summaryrefslogtreecommitdiffstats
path: root/src/network/ssl/qsslsocket_openssl.cpp
blob: 1d675edbbb6c79cb0029dfb43257fe7dfabba7fe (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
/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtNetwork module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia. For licensing terms and
** conditions see http://qt.digia.com/licensing. For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights. These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** $QT_END_LICENSE$
**
****************************************************************************/

/****************************************************************************
**
** In addition, as a special exception, the copyright holders listed above give
** permission to link the code of its release of Qt with the OpenSSL project's
** "OpenSSL" library (or modified versions of the "OpenSSL" library that use the
** same license as the original version), and distribute the linked executables.
**
** You must comply with the GNU General Public License version 2 in all
** respects for all of the code used other than the "OpenSSL" code.  If you
** modify this file, you may extend this exception to your version of the file,
** but you are not obligated to do so.  If you do not wish to do so, delete
** this exception statement from your version of this file.
**
****************************************************************************/

//#define QSSLSOCKET_DEBUG
//#define QT_DECRYPT_SSL_TRAFFIC

#include "qsslsocket_openssl_p.h"
#include "qsslsocket_openssl_symbols_p.h"
#include "qsslsocket.h"
#include "qsslcertificate_p.h"
#include "qsslcipher_p.h"
#include "qsslkey_p.h"

#include <QtCore/qdatetime.h>
#include <QtCore/qdebug.h>
#include <QtCore/qdir.h>
#include <QtCore/qdiriterator.h>
#include <QtCore/qelapsedtimer.h>
#include <QtCore/qfile.h>
#include <QtCore/qfileinfo.h>
#include <QtCore/qmutex.h>
#include <QtCore/qthread.h>
#include <QtCore/qurl.h>
#include <QtCore/qvarlengtharray.h>
#include <QLibrary> // for loading the security lib for the CA store

QT_BEGIN_NAMESPACE

#if defined(Q_OS_MACX)
#define kSecTrustSettingsDomainSystem 2 // so we do not need to include the header file
    PtrSecCertificateCopyData QSslSocketPrivate::ptrSecCertificateCopyData = 0;
    PtrSecTrustSettingsCopyCertificates QSslSocketPrivate::ptrSecTrustSettingsCopyCertificates = 0;
    PtrSecTrustCopyAnchorCertificates QSslSocketPrivate::ptrSecTrustCopyAnchorCertificates = 0;
#elif defined(Q_OS_WIN)
    PtrCertOpenSystemStoreW QSslSocketPrivate::ptrCertOpenSystemStoreW = 0;
    PtrCertFindCertificateInStore QSslSocketPrivate::ptrCertFindCertificateInStore = 0;
    PtrCertCloseStore QSslSocketPrivate::ptrCertCloseStore = 0;
#endif

bool QSslSocketPrivate::s_libraryLoaded = false;
bool QSslSocketPrivate::s_loadedCiphersAndCerts = false;
bool QSslSocketPrivate::s_loadRootCertsOnDemand = false;

/* \internal

    From OpenSSL's thread(3) manual page:

    OpenSSL can safely be used in multi-threaded applications provided that at
    least two callback functions are set.

    locking_function(int mode, int n, const char *file, int line) is needed to
    perform locking on shared data structures.  (Note that OpenSSL uses a
    number of global data structures that will be implicitly shared
    whenever multiple threads use OpenSSL.)  Multi-threaded
    applications will crash at random if it is not set.  ...
    ...
    id_function(void) is a function that returns a thread ID. It is not
    needed on Windows nor on platforms where getpid() returns a different
    ID for each thread (most notably Linux)
*/
class QOpenSslLocks
{
public:
    inline QOpenSslLocks()
        : initLocker(QMutex::Recursive),
          locksLocker(QMutex::Recursive)
    {
        QMutexLocker locker(&locksLocker);
        int numLocks = q_CRYPTO_num_locks();
        locks = new QMutex *[numLocks];
        memset(locks, 0, numLocks * sizeof(QMutex *));
    }
    inline ~QOpenSslLocks()
    {
        QMutexLocker locker(&locksLocker);
        for (int i = 0; i < q_CRYPTO_num_locks(); ++i)
            delete locks[i];
        delete [] locks;

        QSslSocketPrivate::deinitialize();
    }
    inline QMutex *lock(int num)
    {
        QMutexLocker locker(&locksLocker);
        QMutex *tmp = locks[num];
        if (!tmp)
            tmp = locks[num] = new QMutex(QMutex::Recursive);
        return tmp;
    }

    QMutex *globalLock()
    {
        return &locksLocker;
    }

    QMutex *initLock()
    {
        return &initLocker;
    }

private:
    QMutex initLocker;
    QMutex locksLocker;
    QMutex **locks;
};
Q_GLOBAL_STATIC(QOpenSslLocks, openssl_locks)

QString QSslSocketBackendPrivate::getErrorsFromOpenSsl()
{
    QString errorString;
    unsigned long errNum;
    while ((errNum = q_ERR_get_error())) {
        if (! errorString.isEmpty())
            errorString.append(QLatin1String(", "));
        const char *error = q_ERR_error_string(errNum, NULL);
        errorString.append(QString::fromLatin1(error)); // error is ascii according to man ERR_error_string
    }
    return errorString;
}

extern "C" {
static void locking_function(int mode, int lockNumber, const char *, int)
{
    QMutex *mutex = openssl_locks()->lock(lockNumber);

    // Lock or unlock it
    if (mode & CRYPTO_LOCK)
        mutex->lock();
    else
        mutex->unlock();
}
static unsigned long id_function()
{
    return (quintptr)QThread::currentThreadId();
}
} // extern "C"

QSslSocketBackendPrivate::QSslSocketBackendPrivate()
    : ssl(0),
      readBio(0),
      writeBio(0),
      session(0)
{
    // Calls SSL_library_init().
    ensureInitialized();
}

QSslSocketBackendPrivate::~QSslSocketBackendPrivate()
{
    destroySslContext();
}

QSslCipher QSslSocketBackendPrivate::QSslCipher_from_SSL_CIPHER(SSL_CIPHER *cipher)
{
    QSslCipher ciph;

    char buf [256];
    QString descriptionOneLine = QString::fromLatin1(q_SSL_CIPHER_description(cipher, buf, sizeof(buf)));

    QStringList descriptionList = descriptionOneLine.split(QLatin1String(" "), QString::SkipEmptyParts);
    if (descriptionList.size() > 5) {
        // ### crude code.
        ciph.d->isNull = false;
        ciph.d->name = descriptionList.at(0);

        QString protoString = descriptionList.at(1);
        ciph.d->protocolString = protoString;
        ciph.d->protocol = QSsl::UnknownProtocol;
        if (protoString == QLatin1String("SSLv3"))
            ciph.d->protocol = QSsl::SslV3;
        else if (protoString == QLatin1String("SSLv2"))
            ciph.d->protocol = QSsl::SslV2;
        else if (protoString == QLatin1String("TLSv1"))
            ciph.d->protocol = QSsl::TlsV1_0;
        else if (protoString == QLatin1String("TLSv1.1"))
            ciph.d->protocol = QSsl::TlsV1_1;
        else if (protoString == QLatin1String("TLSv1.2"))
            ciph.d->protocol = QSsl::TlsV1_2;

        if (descriptionList.at(2).startsWith(QLatin1String("Kx=")))
            ciph.d->keyExchangeMethod = descriptionList.at(2).mid(3);
        if (descriptionList.at(3).startsWith(QLatin1String("Au=")))
            ciph.d->authenticationMethod = descriptionList.at(3).mid(3);
        if (descriptionList.at(4).startsWith(QLatin1String("Enc=")))
            ciph.d->encryptionMethod = descriptionList.at(4).mid(4);
        ciph.d->exportable = (descriptionList.size() > 6 && descriptionList.at(6) == QLatin1String("export"));

        ciph.d->bits = q_SSL_CIPHER_get_bits(cipher, &ciph.d->supportedBits);
    }
    return ciph;
}

