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