summaryrefslogtreecommitdiffstats
path: root/crypto/lollipop/cryptfs.c
blob: 697593fd773e0f83514f834e73472bf187bbcb66 (plain) (blame)
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
/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* TO DO:
 *   1.  Perhaps keep several copies of the encrypted key, in case something
 *       goes horribly wrong?
 *
 */

#include <sys/types.h>
#include <linux/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <ctype.h>
#include <fcntl.h>
#include <inttypes.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <linux/dm-ioctl.h>
#include <libgen.h>
#include <stdlib.h>
#include <sys/param.h>
#include <string.h>
#include <sys/mount.h>
#include <openssl/evp.h>
#include <errno.h>
#include <linux/kdev_t.h>
#include <time.h>
#include "cryptfs.h"
#include "cutils/properties.h"
#include "crypto_scrypt.h"
#include <hardware/keymaster.h>

#ifndef min /* already defined by windows.h */
#define min(a, b) ((a) < (b) ? (a) : (b))
#endif

#define UNUSED __attribute__((unused))

#define UNUSED __attribute__((unused))

#ifdef CONFIG_HW_DISK_ENCRYPTION
#include "cryptfs_hw.h"
#endif

#define DM_CRYPT_BUF_SIZE 4096

#define HASH_COUNT 2000
#define KEY_LEN_BYTES 16
#define IV_LEN_BYTES 16

#define KEY_IN_FOOTER  "footer"

// "default_password" encoded into hex (d=0x64 etc)
#define DEFAULT_PASSWORD "64656661756c745f70617373776f7264"

#define EXT4_FS 1
#define F2FS_FS 2

#define TABLE_LOAD_RETRIES 10

#define RSA_KEY_SIZE 2048
#define RSA_KEY_SIZE_BYTES (RSA_KEY_SIZE / 8)
#define RSA_EXPONENT 0x10001

#define RETRY_MOUNT_ATTEMPTS 10
#define RETRY_MOUNT_DELAY_SECONDS 1

char *me = "cryptfs";

static unsigned char saved_master_key[KEY_LEN_BYTES];
static char *saved_mount_point;
static int  master_key_saved = 0;
static struct crypt_persist_data *persist_data = NULL;
static char key_fname[PROPERTY_VALUE_MAX] = "";
static char real_blkdev[PROPERTY_VALUE_MAX] = "";
static char file_system[PROPERTY_VALUE_MAX] = "";

void set_partition_data(const char* block_device, const char* key_location, const char* fs)
{
  strcpy(key_fname, key_location);
  strcpy(real_blkdev, block_device);
  strcpy(file_system, fs);
}

static int keymaster_init(keymaster_device_t **keymaster_dev)
{
    int rc;

    const hw_module_t* mod;
    rc = hw_get_module_by_class(KEYSTORE_HARDWARE_MODULE_ID, NULL, &mod);
    if (rc) {
        printf("could not find any keystore module\n");
        goto out;
    }

    rc = keymaster_open(mod, keymaster_dev);
    if (rc) {
        printf("could not open keymaster device in %s (%s)\n",
            KEYSTORE_HARDWARE_MODULE_ID, strerror(-rc));
        goto out;
    }

    return 0;

out:
    *keymaster_dev = NULL;
    return rc;
}

/* Should we use keymaster? */
static int keymaster_check_compatibility()
{
    keymaster_device_t *keymaster_dev = 0;
    int rc = 0;

    if (keymaster_init(&keymaster_dev)) {
        printf("Failed to init keymaster\n");
        rc = -1;
        goto out;
    }

    printf("keymaster version is %d\n", keymaster_dev->common.module->module_api_version);

#if (KEYMASTER_HEADER_VERSION >= 3)
    if (keymaster_dev->common.module->module_api_version
            < KEYMASTER_MODULE_API_VERSION_0_3) {
        rc = 0;
        goto out;
    }

    if (keymaster_dev->flags & KEYMASTER_BLOBS_ARE_STANDALONE) {
        rc = 1;
    }

#endif
out:
    keymaster_close(keymaster_dev);
    return rc;
}

/* Create a new keymaster key and store it in this footer */
static int keymaster_create_key(struct crypt_mnt_ftr *ftr)
{
    uint8_t* key = 0;
    keymaster_device_t *keymaster_dev = 0;

    if (keymaster_init(&keymaster_dev)) {
        printf("Failed to init keymaster\n");
        return -1;
    }

    int rc = 0;

    keymaster_rsa_keygen_params_t params;
    memset(&params, '\0', sizeof(params));
    params.public_exponent = RSA_EXPONENT;
    params.modulus_size = RSA_KEY_SIZE;

    size_t key_size;
    if (keymaster_dev->generate_keypair(keymaster_dev, TYPE_RSA, &params,
                                        &key, &key_size)) {
        printf("Failed to generate keypair\n");
        rc = -1;
        goto out;
    }

    if (key_size > KEYMASTER_BLOB_SIZE) {
        printf("Keymaster key too large for crypto footer\n");
        rc = -1;
        goto out;
    }

    memcpy(ftr->keymaster_blob, key, key_size);
    ftr->keymaster_blob_size = key_size;

out:
    keymaster_close(keymaster_dev);
    free(key);
    return rc;
}

/* This signs the given object using the keymaster key. */
static int keymaster_sign_object(struct crypt_mnt_ftr *ftr,
                                 const unsigned char *object,
                                 const size_t object_size,
                                 unsigned char **signature,
                                 size_t *signature_size)
{
    int rc = 0;
    keymaster_device_t *keymaster_dev = 0;
    if (keymaster_init(&keymaster_dev)) {
        printf("Failed to init keymaster\n");
        return -1;
    }

    /* We currently set the digest type to DIGEST_NONE because it's the
     * only supported value for keymaster. A similar issue exists with
     * PADDING_NONE. Long term both of these should likely change.
     */
    keymaster_rsa_sign_params_t params;
    params.digest_type = DIGEST_NONE;
    params.padding_type = PADDING_NONE;

    unsigned char to_sign[RSA_KEY_SIZE_BYTES];
    size_t to_sign_size = sizeof(to_sign);
    memset(to_sign, 0, RSA_KEY_SIZE_BYTES);

