summaryrefslogtreecommitdiff
path: root/source4/heimdal/lib/hcrypto/des.c
blob: 8be9d649cd3524d9b6a155bc60b563dc135801c9 (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
/*
 * Copyright (c) 2005 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/**
 * @page page_des DES - Data Encryption Standard crypto interface
 *
 * See the library functions here: @ref hcrypto_des
 *
 * DES was created by IBM, modififed by NSA and then adopted by NBS
 * (now NIST) and published ad FIPS PUB 46 (updated by FIPS 46-1).
 *
 * Since the 19th May 2005 DES was withdrawn by NIST and should no
 * longer be used. See @ref page_evp for replacement encryption
 * algorithms and interfaces.
 *
 * Read more the iteresting history of DES on Wikipedia
 * http://www.wikipedia.org/wiki/Data_Encryption_Standard .
 *
 * @section des_keygen DES key generation
 *
 * To generate a DES key safely you have to use the code-snippet
 * below. This is because the DES_random_key() can fail with an
 * abort() in case of and failure to start the random generator.
 *
 * There is a replacement function DES_new_random_key(), however that
 * function does not exists in OpenSSL.
 *
 * @code
 * DES_cblock key;
 * do {
 *     if (RAND_rand(&key, sizeof(key)) != 1)
 *          goto failure;
 *     DES_set_odd_parity(key);
 * } while (DES_is_weak_key(&key));
 * @endcode
 *
 * @section des_impl DES implementation history
 *
 * There was no complete BSD licensed, fast, GPL compatible
 * implementation of DES, so Love wrote the part that was missing,
 * fast key schedule setup and adapted the interface to the orignal
 * libdes.
 *
 * The document that got me started for real was "Efficient
 * Implementation of the Data Encryption Standard" by Dag Arne Osvik.
 * I never got to the PC1 transformation was working, instead I used
 * table-lookup was used for all key schedule setup. The document was
 * very useful since it de-mystified other implementations for me.
 *
 * The core DES function (SBOX + P transformation) is from Richard
 * Outerbridge public domain DES implementation. My sanity is saved
 * thanks to his work. Thank you Richard.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
RCSID("$Id$");
#endif

#define HC_DEPRECATED

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <krb5-types.h>
#include <assert.h>

#include "des.h"
#include "ui.h"

static void desx(uint32_t [2], DES_key_schedule *, int);
static void IP(uint32_t [2]);
static void FP(uint32_t [2]);

#include "des-tables.h"

#define ROTATE_LEFT28(x,one)				\
    if (one) {						\
	x = ( ((x)<<(1)) & 0xffffffe) | ((x) >> 27);	\
    } else {						\
	x = ( ((x)<<(2)) & 0xffffffc) | ((x) >> 26);	\
    }

/**
 * Set the parity of the key block, used to generate a des key from a
 * random key. See @ref des_keygen.
 *
 * @param key key to fixup the parity for.
 * @ingroup hcrypto_des
 */

void
DES_set_odd_parity(DES_cblock *key)
{
    unsigned int i;
    for (i = 0; i < DES_CBLOCK_LEN; i++)
	(*key)[i] = odd_parity[(*key)[i]];
}

/**
 * Check if the key have correct parity.
 *
 * @param key key to check the parity.
 * @return 1 on success, 0 on failure.
 * @ingroup hcrypto_des
 */

int HC_DEPRECATED
DES_check_key_parity(DES_cblock *key)
{
    unsigned int i;

    for (i = 0; i <  DES_CBLOCK_LEN; i++)
	if ((*key)[i] != odd_parity[(*key)[i]])
	    return 0;
    return 1;
}

/*
 *
 */

/* FIPS 74 */
static DES_cblock weak_keys[] = {
    {0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01}, /* weak keys */
    {0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE},
    {0x1F,0x1F,0x1F,0x1F,0x0E,0x0E,0x0E,0x0E},
    {0xE0,0xE0,0xE0,0xE0,0xF1,0xF1,0xF1,0xF1},
    {0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE}, /* semi-weak keys */
    {0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01},
    {0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1},
    {0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E},
    {0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1},
    {0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01},
    {0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE},
    {0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E},
    {0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E},
    {0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01},
    {0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE},
    {0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}
};

