summaryrefslogtreecommitdiffstats
path: root/openssl/ssl/d1_pkt.c
blob: 7a02459f2b7876bfbfbbbe91e7d29fe4b16f4c4f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
/* ssl/d1_pkt.c */
/*
 * DTLS implementation written by Nagendra Modadugu
 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
 */
/* ====================================================================
 * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include <errno.h>
#define USE_SOCKETS
#include "ssl_locl.h"
#include <openssl/evp.h>
#include <openssl/buffer.h>
#include <openssl/pqueue.h>
#include <openssl/rand.h>

/* mod 128 saturating subtract of two 64-bit values in big-endian order */
static int satsub64be(const unsigned char *v1, const unsigned char *v2)
{
    int ret, i;

    if (sizeof(long) == 8)
        do {
            const union {
                long one;
                char little;
            } is_endian = {
                1
            };
            long l;

            if (is_endian.little)
                break;
            /* not reached on little-endians */
            /*
             * following test is redundant, because input is always aligned,
             * but I take no chances...
             */
            if (((size_t)v1 | (size_t)v2) & 0x7)
                break;

            l = *((long *)v1);
            l -= *((long *)v2);
            if (l > 128)
                return 128;
            else if (l < -128)
                return -128;
            else
                return (int)l;
        } while (0);

    ret = 0;
    for (i=0; i<7; i++) {
        if (v1[i] > v2[i]) {
            /* v1 is larger... but by how much? */
            if (v1[i] != v2[i] + 1)
                return 128;
            while (++i <= 6) {
                if (v1[i] != 0x00 || v2[i] != 0xff)
                    return 128; /* too much */
            }
            /* We checked all the way to the penultimate byte,
             * so despite higher bytes changing we actually
             * know that it only changed from (e.g.)
             *       ... (xx)  ff ff ff ??
             * to   ... (xx+1) 00 00 00 ??
             * so we add a 'bias' of 256 for the carry that
             * happened, and will eventually return
             * 256 + v1[7] - v2[7]. */
            ret = 256;
            break;
        } else if (v2[i] > v1[i]) {
            /* v2 is larger... but by how much? */
            if (v2[i] != v1[i] + 1)
                return -128;
            while (++i <= 6) {
                if (v2[i] != 0x00 || v1[i] != 0xff)
                    return -128; /* too much */
            }
            /* Similar to the case above, we know it changed
             * from    ... (xx)  00 00 00 ??
             * to     ... (xx-1) ff ff ff ??
             * so we add a 'bias' of -256 for the borrow,
             * to return -256 + v1[7] - v2[7]. */
            ret = -256;
        }
    }

    ret += (int)v1[7] - (int)v2[7];

    if (ret > 128)
        return 128;
    else if (ret < -128)
        return -128;
    else
        return ret;
}

static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
                                   int len, int peek);
static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
                                      unsigned int *is_next_epoch);
#if 0
static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
                                        unsigned short *priority,
                                        unsigned long *offset);
#endif
static int dtls1_buffer_record(SSL *s, record_pqueue *q,
                               unsigned char *priority);
static int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap);

/* copy buffered record into SSL structure */
static int dtls1_copy_record(SSL *s, pitem *item)
{
    DTLS1_RECORD_DATA *rdata;

    rdata = (DTLS1_RECORD_DATA *)item->data;

    if (s->s3->rbuf.buf != NULL)
        OPENSSL_free(s->s3->rbuf.buf);

    s->packet = rdata->packet;
    s->packet_length = rdata->packet_length;
    memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
    memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));

    /* Set proper sequence number for mac calculation */
    memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);

    return (1);
}

static int
dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
{
    DTLS1_RECORD_DATA *rdata;
    pitem *item;

    /* Limit the size of the queue to prevent DOS attacks */
    if (pqueue_size(queue->q) >= 100)
        return 0;

    rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
    item = pitem_new(priority, rdata);
    if (rdata == NULL || item == NULL) {
        if (rdata != NULL)
            OPENSSL_free(rdata);
        if (item != NULL)
            pitem_free(item);

        SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
        return -1;
    }

    rdata->packet = s->packet;
    rdata->packet_length = s->packet_length;
    memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
    memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));

    item->data = rdata;

#ifndef OPENSSL_NO_SCTP
    /* Store bio_dgram_sctp_rcvinfo struct */
    if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
        (s->state == SSL3_ST_SR_FINISHED_A
         || s->state == SSL3_ST_CR_FINISHED_A)) {
        BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
                 sizeof(rdata->recordinfo), &rdata->recordinfo);
    }
#endif

    s->packet = NULL;
    s->packet_length = 0;
    memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
    memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));

    if (!ssl3_setup_buffers(s)) {
        SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
        if (rdata->rbuf.buf != NULL)
            OPENSSL_free(rdata->rbuf.buf);
        OPENSSL_free(rdata);
        pitem_free(item);
        return (-1);
    }

    /* insert should not fail, since duplicates are dropped */
    if (pqueue_insert(queue->q, item) == NULL) {
        SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
        if (rdata->rbuf.buf != NULL)
            OPENSSL_free(rdata->rbuf.buf);
        OPENSSL_free(rdata);
        pitem_free(item);
        return (-1);
    }

    return (1);
}

static int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
{
    pitem *item;

    item = pqueue_pop(queue->q);
    if (item) {
        dtls1_copy_record(s, item);

        OPENSSL_free(item->data);
        pitem_free(item);

        return (1);
    }

    return (0);
}

/*
 * retrieve a buffered record that belongs to the new epoch, i.e., not
 * processed yet
 */
#define dtls1_get_unprocessed_record(s) \
                   dtls1_retrieve_buffered_record((s), \
                   &((s)->d1->unprocessed_rcds))

/*
 * retrieve a buffered record that belongs to the current epoch, ie,
 * processed
 */
#define dtls1_get_processed_record(s) \
                   dtls1_retrieve_buffered_record((s), \
                   &((s)->d1->processed_rcds))

static int dtls1_process_buffered_records(SSL *s)
{
    pitem *item;
    SSL3_BUFFER *rb;
    SSL3_RECORD *rr;
    DTLS1_BITMAP *bitmap;
    unsigned int is_next_epoch;
    int replayok = 1;

    item = pqueue_peek(s->d1->unprocessed_rcds.q);
    if (item) {
        /* Check if epoch is current. */
        if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
            return 1;         /* Nothing to do. */

        rr = &s->s3->rrec;
        rb = &s->s3->rbuf;

        if (rb->left > 0) {
            /*
             * We've still got data from the current packet to read. There could
             * be a record from the new epoch in it - so don't overwrite it
             * with the unprocessed records yet (we'll do it when we've
             * finished reading the current packet).
             */
            return 1;
        }