    // To sign a message with RSA, the message must satisfy two
    // constraints:
    //
    // 1. The message, when interpreted as a big-endian numeric value, must
    //    be strictly less than the public modulus of the RSA key.  Note
    //    that because the most significant bit of the public modulus is
    //    guaranteed to be 1 (else it's an (n-1)-bit key, not an n-bit
    //    key), an n-bit message with most significant bit 0 always
    //    satisfies this requirement.
    //
    // 2. The message must have the same length in bits as the public
    //    modulus of the RSA key.  This requirement isn't mathematically
    //    necessary, but is necessary to ensure consistency in
    //    implementations.
    switch (ftr->kdf_type) {
        case KDF_SCRYPT_KEYMASTER_UNPADDED:
            // This is broken: It produces a message which is shorter than
            // the public modulus, failing criterion 2.
            memcpy(to_sign, object, object_size);
            to_sign_size = object_size;
            printf("Signing unpadded object\n");
            break;
        case KDF_SCRYPT_KEYMASTER_BADLY_PADDED:
            // This is broken: Since the value of object is uniformly
            // distributed, it produces a message that is larger than the
            // public modulus with probability 0.25.
            memcpy(to_sign, object, min(RSA_KEY_SIZE_BYTES, object_size));
            printf("Signing end-padded object\n");
            break;
        case KDF_SCRYPT_KEYMASTER:
            // This ensures the most significant byte of the signed message
            // is zero.  We could have zero-padded to the left instead, but
            // this approach is slightly more robust against changes in
            // object size.  However, it's still broken (but not unusably
            // so) because we really should be using a proper RSA padding
            // function, such as OAEP.
            //
            // TODO(paullawrence): When keymaster 0.4 is available, change
            // this to use the padding options it provides.
            memcpy(to_sign + 1, object, min(RSA_KEY_SIZE_BYTES - 1, object_size));
            printf("Signing safely-padded object\n");
            break;
        default:
            printf("Unknown KDF type %d\n", ftr->kdf_type);
            return -1;
    }

    rc = keymaster_dev->sign_data(keymaster_dev,
                                  &params,
                                  ftr->keymaster_blob,
                                  ftr->keymaster_blob_size,
                                  to_sign,
                                  to_sign_size,
                                  signature,
                                  signature_size);

    keymaster_close(keymaster_dev);
    return rc;
}

/* Store password when userdata is successfully decrypted and mounted.
 * Cleared by cryptfs_clear_password
 *
 * To avoid a double prompt at boot, we need to store the CryptKeeper
 * password and pass it to KeyGuard, which uses it to unlock KeyStore.
 * Since the entire framework is torn down and rebuilt after encryption,
 * we have to use a daemon or similar to store the password. Since vold
 * is secured against IPC except from system processes, it seems a reasonable
 * place to store this.
 *
 * password should be cleared once it has been used.
 *
 * password is aged out after password_max_age_seconds seconds.
 */
static char* password = 0;
static int password_expiry_time = 0;
static const int password_max_age_seconds = 60;

static void ioctl_init(struct dm_ioctl *io, size_t dataSize, const char *name, unsigned flags)
{
    memset(io, 0, dataSize);
    io->data_size = dataSize;
    io->data_start = sizeof(struct dm_ioctl);
    io->version[0] = 4;
    io->version[1] = 0;
    io->version[2] = 0;
    io->flags = flags;
    if (name) {
        strncpy(io->name, name, sizeof(io->name));
    }
}

/**
 * Gets the default device scrypt parameters for key derivation time tuning.
 * The parameters should lead to about one second derivation time for the
 * given device.
 */
static void get_device_scrypt_params(struct crypt_mnt_ftr *ftr) {
    const int default_params[] = SCRYPT_DEFAULTS;
    int params[] = SCRYPT_DEFAULTS;
    char paramstr[PROPERTY_VALUE_MAX];
    char *token;
    char *saveptr;
    int i;

    property_get(SCRYPT_PROP, paramstr, "");
    if (paramstr[0] != '\0') {
        /*
         * The token we're looking for should be three integers separated by
         * colons (e.g., "12:8:1"). Scan the property to make sure it matches.
         */
        for (i = 0, token = strtok_r(paramstr, ":", &saveptr);
                token != NULL && i < 3;
                i++, token = strtok_r(NULL, ":", &saveptr)) {
            char *endptr;
            params[i] = strtol(token, &endptr, 10);

            /*
             * Check that there was a valid number and it's 8-bit. If not,
             * break out and the end check will take the default values.
             */
            if ((*token == '\0') || (*endptr != '\0') || params[i] < 0 || params[i] > 255) {
                break;
            }
        }

        /*
         * If there were not enough tokens or a token was malformed (not an
         * integer), it will end up here and the default parameters can be
         * taken.
         */
        if ((i != 3) || (token != NULL)) {
            printf("bad scrypt parameters '%s' should be like '12:8:1'; using defaults", paramstr);
            memcpy(params, default_params, sizeof(params));
        }
    }

    ftr->N_factor = params[0];
    ftr->r_factor = params[1];
    ftr->p_factor = params[2];
}

static unsigned int get_blkdev_size(int fd)
{
  unsigned int nr_sec;

  if ( (ioctl(fd, BLKGETSIZE, &nr_sec)) == -1) {
    nr_sec = 0;
  }

  return nr_sec;
}

static int get_crypt_ftr_info(char **metadata_fname, off64_t *off)
{
  static int cached_data = 0;
  static off64_t cached_off = 0;
  static char cached_metadata_fname[PROPERTY_VALUE_MAX] = "";
  int fd;
  unsigned int nr_sec;
  int rc = -1;

  if (!cached_data) {
    printf("get_crypt_ftr_info crypto key location: '%s'\n", key_fname);
    if (!strcmp(key_fname, KEY_IN_FOOTER)) {
      if ( (fd = open(real_blkdev, O_RDWR)) < 0) {
        printf("Cannot open real block device %s\n", real_blkdev);
        return -1;
      }

      if ((nr_sec = get_blkdev_size(fd))) {
        /* If it's an encrypted Android partition, the last 16 Kbytes contain the
         * encryption info footer and key, and plenty of bytes to spare for future
         * growth.
         */
        strlcpy(cached_metadata_fname, real_blkdev, sizeof(cached_metadata_fname));
        cached_off = ((off64_t)nr_sec * 512) - CRYPT_FOOTER_OFFSET;
        cached_data = 1;
      } else {
        printf("Cannot get size of block device %s\n", real_blkdev);
      }
      close(fd);
    } else {
      strlcpy(cached_metadata_fname, key_fname, sizeof(cached_metadata_fname));
      cached_off = 0;
      cached_data = 1;
    }
  }

  if (cached_data) {
    if (metadata_fname) {
        *metadata_fname = cached_metadata_fname;
    }
    if (off) {
        *off = cached_off;
    }
    rc = 0;
  }

  return rc;
}

static inline int unix_read(int  fd, void*  buff, int  len)
{
    return TEMP_FAILURE_RETRY(read(fd, buff, len));
}

static inline int unix_write(int  fd, const void*  buff, int  len)
{
    return TEMP_FAILURE_RETRY(write(fd, buff, len));
}

static void init_empty_persist_data(struct crypt_persist_data *pdata, int len)
{
    memset(pdata, 0, len);
    pdata->persist_magic = PERSIST_DATA_MAGIC;
    pdata->persist_valid_entries = 0;
}

static int get_crypt_ftr_and_key(struct crypt_mnt_ftr *crypt_ftr)
{
  int fd;
  unsigned int nr_sec, cnt;
  off64_t starting_off;
  int rc = -1;
  char *fname = NULL;
  struct stat statbuf;

  if (get_crypt_ftr_info(&fname, &starting_off)) {
    printf("Unable to get crypt_ftr_info\n");
    return -1;
  }
  if (fname[0] != '/') {
    printf("Unexpected value for crypto key location\n");
    return -1;
  }
  if ( (fd = open(fname, O_RDWR)) < 0) {
    printf("Cannot open footer file %s for get\n", fname);
    return -1;
  }