/**
 * Checks if the key is any of the weaks keys that makes DES attacks
 * trival.
 *
 * @param key key to check.
 *
 * @return 1 if the key is weak, 0 otherwise.
 * @ingroup hcrypto_des
 */

int
DES_is_weak_key(DES_cblock *key)
{
    int i;

    for (i = 0; i < sizeof(weak_keys)/sizeof(weak_keys[0]); i++) {
	if (memcmp(weak_keys[i], key, DES_CBLOCK_LEN) == 0)
	    return 1;
    }
    return 0;
}

/**
 * Setup a des key schedule from a key. Deprecated function, use
 * DES_set_key_unchecked() or DES_set_key_checked() instead.
 *
 * @param key a key to initialize the key schedule with.
 * @param ks a key schedule to initialize.
 *
 * @return 0 on success
 * @ingroup hcrypto_des
 */

int HC_DEPRECATED
DES_set_key(DES_cblock *key, DES_key_schedule *ks)
{
    return DES_set_key_checked(key, ks);
}

/**
 * Setup a des key schedule from a key. The key is no longer needed
 * after this transaction and can cleared.
 *
 * Does NOT check that the key is weak for or have wrong parity.
 *
 * @param key a key to initialize the key schedule with.
 * @param ks a key schedule to initialize.
 *
 * @return 0 on success
 * @ingroup hcrypto_des
 */

int
DES_set_key_unchecked(DES_cblock *key, DES_key_schedule *ks)
{
    uint32_t t1, t2;
    uint32_t c, d;
    int shifts[16] = { 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1 };
    uint32_t *k = &ks->ks[0];
    int i;

    t1 = (*key)[0] << 24 | (*key)[1] << 16 | (*key)[2] << 8 | (*key)[3];
    t2 = (*key)[4] << 24 | (*key)[5] << 16 | (*key)[6] << 8 | (*key)[7];

    c =   (pc1_c_3[(t1 >> (5            )) & 0x7] << 3)
	| (pc1_c_3[(t1 >> (5 + 8        )) & 0x7] << 2)
	| (pc1_c_3[(t1 >> (5 + 8 + 8    )) & 0x7] << 1)
	| (pc1_c_3[(t1 >> (5 + 8 + 8 + 8)) & 0x7] << 0)
	| (pc1_c_4[(t2 >> (4            )) & 0xf] << 3)
	| (pc1_c_4[(t2 >> (4 + 8        )) & 0xf] << 2)
	| (pc1_c_4[(t2 >> (4 + 8 + 8    )) & 0xf] << 1)
	| (pc1_c_4[(t2 >> (4 + 8 + 8 + 8)) & 0xf] << 0);

    
    d =   (pc1_d_3[(t2 >> (1            )) & 0x7] << 3)
	| (pc1_d_3[(t2 >> (1 + 8        )) & 0x7] << 2)
	| (pc1_d_3[(t2 >> (1 + 8 + 8    )) & 0x7] << 1)
	| (pc1_d_3[(t2 >> (1 + 8 + 8 + 8)) & 0x7] << 0)
	| (pc1_d_4[(t1 >> (1            )) & 0xf] << 3)
	| (pc1_d_4[(t1 >> (1 + 8        )) & 0xf] << 2)
	| (pc1_d_4[(t1 >> (1 + 8 + 8    )) & 0xf] << 1)
	| (pc1_d_4[(t1 >> (1 + 8 + 8 + 8)) & 0xf] << 0);

    for (i = 0; i < 16; i++) {
	uint32_t kc, kd;
	
	ROTATE_LEFT28(c, shifts[i]);
	ROTATE_LEFT28(d, shifts[i]);
	
	kc = pc2_c_1[(c >> 22) & 0x3f] |
	    pc2_c_2[((c >> 16) & 0x30) | ((c >> 15) & 0xf)] |
	    pc2_c_3[((c >> 9 ) & 0x3c) | ((c >> 8 ) & 0x3)] |
	    pc2_c_4[((c >> 2 ) & 0x20) | ((c >> 1) & 0x18) | (c & 0x7)];
	kd = pc2_d_1[(d >> 22) & 0x3f] |
	    pc2_d_2[((d >> 15) & 0x30) | ((d >> 14) & 0xf)] |
	    pc2_d_3[ (d >> 7 ) & 0x3f] |
	    pc2_d_4[((d >> 1 ) & 0x3c) | ((d      ) & 0x3)];