        /* Process all the records. */
        while (pqueue_peek(s->d1->unprocessed_rcds.q)) {
            dtls1_get_unprocessed_record(s);
            bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
            if (bitmap == NULL) {
                /*
                 * Should not happen. This will only ever be NULL when the
                 * current record is from a different epoch. But that cannot
                 * be the case because we already checked the epoch above
                 */
                 SSLerr(SSL_F_DTLS1_PROCESS_BUFFERED_RECORDS,
                        ERR_R_INTERNAL_ERROR);
                 return 0;
            }
#ifndef OPENSSL_NO_SCTP
            /* Only do replay check if no SCTP bio */
            if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
#endif
            {
                /*
                 * Check whether this is a repeat, or aged record. We did this
                 * check once already when we first received the record - but
                 * we might have updated the window since then due to
                 * records we subsequently processed.
                 */
                replayok = dtls1_record_replay_check(s, bitmap);
            }

            if (!replayok || !dtls1_process_record(s, bitmap)) {
                /* dump this record */
                rr->length = 0;
                s->packet_length = 0;
                continue;
            }

            if (dtls1_buffer_record(s, &(s->d1->processed_rcds),
                                    s->s3->rrec.seq_num) < 0)
                return 0;
        }
    }

    /*
     * sync epoch numbers once all the unprocessed records have been
     * processed
     */
    s->d1->processed_rcds.epoch = s->d1->r_epoch;
    s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;

    return 1;
}

#if 0

static int dtls1_get_buffered_record(SSL *s)
{
    pitem *item;
    PQ_64BIT priority =
        (((PQ_64BIT) s->d1->handshake_read_seq) << 32) |
        ((PQ_64BIT) s->d1->r_msg_hdr.frag_off);

    /* if we're not (re)negotiating, nothing buffered */
    if (!SSL_in_init(s))
        return 0;

    item = pqueue_peek(s->d1->rcvd_records);
    if (item && item->priority == priority) {
        /*
         * Check if we've received the record of interest.  It must be a
         * handshake record, since data records as passed up without
         * buffering
         */
        DTLS1_RECORD_DATA *rdata;
        item = pqueue_pop(s->d1->rcvd_records);
        rdata = (DTLS1_RECORD_DATA *)item->data;

        if (s->s3->rbuf.buf != NULL)
            OPENSSL_free(s->s3->rbuf.buf);

        s->packet = rdata->packet;
        s->packet_length = rdata->packet_length;
        memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
        memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));

        OPENSSL_free(item->data);
        pitem_free(item);

        /* s->d1->next_expected_seq_num++; */
        return (1);
    }

    return 0;
}

#endif

static int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
{
    int i, al;
    int enc_err;
    SSL_SESSION *sess;
    SSL3_RECORD *rr;
    unsigned int mac_size, orig_len;
    unsigned char md[EVP_MAX_MD_SIZE];

    rr = &(s->s3->rrec);
    sess = s->session;

    /*
     * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
     * and we have that many bytes in s->packet
     */
    rr->input = &(s->packet[DTLS1_RT_HEADER_LENGTH]);

    /*
     * ok, we can now read from 's->packet' data into 'rr' rr->input points
     * at rr->length bytes, which need to be copied into rr->data by either
     * the decryption or by the decompression When the data is 'copied' into
     * the rr->data buffer, rr->input will be pointed at the new buffer
     */

    /*
     * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
     * bytes of encrypted compressed stuff.
     */

    /* check is not needed I believe */
    if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
        al = SSL_AD_RECORD_OVERFLOW;
        SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
        goto f_err;
    }

    /* decrypt in place in 'rr->input' */
    rr->data = rr->input;

    enc_err = s->method->ssl3_enc->enc(s, 0);
    /*-
     * enc_err is:
     *    0: (in non-constant time) if the record is publically invalid.
     *    1: if the padding is valid
     *   -1: if the padding is invalid
     */
    if (enc_err == 0) {
        /* For DTLS we simply ignore bad packets. */
        rr->length = 0;
        s->packet_length = 0;
        goto err;
    }
#ifdef TLS_DEBUG
    printf("dec %d\n", rr->length);
    {
        unsigned int z;
        for (z = 0; z < rr->length; z++)
            printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
    }
    printf("\n");
#endif

    /* r->length is now the compressed data plus mac */
    if ((sess != NULL) &&
        (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
        /* s->read_hash != NULL => mac_size != -1 */
        unsigned char *mac = NULL;
        unsigned char mac_tmp[EVP_MAX_MD_SIZE];
        mac_size = EVP_MD_CTX_size(s->read_hash);
        OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);

        /*
         * kludge: *_cbc_remove_padding passes padding length in rr->type
         */
        orig_len = rr->length + ((unsigned int)rr->type >> 8);

        /*
         * orig_len is the length of the record before any padding was
         * removed. This is public information, as is the MAC in use,
         * therefore we can safely process the record in a different amount
         * of time if it's too short to possibly contain a MAC.
         */
        if (orig_len < mac_size ||
            /* CBC records must have a padding length byte too. */
            (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
             orig_len < mac_size + 1)) {
            al = SSL_AD_DECODE_ERROR;
            SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
            goto f_err;
        }

        if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
            /*
             * We update the length so that the TLS header bytes can be
             * constructed correctly but we need to extract the MAC in
             * constant time from within the record, without leaking the
             * contents of the padding bytes.
             */
            mac = mac_tmp;
            ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
            rr->length -= mac_size;
        } else {
            /*
             * In this case there's no padding, so |orig_len| equals
             * |rec->length| and we checked that there's enough bytes for
             * |mac_size| above.
             */
            rr->length -= mac_size;
            mac = &rr->data[rr->length];
        }

        i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
        if (i < 0 || mac == NULL
            || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
            enc_err = -1;
        if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
            enc_err = -1;
    }

    if (enc_err < 0) {
        /* decryption failed, silently discard message */
        rr->length = 0;
        s->packet_length = 0;
        goto err;
    }

