1->r_epoch)
1141                         {
1142                         rr->length = 0;
1143                         goto start;
1144                         }
1145
1146                 /* If we are server, we may have a repeated FINISHED of the
1147                  * client here, then retransmit our CCS and FINISHED.
1148                  */
1149                 if (msg_hdr.type == SSL3_MT_FINISHED)
1150                         {
1151                         dtls1_retransmit_buffered_messages(s);
1152                         rr->length = 0;
1153                         goto start;
1154                         }
1155
1156                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1157                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1158                         {
1159 #if 0 /* worked only because C operator preferences are not as expected (and
1160        * because this is not really needed for clients except for detecting
1161        * protocol violations): */
1162                         s->state=SSL_ST_BEFORE|(s->server)
1163                                 ?SSL_ST_ACCEPT
1164                                 :SSL_ST_CONNECT;
1165 #else
1166                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1167 #endif
1168                         s->new_session=1;
1169                         }
1170                 i=s->handshake_func(s);
1171                 if (i < 0) return(i);
1172                 if (i == 0)
1173                         {
1174                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1175                         return(-1);
1176                         }
1177
1178                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1179                         {
1180                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1181                                 {
1182                                 BIO *bio;
1183                                 /* In the case where we try to read application data,
1184                                  * but we trigger an SSL handshake, we return -1 with
1185                                  * the retry option set.  Otherwise renegotiation may
1186                                  * cause nasty problems in the blocking world */
1187                                 s->rwstate=SSL_READING;
1188                                 bio=SSL_get_rbio(s);
1189                                 BIO_clear_retry_flags(bio);
1190                                 BIO_set_retry_read(bio);
1191                                 return(-1);
1192                                 }
1193                         }
1194                 goto start;
1195                 }
1196
1197         switch (rr->type)
1198                 {
1199         default:
1200 #ifndef OPENSSL_NO_TLS
1201                 /* TLS just ignores unknown message types */
1202                 if (s->version == TLS1_VERSION)
1203                         {
1204                         rr->length = 0;
1205                         goto start;
1206                         }
1207 #endif
1208                 al=SSL_AD_UNEXPECTED_MESSAGE;
1209                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1210                 goto f_err;
1211         case SSL3_RT_CHANGE_CIPHER_SPEC:
1212         case SSL3_RT_ALERT:
1213         case SSL3_RT_HANDSHAKE:
1214                 /* we already handled all of these, with the possible exception
1215                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1216                  * should not happen when type != rr->type */
1217                 al=SSL_AD_UNEXPECTED_MESSAGE;
1218                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1219                 goto f_err;
1220         case SSL3_RT_APPLICATION_DATA:
1221                 /* At this point, we were expecting handshake data,
1222                  * but have application data.  If the library was
1223                  * running inside ssl3_read() (i.e. in_read_app_data
1224                  * is set) and it makes sense to read application data
1225                  * at this point (session renegotiation not yet started),
1226                  * we will indulge it.