// ### This list is shared between all threads, and protected by a
// mutex. Investigate using thread local storage instead.
struct QSslErrorList
{
    QMutex mutex;
    QList<QPair<int, int> > errors;
};
Q_GLOBAL_STATIC(QSslErrorList, _q_sslErrorList)

int q_X509Callback(int ok, X509_STORE_CTX *ctx)
{
    if (!ok) {
        // Store the error and at which depth the error was detected.
        _q_sslErrorList()->errors << qMakePair<int, int>(q_X509_STORE_CTX_get_error(ctx), q_X509_STORE_CTX_get_error_depth(ctx));
#ifdef QSSLSOCKET_DEBUG
        qDebug() << "verification error: dumping bad certificate";
        qDebug() << QSslCertificatePrivate::QSslCertificate_from_X509(q_X509_STORE_CTX_get_current_cert(ctx)).toPem();
        qDebug() << "dumping chain";
        foreach (QSslCertificate cert, QSslSocketBackendPrivate::STACKOFX509_to_QSslCertificates(q_X509_STORE_CTX_get_chain(ctx))) {
            QString certFormat(QStringLiteral("O=%1 CN=%2 L=%3 OU=%4 C=%5 ST=%6"));
            qDebug() << "Issuer:" << "O=" << cert.issuerInfo(QSslCertificate::Organization)
                << "CN=" << cert.issuerInfo(QSslCertificate::CommonName)
                << "L=" << cert.issuerInfo(QSslCertificate::LocalityName)
                << "OU=" << cert.issuerInfo(QSslCertificate::OrganizationalUnitName)
                << "C=" << cert.issuerInfo(QSslCertificate::CountryName)
                << "ST=" << cert.issuerInfo(QSslCertificate::StateOrProvinceName);
            qDebug() << "Subject:" << "O=" << cert.subjectInfo(QSslCertificate::Organization)
                << "CN=" << cert.subjectInfo(QSslCertificate::CommonName)
                << "L=" << cert.subjectInfo(QSslCertificate::LocalityName)
                << "OU=" << cert.subjectInfo(QSslCertificate::OrganizationalUnitName)
                << "C=" << cert.subjectInfo(QSslCertificate::CountryName)
                << "ST=" << cert.subjectInfo(QSslCertificate::StateOrProvinceName);
            qDebug() << "Valid:" << cert.effectiveDate() << "-" << cert.expiryDate();
        }
#endif
    }
    // Always return OK to allow verification to continue. We're handle the
    // errors gracefully after collecting all errors, after verification has
    // completed.
    return 1;
}

long QSslSocketBackendPrivate::setupOpenSslOptions(QSsl::SslProtocol protocol, QSsl::SslOptions sslOptions)
{
    long options;
    if (protocol == QSsl::TlsV1SslV3 || protocol == QSsl::SecureProtocols)
        options = SSL_OP_ALL|SSL_OP_NO_SSLv2;
    else
        options = SSL_OP_ALL;

    // This option is disabled by default, so we need to be able to clear it
    if (sslOptions & QSsl::SslOptionDisableEmptyFragments)
        options |= SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS;
    else
        options &= ~SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS;

#ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
    // This option is disabled by default, so we need to be able to clear it
    if (sslOptions & QSsl::SslOptionDisableLegacyRenegotiation)
        options &= ~SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION;
    else
        options |= SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION;
#endif

#ifdef SSL_OP_NO_TICKET
    if (sslOptions & QSsl::SslOptionDisableSessionTickets)
        options |= SSL_OP_NO_TICKET;
#endif
#ifdef SSL_OP_NO_COMPRESSION
    if (sslOptions & QSsl::SslOptionDisableCompression)
        options |= SSL_OP_NO_COMPRESSION;
#endif

    return options;
}

bool QSslSocketBackendPrivate::initSslContext()
{
    Q_Q(QSslSocket);

    // If no external context was set (e.g. bei QHttpNetworkConnection) we will create a default context
    if (!sslContextPointer) {
        // create a deep copy of our configuration
        QSslConfigurationPrivate *configurationCopy = new QSslConfigurationPrivate(configuration);
        configurationCopy->ref.store(0);              // the QSslConfiguration constructor refs up
        sslContextPointer = QSharedPointer<QSslContext>(
                    QSslContext::fromConfiguration(mode, configurationCopy, allowRootCertOnDemandLoading));
    }

    if (sslContextPointer->error() != QSslError::NoError) {
        q->setErrorString(sslContextPointer->errorString());
        q->setSocketError(QAbstractSocket::SslInvalidUserDataError);
        emit q->error(QAbstractSocket::SslInvalidUserDataError);
        sslContextPointer.clear(); // deletes the QSslContext
        return false;
    }

    // Create and initialize SSL session
    if (!(ssl = sslContextPointer->createSsl())) {
        // ### Bad error code
        q->setErrorString(QSslSocket::tr("Error creating SSL session, %1").arg(getErrorsFromOpenSsl()));
        q->setSocketError(QAbstractSocket::SslInternalError);
        emit q->error(QAbstractSocket::SslInternalError);
        return false;
    }

#if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
    if ((configuration.protocol == QSsl::TlsV1SslV3 ||
        configuration.protocol == QSsl::TlsV1_0 ||
        configuration.protocol == QSsl::TlsV1_1 ||
        configuration.protocol == QSsl::TlsV1_2 ||
        configuration.protocol == QSsl::SecureProtocols ||
        configuration.protocol == QSsl::AnyProtocol) &&
        mode == QSslSocket::SslClientMode && q_SSLeay() >= 0x00090806fL) {
        // Set server hostname on TLS extension. RFC4366 section 3.1 requires it in ACE format.
        QString tlsHostName = verificationPeerName.isEmpty() ? q->peerName() : verificationPeerName;
        if (tlsHostName.isEmpty())
            tlsHostName = hostName;
        QByteArray ace = QUrl::toAce(tlsHostName);
        // only send the SNI header if the URL is valid and not an IP
        if (!ace.isEmpty()
            && !QHostAddress().setAddress(tlsHostName)
            && !(configuration.sslOptions & QSsl::SslOptionDisableServerNameIndication)) {
            if (!q_SSL_ctrl(ssl, SSL_CTRL_SET_TLSEXT_HOSTNAME, TLSEXT_NAMETYPE_host_name, ace.data()))
                qWarning("could not set SSL_CTRL_SET_TLSEXT_HOSTNAME, Server Name Indication disabled");
        }
    }
#endif

    // Clear the session.
    errorList.clear();

    // Initialize memory BIOs for encryption and decryption.
    readBio = q_BIO_new(q_BIO_s_mem());
    writeBio = q_BIO_new(q_BIO_s_mem());
    if (!readBio || !writeBio) {
        q->setErrorString(QSslSocket::tr("Error creating SSL session: %1").arg(getErrorsFromOpenSsl()));
        q->setSocketError(QAbstractSocket::SslInternalError);
        emit q->error(QAbstractSocket::SslInternalError);
        return false;
    }

    // Assign the bios.
    q_SSL_set_bio(ssl, readBio, writeBio);

    if (mode == QSslSocket::SslClientMode)
        q_SSL_set_connect_state(ssl);
    else
        q_SSL_set_accept_state(ssl);

    return true;
}

void QSslSocketBackendPrivate::destroySslContext()
{
    if (ssl) {
        q_SSL_free(ssl);
        ssl = 0;
    }
    sslContextPointer.clear();
}

/*!
    \internal
*/
void QSslSocketPrivate::deinitialize()
{
    q_CRYPTO_set_id_callback(0);
    q_CRYPTO_set_locking_callback(0);
    q_ERR_free_strings();
}

/*!
    \internal

    Does the minimum amount of initialization to determine whether SSL
    is supported or not.
*/

bool QSslSocketPrivate::supportsSsl()
{
    return ensureLibraryLoaded();
}

bool QSslSocketPrivate::ensureLibraryLoaded()
{
    if (!q_resolveOpenSslSymbols())
        return false;

    // Check if the library itself needs to be initialized.
    QMutexLocker locker(openssl_locks()->initLock());

    if (!s_libraryLoaded) {
        s_libraryLoaded = true;

        // Initialize OpenSSL.
        q_CRYPTO_set_id_callback(id_function);
        q_CRYPTO_set_locking_callback(locking_function);
        if (q_SSL_library_init() != 1)
            return false;
        q_SSL_load_error_strings();
        q_OpenSSL_add_all_algorithms();

        // Initialize OpenSSL's random seed.
        if (!q_RAND_status()) {
            struct {
                int msec;
                int sec;
                void *stack;
            } randomish;

            int attempts = 500;
            do {
                if (attempts < 500) {
#ifdef Q_OS_UNIX
                    struct timespec ts = {0, 33333333};
                    nanosleep(&ts, 0);
#else
                    Sleep(3);
#endif
                    randomish.msec = attempts;
                }
                randomish.stack = (void *)&randomish;
                randomish.msec = QTime::currentTime().msec();
                randomish.sec = QTime::currentTime().second();
                q_RAND_seed((const char *)&randomish, sizeof(randomish));
            } while (!q_RAND_status() && --attempts);
            if (!attempts)
                return false;
        }
    }
    return true;
}

void QSslSocketPrivate::ensureCiphersAndCertsLoaded()
{
    QMutexLocker locker(openssl_locks()->initLock());
    if (s_loadedCiphersAndCerts)
        return;
    s_loadedCiphersAndCerts = true;

    resetDefaultCiphers();