  /* Make sure it's 16 Kbytes in length */
  fstat(fd, &statbuf);
  if (S_ISREG(statbuf.st_mode) && (statbuf.st_size != 0x4000)) {
    printf("footer file %s is not the expected size!\n", fname);
    goto errout;
  }

  /* Seek to the start of the crypt footer */
  if (lseek64(fd, starting_off, SEEK_SET) == -1) {
    printf("Cannot seek to real block device footer\n");
    goto errout;
  }

  if ( (cnt = read(fd, crypt_ftr, sizeof(struct crypt_mnt_ftr))) != sizeof(struct crypt_mnt_ftr)) {
    printf("Cannot read real block device footer\n");
    goto errout;
  }

  if (crypt_ftr->magic != CRYPT_MNT_MAGIC) {
    printf("Bad magic for real block device %s\n", fname);
    goto errout;
  }

  if (crypt_ftr->major_version != CURRENT_MAJOR_VERSION) {
    printf("Cannot understand major version %d real block device footer; expected %d\n",
          crypt_ftr->major_version, CURRENT_MAJOR_VERSION);
    goto errout;
  }

  if (crypt_ftr->minor_version > CURRENT_MINOR_VERSION) {
    printf("Warning: crypto footer minor version %d, expected <= %d, continuing...\n",
          crypt_ftr->minor_version, CURRENT_MINOR_VERSION);
  }

  /* If this is a verion 1.0 crypt_ftr, make it a 1.1 crypt footer, and update the
   * copy on disk before returning.
   */
  /*if (crypt_ftr->minor_version < CURRENT_MINOR_VERSION) {
    upgrade_crypt_ftr(fd, crypt_ftr, starting_off);
  }*/

  /* Success! */
  rc = 0;

errout:
  close(fd);
  return rc;
}

static int hexdigit (char c)
{
    if (c >= '0' && c <= '9') return c - '0';
    c = tolower(c);
    if (c >= 'a' && c <= 'f') return c - 'a' + 10;
    return -1;
}

static unsigned char* convert_hex_ascii_to_key(const char* master_key_ascii,
                                               unsigned int* out_keysize)
{
    unsigned int i;
    *out_keysize = 0;

    size_t size = strlen (master_key_ascii);
    if (size % 2) {
        printf("Trying to convert ascii string of odd length");
        return NULL;
    }

    unsigned char* master_key = (unsigned char*) malloc(size / 2);
    if (master_key == 0) {
        printf("Cannot allocate");
        return NULL;
    }

    for (i = 0; i < size; i += 2) {
        int high_nibble = hexdigit (master_key_ascii[i]);
        int low_nibble = hexdigit (master_key_ascii[i + 1]);

        if(high_nibble < 0 || low_nibble < 0) {
            printf("Invalid hex string");
            free (master_key);
            return NULL;
        }

        master_key[*out_keysize] = high_nibble * 16 + low_nibble;
        (*out_keysize)++;
    }

    return master_key;
}

/* Convert a binary key of specified length into an ascii hex string equivalent,
 * without the leading 0x and with null termination
 */
static void convert_key_to_hex_ascii(unsigned char *master_key, unsigned int keysize,
                              char *master_key_ascii)
{
  unsigned int i, a;
  unsigned char nibble;

  for (i=0, a=0; i<keysize; i++, a+=2) {
    /* For each byte, write out two ascii hex digits */
    nibble = (master_key[i] >> 4) & 0xf;
    master_key_ascii[a] = nibble + (nibble > 9 ? 0x37 : 0x30);

    nibble = master_key[i] & 0xf;
    master_key_ascii[a+1] = nibble + (nibble > 9 ? 0x37 : 0x30);
  }

  /* Add the null termination */
  master_key_ascii[a] = '\0';

}

static int load_crypto_mapping_table(struct crypt_mnt_ftr *crypt_ftr, unsigned char *master_key,
                                     char *real_blk_name, const char *name, int fd,
                                     char *extra_params)
{
  char buffer[DM_CRYPT_BUF_SIZE];
  struct dm_ioctl *io;
  struct dm_target_spec *tgt;
  char *crypt_params;
  char master_key_ascii[129]; /* Large enough to hold 512 bit key and null */
  int i;

  io = (struct dm_ioctl *) buffer;

  /* Load the mapping table for this device */
  tgt = (struct dm_target_spec *) &buffer[sizeof(struct dm_ioctl)];

  ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
  io->target_count = 1;
  tgt->status = 0;
  tgt->sector_start = 0;
  tgt->length = crypt_ftr->fs_size;
#ifdef CONFIG_HW_DISK_ENCRYPTION
 if(is_hw_disk_encryption((char*)crypt_ftr->crypto_type_name) && is_hw_fde_enabled()) {
   printf("load_crypto_mapping_table using req-crypt\n");
   strlcpy(tgt->target_type, "req-crypt",DM_MAX_TYPE_NAME);
 } else {
   printf("load_crypto_mapping_table using crypt\n");
   strlcpy(tgt->target_type, "crypt", DM_MAX_TYPE_NAME);
 }
#else
  strcpy(tgt->target_type, "crypt");
#endif

  crypt_params = buffer + sizeof(struct dm_ioctl) + sizeof(struct dm_target_spec);
  convert_key_to_hex_ascii(master_key, crypt_ftr->keysize, master_key_ascii);
  sprintf(crypt_params, "%s %s 0 %s 0 %s", crypt_ftr->crypto_type_name,
          master_key_ascii, real_blk_name, extra_params);

  printf("%s: target_type = %s\n", __func__, tgt->target_type);
  printf("%s: real_blk_name = %s, extra_params = %s\n", __func__, real_blk_name, extra_params);

  crypt_params += strlen(crypt_params) + 1;
  crypt_params = (char *) (((unsigned long)crypt_params + 7) & ~8); /* Align to an 8 byte boundary */
  tgt->next = crypt_params - buffer;

  for (i = 0; i < TABLE_LOAD_RETRIES; i++) {
    if (! ioctl(fd, DM_TABLE_LOAD, io)) {
      break;
    }
    usleep(500000);
  }

  if (i == TABLE_LOAD_RETRIES) {
    /* We failed to load the table, return an error */
    return -1;
  } else {
    return i + 1;
  }
}


static int get_dm_crypt_version(int fd, const char *name,  int *version)
{
    char buffer[DM_CRYPT_BUF_SIZE];
    struct dm_ioctl *io;
    struct dm_target_versions *v;
    int flag;
    int i;

    io = (struct dm_ioctl *) buffer;

    ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);

    if (ioctl(fd, DM_LIST_VERSIONS, io)) {
        return -1;
    }

    /* Iterate over the returned versions, looking for name of "crypt".
     * When found, get and return the version.
     */
    v = (struct dm_target_versions *) &buffer[sizeof(struct dm_ioctl)];
    while (v->next) {
#ifdef CONFIG_HW_DISK_ENCRYPTION
        if (is_hw_fde_enabled()) {
            flag = (!strcmp(v->name, "crypt") || !strcmp(v->name, "req-crypt"));
        } else {
            flag = (!strcmp(v->name, "crypt"));
        }
        printf("get_dm_crypt_version flag: %i, name: '%s'\n", flag, v->name);
        if (flag) {
#else
        if (! strcmp(v->name, "crypt")) {
#endif
            /* We found the crypt driver, return the version, and get out */
            version[0] = v->version[0];
            version[1] = v->version[1];
            version[2] = v->version[2];
            return 0;
        }
        v = (struct dm_target_versions *)(((char *)v) + v->next);
    }

    return -1;
}

static int create_crypto_blk_dev(struct crypt_mnt_ftr *crypt_ftr, unsigned char *master_key,
                                    char *real_blk_name, char *crypto_blk_name, const char *name)
{
  char buffer[DM_CRYPT_BUF_SIZE];
  char master_key_ascii[129]; /* Large enough to hold 512 bit key and null */
  char *crypt_params;
  struct dm_ioctl *io;
  struct dm_target_spec *tgt;
  unsigned int minor;
  int fd=0;
  int i;
  int retval = -1;
  int version[3];
  char *extra_params;
  int load_count;
#ifdef CONFIG_HW_DISK_ENCRYPTION
  char encrypted_state[PROPERTY_VALUE_MAX] = {0};
  char progress[PROPERTY_VALUE_MAX] = {0};
#endif

  if ((fd = open("/dev/device-mapper", O_RDWR)) < 0 ) {
    printf("Cannot open device-mapper\n");
    goto errout;
  }

  io = (struct dm_ioctl *) buffer;

  ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
  if (ioctl(fd, DM_DEV_CREATE, io)) {
    printf("Cannot create dm-crypt device\n");
    goto errout;
  }

  /* Get the device status, in particular, the name of it's device file */
  ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
  if (ioctl(fd, DM_DEV_STATUS, io)) {
    printf("Cannot retrieve dm-crypt device status\n");
    goto errout;
  }
  minor = (io->dev & 0xff) | ((io->dev >> 12) & 0xfff00);
  snprintf(crypto_blk_name, MAXPATHLEN, "/dev/block/dm-%u", minor);

#ifdef CONFIG_HW_DISK_ENCRYPTION
  if (is_hw_fde_enabled() && is_hw_disk_encryption((char*) crypt_ftr->crypto_type_name)) {
      /* Set fde_enabled if either FDE completed or in-progress */
      property_get("ro.crypto.state", encrypted_state, ""); /* FDE completed */
      property_get("vold.encrypt_progress", progress, ""); /* FDE in progress */
      if (!strcmp(encrypted_state, "encrypted") || strcmp(progress, "")) {
          extra_params = "fde_enabled";
          printf("create_crypto_blk_dev extra_params set to fde_enabled\n");
      } else {
          extra_params = "fde_disabled";
          printf("create_crypto_blk_dev extra_params set to fde_disabled\n");
      }
  } else {
      extra_params = "";
      printf("create_crypto_blk_dev extra_params set to empty string\n");
      if (!get_dm_crypt_version(fd, name, version)) {
          /* Support for allow_discards was added in version 1.11.0 */
          if ((version[0] >= 2) ||
              ((version[0] == 1) && (version[1] >= 11))) {
              extra_params = "1 allow_discards";
              printf("Enabling support for allow_discards in dmcrypt.\n");
          }
      }
  }
#else
  extra_params = "";
  if (! get_dm_crypt_version(fd, name, version)) {
      /* Support for allow_discards was added in version 1.11.0 */
      if ((version[0] >= 2) ||
          ((version[0] == 1) && (version[1] >= 11))) {
          extra_params = "1 allow_discards";
          printf("Enabling support for allow_discards in dmcrypt.\n");
      }
  }
#endif

  load_count = load_crypto_mapping_table(crypt_ftr, master_key, real_blk_name, name,
                                         fd, extra_params);
  if (load_count < 0) {
      printf("Cannot load dm-crypt mapping table.\n");
      goto errout;
  } else if (load_count > 1) {
      printf("Took %d tries to load dmcrypt table.\n", load_count);
  }

  /* Resume this device to activate it */
  ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);

  if (ioctl(fd, DM_DEV_SUSPEND, io)) {
    printf("Cannot resume the dm-crypt device\n");
    goto errout;
  }

  /* We made it here with no errors.  Woot! */
  retval = 0;

errout:
  close(fd);   /* If fd is <0 from a failed open call, it's safe to just ignore the close error */

  return retval;
}

int delete_crypto_blk_dev(char *name)
{
  int fd;
  char buffer[DM_CRYPT_BUF_SIZE];
  struct dm_ioctl *io;
  int retval = -1;

  if ((fd = open("/dev/device-mapper", O_RDWR)) < 0 ) {
    printf("Cannot open device-mapper\n");
    goto errout;
  }

  io = (struct dm_ioctl *) buffer;

  ioctl_init(io, DM_CRYPT_BUF_SIZE, name, 0);
  if (ioctl(fd, DM_DEV_REMOVE, io)) {
    printf("Cannot remove dm-crypt device\n");
    goto errout;
  }

  /* We made it here with no errors.  Woot! */
  retval = 0;

errout:
  close(fd);    /* If fd is <0 from a failed open call, it's safe to just ignore the close error */

  return retval;