	/* Change to byte order used by the S boxes */
	*k  =    (kc & 0x00fc0000L) << 6;
	*k |=    (kc & 0x00000fc0L) << 10;
	*k |=    (kd & 0x00fc0000L) >> 10;
	*k++  |= (kd & 0x00000fc0L) >> 6;
	*k  =    (kc & 0x0003f000L) << 12;
	*k |=    (kc & 0x0000003fL) << 16;
	*k |=    (kd & 0x0003f000L) >> 4;
	*k++  |= (kd & 0x0000003fL);
    }

    return 0;
}

/**
 * Just like DES_set_key_unchecked() except checking that the key is
 * not weak for or have correct parity.
 *
 * @param key a key to initialize the key schedule with.
 * @param ks a key schedule to initialize.
 *
 * @return 0 on success, -1 on invalid parity, -2 on weak key.
 * @ingroup hcrypto_des
 */

int
DES_set_key_checked(DES_cblock *key, DES_key_schedule *ks)
{
    if (!DES_check_key_parity(key)) {
	memset(ks, 0, sizeof(*ks));
	return -1;
    }
    if (DES_is_weak_key(key)) {
	memset(ks, 0, sizeof(*ks));
	return -2;
    }
    return DES_set_key_unchecked(key, ks);
}

/**
 * Compatibility function for eay libdes, works just like
 * DES_set_key_checked().
 *
 * @param key a key to initialize the key schedule with.
 * @param ks a key schedule to initialize.
 *
 * @return 0 on success, -1 on invalid parity, -2 on weak key.
 * @ingroup hcrypto_des
 */

int
DES_key_sched(DES_cblock *key, DES_key_schedule *ks)
{
    return DES_set_key_checked(key, ks);
}

/*
 *
 */

static void
load(const unsigned char *b, uint32_t v[2])
{
    v[0] =  b[0] << 24;
    v[0] |= b[1] << 16;
    v[0] |= b[2] << 8;
    v[0] |= b[3] << 0;
    v[1] =  b[4] << 24;
    v[1] |= b[5] << 16;
    v[1] |= b[6] << 8;
    v[1] |= b[7] << 0;
}

static void
store(const uint32_t v[2], unsigned char *b)
{
    b[0] = (v[0] >> 24) & 0xff;
    b[1] = (v[0] >> 16) & 0xff;
    b[2] = (v[0] >>  8) & 0xff;
    b[3] = (v[0] >>  0) & 0xff;
    b[4] = (v[1] >> 24) & 0xff;
    b[5] = (v[1] >> 16) & 0xff;
    b[6] = (v[1] >>  8) & 0xff;
    b[7] = (v[1] >>  0) & 0xff;
}

/**
 * Encrypt/decrypt a block using DES. Also called ECB mode
 *
 * @param u data to encrypt
 * @param ks key schedule to use
 * @param encp if non zero, encrypt. if zero, decrypt.
 *
 * @ingroup hcrypto_des
 */

void
DES_encrypt(uint32_t u[2], DES_key_schedule *ks, int encp)
{
    IP(u);
    desx(u, ks, encp);
    FP(u);
}

/**
 * Encrypt/decrypt a block using DES.
 *
 * @param input data to encrypt
 * @param output data to encrypt
 * @param ks key schedule to use
 * @param encp if non zero, encrypt. if zero, decrypt.
 *
 * @ingroup hcrypto_des
 */

void
DES_ecb_encrypt(DES_cblock *input, DES_cblock *output,
		DES_key_schedule *ks, int encp)
{
    uint32_t u[2];
    load(*input, u);
    DES_encrypt(u, ks, encp);
    store(u, *output);
}