    /* r->length is now just compressed */
    if (s->expand != NULL) {
        if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
            al = SSL_AD_RECORD_OVERFLOW;
            SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
                   SSL_R_COMPRESSED_LENGTH_TOO_LONG);
            goto f_err;
        }
        if (!ssl3_do_uncompress(s)) {
            al = SSL_AD_DECOMPRESSION_FAILURE;
            SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
            goto f_err;
        }
    }

    if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
        al = SSL_AD_RECORD_OVERFLOW;
        SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
        goto f_err;
    }

    rr->off = 0;
    /*-
     * So at this point the following is true
     * ssl->s3->rrec.type   is the type of record
     * ssl->s3->rrec.length == number of bytes in record
     * ssl->s3->rrec.off    == offset to first valid byte
     * ssl->s3->rrec.data   == where to take bytes from, increment
     *                         after use :-).
     */

    /* we have pulled in a full packet so zero things */
    s->packet_length = 0;

    /* Mark receipt of record. */
    dtls1_record_bitmap_update(s, bitmap);

    return (1);

 f_err:
    ssl3_send_alert(s, SSL3_AL_FATAL, al);
 err:
    return (0);
}

/*-
 * Call this to get a new input record.
 * It will return <= 0 if more data is needed, normally due to an error
 * or non-blocking IO.
 * When it finishes, one packet has been decoded and can be found in
 * ssl->s3->rrec.type    - is the type of record
 * ssl->s3->rrec.data,   - data
 * ssl->s3->rrec.length, - number of bytes
 */
/* used only by dtls1_read_bytes */
int dtls1_get_record(SSL *s)
{
    int ssl_major, ssl_minor;
    int i, n;
    SSL3_RECORD *rr;
    unsigned char *p = NULL;
    unsigned short version;
    DTLS1_BITMAP *bitmap;
    unsigned int is_next_epoch;

    rr = &(s->s3->rrec);

 again:
    /*
     * The epoch may have changed.  If so, process all the pending records.
     * This is a non-blocking operation.
     */
    if (!dtls1_process_buffered_records(s))
        return -1;

    /* if we're renegotiating, then there may be buffered records */
    if (dtls1_get_processed_record(s))
        return 1;

    /* get something from the wire */
    /* check if we have the header */
    if ((s->rstate != SSL_ST_READ_BODY) ||
        (s->packet_length < DTLS1_RT_HEADER_LENGTH)) {
        n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
        /* read timeout is handled by dtls1_read_bytes */
        if (n <= 0)
            return (n);         /* error or non-blocking */

        /* this packet contained a partial record, dump it */
        if (s->packet_length != DTLS1_RT_HEADER_LENGTH) {
            s->packet_length = 0;
            goto again;
        }

        s->rstate = SSL_ST_READ_BODY;

        p = s->packet;

        if (s->msg_callback)
            s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
                            s, s->msg_callback_arg);

        /* Pull apart the header into the DTLS1_RECORD */
        rr->type = *(p++);
        ssl_major = *(p++);
        ssl_minor = *(p++);
        version = (ssl_major << 8) | ssl_minor;

        /* sequence number is 64 bits, with top 2 bytes = epoch */
        n2s(p, rr->epoch);

        memcpy(&(s->s3->read_sequence[2]), p, 6);
        p += 6;

        n2s(p, rr->length);

        /* Lets check version */
        if (!s->first_packet) {
            if (version != s->version) {
                /* unexpected version, silently discard */
                rr->length = 0;
                s->packet_length = 0;
                goto again;
            }
        }

        if ((version & 0xff00) != (s->version & 0xff00)) {
            /* wrong version, silently discard record */
            rr->length = 0;
            s->packet_length = 0;
            goto again;
        }

        if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
            /* record too long, silently discard it */
            rr->length = 0;
            s->packet_length = 0;
            goto again;
        }

        /* now s->rstate == SSL_ST_READ_BODY */
    }

    /* s->rstate == SSL_ST_READ_BODY, get and decode the data */

    if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) {
        /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
        i = rr->length;
        n = ssl3_read_n(s, i, i, 1);
        /* this packet contained a partial record, dump it */
        if (n != i) {
            rr->length = 0;
            s->packet_length = 0;
            goto again;
        }

        /*
         * now n == rr->length, and s->packet_length ==
         * DTLS1_RT_HEADER_LENGTH + rr->length
         */
    }
    s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */

    /* match epochs.  NULL means the packet is dropped on the floor */
    bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
    if (bitmap == NULL) {
        rr->length = 0;
        s->packet_length = 0;   /* dump this record */
        goto again;             /* get another record */
    }
#ifndef OPENSSL_NO_SCTP
    /* Only do replay check if no SCTP bio */
    if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
#endif
        /*
         * Check whether this is a repeat, or aged record. Don't check if
         * we're listening and this message is a ClientHello. They can look
         * as if they're replayed, since they arrive from different
         * connections and would be dropped unnecessarily.
         */
        if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
              s->packet_length > DTLS1_RT_HEADER_LENGTH &&
              s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) &&
            !dtls1_record_replay_check(s, bitmap)) {
            rr->length = 0;
            s->packet_length = 0; /* dump this record */
            goto again;         /* get another record */
        }
#ifndef OPENSSL_NO_SCTP
    }
#endif

    /* just read a 0 length packet */
    if (rr->length == 0)
        goto again;

    /*
     * If this record is from the next epoch (either HM or ALERT), and a
     * handshake is currently in progress, buffer it since it cannot be
     * processed at this time. However, do not buffer anything while
     * listening.
     */
    if (is_next_epoch) {
        if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) {
            if (dtls1_buffer_record
                (s, &(s->d1->unprocessed_rcds), rr->seq_num) < 0)
                return -1;
        }
        rr->length = 0;
        s->packet_length = 0;
        goto again;
    }

    if (!dtls1_process_record(s, bitmap)) {
        rr->length = 0;
        s->packet_length = 0;   /* dump this record */
        goto again;             /* get another record */
    }

    return (1);