#ifndef QT_NO_LIBRARY
    //load symbols needed to receive certificates from system store
#if defined(Q_OS_MACX)
    QLibrary securityLib("/System/Library/Frameworks/Security.framework/Versions/Current/Security");
    if (securityLib.load()) {
        ptrSecCertificateCopyData = (PtrSecCertificateCopyData) securityLib.resolve("SecCertificateCopyData");
        if (!ptrSecCertificateCopyData)
            qWarning("could not resolve symbols in security library"); // should never happen

        ptrSecTrustSettingsCopyCertificates = (PtrSecTrustSettingsCopyCertificates) securityLib.resolve("SecTrustSettingsCopyCertificates");
        if (!ptrSecTrustSettingsCopyCertificates) { // method was introduced in Leopard, use legacy method if it's not there
            ptrSecTrustCopyAnchorCertificates = (PtrSecTrustCopyAnchorCertificates) securityLib.resolve("SecTrustCopyAnchorCertificates");
            if (!ptrSecTrustCopyAnchorCertificates)
                qWarning("could not resolve symbols in security library"); // should never happen
        }
    } else {
        qWarning("could not load security library");
    }
#elif defined(Q_OS_WIN)
    HINSTANCE hLib = LoadLibraryW(L"Crypt32");
    if (hLib) {
#if defined(Q_OS_WINCE)
        ptrCertOpenSystemStoreW = (PtrCertOpenSystemStoreW)GetProcAddress(hLib, L"CertOpenStore");
        ptrCertFindCertificateInStore = (PtrCertFindCertificateInStore)GetProcAddress(hLib, L"CertFindCertificateInStore");
        ptrCertCloseStore = (PtrCertCloseStore)GetProcAddress(hLib, L"CertCloseStore");
#else
        ptrCertOpenSystemStoreW = (PtrCertOpenSystemStoreW)GetProcAddress(hLib, "CertOpenSystemStoreW");
        ptrCertFindCertificateInStore = (PtrCertFindCertificateInStore)GetProcAddress(hLib, "CertFindCertificateInStore");
        ptrCertCloseStore = (PtrCertCloseStore)GetProcAddress(hLib, "CertCloseStore");
#endif
        if (!ptrCertOpenSystemStoreW || !ptrCertFindCertificateInStore || !ptrCertCloseStore)
            qWarning("could not resolve symbols in crypt32 library"); // should never happen
    } else {
        qWarning("could not load crypt32 library"); // should never happen
    }
#elif defined(Q_OS_QNX)
    s_loadRootCertsOnDemand = true;
#elif defined(Q_OS_UNIX) && !defined(Q_OS_MAC)
    // check whether we can enable on-demand root-cert loading (i.e. check whether the sym links are there)
    QList<QByteArray> dirs = unixRootCertDirectories();
    QStringList symLinkFilter;
    symLinkFilter << QLatin1String("[0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f][0-9a-f].[0-9]");
    for (int a = 0; a < dirs.count(); ++a) {
        QDirIterator iterator(QLatin1String(dirs.at(a)), symLinkFilter, QDir::Files);
        if (iterator.hasNext()) {
            s_loadRootCertsOnDemand = true;
            break;
        }
    }
#endif
#endif //QT_NO_LIBRARY
    // if on-demand loading was not enabled, load the certs now
    if (!s_loadRootCertsOnDemand)
        setDefaultCaCertificates(systemCaCertificates());
#ifdef Q_OS_WIN
    //Enabled for fetching additional root certs from windows update on windows 6+
    //This flag is set false by setDefaultCaCertificates() indicating the app uses
    //its own cert bundle rather than the system one.
    //Same logic that disables the unix on demand cert loading.
    //Unlike unix, we do preload the certificates from the cert store.
    if ((QSysInfo::windowsVersion() & QSysInfo::WV_NT_based) >= QSysInfo::WV_6_0)
        s_loadRootCertsOnDemand = true;
#endif
}

/*!
    \internal

    Declared static in QSslSocketPrivate, makes sure the SSL libraries have
    been initialized.
*/

void QSslSocketPrivate::ensureInitialized()
{
    if (!supportsSsl())
        return;

    ensureCiphersAndCertsLoaded();
}

long QSslSocketPrivate::sslLibraryVersionNumber()
{
    if (!supportsSsl())
        return 0;

    return q_SSLeay();
}

QString QSslSocketPrivate::sslLibraryVersionString()
{
    if (!supportsSsl())
        return QString();

    const char *versionString = q_SSLeay_version(SSLEAY_VERSION);
    if (!versionString)
        return QString();

    return QString::fromLatin1(versionString);
}

long QSslSocketPrivate::sslLibraryBuildVersionNumber()
{
    return OPENSSL_VERSION_NUMBER;
}

QString QSslSocketPrivate::sslLibraryBuildVersionString()
{
    return QLatin1String(OPENSSL_VERSION_TEXT);
}

/*!
    \internal

    Declared static in QSslSocketPrivate, backend-dependent loading of
    application-wide global ciphers.
*/
void QSslSocketPrivate::resetDefaultCiphers()
{
    SSL_CTX *myCtx = q_SSL_CTX_new(q_SSLv23_client_method());
    SSL *mySsl = q_SSL_new(myCtx);

    QList<QSslCipher> ciphers;
    QList<QSslCipher> defaultCiphers;

    STACK_OF(SSL_CIPHER) *supportedCiphers = q_SSL_get_ciphers(mySsl);
    for (int i = 0; i < q_sk_SSL_CIPHER_num(supportedCiphers); ++i) {
        if (SSL_CIPHER *cipher = q_sk_SSL_CIPHER_value(supportedCiphers, i)) {
            if (cipher->valid) {
                QSslCipher ciph = QSslSocketBackendPrivate::QSslCipher_from_SSL_CIPHER(cipher);
                if (!ciph.isNull()) {
                    // Unconditionally exclude ADH ciphers since they offer no MITM protection
                    if (!ciph.name().toLower().startsWith(QLatin1String("adh")))
                        ciphers << ciph;
                    if (ciph.usedBits() >= 128)
                        defaultCiphers << ciph;
                }
            }
        }
    }

    q_SSL_CTX_free(myCtx);
    q_SSL_free(mySsl);

    setDefaultSupportedCiphers(ciphers);
    setDefaultCiphers(defaultCiphers);
}

QList<QSslCertificate> QSslSocketPrivate::systemCaCertificates()
{
    ensureInitialized();
#ifdef QSSLSOCKET_DEBUG
    QElapsedTimer timer;
    timer.start();
#endif
    QList<QSslCertificate> systemCerts;
#if defined(Q_OS_MACX)
    CFArrayRef cfCerts;
    OSStatus status = 1;

    CFDataRef SecCertificateCopyData (
       SecCertificateRef certificate
    );

    if (ptrSecCertificateCopyData) {
        if (ptrSecTrustSettingsCopyCertificates)
            status = ptrSecTrustSettingsCopyCertificates(kSecTrustSettingsDomainSystem, &cfCerts);
        else if (ptrSecTrustCopyAnchorCertificates)
            status = ptrSecTrustCopyAnchorCertificates(&cfCerts);
        if (!status) {
            CFIndex size = CFArrayGetCount(cfCerts);
            for (CFIndex i = 0; i < size; ++i) {
                SecCertificateRef cfCert = (SecCertificateRef)CFArrayGetValueAtIndex(cfCerts, i);
                CFDataRef data;

                data = ptrSecCertificateCopyData(cfCert);