/**
 * Encrypt/decrypt a block using DES in Chain Block Cipher mode (cbc).
 *
 * The IV must always be diffrent for diffrent input data blocks.
 *
 * @param in data to encrypt
 * @param out data to encrypt
 * @param length length of data
 * @param ks key schedule to use
 * @param iv initial vector to use
 * @param encp if non zero, encrypt. if zero, decrypt.
 *
 * @ingroup hcrypto_des
 */

void
DES_cbc_encrypt(const void *in, void *out, long length,
		DES_key_schedule *ks, DES_cblock *iv, int encp)
{
    const unsigned char *input = in;
    unsigned char *output = out;
    uint32_t u[2];
    uint32_t uiv[2];

    load(*iv, uiv);

    if (encp) {
	while (length >= DES_CBLOCK_LEN) {
	    load(input, u);
	    u[0] ^= uiv[0]; u[1] ^= uiv[1];
	    DES_encrypt(u, ks, 1);
	    uiv[0] = u[0]; uiv[1] = u[1];
	    store(u, output);

	    length -= DES_CBLOCK_LEN;
	    input += DES_CBLOCK_LEN;
	    output += DES_CBLOCK_LEN;
	}
	if (length) {
	    unsigned char tmp[DES_CBLOCK_LEN];
	    memcpy(tmp, input, length);
	    memset(tmp + length, 0, DES_CBLOCK_LEN - length);
	    load(tmp, u);
	    u[0] ^= uiv[0]; u[1] ^= uiv[1];
	    DES_encrypt(u, ks, 1);
	    store(u, output);
	}
    } else {
	uint32_t t[2];
	while (length >= DES_CBLOCK_LEN) {
	    load(input, u);
	    t[0] = u[0]; t[1] = u[1];
	    DES_encrypt(u, ks, 0);
	    u[0] ^= uiv[0]; u[1] ^= uiv[1];
	    store(u, output);
	    uiv[0] = t[0]; uiv[1] = t[1];

	    length -= DES_CBLOCK_LEN;
	    input += DES_CBLOCK_LEN;
	    output += DES_CBLOCK_LEN;
	}
	if (length) {
	    unsigned char tmp[DES_CBLOCK_LEN];
	    memcpy(tmp, input, length);
	    memset(tmp + length, 0, DES_CBLOCK_LEN - length);
	    load(tmp, u);
	    DES_encrypt(u, ks, 0);
	    u[0] ^= uiv[0]; u[1] ^= uiv[1];
	    store(u, output);
	}
    }
    uiv[0] = 0; u[0] = 0; uiv[1] = 0; u[1] = 0;
}

/**
 * Encrypt/decrypt a block using DES in Propagating Cipher Block
 * Chaining mode. This mode is only used for Kerberos 4, and it should
 * stay that way.
 *
 * The IV must always be diffrent for diffrent input data blocks.
 *
 * @param in data to encrypt
 * @param out data to encrypt
 * @param length length of data
 * @param ks key schedule to use
 * @param iv initial vector to use
 * @param encp if non zero, encrypt. if zero, decrypt.
 *
 * @ingroup hcrypto_des
 */

void
DES_pcbc_encrypt(const void *in, void *out, long length,
		 DES_key_schedule *ks, DES_cblock *iv, int encp)
{
    const unsigned char *input = in;
    unsigned char *output = out;
    uint32_t u[2];
    uint32_t uiv[2];

    load(*iv, uiv);

    if (encp) {
	uint32_t t[2];
	while (length >= DES_CBLOCK_LEN) {
	    load(input, u);
	    t[0] = u[0]; t[1] = u[1];
	    u[0] ^= uiv[0]; u[1] ^= uiv[1];
	    DES_encrypt(u, ks, 1);
	    uiv[0] = u[0] ^ t[0]; uiv[1] = u[1] ^ t[1];
	    store(u, output);

	    length -= DES_CBLOCK_LEN;
	    input += DES_CBLOCK_LEN;
	    output += DES_CBLOCK_LEN;
	}
	if (length) {
	    unsigned char tmp[DES_CBLOCK_LEN];
	    memcpy(tmp, input, length);
	    memset(tmp + length, 0, DES_CBLOCK_LEN - length);
	    load(tmp, u);
	    u[0] ^= uiv[0]; u[1] ^= uiv[1];
	    DES_encrypt(u, ks, 1);
	    store(u, output);
	}
    } else {
	uint32_t t[2];
	while (length >= DES_CBLOCK_LEN) {
	    load(input, u);
	    t[0] = u[0]; t[1] = u[1];
	    DES_encrypt(u, ks, 0);
	    u[0] ^= uiv[0]; u[1] ^= uiv[1];
	    store(u, output);
	    uiv[0] = t[0] ^ u[0]; uiv[1] = t[1] ^ u[1];