}

/*-
 * Return up to 'len' payload bytes received in 'type' records.
 * 'type' is one of the following:
 *
 *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
 *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
 *   -  0 (during a shutdown, no data has to be returned)
 *
 * If we don't have stored data to work from, read a SSL/TLS record first
 * (possibly multiple records if we still don't have anything to return).
 *
 * This function must handle any surprises the peer may have for us, such as
 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
 * a surprise, but handled as if it were), or renegotiation requests.
 * Also if record payloads contain fragments too small to process, we store
 * them until there is enough for the respective protocol (the record protocol
 * may use arbitrary fragmentation and even interleaving):
 *     Change cipher spec protocol
 *             just 1 byte needed, no need for keeping anything stored
 *     Alert protocol
 *             2 bytes needed (AlertLevel, AlertDescription)
 *     Handshake protocol
 *             4 bytes needed (HandshakeType, uint24 length) -- we just have
 *             to detect unexpected Client Hello and Hello Request messages
 *             here, anything else is handled by higher layers
 *     Application data protocol
 *             none of our business
 */
int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
{
    int al, i, j, ret;
    unsigned int n;
    SSL3_RECORD *rr;
    void (*cb) (const SSL *ssl, int type2, int val) = NULL;

    if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
        if (!ssl3_setup_buffers(s))
            return (-1);

    /* XXX: check what the second '&& type' is about */
    if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
         (type != SSL3_RT_HANDSHAKE) && type) ||
        (peek && (type != SSL3_RT_APPLICATION_DATA))) {
        SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
        return -1;
    }

    /*
     * check whether there's a handshake message (client hello?) waiting
     */
    if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
        return ret;

    /*
     * Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE.
     */

#ifndef OPENSSL_NO_SCTP
    /*
     * Continue handshake if it had to be interrupted to read app data with
     * SCTP.
     */
    if ((!s->in_handshake && SSL_in_init(s)) ||
        (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
         (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
          || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)
         && s->s3->in_read_app_data != 2))
#else
    if (!s->in_handshake && SSL_in_init(s))
#endif
    {
        /* type == SSL3_RT_APPLICATION_DATA */
        i = s->handshake_func(s);
        if (i < 0)
            return (i);
        if (i == 0) {
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
            return (-1);
        }
    }

 start:
    s->rwstate = SSL_NOTHING;

    /*-
     * s->s3->rrec.type         - is the type of record
     * s->s3->rrec.data,    - data
     * s->s3->rrec.off,     - offset into 'data' for next read
     * s->s3->rrec.length,  - number of bytes.
     */
    rr = &(s->s3->rrec);

    /*
     * We are not handshaking and have no data yet, so process data buffered
     * during the last handshake in advance, if any.
     */
    if (s->state == SSL_ST_OK && rr->length == 0) {
        pitem *item;
        item = pqueue_pop(s->d1->buffered_app_data.q);
        if (item) {
#ifndef OPENSSL_NO_SCTP
            /* Restore bio_dgram_sctp_rcvinfo struct */
            if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
                DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
                BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
                         sizeof(rdata->recordinfo), &rdata->recordinfo);
            }
#endif

            dtls1_copy_record(s, item);

            OPENSSL_free(item->data);
            pitem_free(item);
        }
    }

    /* Check for timeout */
    if (dtls1_handle_timeout(s) > 0)
        goto start;

    /* get new packet if necessary */
    if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) {
        ret = dtls1_get_record(s);
        if (ret <= 0) {
            ret = dtls1_read_failed(s, ret);
            /* anything other than a timeout is an error */
            if (ret <= 0)
                return (ret);
            else
                goto start;
        }
    }

    if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) {
        rr->length = 0;
        goto start;
    }

    /*
     * Reset the count of consecutive warning alerts if we've got a non-empty
     * record that isn't an alert.
     */
    if (rr->type != SSL3_RT_ALERT && rr->length != 0)
        s->cert->alert_count = 0;

    /* we now have a packet which can be read and processed */

    if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
                                   * reset by ssl3_get_finished */
        && (rr->type != SSL3_RT_HANDSHAKE)) {
        /*
         * We now have application data between CCS and Finished. Most likely
         * the packets were reordered on their way, so buffer the application
         * data for later processing rather than dropping the connection.
         */
        if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) <
            0) {
            SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
            return -1;
        }
        rr->length = 0;
        goto start;
    }

    /*
     * If the other end has shut down, throw anything we read away (even in
     * 'peek' mode)
     */
    if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
        rr->length = 0;
        s->rwstate = SSL_NOTHING;
        return (0);
    }

    if (type == rr->type) {     /* SSL3_RT_APPLICATION_DATA or
                                 * SSL3_RT_HANDSHAKE */
        /*
         * make sure that we are not getting application data when we are
         * doing a handshake for the first time
         */
        if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
            (s->enc_read_ctx == NULL)) {
            al = SSL_AD_UNEXPECTED_MESSAGE;
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
            goto f_err;
        }

        if (len <= 0)
            return (len);

        if ((unsigned int)len > rr->length)
            n = rr->length;
        else
            n = (unsigned int)len;

        memcpy(buf, &(rr->data[rr->off]), n);
        if (!peek) {
            rr->length -= n;
            rr->off += n;
            if (rr->length == 0) {
                s->rstate = SSL_ST_READ_HEADER;
                rr->off = 0;
            }
        }
#ifndef OPENSSL_NO_SCTP
        /*
         * We were about to renegotiate but had to read belated application
         * data first, so retry.
         */
        if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
            rr->type == SSL3_RT_APPLICATION_DATA &&
            (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
             || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) {
            s->rwstate = SSL_READING;
            BIO_clear_retry_flags(SSL_get_rbio(s));
            BIO_set_retry_read(SSL_get_rbio(s));
        }

        /*
         * We might had to delay a close_notify alert because of reordered
         * app data. If there was an alert and there is no message to read
         * anymore, finally set shutdown.
         */
        if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
            s->d1->shutdown_received
            && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
            s->shutdown |= SSL_RECEIVED_SHUTDOWN;
            return (0);
        }
#endif
        return (n);
    }

    /*
     * If we get here, then type != rr->type; if we have a handshake message,
     * then it was unexpected (Hello Request or Client Hello).
     */

    /*
     * In case of record types for which we have 'fragment' storage, fill
     * that so that we can process the data at a fixed place.
     */
    {
        unsigned int k, dest_maxlen = 0;
        unsigned char *dest = NULL;
        unsigned int *dest_len = NULL;

        if (rr->type == SSL3_RT_HANDSHAKE) {
            dest_maxlen = sizeof s->d1->handshake_fragment;
            dest = s->d1->handshake_fragment;
            dest_len = &s->d1->handshake_fragment_len;
        } else if (rr->type == SSL3_RT_ALERT) {
            dest_maxlen = sizeof(s->d1->alert_fragment);
            dest = s->d1->alert_fragment;
            dest_len = &s->d1->alert_fragment_len;
        }
#ifndef OPENSSL_NO_HEARTBEATS
        else if (rr->type == TLS1_RT_HEARTBEAT) {
            dtls1_process_heartbeat(s);