}

static int pbkdf2(const char *passwd, const unsigned char *salt,
                  unsigned char *ikey, void *params UNUSED)
{
    printf("Using pbkdf2 for cryptfs KDF");

    /* Turn the password into a key and IV that can decrypt the master key */
    unsigned int keysize;
    char* master_key = (char*)convert_hex_ascii_to_key(passwd, &keysize);
    if (!master_key) return -1;
    PKCS5_PBKDF2_HMAC_SHA1(master_key, keysize, salt, SALT_LEN,
                           HASH_COUNT, KEY_LEN_BYTES+IV_LEN_BYTES, ikey);

    memset(master_key, 0, keysize);
    free (master_key);
    return 0;
}

static int scrypt(const char *passwd, const unsigned char *salt,
                  unsigned char *ikey, void *params)
{
    printf("Using scrypt for cryptfs KDF\n");

    struct crypt_mnt_ftr *ftr = (struct crypt_mnt_ftr *) params;

    int N = 1 << ftr->N_factor;
    int r = 1 << ftr->r_factor;
    int p = 1 << ftr->p_factor;

    /* Turn the password into a key and IV that can decrypt the master key */
    unsigned int keysize;
    unsigned char* master_key = convert_hex_ascii_to_key(passwd, &keysize);
    if (!master_key) return -1;
    crypto_scrypt(master_key, keysize, salt, SALT_LEN, N, r, p, ikey,
            KEY_LEN_BYTES + IV_LEN_BYTES);

    memset(master_key, 0, keysize);
    free (master_key);
    return 0;
}

static int scrypt_keymaster(const char *passwd, const unsigned char *salt,
                            unsigned char *ikey, void *params)
{
    printf("Using scrypt with keymaster for cryptfs KDF\n");

    int rc;
    unsigned int key_size;
    size_t signature_size;
    unsigned char* signature;
    struct crypt_mnt_ftr *ftr = (struct crypt_mnt_ftr *) params;

    int N = 1 << ftr->N_factor;
    int r = 1 << ftr->r_factor;
    int p = 1 << ftr->p_factor;

    unsigned char* master_key = convert_hex_ascii_to_key(passwd, &key_size);
    if (!master_key) {
        printf("Failed to convert passwd from hex\n");
        return -1;
    }

    rc = crypto_scrypt(master_key, key_size, salt, SALT_LEN,
                       N, r, p, ikey, KEY_LEN_BYTES + IV_LEN_BYTES);
    memset(master_key, 0, key_size);
    free(master_key);

    if (rc) {
        printf("scrypt failed\n");
        return -1;
    }

    if (keymaster_sign_object(ftr, ikey, KEY_LEN_BYTES + IV_LEN_BYTES,
                              &signature, &signature_size)) {
        printf("Signing failed\n");
        return -1;
    }

    rc = crypto_scrypt(signature, signature_size, salt, SALT_LEN,
                       N, r, p, ikey, KEY_LEN_BYTES + IV_LEN_BYTES);
    free(signature);

    if (rc) {
        printf("scrypt failed\n");
        return -1;
    }

    return 0;
}

static int encrypt_master_key(const char *passwd, const unsigned char *salt,
                              const unsigned char *decrypted_master_key,
                              unsigned char *encrypted_master_key,
                              struct crypt_mnt_ftr *crypt_ftr)
{
    unsigned char ikey[32+32] = { 0 }; /* Big enough to hold a 256 bit key and 256 bit IV */
    EVP_CIPHER_CTX e_ctx;
    int encrypted_len, final_len;
    int rc = 0;

    /* Turn the password into an intermediate key and IV that can decrypt the master key */
    get_device_scrypt_params(crypt_ftr);

    switch (crypt_ftr->kdf_type) {
    case KDF_SCRYPT_KEYMASTER_UNPADDED:
    case KDF_SCRYPT_KEYMASTER_BADLY_PADDED:
    case KDF_SCRYPT_KEYMASTER:
        if (keymaster_create_key(crypt_ftr)) {
            printf("keymaster_create_key failed");
            return -1;
        }

        if (scrypt_keymaster(passwd, salt, ikey, crypt_ftr)) {
            printf("scrypt failed");
            return -1;
        }
        break;

    case KDF_SCRYPT:
        if (scrypt(passwd, salt, ikey, crypt_ftr)) {
            printf("scrypt failed");
            return -1;
        }
        break;

    default:
        printf("Invalid kdf_type");
        return -1;
    }

    /* Initialize the decryption engine */
    if (! EVP_EncryptInit(&e_ctx, EVP_aes_128_cbc(), ikey, ikey+KEY_LEN_BYTES)) {
        printf("EVP_EncryptInit failed\n");
        return -1;
    }
    EVP_CIPHER_CTX_set_padding(&e_ctx, 0); /* Turn off padding as our data is block aligned */

    /* Encrypt the master key */
    if (! EVP_EncryptUpdate(&e_ctx, encrypted_master_key, &encrypted_len,
                              decrypted_master_key, KEY_LEN_BYTES)) {
        printf("EVP_EncryptUpdate failed\n");
        return -1;
    }
    if (! EVP_EncryptFinal(&e_ctx, encrypted_master_key + encrypted_len, &final_len)) {
        printf("EVP_EncryptFinal failed\n");
        return -1;
    }

    if (encrypted_len + final_len != KEY_LEN_BYTES) {
        printf("EVP_Encryption length check failed with %d, %d bytes\n", encrypted_len, final_len);
        return -1;
    }

    /* Store the scrypt of the intermediate key, so we can validate if it's a
       password error or mount error when things go wrong.
       Note there's no need to check for errors, since if this is incorrect, we
       simply won't wipe userdata, which is the correct default behavior
    */
    int N = 1 << crypt_ftr->N_factor;
    int r = 1 << crypt_ftr->r_factor;
    int p = 1 << crypt_ftr->p_factor;

    rc = crypto_scrypt(ikey, KEY_LEN_BYTES,
                       crypt_ftr->salt, sizeof(crypt_ftr->salt), N, r, p,
                       crypt_ftr->scrypted_intermediate_key,
                       sizeof(crypt_ftr->scrypted_intermediate_key));

    if (rc) {
      printf("encrypt_master_key: crypto_scrypt failed");
    }

    return 0;
}

static int decrypt_master_key_aux(char *passwd, unsigned char *salt,
                                  unsigned char *encrypted_master_key,
                                  unsigned char *decrypted_master_key,
                                  kdf_func kdf, void *kdf_params,
                                  unsigned char** intermediate_key,
                                  size_t* intermediate_key_size)
{
  unsigned char ikey[32+32] = { 0 }; /* Big enough to hold a 256 bit key and 256 bit IV */
  EVP_CIPHER_CTX d_ctx;
  int decrypted_len, final_len;