1227                  */
1228                 if (s->s3->in_read_app_data &&
1229                         (s->s3->total_renegotiations != 0) &&
1230                         ((
1231                                 (s->state & SSL_ST_CONNECT) &&
1232                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1233                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1234                                 ) || (
1235                                         (s->state & SSL_ST_ACCEPT) &&
1236                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1237                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1238                                         )
1239                                 ))
1240                         {
1241                         s->s3->in_read_app_data=2;
1242                         return(-1);
1243                         }
1244                 else
1245                         {
1246                         al=SSL_AD_UNEXPECTED_MESSAGE;
1247                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1248                         goto f_err;
1249                         }
1250                 }
1251         /* not reached */
1252
1253 f_err:
1254         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1255 err:
1256         return(-1);
1257         }
1258
1259 int
1260 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1261         {
1262         unsigned int n,tot;
1263         int i;
1264
1265         if (SSL_in_init(s) && !s->in_handshake)
1266                 {
1267                 i=s->handshake_func(s);
1268                 if (i < 0) return(i);
1269                 if (i == 0)
1270                         {
1271                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1272                         return -1;
1273                         }
1274                 }
1275
1276         tot = s->s3->wnum;
1277         n = len - tot;
1278
1279         while( n)
1280                 {
1281                 /* dtls1_write_bytes sends one record at a time, sized according to
1282                  * the currently known MTU */
1283                 i = dtls1_write_bytes(s, type, buf_, len);
1284                 if (i <= 0) return i;
1285
1286                 if ((i == (int)n) ||
1287                         (type == SSL3_RT_APPLICATION_DATA &&
1288                                 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1289                         {
1290                         /* next chunk of data should get another prepended empty fragment
1291                          * in ciphersuites with known-IV weakness: */
1292                         s->s3->empty_fragment_done = 0;
1293                         return tot+i;
1294                         }
1295
1296                 tot += i;
1297                 n-=i;
1298                 }
1299
1300         return tot;
1301         }
1302
1303
1304         /* this only happens when a client hello is received and a handshake
1305          * is started. */
1306 static int
1307 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1308         int len, int peek)
1309         {
1310
1311         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1312                 /* (partially) satisfy request from storage */
1313                 {
1314                 unsigned char *src = s->d1->handshake_fragment;
1315                 unsigned char *dst = buf;
1316                 unsigned int k,n;
1317
1318                 /* peek == 0 */
1319                 n = 0;
1320                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1321                         {
1322                         *dst++ = *src++;
1323                         len--; s->d1->handshake_fragment_len--;
1324                         n++;
1325                         }
1326                 /* move any remaining fragment bytes: */
1327                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1328                         s->d1->handshake_fragment[k] = *src++;
1329                 return n;
1330                 }
1331
1332         return 0;
1333         }
1334
1335
1336
1337
1338 /* Call this to write data in records of type 'type'
1339  * It will return <= 0 if not all data has been sent or non-blocking IO.
1340  */
1341 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1342         {
1343         const unsigned char *buf=buf_;
1344         unsigned int tot,n,nw;
1345         int i;
1346         unsigned int mtu;
1347
1348         s->rwstate=SSL_NOTHING;
1349         tot=s->s3->wnum;
1350
1351         n=(len-tot);
1352
1353         /* handshake layer figures out MTU for itself, but data records
1354          * are also sent through this interface, so need to figure out MTU */
1355 #if 0
1356         mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1357         mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
1358 #endif
1359         mtu = s->d1->mtu;
1360
1361         if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1362                 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1363
1364         if (n > mtu)
1365                 nw=mtu;
1366         else
1367                 nw=n;
1368
1369         i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1370         if (i <= 0)