	    length -= DES_CBLOCK_LEN;
	    input += DES_CBLOCK_LEN;
	    output += DES_CBLOCK_LEN;
	}
	if (length) {
	    unsigned char tmp[DES_CBLOCK_LEN];
	    memcpy(tmp, input, length);
	    memset(tmp + length, 0, DES_CBLOCK_LEN - length);
	    load(tmp, u);
	    DES_encrypt(u, ks, 0);
	    u[0] ^= uiv[0]; u[1] ^= uiv[1];
	}
    }
    uiv[0] = 0; u[0] = 0; uiv[1] = 0; u[1] = 0;
}

/*
 *
 */

static void
_des3_encrypt(uint32_t u[2], DES_key_schedule *ks1, DES_key_schedule *ks2, 
	      DES_key_schedule *ks3, int encp)
{
    IP(u);
    if (encp) {
	desx(u, ks1, 1); /* IP + FP cancel out each other */
	desx(u, ks2, 0);
	desx(u, ks3, 1);
    } else {
	desx(u, ks3, 0);
	desx(u, ks2, 1);
	desx(u, ks1, 0);
    }
    FP(u);
}

/**
 * Encrypt/decrypt a block using triple DES using EDE mode,
 * encrypt/decrypt/encrypt.
 *
 * @param input data to encrypt
 * @param output data to encrypt
 * @param ks1 key schedule to use
 * @param ks2 key schedule to use
 * @param ks3 key schedule to use
 * @param encp if non zero, encrypt. if zero, decrypt.
 *
 * @ingroup hcrypto_des
 */

void
DES_ecb3_encrypt(DES_cblock *input,
		 DES_cblock *output,
		 DES_key_schedule *ks1,
		 DES_key_schedule *ks2,
		 DES_key_schedule *ks3,
		 int encp)
{
    uint32_t u[2];
    load(*input, u);
    _des3_encrypt(u, ks1, ks2, ks3, encp);
    store(u, *output);
    return;
}

/**
 * Encrypt/decrypt using Triple DES in Chain Block Cipher mode (cbc).
 *
 * The IV must always be diffrent for diffrent input data blocks.
 *
 * @param in data to encrypt
 * @param out data to encrypt
 * @param length length of data
 * @param ks1 key schedule to use
 * @param ks2 key schedule to use
 * @param ks3 key schedule to use
 * @param iv initial vector to use
 * @param encp if non zero, encrypt. if zero, decrypt.
 *
 * @ingroup hcrypto_des
 */

void
DES_ede3_cbc_encrypt(const void *in, void *out,
		     long length, DES_key_schedule *ks1, 
		     DES_key_schedule *ks2, DES_key_schedule *ks3,
		     DES_cblock *iv, int encp)
{
    const unsigned char *input = in;
    unsigned char *output = out;
    uint32_t u[2];
    uint32_t uiv[2];

    load(*iv, uiv);

    if (encp) {
	while (length >= DES_CBLOCK_LEN) {
	    load(input, u);
	    u[0] ^= uiv[0]; u[1] ^= uiv[1];
	    _des3_encrypt(u, ks1, ks2, ks3, 1);
	    uiv[0] = u[0]; uiv[1] = u[1];
	    store(u, output);

	    length -= DES_CBLOCK_LEN;
	    input += DES_CBLOCK_LEN;
	    output += DES_CBLOCK_LEN;
	}
	if (length) {
	    unsigned char tmp[DES_CBLOCK_LEN];
	    memcpy(tmp, input, length);
	    memset(tmp + length, 0, DES_CBLOCK_LEN - length);
	    load(tmp, u);
	    u[0] ^= uiv[0]; u[1] ^= uiv[1];
	    _des3_encrypt(u, ks1, ks2, ks3, 1);
	    store(u, output);
	}
    } else {
	uint32_t t[2];
	while (length >= DES_CBLOCK_LEN) {
	    load(input, u);
	    t[0] = u[0]; t[1] = u[1];
	    _des3_encrypt(u, ks1, ks2, ks3, 0);
	    u[0] ^= uiv[0]; u[1] ^= uiv[1];
	    store(u, output);
	    uiv[0] = t[0]; uiv[1] = t[1];