  /* Turn the password into an intermediate key and IV that can decrypt the
     master key */
  if (kdf(passwd, salt, ikey, kdf_params)) {
    printf("kdf failed");
    return -1;
  }

  /* Initialize the decryption engine */
  if (! EVP_DecryptInit(&d_ctx, EVP_aes_128_cbc(), ikey, ikey+KEY_LEN_BYTES)) {
    return -1;
  }
  EVP_CIPHER_CTX_set_padding(&d_ctx, 0); /* Turn off padding as our data is block aligned */
  /* Decrypt the master key */
  if (! EVP_DecryptUpdate(&d_ctx, decrypted_master_key, &decrypted_len,
                            encrypted_master_key, KEY_LEN_BYTES)) {
    return -1;
  }
  if (! EVP_DecryptFinal(&d_ctx, decrypted_master_key + decrypted_len, &final_len)) {
    return -1;
  }

  if (decrypted_len + final_len != KEY_LEN_BYTES) {
    return -1;
  }

  /* Copy intermediate key if needed by params */
  if (intermediate_key && intermediate_key_size) {
    *intermediate_key = (unsigned char*) malloc(KEY_LEN_BYTES);
    if (intermediate_key) {
      memcpy(*intermediate_key, ikey, KEY_LEN_BYTES);
      *intermediate_key_size = KEY_LEN_BYTES;
    }
  }

  return 0;
}

static void get_kdf_func(struct crypt_mnt_ftr *ftr, kdf_func *kdf, void** kdf_params)
{
    if (ftr->kdf_type == KDF_SCRYPT_KEYMASTER_UNPADDED ||
        ftr->kdf_type == KDF_SCRYPT_KEYMASTER_BADLY_PADDED ||
        ftr->kdf_type == KDF_SCRYPT_KEYMASTER) {
        *kdf = scrypt_keymaster;
        *kdf_params = ftr;
    } else if (ftr->kdf_type == KDF_SCRYPT) {
        *kdf = scrypt;
        *kdf_params = ftr;
    } else {
        *kdf = pbkdf2;
        *kdf_params = NULL;
    }
}

static int decrypt_master_key(char *passwd, unsigned char *decrypted_master_key,
                              struct crypt_mnt_ftr *crypt_ftr,
                              unsigned char** intermediate_key,
                              size_t* intermediate_key_size)
{
    kdf_func kdf;
    void *kdf_params;
    int ret;

    get_kdf_func(crypt_ftr, &kdf, &kdf_params);
    ret = decrypt_master_key_aux(passwd, crypt_ftr->salt, crypt_ftr->master_key,
                                 decrypted_master_key, kdf, kdf_params,
                                 intermediate_key, intermediate_key_size);
    if (ret != 0) {
        printf("failure decrypting master key");
    }

    return ret;
}

static int test_mount_encrypted_fs(struct crypt_mnt_ftr* crypt_ftr,
                                   char *passwd, char *mount_point, char *label)
{
  /* Allocate enough space for a 256 bit key, but we may use less */
  unsigned char decrypted_master_key[32];
  char crypto_blkdev[MAXPATHLEN];
  char tmp_mount_point[64];
  unsigned int orig_failed_decrypt_count;
  int rc = 0;
  kdf_func kdf;
  void *kdf_params;
  int use_keymaster = 0;
  int upgrade = 0;
  unsigned char* intermediate_key = 0;
  size_t intermediate_key_size = 0;

  printf("crypt_ftr->fs_size = %lld\n", crypt_ftr->fs_size);
  orig_failed_decrypt_count = crypt_ftr->failed_decrypt_count;

  if (! (crypt_ftr->flags & CRYPT_MNT_KEY_UNENCRYPTED) ) {
    if (decrypt_master_key(passwd, decrypted_master_key, crypt_ftr,
                           &intermediate_key, &intermediate_key_size)) {
      printf("Failed to decrypt master key\n");
      rc = -1;
      goto errout;
    }
  }

#ifdef CONFIG_HW_DISK_ENCRYPTION
  if (is_hw_fde_enabled()) {
    if(is_hw_disk_encryption((char*) crypt_ftr->crypto_type_name)) {
      if (!set_hw_device_encryption_key(passwd, (char*) crypt_ftr->crypto_type_name)) {
        rc = -1;
        printf("Failed to set_hw_device_encryption_key\n");
        goto errout;
      }
    }
  }
#endif

  // Create crypto block device - all (non fatal) code paths
  // need it
  if (create_crypto_blk_dev(crypt_ftr, decrypted_master_key,
                            real_blkdev, crypto_blkdev, label)) {
     printf("Error creating decrypted block device\n");
     rc = -1;
     goto errout;
  }

  /* Work out if the problem is the password or the data */
  unsigned char scrypted_intermediate_key[sizeof(crypt_ftr->
                                                 scrypted_intermediate_key)];
  int N = 1 << crypt_ftr->N_factor;
  int r = 1 << crypt_ftr->r_factor;
  int p = 1 << crypt_ftr->p_factor;

  rc = crypto_scrypt(intermediate_key, intermediate_key_size,
                     crypt_ftr->salt, sizeof(crypt_ftr->salt),
                     N, r, p, scrypted_intermediate_key,
                     sizeof(scrypted_intermediate_key));

  // Does the key match the crypto footer?
  if (rc == 0 && memcmp(scrypted_intermediate_key,
                        crypt_ftr->scrypted_intermediate_key,
                        sizeof(scrypted_intermediate_key)) == 0) {
    printf("Password matches\n");
    rc = 0;
  } else {
    /* Try mounting the file system anyway, just in case the problem's with
     * the footer, not the key. */
    sprintf(tmp_mount_point, "%s/tmp_mnt", mount_point);
    mkdir(tmp_mount_point, 0755);
    if (mount(crypto_blkdev, tmp_mount_point, file_system, NULL, NULL) != 0) {
      printf("Error temp mounting decrypted block device '%s'\n", crypto_blkdev);
      delete_crypto_blk_dev(label);

      rc = ++crypt_ftr->failed_decrypt_count;
      //put_crypt_ftr_and_key(crypt_ftr); // Do not penalize for attempting to decrypt in recovery
    } else {
      /* Success! */
      printf("Password did not match but decrypted drive mounted - continue\n");
      umount(tmp_mount_point);
      rc = 0;
    }
  }

  if (rc == 0) {
    /*crypt_ftr->failed_decrypt_count = 0;
    if (orig_failed_decrypt_count != 0) {
      put_crypt_ftr_and_key(crypt_ftr);
    }*/