1371                 {
1372                 s->s3->wnum=tot;
1373                 return i;
1374                 }
1375
1376         if ( (int)s->s3->wnum + i == len)
1377                 s->s3->wnum = 0;
1378         else
1379                 s->s3->wnum += i;
1380
1381         return i;
1382         }
1383
1384 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1385         {
1386         unsigned char *p,*pseq;
1387         int i,mac_size,clear=0;
1388         int prefix_len = 0;
1389         SSL3_RECORD *wr;
1390         SSL3_BUFFER *wb;
1391         SSL_SESSION *sess;
1392         int bs;
1393
1394         /* first check if there is a SSL3_BUFFER still being written
1395          * out.  This will happen with non blocking IO */
1396         if (s->s3->wbuf.left != 0)
1397                 {
1398                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1399                 return(ssl3_write_pending(s,type,buf,len));
1400                 }
1401
1402         /* If we have an alert to send, lets send it */
1403         if (s->s3->alert_dispatch)
1404                 {
1405                 i=s->method->ssl_dispatch_alert(s);
1406                 if (i <= 0)
1407                         return(i);
1408                 /* if it went, fall through and send more stuff */
1409                 }
1410
1411         if (len == 0 && !create_empty_fragment)
1412                 return 0;
1413
1414         wr= &(s->s3->wrec);
1415         wb= &(s->s3->wbuf);
1416         sess=s->session;
1417
1418         if (    (sess == NULL) ||
1419                 (s->enc_write_ctx == NULL) ||
1420                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1421                 clear=1;
1422
1423         if (clear)
1424                 mac_size=0;
1425         else
1426                 {
1427                 mac_size=EVP_MD_CTX_size(s->write_hash);
1428                 if (mac_size < 0)
1429                         goto err;
1430                 }
1431
1432         /* DTLS implements explicit IV, so no need for empty fragments */
1433 #if 0
1434         /* 'create_empty_fragment' is true only when this function calls itself */
1435         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1436             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1437                 {
1438                 /* countermeasure against known-IV weakness in CBC ciphersuites
1439                  * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1440                  */
1441
1442                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1443                         {
1444                         /* recursive function call with 'create_empty_fragment' set;
1445                          * this prepares and buffers the data for an empty fragment
1446                          * (these 'prefix_len' bytes are sent out later
1447                          * together with the actual payload) */
1448                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1449                         if (prefix_len <= 0)
1450                                 goto err;
1451
1452                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1453                                 {
1454                                 /* insufficient space */
1455                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1456                                 goto err;
1457                                 }
1458                         }
1459
1460                 s->s3->empty_fragment_done = 1;
1461                 }
1462 #endif
1463         p = wb->buf + prefix_len;
1464
1465         /* write the header */
1466
1467         *(p++)=type&0xff;
1468         wr->type=type;
1469
1470         *(p++)=(s->version>>8);
1471         *(p++)=s->version&0xff;
1472
1473         /* field where we are to write out packet epoch, seq num and len */
1474         pseq=p;
1475         p+=10;
1476
1477         /* lets setup the record stuff. */
1478
1479         /* Make space for the explicit IV in case of CBC.
1480          * (this is a bit of a boundary violation, but what the heck).
1481          */
1482         if ( s->enc_write_ctx &&
1483                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1484                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1485         else
1486                 bs = 0;
1487
1488         wr->data=p + bs;  /* make room for IV in case of CBC */
1489         wr->length=(int)len;
1490         wr->input=(unsigned char *)buf;
1491
1492         /* we now 'read' from wr->input, wr->length bytes into
1493          * wr->data */
1494
1495         /* first we compress */
1496         if (s->compress != NULL)
1497                 {
1498                 if (!ssl3_do_compress(s))
1499                         {
1500                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1501                         goto err;
1502                         }
1503                 }
1504         else
1505                 {
1506                 memcpy(wr->data,wr->input,wr->length);
1507                 wr->input=wr->data;
1508                 }
1509
1510         /* we should still have the output to wr->data and the input
1511          * from wr->input.  Length should be wr->length.