                if (data == NULL) {
                    qWarning("error retrieving a CA certificate from the system store");
                } else {
                    QByteArray rawCert = QByteArray::fromRawData((const char *)CFDataGetBytePtr(data), CFDataGetLength(data));
                    systemCerts.append(QSslCertificate::fromData(rawCert, QSsl::Der));
                    CFRelease(data);
                }
            }
            CFRelease(cfCerts);
        }
        else {
           // no detailed error handling here
           qWarning("could not retrieve system CA certificates");
        }
    }
#elif defined(Q_OS_WIN)
    if (ptrCertOpenSystemStoreW && ptrCertFindCertificateInStore && ptrCertCloseStore) {
        HCERTSTORE hSystemStore;
#if defined(Q_OS_WINCE)
        hSystemStore = ptrCertOpenSystemStoreW(CERT_STORE_PROV_SYSTEM_W,
                                               0,
                                               0,
                                               CERT_STORE_NO_CRYPT_RELEASE_FLAG|CERT_SYSTEM_STORE_CURRENT_USER,
                                               L"ROOT");
#else
        hSystemStore = ptrCertOpenSystemStoreW(0, L"ROOT");
#endif
        if(hSystemStore) {
            PCCERT_CONTEXT pc = NULL;
            while(1) {
                pc = ptrCertFindCertificateInStore( hSystemStore, X509_ASN_ENCODING, 0, CERT_FIND_ANY, NULL, pc);
                if(!pc)
                    break;
                QByteArray der((const char *)(pc->pbCertEncoded), static_cast<int>(pc->cbCertEncoded));
                QSslCertificate cert(der, QSsl::Der);
                systemCerts.append(cert);
            }
            ptrCertCloseStore(hSystemStore, 0);
        }
    }
#elif defined(Q_OS_UNIX)
    QSet<QString> certFiles;
    QDir currentDir;
    QStringList nameFilters;
    QList<QByteArray> directories;
    QSsl::EncodingFormat platformEncodingFormat;
# ifndef Q_OS_ANDROID
    directories = unixRootCertDirectories();
    nameFilters << QLatin1String("*.pem") << QLatin1String("*.crt");
    platformEncodingFormat = QSsl::Pem;
# else
    // Q_OS_ANDROID
    QByteArray ministroPath = qgetenv("MINISTRO_SSL_CERTS_PATH"); // Set by Ministro
    directories << ministroPath;
    nameFilters << QLatin1String("*.der");
    platformEncodingFormat = QSsl::Der;
#  ifndef Q_OS_ANDROID_NO_SDK
    if (ministroPath.isEmpty()) {
        QList<QByteArray> certificateData = fetchSslCertificateData();
        for (int i = 0; i < certificateData.size(); ++i) {
            systemCerts.append(QSslCertificate::fromData(certificateData.at(i), QSsl::Der));
        }
    } else
#   endif //Q_OS_ANDROID_NO_SDK
# endif //Q_OS_ANDROID
    {
        currentDir.setNameFilters(nameFilters);
        for (int a = 0; a < directories.count(); a++) {
            currentDir.setPath(QLatin1String(directories.at(a)));
            QDirIterator it(currentDir);
            while (it.hasNext()) {
                it.next();
                // use canonical path here to not load the same certificate twice if symlinked
                certFiles.insert(it.fileInfo().canonicalFilePath());
            }
        }
        QSetIterator<QString> it(certFiles);
        while (it.hasNext())
            systemCerts.append(QSslCertificate::fromPath(it.next(), platformEncodingFormat));
# ifndef Q_OS_ANDROID
        systemCerts.append(QSslCertificate::fromPath(QLatin1String("/etc/pki/tls/certs/ca-bundle.crt"), QSsl::Pem)); // Fedora, Mandriva
        systemCerts.append(QSslCertificate::fromPath(QLatin1String("/usr/local/share/certs/ca-root-nss.crt"), QSsl::Pem)); // FreeBSD's ca_root_nss
# endif
    }
#endif
#ifdef QSSLSOCKET_DEBUG
    qDebug() << "systemCaCertificates retrieval time " << timer.elapsed() << "ms";
    qDebug() << "imported " << systemCerts.count() << " certificates";
#endif

    return systemCerts;
}

void QSslSocketBackendPrivate::startClientEncryption()
{
    Q_Q(QSslSocket);
    if (!initSslContext()) {
        q->setErrorString(QSslSocket::tr("Unable to init SSL Context: %1").arg(getErrorsFromOpenSsl()));
        q->setSocketError(QAbstractSocket::SslInternalError);
        emit q->error(QAbstractSocket::SslInternalError);
        return;
    }

    // Start connecting. This will place outgoing data in the BIO, so we
    // follow up with calling transmit().
    startHandshake();
    transmit();
}

void QSslSocketBackendPrivate::startServerEncryption()
{
    Q_Q(QSslSocket);
    if (!initSslContext()) {
        q->setErrorString(QSslSocket::tr("Unable to init SSL Context: %1").arg(getErrorsFromOpenSsl()));
        q->setSocketError(QAbstractSocket::SslInternalError);
        emit q->error(QAbstractSocket::SslInternalError);
        return;
    }

    // Start connecting. This will place outgoing data in the BIO, so we
    // follow up with calling transmit().
    startHandshake();
    transmit();
}

/*!
    \internal

    Transmits encrypted data between the BIOs and the socket.
*/
void QSslSocketBackendPrivate::transmit()
{
    Q_Q(QSslSocket);

    // If we don't have any SSL context, don't bother transmitting.
    if (!ssl)
        return;

    bool transmitting;
    do {
        transmitting = false;

        // If the connection is secure, we can transfer data from the write
        // buffer (in plain text) to the write BIO through SSL_write.
        if (connectionEncrypted && !writeBuffer.isEmpty()) {
            qint64 totalBytesWritten = 0;
            int nextDataBlockSize;
            while ((nextDataBlockSize = writeBuffer.nextDataBlockSize()) > 0) {
                int writtenBytes = q_SSL_write(ssl, writeBuffer.readPointer(), nextDataBlockSize);
                if (writtenBytes <= 0) {
                    int error = q_SSL_get_error(ssl, writtenBytes);
                    //write can result in a want_write_error - not an error - continue transmitting
                    if (error == SSL_ERROR_WANT_WRITE) {
                        transmitting = true;
                        break;
                    } else if (error == SSL_ERROR_WANT_READ) {
                        //write can result in a want_read error, possibly due to renegotiation - not an error - stop transmitting
                        transmitting = false;
                        break;
                    } else {
                        // ### Better error handling.
                        q->setErrorString(QSslSocket::tr("Unable to write data: %1").arg(getErrorsFromOpenSsl()));
                        q->setSocketError(QAbstractSocket::SslInternalError);
                        emit q->error(QAbstractSocket::SslInternalError);
                        return;
                    }
                }
#ifdef QSSLSOCKET_DEBUG
                qDebug() << "QSslSocketBackendPrivate::transmit: encrypted" << writtenBytes << "bytes";
#endif
                writeBuffer.free(writtenBytes);
                totalBytesWritten += writtenBytes;

                if (writtenBytes < nextDataBlockSize) {
                    // break out of the writing loop and try again after we had read
                    transmitting = true;
                    break;
                }
            }

            if (totalBytesWritten > 0) {
                // Don't emit bytesWritten() recursively.
                if (!emittedBytesWritten) {
                    emittedBytesWritten = true;
                    emit q->bytesWritten(totalBytesWritten);
                    emittedBytesWritten = false;
                }
            }
        }

        // Check if we've got any data to be written to the socket.
        QVarLengthArray<char, 4096> data;
        int pendingBytes;
        while (plainSocket->isValid() && (pendingBytes = q_BIO_pending(writeBio)) > 0) {
            // Read encrypted data from the write BIO into a buffer.
            data.resize(pendingBytes);
            int encryptedBytesRead = q_BIO_read(writeBio, data.data(), pendingBytes);

            // Write encrypted data from the buffer to the socket.
            qint64 actualWritten = plainSocket->write(data.constData(), encryptedBytesRead);
#ifdef QSSLSOCKET_DEBUG
            qDebug() << "QSslSocketBackendPrivate::transmit: wrote" << encryptedBytesRead << "encrypted bytes to the socket" << actualWritten << "actual.";
#endif
            if (actualWritten < 0) {
                //plain socket write fails if it was in the pending close state.
                q->setErrorString(plainSocket->errorString());
                q->setSocketError(plainSocket->error());
                emit q->error(plainSocket->error());
                return;
            }
            transmitting = true;
        }

        // Check if we've got any data to be read from the socket.
        if (!connectionEncrypted || !readBufferMaxSize || buffer.size() < readBufferMaxSize)
            while ((pendingBytes = plainSocket->bytesAvailable()) > 0) {
                // Read encrypted data from the socket into a buffer.
                data.resize(pendingBytes);
                // just peek() here because q_BIO_write could write less data than expected
                int encryptedBytesRead = plainSocket->peek(data.data(), pendingBytes);

#ifdef QSSLSOCKET_DEBUG
                qDebug() << "QSslSocketBackendPrivate::transmit: read" << encryptedBytesRead << "encrypted bytes from the socket";
#endif
                // Write encrypted data from the buffer into the read BIO.
                int writtenToBio = q_BIO_write(readBio, data.constData(), encryptedBytesRead);