            /* Exit and notify application to read again */
            rr->length = 0;
            s->rwstate = SSL_READING;
            BIO_clear_retry_flags(SSL_get_rbio(s));
            BIO_set_retry_read(SSL_get_rbio(s));
            return (-1);
        }
#endif
        /* else it's a CCS message, or application data or wrong */
        else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
            /*
             * Application data while renegotiating is allowed. Try again
             * reading.
             */
            if (rr->type == SSL3_RT_APPLICATION_DATA) {
                BIO *bio;
                s->s3->in_read_app_data = 2;
                bio = SSL_get_rbio(s);
                s->rwstate = SSL_READING;
                BIO_clear_retry_flags(bio);
                BIO_set_retry_read(bio);
                return (-1);
            }

            /* Not certain if this is the right error handling */
            al = SSL_AD_UNEXPECTED_MESSAGE;
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
            goto f_err;
        }

        if (dest_maxlen > 0) {
            /*
             * XDTLS: In a pathalogical case, the Client Hello may be
             * fragmented--don't always expect dest_maxlen bytes
             */
            if (rr->length < dest_maxlen) {
#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
                /*
                 * for normal alerts rr->length is 2, while
                 * dest_maxlen is 7 if we were to handle this
                 * non-existing alert...
                 */
                FIX ME
#endif
                 s->rstate = SSL_ST_READ_HEADER;
                rr->length = 0;
                goto start;
            }

            /* now move 'n' bytes: */
            for (k = 0; k < dest_maxlen; k++) {
                dest[k] = rr->data[rr->off++];
                rr->length--;
            }
            *dest_len = dest_maxlen;
        }
    }

    /*-
     * s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
     * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
     * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
     */

    /* If we are a client, check for an incoming 'Hello Request': */
    if ((!s->server) &&
        (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
        (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
        (s->session != NULL) && (s->session->cipher != NULL)) {
        s->d1->handshake_fragment_len = 0;

        if ((s->d1->handshake_fragment[1] != 0) ||
            (s->d1->handshake_fragment[2] != 0) ||
            (s->d1->handshake_fragment[3] != 0)) {
            al = SSL_AD_DECODE_ERROR;
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
            goto f_err;
        }

        /*
         * no need to check sequence number on HELLO REQUEST messages
         */

        if (s->msg_callback)
            s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
                            s->d1->handshake_fragment, 4, s,
                            s->msg_callback_arg);

        if (SSL_is_init_finished(s) &&
            !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
            !s->s3->renegotiate) {
            s->d1->handshake_read_seq++;
            s->new_session = 1;
            ssl3_renegotiate(s);
            if (ssl3_renegotiate_check(s)) {
                i = s->handshake_func(s);
                if (i < 0)
                    return (i);
                if (i == 0) {
                    SSLerr(SSL_F_DTLS1_READ_BYTES,
                           SSL_R_SSL_HANDSHAKE_FAILURE);
                    return (-1);
                }

                if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
                    if (s->s3->rbuf.left == 0) { /* no read-ahead left? */
                        BIO *bio;
                        /*
                         * In the case where we try to read application data,
                         * but we trigger an SSL handshake, we return -1 with
                         * the retry option set.  Otherwise renegotiation may
                         * cause nasty problems in the blocking world
                         */
                        s->rwstate = SSL_READING;
                        bio = SSL_get_rbio(s);
                        BIO_clear_retry_flags(bio);
                        BIO_set_retry_read(bio);
                        return (-1);
                    }
                }
            }
        }
        /*
         * we either finished a handshake or ignored the request, now try
         * again to obtain the (application) data we were asked for
         */
        goto start;
    }

    if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
        int alert_level = s->d1->alert_fragment[0];
        int alert_descr = s->d1->alert_fragment[1];

        s->d1->alert_fragment_len = 0;

        if (s->msg_callback)
            s->msg_callback(0, s->version, SSL3_RT_ALERT,
                            s->d1->alert_fragment, 2, s, s->msg_callback_arg);

        if (s->info_callback != NULL)
            cb = s->info_callback;
        else if (s->ctx->info_callback != NULL)
            cb = s->ctx->info_callback;

        if (cb != NULL) {
            j = (alert_level << 8) | alert_descr;
            cb(s, SSL_CB_READ_ALERT, j);
        }

        if (alert_level == SSL3_AL_WARNING) {
            s->s3->warn_alert = alert_descr;

            s->cert->alert_count++;
            if (s->cert->alert_count == MAX_WARN_ALERT_COUNT) {
                al = SSL_AD_UNEXPECTED_MESSAGE;
                SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_TOO_MANY_WARN_ALERTS);
                goto f_err;
            }

            if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
#ifndef OPENSSL_NO_SCTP
                /*
                 * With SCTP and streams the socket may deliver app data
                 * after a close_notify alert. We have to check this first so
                 * that nothing gets discarded.
                 */
                if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
                    BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
                    s->d1->shutdown_received = 1;
                    s->rwstate = SSL_READING;
                    BIO_clear_retry_flags(SSL_get_rbio(s));
                    BIO_set_retry_read(SSL_get_rbio(s));
                    return -1;
                }
#endif
                s->shutdown |= SSL_RECEIVED_SHUTDOWN;
                return (0);
            }
#if 0
            /* XXX: this is a possible improvement in the future */
            /* now check if it's a missing record */
            if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
                unsigned short seq;
                unsigned int frag_off;
                unsigned char *p = &(s->d1->alert_fragment[2]);

                n2s(p, seq);
                n2l3(p, frag_off);

                dtls1_retransmit_message(s,
                                         dtls1_get_queue_priority
                                         (frag->msg_header.seq, 0), frag_off,
                                         &found);
                if (!found && SSL_in_init(s)) {
                    /*
                     * fprintf( stderr,"in init = %d\n", SSL_in_init(s));
                     */
                    /*
                     * requested a message not yet sent, send an alert
                     * ourselves
                     */
                    ssl3_send_alert(s, SSL3_AL_WARNING,
                                    DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
                }
            }
#endif
        } else if (alert_level == SSL3_AL_FATAL) {
            char tmp[16];

            s->rwstate = SSL_NOTHING;
            s->s3->fatal_alert = alert_descr;
            SSLerr(SSL_F_DTLS1_READ_BYTES,
                   SSL_AD_REASON_OFFSET + alert_descr);
            BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
            ERR_add_error_data(2, "SSL alert number ", tmp);
            s->shutdown |= SSL_RECEIVED_SHUTDOWN;
            SSL_CTX_remove_session(s->session_ctx, s->session);
            return (0);
        } else {
            al = SSL_AD_ILLEGAL_PARAMETER;
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
            goto f_err;
        }

        goto start;
    }

    if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
                                            * shutdown */
        s->rwstate = SSL_NOTHING;
        rr->length = 0;
        return (0);
    }

    if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
        struct ccs_header_st ccs_hdr;
        unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;

        dtls1_get_ccs_header(rr->data, &ccs_hdr);

        if (s->version == DTLS1_BAD_VER)
            ccs_hdr_len = 3;