1512          * wr->data still points in the wb->buf */
1513
1514         if (mac_size != 0)
1515                 {
1516                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1517                         goto err;
1518                 wr->length+=mac_size;
1519                 }
1520
1521         /* this is true regardless of mac size */
1522         wr->input=p;
1523         wr->data=p;
1524
1525
1526         /* ssl3_enc can only have an error on read */
1527         if (bs) /* bs != 0 in case of CBC */
1528                 {
1529                 RAND_pseudo_bytes(p,bs);
1530                 /* master IV and last CBC residue stand for
1531                  * the rest of randomness */
1532                 wr->length += bs;
1533                 }
1534
1535         s->method->ssl3_enc->enc(s,1);
1536
1537         /* record length after mac and block padding */
1538 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1539         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1540
1541         /* there's only one epoch between handshake and app data */
1542
1543         s2n(s->d1->w_epoch, pseq);
1544
1545         /* XDTLS: ?? */
1546 /*      else
1547         s2n(s->d1->handshake_epoch, pseq); */
1548
1549         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1550         pseq+=6;
1551         s2n(wr->length,pseq);
1552
1553         /* we should now have
1554          * wr->data pointing to the encrypted data, which is
1555          * wr->length long */
1556         wr->type=type; /* not needed but helps for debugging */
1557         wr->length+=DTLS1_RT_HEADER_LENGTH;
1558
1559 #if 0  /* this is now done at the message layer */
1560         /* buffer the record, making it easy to handle retransmits */
1561         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1562                 dtls1_buffer_record(s, wr->data, wr->length,
1563                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1564 #endif
1565
1566         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1567
1568         if (create_empty_fragment)
1569                 {
1570                 /* we are in a recursive call;
1571                  * just return the length, don't write out anything here
1572                  */
1573                 return wr->length;
1574                 }
1575
1576         /* now let's set up wb */
1577         wb->left = prefix_len + wr->length;
1578         wb->offset = 0;
1579
1580         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1581         s->s3->wpend_tot=len;
1582         s->s3->wpend_buf=buf;
1583         s->s3->wpend_type=type;
1584         s->s3->wpend_ret=len;
1585
1586         /* we now just need to write the buffer */
1587         return ssl3_write_pending(s,type,buf,len);
1588 err:
1589         return -1;
1590         }
1591
1592
1593
1594 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1595         {
1596         int cmp;
1597         unsigned int shift;
1598         const unsigned char *seq = s->s3->read_sequence;
1599
1600         cmp = satsub64be(seq,bitmap->max_seq_num);
1601         if (cmp > 0)
1602                 {
1603                 memcpy (s->s3->rrec.seq_num,seq,8);
1604                 return 1; /* this record in new */
1605                 }
1606         shift = -cmp;
1607         if (shift >= sizeof(bitmap->map)*8)
1608                 return 0; /* stale, outside the window */
1609         else if (bitmap->map & (1UL<<shift))
1610                 return 0; /* record previously received */
1611
1612         memcpy (s->s3->rrec.seq_num,seq,8);
1613         return 1;
1614         }
1615
1616
1617 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1618         {
1619         int cmp;
1620         unsigned int shift;
1621         const unsigned char *seq = s->s3->read_sequence;
1622
1623         cmp = satsub64be(seq,bitmap->max_seq_num);
1624         if (cmp > 0)
1625                 {
1626                 shift = cmp;
1627                 if (shift < sizeof(bitmap->map)*8)
1628                         bitmap->map <<= shift, bitmap->map |= 1UL;
1629                 else
1630                         bitmap->map = 1UL;
1631                 memcpy(bitmap->max_seq_num,seq,8);
1632                 }
1633         else    {
1634                 shift = -cmp;
1635                 if (shift < sizeof(bitmap->map)*8)
1636                         bitmap->map |= 1UL<<shift;
1637                 }
1638         }
1639
1640
1641 int dtls1_dispatch_alert(SSL *s)
1642         {
1643         int i,j;
1644         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1645         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1646         unsigned char *ptr = &buf[0];
1647
1648         s->s3->alert_dispatch=0;
1649
1650         memset(buf, 0x00, sizeof(buf));
1651         *ptr++ = s->s3->send_alert[0];
1652         *ptr++ = s->s3->send_alert[1];
1653
1654 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1655         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1656                 {
1657                 s2n(s->d1->handshake_read_seq, ptr);
1658 #if 0
1659                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1660
1661                 else
1662                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1663 #endif
1664
1665 #if 0
1666                 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);
1667 #endif
1668                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1669                 }
1670 #endif
1671
1672         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1673         if (i <= 0)
1674                 {
1675                 s->s3->alert_dispatch=1;