                // do the actual read() here and throw away the results.
                if (writtenToBio > 0) {
                    // ### TODO: make this cheaper by not making it memcpy. E.g. make it work with data=0x0 or make it work with seek
                    plainSocket->read(data.data(), writtenToBio);
                } else {
                    // ### Better error handling.
                    q->setErrorString(QSslSocket::tr("Unable to decrypt data: %1").arg(getErrorsFromOpenSsl()));
                    q->setSocketError(QAbstractSocket::SslInternalError);
                    emit q->error(QAbstractSocket::SslInternalError);
                    return;
                }

                transmitting = true;
            }

        // If the connection isn't secured yet, this is the time to retry the
        // connect / accept.
        if (!connectionEncrypted) {
#ifdef QSSLSOCKET_DEBUG
            qDebug() << "QSslSocketBackendPrivate::transmit: testing encryption";
#endif
            if (startHandshake()) {
#ifdef QSSLSOCKET_DEBUG
                qDebug() << "QSslSocketBackendPrivate::transmit: encryption established";
#endif
                connectionEncrypted = true;
                transmitting = true;
            } else if (plainSocket->state() != QAbstractSocket::ConnectedState) {
#ifdef QSSLSOCKET_DEBUG
                qDebug() << "QSslSocketBackendPrivate::transmit: connection lost";
#endif
                break;
            } else if (paused) {
                // just wait until the user continues
                return;
            } else {
#ifdef QSSLSOCKET_DEBUG
                qDebug() << "QSslSocketBackendPrivate::transmit: encryption not done yet";
#endif
            }
        }

        // If the request is small and the remote host closes the transmission
        // after sending, there's a chance that startHandshake() will already
        // have triggered a shutdown.
        if (!ssl)
            continue;

        // We always read everything from the SSL decryption buffers, even if
        // we have a readBufferMaxSize. There's no point in leaving data there
        // just so that readBuffer.size() == readBufferMaxSize.
        int readBytes = 0;
        data.resize(4096);
        ::memset(data.data(), 0, data.size());
        do {
            // Don't use SSL_pending(). It's very unreliable.
            if ((readBytes = q_SSL_read(ssl, data.data(), data.size())) > 0) {
#ifdef QSSLSOCKET_DEBUG
                qDebug() << "QSslSocketBackendPrivate::transmit: decrypted" << readBytes << "bytes";
#endif
                char *ptr = buffer.reserve(readBytes);
                ::memcpy(ptr, data.data(), readBytes);

                if (readyReadEmittedPointer)
                    *readyReadEmittedPointer = true;
                emit q->readyRead();
                transmitting = true;
                continue;
            }

            // Error.
            switch (q_SSL_get_error(ssl, readBytes)) {
            case SSL_ERROR_WANT_READ:
            case SSL_ERROR_WANT_WRITE:
                // Out of data.
                break;
            case SSL_ERROR_ZERO_RETURN:
                // The remote host closed the connection.
#ifdef QSSLSOCKET_DEBUG
                qDebug() << "QSslSocketBackendPrivate::transmit: remote disconnect";
#endif
                shutdown = true; // the other side shut down, make sure we do not send shutdown ourselves
                q->setErrorString(QSslSocket::tr("The TLS/SSL connection has been closed"));
                q->setSocketError(QAbstractSocket::RemoteHostClosedError);
                emit q->error(QAbstractSocket::RemoteHostClosedError);
                return;
            case SSL_ERROR_SYSCALL: // some IO error
            case SSL_ERROR_SSL: // error in the SSL library
                // we do not know exactly what the error is, nor whether we can recover from it,
                // so just return to prevent an endless loop in the outer "while" statement
                q->setErrorString(QSslSocket::tr("Error while reading: %1").arg(getErrorsFromOpenSsl()));
                q->setSocketError(QAbstractSocket::SslInternalError);
                emit q->error(QAbstractSocket::SslInternalError);
                return;
            default:
                // SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT: can only happen with a
                // BIO_s_connect() or BIO_s_accept(), which we do not call.
                // SSL_ERROR_WANT_X509_LOOKUP: can only happen with a
                // SSL_CTX_set_client_cert_cb(), which we do not call.
                // So this default case should never be triggered.
                q->setErrorString(QSslSocket::tr("Error while reading: %1").arg(getErrorsFromOpenSsl()));
                q->setSocketError(QAbstractSocket::SslInternalError);
                emit q->error(QAbstractSocket::SslInternalError);
                break;
            }
        } while (ssl && readBytes > 0);
    } while (ssl && transmitting);
}

static QSslError _q_OpenSSL_to_QSslError(int errorCode, const QSslCertificate &cert)
{
    QSslError error;
    switch (errorCode) {
    case X509_V_OK:
        // X509_V_OK is also reported if the peer had no certificate.
        break;
    case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
        error = QSslError(QSslError::UnableToGetIssuerCertificate, cert); break;
    case X509_V_ERR_UNABLE_TO_DECRYPT_CERT_SIGNATURE:
        error = QSslError(QSslError::UnableToDecryptCertificateSignature, cert); break;
    case X509_V_ERR_UNABLE_TO_DECODE_ISSUER_PUBLIC_KEY:
        error = QSslError(QSslError::UnableToDecodeIssuerPublicKey, cert); break;
    case X509_V_ERR_CERT_SIGNATURE_FAILURE:
        error = QSslError(QSslError::CertificateSignatureFailed, cert); break;
    case X509_V_ERR_CERT_NOT_YET_VALID:
        error = QSslError(QSslError::CertificateNotYetValid, cert); break;
    case X509_V_ERR_CERT_HAS_EXPIRED:
        error = QSslError(QSslError::CertificateExpired, cert); break;
    case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
        error = QSslError(QSslError::InvalidNotBeforeField, cert); break;
    case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
        error = QSslError(QSslError::InvalidNotAfterField, cert); break;
    case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
        error = QSslError(QSslError::SelfSignedCertificate, cert); break;
    case X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN:
        error = QSslError(QSslError::SelfSignedCertificateInChain, cert); break;
    case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY:
        error = QSslError(QSslError::UnableToGetLocalIssuerCertificate, cert); break;
    case X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE:
        error = QSslError(QSslError::UnableToVerifyFirstCertificate, cert); break;
    case X509_V_ERR_CERT_REVOKED:
        error = QSslError(QSslError::CertificateRevoked, cert); break;
    case X509_V_ERR_INVALID_CA:
        error = QSslError(QSslError::InvalidCaCertificate, cert); break;
    case X509_V_ERR_PATH_LENGTH_EXCEEDED:
        error = QSslError(QSslError::PathLengthExceeded, cert); break;
    case X509_V_ERR_INVALID_PURPOSE:
        error = QSslError(QSslError::InvalidPurpose, cert); break;
    case X509_V_ERR_CERT_UNTRUSTED:
        error = QSslError(QSslError::CertificateUntrusted, cert); break;
    case X509_V_ERR_CERT_REJECTED:
        error = QSslError(QSslError::CertificateRejected, cert); break;
    default:
        error = QSslError(QSslError::UnspecifiedError, cert); break;
    }
    return error;
}

bool QSslSocketBackendPrivate::startHandshake()
{
    Q_Q(QSslSocket);

    // Check if the connection has been established. Get all errors from the
    // verification stage.
    _q_sslErrorList()->mutex.lock();
    _q_sslErrorList()->errors.clear();
    int result = (mode == QSslSocket::SslClientMode) ? q_SSL_connect(ssl) : q_SSL_accept(ssl);

    const QList<QPair<int, int> > &lastErrors = _q_sslErrorList()->errors;
    for (int i = 0; i < lastErrors.size(); ++i) {
        const QPair<int, int> &currentError = lastErrors.at(i);
        // Initialize the peer certificate chain in order to find which certificate caused this error
        if (configuration.peerCertificateChain.isEmpty())
            configuration.peerCertificateChain = STACKOFX509_to_QSslCertificates(q_SSL_get_peer_cert_chain(ssl));
        emit q->peerVerifyError(_q_OpenSSL_to_QSslError(currentError.first,
                                configuration.peerCertificateChain.value(currentError.second)));
        if (q->state() != QAbstractSocket::ConnectedState)
            break;
    }

    errorList << lastErrors;
    _q_sslErrorList()->mutex.unlock();

    // Connection aborted during handshake phase.
    if (q->state() != QAbstractSocket::ConnectedState)
        return false;

    // Check if we're encrypted or not.
    if (result <= 0) {
        switch (q_SSL_get_error(ssl, result)) {
        case SSL_ERROR_WANT_READ:
        case SSL_ERROR_WANT_WRITE:
            // The handshake is not yet complete.
            break;
        default:
            q->setErrorString(QSslSocket::tr("Error during SSL handshake: %1").arg(getErrorsFromOpenSsl()));
            q->setSocketError(QAbstractSocket::SslHandshakeFailedError);
#ifdef QSSLSOCKET_DEBUG
            qDebug() << "QSslSocketBackendPrivate::startHandshake: error!" << q->errorString();
#endif
            emit q->error(QAbstractSocket::SslHandshakeFailedError);
            q->abort();
        }
        return false;
    }