	    length -= DES_CBLOCK_LEN;
	    input += DES_CBLOCK_LEN;
	    output += DES_CBLOCK_LEN;
	}
	if (length) {
	    unsigned char tmp[DES_CBLOCK_LEN];
	    memcpy(tmp, input, length);
	    memset(tmp + length, 0, DES_CBLOCK_LEN - length);
	    load(tmp, u);
	    _des3_encrypt(u, ks1, ks2, ks3, 0);
	    u[0] ^= uiv[0]; u[1] ^= uiv[1];
	    store(u, output);
	}
    }
    store(uiv, *iv);
    uiv[0] = 0; u[0] = 0; uiv[1] = 0; u[1] = 0;
}

/**
 * Encrypt/decrypt using DES in cipher feedback mode with 64 bit
 * feedback.
 *
 * The IV must always be diffrent for diffrent input data blocks.
 *
 * @param in data to encrypt
 * @param out data to encrypt
 * @param length length of data
 * @param ks key schedule to use
 * @param iv initial vector to use
 * @param num offset into in cipher block encryption/decryption stop last time.
 * @param encp if non zero, encrypt. if zero, decrypt.
 *
 * @ingroup hcrypto_des
 */

void
DES_cfb64_encrypt(const void *in, void *out, 
		  long length, DES_key_schedule *ks, DES_cblock *iv,
		  int *num, int encp)
{
    const unsigned char *input = in;
    unsigned char *output = out;
    unsigned char tmp[DES_CBLOCK_LEN];
    uint32_t uiv[2];

    load(*iv, uiv);

    assert(*num >= 0 && *num < DES_CBLOCK_LEN);

    if (encp) {
	int i = *num;

	while (length > 0) {
	    if (i == 0)
		DES_encrypt(uiv, ks, 1);
	    store(uiv, tmp);
	    for (; i < DES_CBLOCK_LEN && i < length; i++) {
		output[i] = tmp[i] ^ input[i];
	    }
	    if (i == DES_CBLOCK_LEN)
		load(output, uiv);
	    output += i;
	    input += i;
	    length -= i;
	    if (i == DES_CBLOCK_LEN)
		i = 0;
	}
	store(uiv, *iv);
	*num = i;
    } else {
	int i = *num;
	unsigned char c;

	while (length > 0) {
	    if (i == 0) {
		DES_encrypt(uiv, ks, 1);
		store(uiv, tmp);
	    }
	    for (; i < DES_CBLOCK_LEN && i < length; i++) {
		c = input[i];
		output[i] = tmp[i] ^ input[i];
		(*iv)[i] = c;
	    }
	    output += i;
	    input += i;
	    length -= i;
	    if (i == DES_CBLOCK_LEN) {
		i = 0;
		load(*iv, uiv);
	    }
	}
	store(uiv, *iv);
	*num = i;
    }
}

/**
 * Crete a checksum using DES in CBC encryption mode. This mode is
 * only used for Kerberos 4, and it should stay that way.
 *
 * The IV must always be diffrent for diffrent input data blocks.
 *
 * @param in data to checksum
 * @param output the checksum
 * @param length length of data
 * @param ks key schedule to use
 * @param iv initial vector to use
 *
 * @ingroup hcrypto_des
 */

uint32_t
DES_cbc_cksum(const void *in, DES_cblock *output,
	      long length, DES_key_schedule *ks, DES_cblock *iv)
{
    const unsigned char *input = in;
    uint32_t uiv[2];
    uint32_t u[2] = { 0, 0 };

    load(*iv, uiv);

    while (length >= DES_CBLOCK_LEN) {
	load(input, u);
	u[0] ^= uiv[0]; u[1] ^= uiv[1];
	DES_encrypt(u, ks, 1);
	uiv[0] = u[0]; uiv[1] = u[1];
	
	length -= DES_CBLOCK_LEN;
	input += DES_CBLOCK_LEN;
    }
    if (length) {
	unsigned char tmp[DES_CBLOCK_LEN];
	memcpy(tmp, input, length);
	memset(tmp + length, 0, DES_CBLOCK_LEN - length);
	load(tmp, u);
	u[0] ^= uiv[0]; u[1] ^= uiv[1];
	DES_encrypt(u, ks, 1);
    }
    if (output)
	store(u, *output);

    uiv[0] = 0; u[0] = 0; uiv[1] = 0;
    return u[1];
}

/*
 *
 */

static unsigned char
bitswap8(unsigned char b)
{
    unsigned char r = 0;
    int i;
    for (i = 0; i < 8; i++) {
	r = r << 1 | (b & 1);
	b = b >> 1;
    }
    return r;
}