1676                 /* fprintf( stderr, "not done with alert\n" ); */
1677                 }
1678         else
1679                 {
1680                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1681 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1682                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1683 #endif
1684                     )
1685                         (void)BIO_flush(s->wbio);
1686
1687                 if (s->msg_callback)
1688                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1689                                 2, s, s->msg_callback_arg);
1690
1691                 if (s->info_callback != NULL)
1692                         cb=s->info_callback;
1693                 else if (s->ctx->info_callback != NULL)
1694                         cb=s->ctx->info_callback;
1695
1696                 if (cb != NULL)
1697                         {
1698                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1699                         cb(s,SSL_CB_WRITE_ALERT,j);
1700                         }
1701                 }
1702         return(i);
1703         }
1704
1705
1706 static DTLS1_BITMAP *
1707 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1708     {
1709
1710     *is_next_epoch = 0;
1711
1712     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1713     if (rr->epoch == s->d1->r_epoch)
1714         return &s->d1->bitmap;
1715
1716     /* Only HM and ALERT messages can be from the next epoch */
1717     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1718         (rr->type == SSL3_RT_HANDSHAKE ||
1719             rr->type == SSL3_RT_ALERT))
1720         {
1721         *is_next_epoch = 1;
1722         return &s->d1->next_bitmap;
1723         }
1724
1725     return NULL;
1726     }
1727
1728 #if 0
1729 static int
1730 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1731         unsigned long *offset)
1732         {
1733
1734         /* alerts are passed up immediately */
1735         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1736                 rr->type == SSL3_RT_ALERT)
1737                 return 0;
1738
1739         /* Only need to buffer if a handshake is underway.
1740          * (this implies that Hello Request and Client Hello are passed up
1741          * immediately) */
1742         if ( SSL_in_init(s))
1743                 {
1744                 unsigned char *data = rr->data;
1745                 /* need to extract the HM/CCS sequence number here */
1746                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1747                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1748                         {
1749                         unsigned short seq_num;
1750                         struct hm_header_st msg_hdr;
1751                         struct ccs_header_st ccs_hdr;
1752
1753                         if ( rr->type == SSL3_RT_HANDSHAKE)
1754                                 {
1755                                 dtls1_get_message_header(data, &msg_hdr);
1756                                 seq_num = msg_hdr.seq;
1757                                 *offset = msg_hdr.frag_off;
1758                                 }
1759                         else
1760                                 {
1761                                 dtls1_get_ccs_header(data, &ccs_hdr);
1762                                 seq_num = ccs_hdr.seq;
1763                                 *offset = 0;
1764                                 }
1765
1766                         /* this is either a record we're waiting for, or a
1767                          * retransmit of something we happened to previously
1768                          * receive (higher layers will drop the repeat silently */
1769                         if ( seq_num < s->d1->handshake_read_seq)
1770                                 return 0;
1771                         if (rr->type == SSL3_RT_HANDSHAKE &&
1772                                 seq_num == s->d1->handshake_read_seq &&
1773                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1774                                 return 0;
1775                         else if ( seq_num == s->d1->handshake_read_seq &&
1776                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1777                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1778                                 return 0;
1779                         else
1780                                 {
1781                                 *priority = seq_num;
1782                                 return 1;
1783                                 }
1784                         }
1785                 else /* unknown record type */
1786                         return 0;
1787                 }
1788
1789         return 0;
1790         }
1791 #endif
1792
1793 void
1794 dtls1_reset_seq_numbers(SSL *s, int rw)
1795         {
1796         unsigned char *seq;
1797         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1798
1799         if ( rw & SSL3_CC_READ)
1800                 {
1801                 seq = s->s3->read_sequence;
1802                 s->d1->r_epoch++;
1803                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1804                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1805                 }
1806         else
1807                 {
1808                 seq = s->s3->write_sequence;
1809                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1810                 s->d1->w_epoch++;
1811                 }
1812
1813         memset(seq, 0x00, seq_bytes);
1814         }
1815
1816
1817 static void
1818 dtls1_clear_timeouts(SSL *s)
1819         {
1820         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1821         }