    // Store the peer certificate and chain. For clients, the peer certificate
    // chain includes the peer certificate; for servers, it doesn't. Both the
    // peer certificate and the chain may be empty if the peer didn't present
    // any certificate.
    if (configuration.peerCertificateChain.isEmpty())
        configuration.peerCertificateChain = STACKOFX509_to_QSslCertificates(q_SSL_get_peer_cert_chain(ssl));
    X509 *x509 = q_SSL_get_peer_certificate(ssl);
    configuration.peerCertificate = QSslCertificatePrivate::QSslCertificate_from_X509(x509);
    q_X509_free(x509);

    // Start translating errors.
    QList<QSslError> errors;

    // check the whole chain for blacklisting (including root, as we check for subjectInfo and issuer)
    foreach (const QSslCertificate &cert, configuration.peerCertificateChain) {
        if (QSslCertificatePrivate::isBlacklisted(cert)) {
            QSslError error(QSslError::CertificateBlacklisted, cert);
            errors << error;
            emit q->peerVerifyError(error);
            if (q->state() != QAbstractSocket::ConnectedState)
                return false;
        }
    }

    bool doVerifyPeer = configuration.peerVerifyMode == QSslSocket::VerifyPeer
                        || (configuration.peerVerifyMode == QSslSocket::AutoVerifyPeer
                            && mode == QSslSocket::SslClientMode);

    // Check the peer certificate itself. First try the subject's common name
    // (CN) as a wildcard, then try all alternate subject name DNS entries the
    // same way.
    if (!configuration.peerCertificate.isNull()) {
        // but only if we're a client connecting to a server
        // if we're the server, don't check CN
        if (mode == QSslSocket::SslClientMode) {
            QString peerName = (verificationPeerName.isEmpty () ? q->peerName() : verificationPeerName);

            if (!isMatchingHostname(configuration.peerCertificate, peerName)) {
                // No matches in common names or alternate names.
                QSslError error(QSslError::HostNameMismatch, configuration.peerCertificate);
                errors << error;
                emit q->peerVerifyError(error);
                if (q->state() != QAbstractSocket::ConnectedState)
                    return false;
            }
        }
    } else {
        // No peer certificate presented. Report as error if the socket
        // expected one.
        if (doVerifyPeer) {
            QSslError error(QSslError::NoPeerCertificate);
            errors << error;
            emit q->peerVerifyError(error);
            if (q->state() != QAbstractSocket::ConnectedState)
                return false;
        }
    }

    // Translate errors from the error list into QSslErrors.
    for (int i = 0; i < errorList.size(); ++i) {
        const QPair<int, int> &errorAndDepth = errorList.at(i);
        int err = errorAndDepth.first;
        int depth = errorAndDepth.second;
        errors << _q_OpenSSL_to_QSslError(err, configuration.peerCertificateChain.value(depth));
    }

    if (!errors.isEmpty()) {
        sslErrors = errors;

#ifdef Q_OS_WIN
        //Skip this if not using system CAs, or if the SSL errors are configured in advance to be ignorable
        if (doVerifyPeer
            && s_loadRootCertsOnDemand
            && allowRootCertOnDemandLoading
            && !verifyErrorsHaveBeenIgnored()) {
            //Windows desktop versions starting from vista ship with minimal set of roots
            //and download on demand from the windows update server CA roots that are
            //trusted by MS.
            //However, this is only transparent if using WinINET - we have to trigger it
            //ourselves.
            QSslCertificate certToFetch;
            bool fetchCertificate = true;
            for (int i=0; i< sslErrors.count(); i++) {
                switch (sslErrors.at(i).error()) {
                case QSslError::UnableToGetLocalIssuerCertificate: // site presented intermediate cert, but root is unknown
                case QSslError::SelfSignedCertificateInChain: // site presented a complete chain, but root is unknown
                    certToFetch = sslErrors.at(i).certificate();
                    break;
                case QSslError::SelfSignedCertificate:
                case QSslError::CertificateBlacklisted:
                    //With these errors, we know it will be untrusted so save time by not asking windows
                    fetchCertificate = false;
                    break;
                default:
#ifdef QSSLSOCKET_DEBUG
                    qDebug() << sslErrors.at(i).errorString();
#endif
                    break;
                }
            }
            if (fetchCertificate && !certToFetch.isNull()) {
                fetchCaRootForCert(certToFetch);
                return false;
            }
        }
#endif
        if (!checkSslErrors())
            return false;
    } else {
        sslErrors.clear();
    }

    continueHandshake();
    return true;
}

bool QSslSocketBackendPrivate::checkSslErrors()
{
    Q_Q(QSslSocket);
    if (sslErrors.isEmpty())
        return true;

    emit q->sslErrors(sslErrors);

    bool doVerifyPeer = configuration.peerVerifyMode == QSslSocket::VerifyPeer
                        || (configuration.peerVerifyMode == QSslSocket::AutoVerifyPeer
                            && mode == QSslSocket::SslClientMode);
    bool doEmitSslError = !verifyErrorsHaveBeenIgnored();
    // check whether we need to emit an SSL handshake error
    if (doVerifyPeer && doEmitSslError) {
        if (q->pauseMode() & QAbstractSocket::PauseOnSslErrors) {
            pauseSocketNotifiers(q);
            paused = true;
        } else {
            q->setErrorString(sslErrors.first().errorString());
            q->setSocketError(QAbstractSocket::SslHandshakeFailedError);
            emit q->error(QAbstractSocket::SslHandshakeFailedError);
            plainSocket->disconnectFromHost();
        }
        return false;
    }
    return true;
}

#ifdef Q_OS_WIN

void QSslSocketBackendPrivate::fetchCaRootForCert(const QSslCertificate &cert)
{
    Q_Q(QSslSocket);
    //The root certificate is downloaded from windows update, which blocks for 15 seconds in the worst case
    //so the request is done in a worker thread.
    QWindowsCaRootFetcher *fetcher = new QWindowsCaRootFetcher(cert, mode);
    QObject::connect(fetcher, SIGNAL(finished(QSslCertificate,QSslCertificate)), q, SLOT(_q_caRootLoaded(QSslCertificate,QSslCertificate)), Qt::QueuedConnection);
    QMetaObject::invokeMethod(fetcher, "start", Qt::QueuedConnection);
    pauseSocketNotifiers(q);
    paused = true;
}

//This is the callback from QWindowsCaRootFetcher, trustedRoot will be invalid (default constructed) if it failed.
void QSslSocketBackendPrivate::_q_caRootLoaded(QSslCertificate cert, QSslCertificate trustedRoot)
{
    Q_Q(QSslSocket);
    if (!trustedRoot.isNull() && !trustedRoot.isBlacklisted()) {
        if (s_loadRootCertsOnDemand) {
            //Add the new root cert to default cert list for use by future sockets
            QSslSocket::addDefaultCaCertificate(trustedRoot);
        }
        //Add the new root cert to this socket for future connections
        q->addCaCertificate(trustedRoot);
        //Remove the broken chain ssl errors (as chain is verified by windows)
        for (int i=sslErrors.count() - 1; i >= 0; --i) {
            if (sslErrors.at(i).certificate() == cert) {
                switch (sslErrors.at(i).error()) {
                case QSslError::UnableToGetLocalIssuerCertificate:
                case QSslError::CertificateUntrusted:
                case QSslError::UnableToVerifyFirstCertificate:
                case QSslError::SelfSignedCertificateInChain:
                    // error can be ignored if OS says the chain is trusted
                    sslErrors.removeAt(i);
                    break;
                default:
                    // error cannot be ignored
                    break;
                }
            }
        }
    }
    // Continue with remaining errors
    if (plainSocket)
        plainSocket->resume();
    paused = false;
    if (checkSslErrors())
        continueHandshake();
}

class QWindowsCaRootFetcherThread : public QThread
{
public:
    QWindowsCaRootFetcherThread()
    {
        qRegisterMetaType<QSslCertificate>();
        setObjectName(QStringLiteral("QWindowsCaRootFetcher"));
        start();
    }
    ~QWindowsCaRootFetcherThread()
    {
        quit();
        wait(15500); // worst case, a running request can block for 15 seconds
    }
};

Q_GLOBAL_STATIC(QWindowsCaRootFetcherThread, windowsCaRootFetcherThread);

QWindowsCaRootFetcher::QWindowsCaRootFetcher(const QSslCertificate &certificate, QSslSocket::SslMode sslMode)
    : cert(certificate), mode(sslMode)
{
    moveToThread(windowsCaRootFetcherThread());
}

QWindowsCaRootFetcher::~QWindowsCaRootFetcher()
{
}

void QWindowsCaRootFetcher::start()
{
    QByteArray der = cert.toDer();
    PCCERT_CONTEXT wincert = CertCreateCertificateContext(X509_ASN_ENCODING, (const BYTE *)der.constData(), der.length());
    if (!wincert) {
#ifdef QSSLSOCKET_DEBUG
        qDebug("QWindowsCaRootFetcher failed to convert certificate to windows form");
#endif
        emit finished(cert, QSslCertificate());
        deleteLater();
        return;
    }