        /*
         * 'Change Cipher Spec' is just a single byte, so we know exactly
         * what the record payload has to look like
         */
        /* XDTLS: check that epoch is consistent */
        if ((rr->length != ccs_hdr_len) ||
            (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) {
            i = SSL_AD_ILLEGAL_PARAMETER;
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC);
            goto err;
        }

        rr->length = 0;

        if (s->msg_callback)
            s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
                            rr->data, 1, s, s->msg_callback_arg);

        /*
         * We can't process a CCS now, because previous handshake messages
         * are still missing, so just drop it.
         */
        if (!s->d1->change_cipher_spec_ok) {
            goto start;
        }

        s->d1->change_cipher_spec_ok = 0;

        s->s3->change_cipher_spec = 1;
        if (!ssl3_do_change_cipher_spec(s))
            goto err;

        /* do this whenever CCS is processed */
        dtls1_reset_seq_numbers(s, SSL3_CC_READ);

        if (s->version == DTLS1_BAD_VER)
            s->d1->handshake_read_seq++;

#ifndef OPENSSL_NO_SCTP
        /*
         * Remember that a CCS has been received, so that an old key of
         * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
         * SCTP is used
         */
        BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
#endif

        goto start;
    }

    /*
     * Unexpected handshake message (Client Hello, or protocol violation)
     */
    if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
        !s->in_handshake) {
        struct hm_header_st msg_hdr;

        /* this may just be a stale retransmit */
        dtls1_get_message_header(rr->data, &msg_hdr);
        if (rr->epoch != s->d1->r_epoch) {
            rr->length = 0;
            goto start;
        }

        /*
         * If we are server, we may have a repeated FINISHED of the client
         * here, then retransmit our CCS and FINISHED.
         */
        if (msg_hdr.type == SSL3_MT_FINISHED) {
            if (dtls1_check_timeout_num(s) < 0)
                return -1;

            dtls1_retransmit_buffered_messages(s);
            rr->length = 0;
            goto start;
        }

        if (((s->state & SSL_ST_MASK) == SSL_ST_OK) &&
            !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
#if 0                           /* worked only because C operator preferences
                                 * are not as expected (and because this is
                                 * not really needed for clients except for
                                 * detecting protocol violations): */
            s->state = SSL_ST_BEFORE | (s->server)
                ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
#else
            s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
#endif
            s->renegotiate = 1;
            s->new_session = 1;
        }
        i = s->handshake_func(s);
        if (i < 0)
            return (i);
        if (i == 0) {
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
            return (-1);
        }

        if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
            if (s->s3->rbuf.left == 0) { /* no read-ahead left? */
                BIO *bio;
                /*
                 * In the case where we try to read application data, but we
                 * trigger an SSL handshake, we return -1 with the retry
                 * option set.  Otherwise renegotiation may cause nasty
                 * problems in the blocking world
                 */
                s->rwstate = SSL_READING;
                bio = SSL_get_rbio(s);
                BIO_clear_retry_flags(bio);
                BIO_set_retry_read(bio);
                return (-1);
            }
        }
        goto start;
    }

    switch (rr->type) {
    default:
#ifndef OPENSSL_NO_TLS
        /* TLS just ignores unknown message types */
        if (s->version == TLS1_VERSION) {
            rr->length = 0;
            goto start;
        }
#endif
        al = SSL_AD_UNEXPECTED_MESSAGE;
        SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
        goto f_err;
    case SSL3_RT_CHANGE_CIPHER_SPEC:
    case SSL3_RT_ALERT:
    case SSL3_RT_HANDSHAKE:
        /*
         * we already handled all of these, with the possible exception of
         * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not
         * happen when type != rr->type
         */
        al = SSL_AD_UNEXPECTED_MESSAGE;
        SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
        goto f_err;
    case SSL3_RT_APPLICATION_DATA:
        /*
         * At this point, we were expecting handshake data, but have
         * application data.  If the library was running inside ssl3_read()
         * (i.e. in_read_app_data is set) and it makes sense to read
         * application data at this point (session renegotiation not yet
         * started), we will indulge it.
         */
        if (s->s3->in_read_app_data &&
            (s->s3->total_renegotiations != 0) &&
            (((s->state & SSL_ST_CONNECT) &&
              (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
              (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
             ) || ((s->state & SSL_ST_ACCEPT) &&
                   (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
                   (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
             )
            )) {
            s->s3->in_read_app_data = 2;
            return (-1);
        } else {
            al = SSL_AD_UNEXPECTED_MESSAGE;
            SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
            goto f_err;
        }
    }
    /* not reached */

 f_err:
    ssl3_send_alert(s, SSL3_AL_FATAL, al);
 err:
    return (-1);
}

int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
{
    int i;

#ifndef OPENSSL_NO_SCTP
    /*
     * Check if we have to continue an interrupted handshake for reading
     * belated app data with SCTP.
     */
    if ((SSL_in_init(s) && !s->in_handshake) ||
        (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
         (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
          || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
#else
    if (SSL_in_init(s) && !s->in_handshake)
#endif
    {
        i = s->handshake_func(s);
        if (i < 0)
            return (i);
        if (i == 0) {
            SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,
                   SSL_R_SSL_HANDSHAKE_FAILURE);
            return -1;
        }
    }

    if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
        SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_DTLS_MESSAGE_TOO_BIG);
        return -1;
    }

    i = dtls1_write_bytes(s, type, buf_, len);
    return i;
}

        /*
         * this only happens when a client hello is received and a handshake
         * is started.
         */
static int
have_handshake_fragment(SSL *s, int type, unsigned char *buf,
                        int len, int peek)
{

    if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
        /* (partially) satisfy request from storage */
    {
        unsigned char *src = s->d1->handshake_fragment;
        unsigned char *dst = buf;
        unsigned int k, n;