    /* Save the name of the crypto block device
     * so we can mount it when restarting the framework. */
    property_set("ro.crypto.fs_crypto_blkdev", crypto_blkdev);

    /* Also save a the master key so we can reencrypted the key
     * the key when we want to change the password on it. */
    /*memcpy(saved_master_key, decrypted_master_key, KEY_LEN_BYTES);
    saved_mount_point = strdup(mount_point);
    master_key_saved = 1;
    printf("%s(): Master key saved\n", __FUNCTION__);*/
    rc = 0;

    // Upgrade if we're not using the latest KDF.
    /*use_keymaster = keymaster_check_compatibility();
    if (crypt_ftr->kdf_type == KDF_SCRYPT_KEYMASTER) {
        // Don't allow downgrade
    } else if (use_keymaster == 1 && crypt_ftr->kdf_type != KDF_SCRYPT_KEYMASTER) {
        crypt_ftr->kdf_type = KDF_SCRYPT_KEYMASTER;
        upgrade = 1;
    } else if (use_keymaster == 0 && crypt_ftr->kdf_type != KDF_SCRYPT) {
        crypt_ftr->kdf_type = KDF_SCRYPT;
        upgrade = 1;
    }

    if (upgrade) {
        rc = encrypt_master_key(passwd, crypt_ftr->salt, saved_master_key,
                                crypt_ftr->master_key, crypt_ftr);
        if (!rc) {
            rc = put_crypt_ftr_and_key(crypt_ftr);
        }
        printf("Key Derivation Function upgrade: rc=%d\n", rc);

        // Do not fail even if upgrade failed - machine is bootable
        // Note that if this code is ever hit, there is a *serious* problem
        // since KDFs should never fail. You *must* fix the kdf before
        // proceeding!
        if (rc) {
          printf("Upgrade failed with error %d,"
                " but continuing with previous state\n",
                rc);
          rc = 0;
        }
    }*/
  }

 errout:
  if (intermediate_key) {
    memset(intermediate_key, 0, intermediate_key_size);
    free(intermediate_key);
  }
  return rc;
}

/* Called by vold when it wants to undo the crypto mapping of a volume it
 * manages.  This is usually in response to a factory reset, when we want
 * to undo the crypto mapping so the volume is formatted in the clear.
 */
int cryptfs_revert_volume(const char *label)
{
    return delete_crypto_blk_dev((char *)label);
}

int check_unmounted_and_get_ftr(struct crypt_mnt_ftr* crypt_ftr)
{
    char encrypted_state[PROPERTY_VALUE_MAX];
    property_get("ro.crypto.state", encrypted_state, "");
    if ( master_key_saved || strcmp(encrypted_state, "encrypted") ) {
        printf("encrypted fs already validated or not running with encryption,"
              " aborting\n");
        //return -1;
    }

    if (get_crypt_ftr_and_key(crypt_ftr)) {
        printf("Error getting crypt footer and key\n");
        return -1;
    }

    return 0;
}

/*
 * TODO - transition patterns to new format in calling code
 *        and remove this vile hack, and the use of hex in
 *        the password passing code.
 *
 * Patterns are passed in zero based (i.e. the top left dot
 * is represented by zero, the top middle one etc), but we want
 * to store them '1' based.
 * This is to allow us to migrate the calling code to use this
 * convention. It also solves a nasty problem whereby scrypt ignores
 * trailing zeros, so patterns ending at the top left could be
 * truncated, and similarly, you could add the top left to any
 * pattern and still match.
 * adjust_passwd is a hack function that returns the alternate representation
 * if the password appears to be a pattern (hex numbers all less than 09)
 * If it succeeds we need to try both, and in particular try the alternate
 * first. If the original matches, then we need to update the footer
 * with the alternate.
 * All code that accepts passwords must adjust them first. Since
 * cryptfs_check_passwd is always the first function called after a migration
 * (and indeed on any boot) we only need to do the double try in this
 * function.
 */
char* adjust_passwd(const char* passwd)
{
    size_t index, length;

    if (!passwd) {
        return 0;
    }

    // Check even length. Hex encoded passwords are always
    // an even length, since each character encodes to two characters.
    length = strlen(passwd);
    if (length % 2) {
        printf("Password not correctly hex encoded.\n");
        return 0;
    }

    // Check password is old-style pattern - a collection of hex
    // encoded bytes less than 9 (00 through 08)
    for (index = 0; index < length; index +=2) {
        if (passwd[index] != '0'
            || passwd[index + 1] < '0' || passwd[index + 1] > '8') {
            return 0;
        }
    }

    // Allocate room for adjusted passwd and null terminate
    char* adjusted = malloc(length + 1);
    adjusted[length] = 0;

    // Add 0x31 ('1') to each character
    for (index = 0; index < length; index += 2) {
        // output is 31 through 39 so set first byte to three, second to src + 1
        adjusted[index] = '3';
        adjusted[index + 1] = passwd[index + 1] + 1;
    }

    return adjusted;
}

/*
 * Passwords in L get passed from Android to cryptfs in hex, so a '1'
 * gets converted to '31' where 31 is 0x31 which is the ascii character
 * code in hex of the character '1'. This function will convert the
 * regular character codes to their hexadecimal representation to make
 * decrypt work properly with Android 5.0 lollipop decryption.
 */
char* hexadj_passwd(const char* passwd, int has_hw_crypto)
{
    size_t index, length;
    const char* ptr = passwd;

    if (!passwd) {
        return 0;
    }

    length = strlen(passwd);

    // Allocate room for hex passwd and null terminate
    char* hex = malloc((length * 2) + 1);
    hex[length * 2] = 0;

    // Convert to hex
    for (index = 0; index < length; index++) {
        sprintf(hex + (index * 2), "%02X", *ptr);
        ptr++;
    }
#ifdef CONFIG_HW_DISK_ENCRYPTION
    if (has_hw_crypto) {
        printf("hexadj_passwd converting to lower case for hardware disk crypto.\n");
        length *= 2;
        for (index = 0; index < length; index++) {
            hex[index] = tolower(hex[index]);
        }
    }
#endif
    return hex;
}

int cryptfs_check_footer()
{
    int rc = -1;
    struct crypt_mnt_ftr crypt_ftr;

    rc = get_crypt_ftr_and_key(&crypt_ftr);

    return rc;
}

int cryptfs_check_passwd(char *passwd)
{
    struct crypt_mnt_ftr crypt_ftr;
    int rc;
    int has_hw_crypto = 0;

    rc = check_unmounted_and_get_ftr(&crypt_ftr);
    if (rc)
        return rc;

#ifdef CONFIG_HW_DISK_ENCRYPTION
    printf("CONFIG_HW_DISK_ENCRYPTION present\n");
    if (is_hw_fde_enabled() && is_hw_disk_encryption((char*) crypt_ftr.crypto_type_name))
        has_hw_crypto = 1;
#endif