    CERT_CHAIN_PARA parameters;
    memset(&parameters, 0, sizeof(parameters));
    parameters.cbSize = sizeof(parameters);
    // set key usage constraint
    parameters.RequestedUsage.dwType = USAGE_MATCH_TYPE_AND;
    parameters.RequestedUsage.Usage.cUsageIdentifier = 1;
    LPSTR oid = (LPSTR)(mode == QSslSocket::SslClientMode ? szOID_PKIX_KP_SERVER_AUTH : szOID_PKIX_KP_CLIENT_AUTH);
    parameters.RequestedUsage.Usage.rgpszUsageIdentifier = &oid;

#ifdef QSSLSOCKET_DEBUG
    QElapsedTimer stopwatch;
    stopwatch.start();
#endif
    PCCERT_CHAIN_CONTEXT chain;
    BOOL result = CertGetCertificateChain(
        0, //default engine
        wincert,
        0, //current date/time
        0, //default store
        &parameters,
        0, //default dwFlags
        0, //reserved
        &chain);
#ifdef QSSLSOCKET_DEBUG
    qDebug() << "QWindowsCaRootFetcher" << stopwatch.elapsed() << "ms to get chain";
#endif

    QSslCertificate trustedRoot;
    if (result) {
#ifdef QSSLSOCKET_DEBUG
        qDebug() << "QWindowsCaRootFetcher - examining windows chains";
        if (chain->TrustStatus.dwErrorStatus == CERT_TRUST_NO_ERROR)
            qDebug() << " - TRUSTED";
        else
            qDebug() << " - NOT TRUSTED" << chain->TrustStatus.dwErrorStatus;
        if (chain->TrustStatus.dwInfoStatus & CERT_TRUST_IS_SELF_SIGNED)
            qDebug() << " - SELF SIGNED";
        qDebug() << "QSslSocketBackendPrivate::fetchCaRootForCert - dumping simple chains";
        for (unsigned int i = 0; i < chain->cChain; i++) {
            if (chain->rgpChain[i]->TrustStatus.dwErrorStatus == CERT_TRUST_NO_ERROR)
                qDebug() << " - TRUSTED SIMPLE CHAIN" << i;
            else
                qDebug() << " - UNTRUSTED SIMPLE CHAIN" << i << "reason:" << chain->rgpChain[i]->TrustStatus.dwErrorStatus;
            for (unsigned int j = 0; j < chain->rgpChain[i]->cElement; j++) {
                QSslCertificate foundCert(QByteArray((const char *)chain->rgpChain[i]->rgpElement[j]->pCertContext->pbCertEncoded
                    , chain->rgpChain[i]->rgpElement[j]->pCertContext->cbCertEncoded), QSsl::Der);
                qDebug() << "   - " << foundCert;
            }
        }
        qDebug() << " - and" << chain->cLowerQualityChainContext << "low quality chains"; //expect 0, we haven't asked for them
#endif

        //based on http://msdn.microsoft.com/en-us/library/windows/desktop/aa377182%28v=vs.85%29.aspx
        //about the final chain rgpChain[cChain-1] which must begin with a trusted root to be valid
        if (chain->TrustStatus.dwErrorStatus == CERT_TRUST_NO_ERROR
            && chain->cChain > 0) {
            const PCERT_SIMPLE_CHAIN finalChain = chain->rgpChain[chain->cChain - 1];
            // http://msdn.microsoft.com/en-us/library/windows/desktop/aa377544%28v=vs.85%29.aspx
            // rgpElement[0] is the end certificate chain element. rgpElement[cElement-1] is the self-signed "root" certificate element.
            if (finalChain->TrustStatus.dwErrorStatus == CERT_TRUST_NO_ERROR
                && finalChain->cElement > 0) {
                    trustedRoot = QSslCertificate(QByteArray((const char *)finalChain->rgpElement[finalChain->cElement - 1]->pCertContext->pbCertEncoded
                        , finalChain->rgpElement[finalChain->cElement - 1]->pCertContext->cbCertEncoded), QSsl::Der);
            }
        }
        CertFreeCertificateChain(chain);
    }
    CertFreeCertificateContext(wincert);

    emit finished(cert, trustedRoot);
    deleteLater();
}
#endif

void QSslSocketBackendPrivate::disconnectFromHost()
{
    if (ssl) {
        if (!shutdown) {
            q_SSL_shutdown(ssl);
            shutdown = true;
            transmit();
        }
    }
    plainSocket->disconnectFromHost();
}

void QSslSocketBackendPrivate::disconnected()
{
    if (plainSocket->bytesAvailable() <= 0)
        destroySslContext();
    //if there is still buffered data in the plain socket, don't destroy the ssl context yet.
    //it will be destroyed when the socket is deleted.
}

QSslCipher QSslSocketBackendPrivate::sessionCipher() const
{
    if (!ssl)
        return QSslCipher();
#if OPENSSL_VERSION_NUMBER >= 0x10000000L
    // FIXME This is fairly evil, but needed to keep source level compatibility
    // with the OpenSSL 0.9.x implementation at maximum -- some other functions
    // don't take a const SSL_CIPHER* when they should
    SSL_CIPHER *sessionCipher = const_cast<SSL_CIPHER *>(q_SSL_get_current_cipher(ssl));
#else
    SSL_CIPHER *sessionCipher = q_SSL_get_current_cipher(ssl);
#endif
    return sessionCipher ? QSslCipher_from_SSL_CIPHER(sessionCipher) : QSslCipher();
}

QSsl::SslProtocol QSslSocketBackendPrivate::sessionProtocol() const
{
    if (!ssl)
        return QSsl::UnknownProtocol;
    int ver = q_SSL_version(ssl);

    switch (ver) {
    case 0x2:
        return QSsl::SslV2;
    case 0x300:
        return QSsl::SslV3;
    case 0x301:
        return QSsl::TlsV1_0;
    case 0x302:
        return QSsl::TlsV1_1;
    case 0x303:
        return QSsl::TlsV1_2;
    }

    return QSsl::UnknownProtocol;
}

void QSslSocketBackendPrivate::continueHandshake()
{
    Q_Q(QSslSocket);
    // if we have a max read buffer size, reset the plain socket's to match
    if (readBufferMaxSize)
        plainSocket->setReadBufferSize(readBufferMaxSize);

#if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
    if (q_SSL_ctrl((ssl), SSL_CTRL_GET_SESSION_REUSED, 0, NULL))
        configuration.peerSessionShared = true;
#endif

#ifdef QT_DECRYPT_SSL_TRAFFIC
    if (ssl->session && ssl->s3) {
        const char *mk = reinterpret_cast<const char *>(ssl->session->master_key);
        QByteArray masterKey(mk, ssl->session->master_key_length);
        const char *random = reinterpret_cast<const char *>(ssl->s3->client_random);
        QByteArray clientRandom(random, SSL3_RANDOM_SIZE);

        // different format, needed for e.g. older Wireshark versions:
//        const char *sid = reinterpret_cast<const char *>(ssl->session->session_id);
//        QByteArray sessionID(sid, ssl->session->session_id_length);
//        QByteArray debugLineRSA("RSA Session-ID:");
//        debugLineRSA.append(sessionID.toHex().toUpper());
//        debugLineRSA.append(" Master-Key:");
//        debugLineRSA.append(masterKey.toHex().toUpper());
//        debugLineRSA.append("\n");

        QByteArray debugLineClientRandom("CLIENT_RANDOM ");
        debugLineClientRandom.append(clientRandom.toHex().toUpper());
        debugLineClientRandom.append(" ");
        debugLineClientRandom.append(masterKey.toHex().toUpper());
        debugLineClientRandom.append("\n");

        QString sslKeyFile = QDir::tempPath() + QLatin1String("/qt-ssl-keys");
        QFile file(sslKeyFile);
        if (!file.open(QIODevice::Append))
            qWarning() << "could not open file" << sslKeyFile << "for appending";
        if (!file.write(debugLineClientRandom))
            qWarning() << "could not write to file" << sslKeyFile;
        file.close();
    } else {
        qWarning("could not decrypt SSL traffic");
    }
#endif

    // Cache this SSL session inside the QSslContext
    if (!(configuration.sslOptions & QSsl::SslOptionDisableSessionSharing)) {
        if (!sslContextPointer->cacheSession(ssl)) {
            sslContextPointer.clear(); // we could not cache the session
        } else {
            // Cache the session for permanent usage as well
            if (!(configuration.sslOptions & QSsl::SslOptionDisableSessionPersistence)) {
                if (!sslContextPointer->sessionASN1().isEmpty())
                    configuration.sslSession = sslContextPointer->sessionASN1();
                configuration.sslSessionTicketLifeTimeHint = sslContextPointer->sessionTicketLifeTimeHint();
            }
        }
    }