        /* peek == 0 */
        n = 0;
        while ((len > 0) && (s->d1->handshake_fragment_len > 0)) {
            *dst++ = *src++;
            len--;
            s->d1->handshake_fragment_len--;
            n++;
        }
        /* move any remaining fragment bytes: */
        for (k = 0; k < s->d1->handshake_fragment_len; k++)
            s->d1->handshake_fragment[k] = *src++;
        return n;
    }

    return 0;
}

/*
 * Call this to write data in records of type 'type' It will return <= 0 if
 * not all data has been sent or non-blocking IO.
 */
int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
{
    int i;

    OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
    s->rwstate = SSL_NOTHING;
    i = do_dtls1_write(s, type, buf, len, 0);
    return i;
}

int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
                   unsigned int len, int create_empty_fragment)
{
    unsigned char *p, *pseq;
    int i, mac_size, clear = 0;
    int prefix_len = 0;
    int eivlen;
    SSL3_RECORD *wr;
    SSL3_BUFFER *wb;
    SSL_SESSION *sess;

    /*
     * first check if there is a SSL3_BUFFER still being written out.  This
     * will happen with non blocking IO
     */
    if (s->s3->wbuf.left != 0) {
        OPENSSL_assert(0);      /* XDTLS: want to see if we ever get here */
        return (ssl3_write_pending(s, type, buf, len));
    }

    /* If we have an alert to send, lets send it */
    if (s->s3->alert_dispatch) {
        i = s->method->ssl_dispatch_alert(s);
        if (i <= 0)
            return (i);
        /* if it went, fall through and send more stuff */
    }

    if (len == 0 && !create_empty_fragment)
        return 0;

    wr = &(s->s3->wrec);
    wb = &(s->s3->wbuf);
    sess = s->session;

    if ((sess == NULL) ||
        (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
        clear = 1;

    if (clear)
        mac_size = 0;
    else {
        mac_size = EVP_MD_CTX_size(s->write_hash);
        if (mac_size < 0)
            goto err;
    }

    /* DTLS implements explicit IV, so no need for empty fragments */
#if 0
    /*
     * 'create_empty_fragment' is true only when this function calls itself
     */
    if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
        && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
    {
        /*
         * countermeasure against known-IV weakness in CBC ciphersuites (see
         * http://www.openssl.org/~bodo/tls-cbc.txt)
         */

        if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) {
            /*
             * recursive function call with 'create_empty_fragment' set; this
             * prepares and buffers the data for an empty fragment (these
             * 'prefix_len' bytes are sent out later together with the actual
             * payload)
             */
            prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
            if (prefix_len <= 0)
                goto err;

            if (s->s3->wbuf.len <
                (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) {
                /* insufficient space */
                SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
                goto err;
            }
        }

        s->s3->empty_fragment_done = 1;
    }
#endif
    p = wb->buf + prefix_len;

    /* write the header */

    *(p++) = type & 0xff;
    wr->type = type;
    /*
     * Special case: for hello verify request, client version 1.0 and we
     * haven't decided which version to use yet send back using version 1.0
     * header: otherwise some clients will ignore it.
     */
    if (s->method->version == DTLS_ANY_VERSION) {
        *(p++) = DTLS1_VERSION >> 8;
        *(p++) = DTLS1_VERSION & 0xff;
    } else {
        *(p++) = s->version >> 8;
        *(p++) = s->version & 0xff;
    }

    /* field where we are to write out packet epoch, seq num and len */
    pseq = p;
    p += 10;

    /* Explicit IV length, block ciphers appropriate version flag */
    if (s->enc_write_ctx) {
        int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
        if (mode == EVP_CIPH_CBC_MODE) {
            eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
            if (eivlen <= 1)
                eivlen = 0;
        }
        /* Need explicit part of IV for GCM mode */
        else if (mode == EVP_CIPH_GCM_MODE)
            eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
        else
            eivlen = 0;
    } else
        eivlen = 0;

    /* lets setup the record stuff. */
    wr->data = p + eivlen;      /* make room for IV in case of CBC */
    wr->length = (int)len;
    wr->input = (unsigned char *)buf;

    /*
     * we now 'read' from wr->input, wr->length bytes into wr->data
     */

    /* first we compress */
    if (s->compress != NULL) {
        if (!ssl3_do_compress(s)) {
            SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
            goto err;
        }
    } else {
        memcpy(wr->data, wr->input, wr->length);
        wr->input = wr->data;
    }

    /*
     * we should still have the output to wr->data and the input from
     * wr->input.  Length should be wr->length. wr->data still points in the
     * wb->buf
     */

    if (mac_size != 0) {
        if (s->method->ssl3_enc->mac(s, &(p[wr->length + eivlen]), 1) < 0)
            goto err;
        wr->length += mac_size;
    }

    /* this is true regardless of mac size */
    wr->input = p;
    wr->data = p;

    if (eivlen)
        wr->length += eivlen;

    if (s->method->ssl3_enc->enc(s, 1) < 1)
        goto err;

    /* record length after mac and block padding */
    /*
     * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && !
     * SSL_in_init(s)))
     */

    /* there's only one epoch between handshake and app data */

    s2n(s->d1->w_epoch, pseq);

    /* XDTLS: ?? */
    /*
     * else s2n(s->d1->handshake_epoch, pseq);
     */

    memcpy(pseq, &(s->s3->write_sequence[2]), 6);
    pseq += 6;
    s2n(wr->length, pseq);

    if (s->msg_callback)
        s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
                        DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);

    /*
     * we should now have wr->data pointing to the encrypted data, which is
     * wr->length long
     */
    wr->type = type;            /* not needed but helps for debugging */
    wr->length += DTLS1_RT_HEADER_LENGTH;

#if 0                           /* this is now done at the message layer */
    /* buffer the record, making it easy to handle retransmits */
    if (type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
        dtls1_buffer_record(s, wr->data, wr->length,
                            *((PQ_64BIT *) & (s->s3->write_sequence[0])));
#endif

    ssl3_record_sequence_update(&(s->s3->write_sequence[0]));

    if (create_empty_fragment) {
        /*
         * we are in a recursive call; just return the length, don't write
         * out anything here
         */
        return wr->length;
    }