    //if (passwd) printf("passwd: '%s'\n", passwd);
    char* adjusted_passwd;
    if (!has_hw_crypto)
        adjusted_passwd = adjust_passwd(passwd);
    //if (adjusted_passwd) printf("adjusted_passwd: '%s'\n", adjusted_passwd);
    char* hex_passwd = hexadj_passwd(passwd, has_hw_crypto);
    //if (hex_passwd) printf("hex_passwd: '%s'\n", hex_passwd);
    printf("has_hw_crypto is %i\n", has_hw_crypto);
    if (!has_hw_crypto && adjusted_passwd) {
        int failed_decrypt_count = crypt_ftr.failed_decrypt_count;
        //printf("trying adjusted password '%s'\n", adjusted_passwd);
        rc = test_mount_encrypted_fs(&crypt_ftr, hex_passwd,
                                     DATA_MNT_POINT, "userdata");

        // Maybe the original one still works?
        if (rc) {
            // Don't double count this failure
            //printf("trying passwd '%s'\n", passwd);
            crypt_ftr.failed_decrypt_count = failed_decrypt_count;
            rc = test_mount_encrypted_fs(&crypt_ftr, passwd,
                                         DATA_MNT_POINT, "userdata");
            if (!rc) {
                // cryptfs_changepw also adjusts so pass original
                // Note that adjust_passwd only recognises patterns
                // so we can safely use CRYPT_TYPE_PATTERN
                printf("TWRP NOT Updating pattern to new format");
                //cryptfs_changepw(CRYPT_TYPE_PATTERN, passwd);
            } else if (hex_passwd) {
                //printf("trying hex_passwd '%s'\n", hex_passwd);
                rc = test_mount_encrypted_fs(&crypt_ftr, hex_passwd,
                                         DATA_MNT_POINT, "userdata");
            }
        }
        free(adjusted_passwd);
    } else {
        if (hex_passwd) {
            //printf("2trying hex_passwd '%s'\n", hex_passwd);
            rc = test_mount_encrypted_fs(&crypt_ftr, hex_passwd,
                                         DATA_MNT_POINT, "userdata");
        } else {
            rc = 1;
        }
        if (rc && passwd) {
            //printf("2trying passwd '%s'\n", passwd);
            rc = test_mount_encrypted_fs(&crypt_ftr, passwd,
                                     DATA_MNT_POINT, "userdata");
        }
    }

    if (hex_passwd)
        free(hex_passwd);

    /*if (rc == 0 && crypt_ftr.crypt_type != CRYPT_TYPE_DEFAULT) {
        printf("cryptfs_check_passwd update expiry time?\n");
        cryptfs_clear_password();
        password = strdup(passwd);
        struct timespec now;
        clock_gettime(CLOCK_BOOTTIME, &now);
        password_expiry_time = now.tv_sec + password_max_age_seconds;
    }*/

    return rc;
}

int cryptfs_verify_passwd(char *passwd)
{
    struct crypt_mnt_ftr crypt_ftr;
    /* Allocate enough space for a 256 bit key, but we may use less */
    unsigned char decrypted_master_key[32];
    char encrypted_state[PROPERTY_VALUE_MAX];
    int rc;

    property_get("ro.crypto.state", encrypted_state, "");
    if (strcmp(encrypted_state, "encrypted") ) {
        printf("device not encrypted, aborting");
        return -2;
    }

    if (!master_key_saved) {
        printf("encrypted fs not yet mounted, aborting");
        return -1;
    }

    if (!saved_mount_point) {
        printf("encrypted fs failed to save mount point, aborting");
        return -1;
    }

    if (get_crypt_ftr_and_key(&crypt_ftr)) {
        printf("Error getting crypt footer and key\n");
        return -1;
    }

    if (crypt_ftr.flags & CRYPT_MNT_KEY_UNENCRYPTED) {
        /* If the device has no password, then just say the password is valid */
        rc = 0;
    } else {
        char* adjusted_passwd = adjust_passwd(passwd);
        if (adjusted_passwd) {
            passwd = adjusted_passwd;
        }

        decrypt_master_key(passwd, decrypted_master_key, &crypt_ftr, 0, 0);
        if (!memcmp(decrypted_master_key, saved_master_key, crypt_ftr.keysize)) {
            /* They match, the password is correct */
            rc = 0;
        } else {
            /* If incorrect, sleep for a bit to prevent dictionary attacks */
            sleep(1);
            rc = 1;
        }

        free(adjusted_passwd);
    }

    return rc;
}

/* Initialize a crypt_mnt_ftr structure.  The keysize is
 * defaulted to 16 bytes, and the filesystem size to 0.
 * Presumably, at a minimum, the caller will update the
 * filesystem size and crypto_type_name after calling this function.
 */
static int cryptfs_init_crypt_mnt_ftr(struct crypt_mnt_ftr *ftr)
{
    off64_t off;

    memset(ftr, 0, sizeof(struct crypt_mnt_ftr));
    ftr->magic = CRYPT_MNT_MAGIC;
    ftr->major_version = CURRENT_MAJOR_VERSION;
    ftr->minor_version = CURRENT_MINOR_VERSION;
    ftr->ftr_size = sizeof(struct crypt_mnt_ftr);
    ftr->keysize = KEY_LEN_BYTES;

    switch (keymaster_check_compatibility()) {
    case 1:
        ftr->kdf_type = KDF_SCRYPT_KEYMASTER;
        break;

    case 0:
        ftr->kdf_type = KDF_SCRYPT;
        break;

    default:
        printf("keymaster_check_compatibility failed");
        return -1;
    }

    get_device_scrypt_params(ftr);

    ftr->persist_data_size = CRYPT_PERSIST_DATA_SIZE;
    if (get_crypt_ftr_info(NULL, &off) == 0) {
        ftr->persist_data_offset[0] = off + CRYPT_FOOTER_TO_PERSIST_OFFSET;
        ftr->persist_data_offset[1] = off + CRYPT_FOOTER_TO_PERSIST_OFFSET +
                                    ftr->persist_data_size;
    }

    return 0;
}

/* Returns type of the password, default, pattern, pin or password.
 */
int cryptfs_get_password_type(void)
{
    struct crypt_mnt_ftr crypt_ftr;

    if (get_crypt_ftr_and_key(&crypt_ftr)) {
        printf("Error getting crypt footer and key\n");
        return -1;
    }

    if (crypt_ftr.flags & CRYPT_INCONSISTENT_STATE) {
        return -1;
    }

    return crypt_ftr.crypt_type;
}