#if OPENSSL_VERSION_NUMBER >= 0x1000100fL && !defined(OPENSSL_NO_TLSEXT) && !defined(OPENSSL_NO_NEXTPROTONEG)
    const unsigned char *proto = 0;
    unsigned int proto_len = 0;
    q_SSL_get0_next_proto_negotiated(ssl, &proto, &proto_len);
    if (proto_len)
        configuration.nextNegotiatedProtocol = QByteArray(reinterpret_cast<const char *>(proto), proto_len);
    else
        configuration.nextNegotiatedProtocol.clear();
    configuration.nextProtocolNegotiationStatus = sslContextPointer->npnContext().status;
#endif // OPENSSL_VERSION_NUMBER >= 0x1000100fL ...

    connectionEncrypted = true;
    emit q->encrypted();
    if (autoStartHandshake && pendingClose) {
        pendingClose = false;
        q->disconnectFromHost();
    }
}

QList<QSslCertificate> QSslSocketBackendPrivate::STACKOFX509_to_QSslCertificates(STACK_OF(X509) *x509)
{
    ensureInitialized();
    QList<QSslCertificate> certificates;
    for (int i = 0; i < q_sk_X509_num(x509); ++i) {
        if (X509 *entry = q_sk_X509_value(x509, i))
            certificates << QSslCertificatePrivate::QSslCertificate_from_X509(entry);
    }
    return certificates;
}

QList<QSslError> QSslSocketBackendPrivate::verify(QList<QSslCertificate> certificateChain, const QString &hostName)
{
    QList<QSslError> errors;
    if (certificateChain.count() <= 0) {
        errors << QSslError(QSslError::UnspecifiedError);
        return errors;
    }

    // Setup the store with the default CA certificates
    X509_STORE *certStore = q_X509_STORE_new();
    if (!certStore) {
        qWarning() << "Unable to create certificate store";
        errors << QSslError(QSslError::UnspecifiedError);
        return errors;
    }

    if (s_loadRootCertsOnDemand) {
        setDefaultCaCertificates(defaultCaCertificates() + systemCaCertificates());
    }

    foreach (const QSslCertificate &caCertificate, QSslSocket::defaultCaCertificates()) {
        // From https://www.openssl.org/docs/ssl/SSL_CTX_load_verify_locations.html:
        //
        // If several CA certificates matching the name, key identifier, and
        // serial number condition are available, only the first one will be
        // examined. This may lead to unexpected results if the same CA
        // certificate is available with different expiration dates. If a
        // ``certificate expired'' verification error occurs, no other
        // certificate will be searched. Make sure to not have expired
        // certificates mixed with valid ones.
        //
        // See also: QSslContext::fromConfiguration()
        if (caCertificate.expiryDate() >= QDateTime::currentDateTime()) {
            q_X509_STORE_add_cert(certStore, reinterpret_cast<X509 *>(caCertificate.handle()));
        }
    }

    QMutexLocker sslErrorListMutexLocker(&_q_sslErrorList()->mutex);

    // Register a custom callback to get all verification errors.
    X509_STORE_set_verify_cb_func(certStore, q_X509Callback);

    // Build the chain of intermediate certificates
    STACK_OF(X509) *intermediates = 0;
    if (certificateChain.length() > 1) {
        intermediates = (STACK_OF(X509) *) q_sk_new_null();

        if (!intermediates) {
            q_X509_STORE_free(certStore);
            errors << QSslError(QSslError::UnspecifiedError);
            return errors;
        }

        bool first = true;
        foreach (const QSslCertificate &cert, certificateChain) {
            if (first) {
                first = false;
                continue;
            }
#if OPENSSL_VERSION_NUMBER >= 0x10000000L
            q_sk_push( (_STACK *)intermediates, reinterpret_cast<X509 *>(cert.handle()));
#else
            q_sk_push( (STACK *)intermediates, reinterpret_cast<char *>(cert.handle()));
#endif
        }
    }

    X509_STORE_CTX *storeContext = q_X509_STORE_CTX_new();
    if (!storeContext) {
        q_X509_STORE_free(certStore);
        errors << QSslError(QSslError::UnspecifiedError);
        return errors;
    }

    if (!q_X509_STORE_CTX_init(storeContext, certStore, reinterpret_cast<X509 *>(certificateChain[0].handle()), intermediates)) {
        q_X509_STORE_CTX_free(storeContext);
        q_X509_STORE_free(certStore);
        errors << QSslError(QSslError::UnspecifiedError);
        return errors;
    }

    // Now we can actually perform the verification of the chain we have built.
    // We ignore the result of this function since we process errors via the
    // callback.
    (void) q_X509_verify_cert(storeContext);

    q_X509_STORE_CTX_free(storeContext);
#if OPENSSL_VERSION_NUMBER >= 0x10000000L
    q_sk_free( (_STACK *) intermediates);
#else
    q_sk_free( (STACK *) intermediates);
#endif

    // Now process the errors
    const QList<QPair<int, int> > errorList = _q_sslErrorList()->errors;
    _q_sslErrorList()->errors.clear();

    sslErrorListMutexLocker.unlock();

    // Translate the errors
    if (QSslCertificatePrivate::isBlacklisted(certificateChain[0])) {
        QSslError error(QSslError::CertificateBlacklisted, certificateChain[0]);
        errors << error;
    }

    // Check the certificate name against the hostname if one was specified
    if ((!hostName.isEmpty()) && (!isMatchingHostname(certificateChain[0], hostName))) {
        // No matches in common names or alternate names.
        QSslError error(QSslError::HostNameMismatch, certificateChain[0]);
        errors << error;
    }

    // Translate errors from the error list into QSslErrors.
    for (int i = 0; i < errorList.size(); ++i) {
        const QPair<int, int> &errorAndDepth = errorList.at(i);
        int err = errorAndDepth.first;
        int depth = errorAndDepth.second;
        errors << _q_OpenSSL_to_QSslError(err, certificateChain.value(depth));
    }

    q_X509_STORE_free(certStore);

    return errors;
}

bool QSslSocketBackendPrivate::importPKCS12(QIODevice *device,
                                            QSslKey *key, QSslCertificate *cert,
                                            QList<QSslCertificate> *caCertificates,
                                            const QByteArray &passPhrase)
{
    if (!supportsSsl())
        return false;

    // These are required
    Q_ASSERT(device);
    Q_ASSERT(key);
    Q_ASSERT(cert);

    // Read the file into a BIO
    QByteArray pkcs12data = device->readAll();
    if (pkcs12data.size() == 0)
        return false;

    BIO *bio = q_BIO_new_mem_buf(const_cast<char *>(pkcs12data.constData()), pkcs12data.size());

    // Create the PKCS#12 object
    PKCS12 *p12 = q_d2i_PKCS12_bio(bio, 0);
    if (!p12) {
        qWarning("Unable to read PKCS#12 structure, %s", q_ERR_error_string(q_ERR_get_error(), 0));
        q_BIO_free(bio);
        return false;
    }

    // Extract the data
    EVP_PKEY *pkey;
    X509 *x509;
    STACK_OF(X509) *ca = 0;

    if (!q_PKCS12_parse(p12, passPhrase.constData(), &pkey, &x509, &ca)) {
        qWarning("Unable to parse PKCS#12 structure, %s", q_ERR_error_string(q_ERR_get_error(), 0));
        q_PKCS12_free(p12);
        q_BIO_free(bio);
        return false;
    }

    // Convert to Qt types
    if (!key->d->fromEVP_PKEY(pkey)) {
        qWarning("Unable to convert private key");
        q_sk_pop_free(reinterpret_cast<STACK *>(ca), reinterpret_cast<void(*)(void*)>(q_sk_free));
        q_X509_free(x509);
        q_EVP_PKEY_free(pkey);
        q_PKCS12_free(p12);
        q_BIO_free(bio);

        return false;
    }

    *cert = QSslCertificatePrivate::QSslCertificate_from_X509(x509);

    if (caCertificates)
        *caCertificates = QSslSocketBackendPrivate::STACKOFX509_to_QSslCertificates(ca);

    // Clean up
    q_sk_pop_free(reinterpret_cast<STACK *>(ca), reinterpret_cast<void(*)(void*)>(q_sk_free));
    q_X509_free(x509);
    q_EVP_PKEY_free(pkey);
    q_PKCS12_free(p12);
    q_BIO_free(bio);

    return true;
}


QT_END_NAMESPACE