    /* now let's set up wb */
    wb->left = prefix_len + wr->length;
    wb->offset = 0;

    /*
     * memorize arguments so that ssl3_write_pending can detect bad write
     * retries later
     */
    s->s3->wpend_tot = len;
    s->s3->wpend_buf = buf;
    s->s3->wpend_type = type;
    s->s3->wpend_ret = len;

    /* we now just need to write the buffer */
    return ssl3_write_pending(s, type, buf, len);
 err:
    return -1;
}

static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
{
    int cmp;
    unsigned int shift;
    const unsigned char *seq = s->s3->read_sequence;

    cmp = satsub64be(seq, bitmap->max_seq_num);
    if (cmp > 0) {
        memcpy(s->s3->rrec.seq_num, seq, 8);
        return 1;               /* this record in new */
    }
    shift = -cmp;
    if (shift >= sizeof(bitmap->map) * 8)
        return 0;               /* stale, outside the window */
    else if (bitmap->map & (1UL << shift))
        return 0;               /* record previously received */

    memcpy(s->s3->rrec.seq_num, seq, 8);
    return 1;
}

static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
{
    int cmp;
    unsigned int shift;
    const unsigned char *seq = s->s3->read_sequence;

    cmp = satsub64be(seq, bitmap->max_seq_num);
    if (cmp > 0) {
        shift = cmp;
        if (shift < sizeof(bitmap->map) * 8)
            bitmap->map <<= shift, bitmap->map |= 1UL;
        else
            bitmap->map = 1UL;
        memcpy(bitmap->max_seq_num, seq, 8);
    } else {
        shift = -cmp;
        if (shift < sizeof(bitmap->map) * 8)
            bitmap->map |= 1UL << shift;
    }
}

int dtls1_dispatch_alert(SSL *s)
{
    int i, j;
    void (*cb) (const SSL *ssl, int type, int val) = NULL;
    unsigned char buf[DTLS1_AL_HEADER_LENGTH];
    unsigned char *ptr = &buf[0];

    s->s3->alert_dispatch = 0;

    memset(buf, 0x00, sizeof(buf));
    *ptr++ = s->s3->send_alert[0];
    *ptr++ = s->s3->send_alert[1];

#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
    if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
        s2n(s->d1->handshake_read_seq, ptr);
# if 0
        if (s->d1->r_msg_hdr.frag_off == 0)
            /*
             * waiting for a new msg
             */
            else
            s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
# endif

# if 0
        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);
# endif
        l2n3(s->d1->r_msg_hdr.frag_off, ptr);
    }
#endif

    i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
    if (i <= 0) {
        s->s3->alert_dispatch = 1;
        /* fprintf( stderr, "not done with alert\n" ); */
    } else {
        if (s->s3->send_alert[0] == SSL3_AL_FATAL
#ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
            || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
#endif
            )
            (void)BIO_flush(s->wbio);

        if (s->msg_callback)
            s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
                            2, s, s->msg_callback_arg);

        if (s->info_callback != NULL)
            cb = s->info_callback;
        else if (s->ctx->info_callback != NULL)
            cb = s->ctx->info_callback;

        if (cb != NULL) {
            j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1];
            cb(s, SSL_CB_WRITE_ALERT, j);
        }
    }
    return (i);
}

static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
                                      unsigned int *is_next_epoch)
{

    *is_next_epoch = 0;

    /* In current epoch, accept HM, CCS, DATA, & ALERT */
    if (rr->epoch == s->d1->r_epoch)
        return &s->d1->bitmap;

    /*
     * Only HM and ALERT messages can be from the next epoch and only if we
     * have already processed all of the unprocessed records from the last
     * epoch
     */
    else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
             s->d1->unprocessed_rcds.epoch != s->d1->r_epoch &&
             (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
        *is_next_epoch = 1;
        return &s->d1->next_bitmap;
    }

    return NULL;
}

#if 0
static int
dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
                             unsigned short *priority, unsigned long *offset)
{

    /* alerts are passed up immediately */
    if (rr->type == SSL3_RT_APPLICATION_DATA || rr->type == SSL3_RT_ALERT)
        return 0;

    /*
     * Only need to buffer if a handshake is underway. (this implies that
     * Hello Request and Client Hello are passed up immediately)
     */
    if (SSL_in_init(s)) {
        unsigned char *data = rr->data;
        /* need to extract the HM/CCS sequence number here */
        if (rr->type == SSL3_RT_HANDSHAKE ||
            rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
            unsigned short seq_num;
            struct hm_header_st msg_hdr;
            struct ccs_header_st ccs_hdr;

            if (rr->type == SSL3_RT_HANDSHAKE) {
                dtls1_get_message_header(data, &msg_hdr);
                seq_num = msg_hdr.seq;
                *offset = msg_hdr.frag_off;
            } else {
                dtls1_get_ccs_header(data, &ccs_hdr);
                seq_num = ccs_hdr.seq;
                *offset = 0;
            }

            /*
             * this is either a record we're waiting for, or a retransmit of
             * something we happened to previously receive (higher layers
             * will drop the repeat silently
             */
            if (seq_num < s->d1->handshake_read_seq)
                return 0;
            if (rr->type == SSL3_RT_HANDSHAKE &&
                seq_num == s->d1->handshake_read_seq &&
                msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
                return 0;
            else if (seq_num == s->d1->handshake_read_seq &&
                     (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
                      msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
                return 0;
            else {
                *priority = seq_num;
                return 1;
            }
        } else                  /* unknown record type */
            return 0;
    }

    return 0;
}
#endif

void dtls1_reset_seq_numbers(SSL *s, int rw)
{
    unsigned char *seq;
    unsigned int seq_bytes = sizeof(s->s3->read_sequence);

    if (rw & SSL3_CC_READ) {
        seq = s->s3->read_sequence;
        s->d1->r_epoch++;
        memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
        memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));

        /*
         * We must not use any buffered messages received from the previous
         * epoch
         */
        dtls1_clear_received_buffer(s);
    } else {
        seq = s->s3->write_sequence;
        memcpy(s->d1->last_write_sequence, seq,
               sizeof(s->s3->write_sequence));
        s->d1->w_epoch++;
    }

    memset(seq, 0x00, seq_bytes);
}