/**
 * Convert a string to a DES key. Use something like
 * PKCS5_PBKDF2_HMAC_SHA1() to create key from passwords.
 *
 * @param str The string to convert to a key
 * @param key the resulting key
 *
 * @ingroup hcrypto_des
 */

void
DES_string_to_key(const char *str, DES_cblock *key)
{
    const unsigned char *s;
    unsigned char *k;
    DES_key_schedule ks;
    size_t i, len;

    memset(key, 0, sizeof(*key));
    k = *key;
    s = (const unsigned char *)str;

    len = strlen(str);
    for (i = 0; i < len; i++) {
	if ((i % 16) < 8)
	    k[i % 8] ^= s[i] << 1;
	else
	    k[7 - (i % 8)] ^= bitswap8(s[i]);
    }
    DES_set_odd_parity(key);
    if (DES_is_weak_key(key))
	k[7] ^= 0xF0;
    DES_set_key(key, &ks);
    DES_cbc_cksum(s, key, len, &ks, key);
    memset(&ks, 0, sizeof(ks));
    DES_set_odd_parity(key);
    if (DES_is_weak_key(key))
	k[7] ^= 0xF0;
}

/**
 * Read password from prompt and create a DES key. Internal uses
 * DES_string_to_key(). Really, go use a really string2key function
 * like PKCS5_PBKDF2_HMAC_SHA1().
 *
 * @param key key to convert to
 * @param prompt prompt to display user
 * @param verify prompt twice.
 *
 * @return 1 on success, non 1 on failure.
 */

int
DES_read_password(DES_cblock *key, char *prompt, int verify)
{
    char buf[512];
    int ret;

    ret = UI_UTIL_read_pw_string(buf, sizeof(buf) - 1, prompt, verify);
    if (ret == 1)
	DES_string_to_key(buf, key);
    return ret;
}

/*
 *
 */


void
_DES_ipfp_test(void)
{
    DES_cblock k = "\x01\x02\x04\x08\x10\x20\x40\x80", k2;
    uint32_t u[2] = { 1, 0 };
    IP(u);
    FP(u);
    IP(u);
    FP(u);
    if (u[0] != 1 || u[1] != 0)
	abort();

    load(k, u);
    store(u, k2);
    if (memcmp(k, k2, 8) != 0)
	abort();
}    

/* D3DES (V5.09) - 
 *
 * A portable, public domain, version of the Data Encryption Standard.
 *
 * Written with Symantec's THINK (Lightspeed) C by Richard Outerbridge.
 * Thanks to: Dan Hoey for his excellent Initial and Inverse permutation
 * code;  Jim Gillogly & Phil Karn for the DES key schedule code; Dennis
 * Ferguson, Eric Young and Dana How for comparing notes; and Ray Lau,
 * for humouring me on. 
 *
 * Copyright (c) 1988,1989,1990,1991,1992 by Richard Outerbridge.
 * (GEnie : OUTER; CIS : [71755,204]) Graven Imagery, 1992.
 */

static uint32_t SP1[64] = {
    0x01010400L, 0x00000000L, 0x00010000L, 0x01010404L,
    0x01010004L, 0x00010404L, 0x00000004L, 0x00010000L,
    0x00000400L, 0x01010400L, 0x01010404L, 0x00000400L,
    0x01000404L, 0x01010004L, 0x01000000L, 0x00000004L,
    0x00000404L, 0x01000400L, 0x01000400L, 0x00010400L,
    0x00010400L, 0x01010000L, 0x01010000L, 0x01000404L,
    0x00010004L, 0x01000004L, 0x01000004L, 0x00010004L,
    0x00000000L, 0x00000404L, 0x00010404L, 0x01000000L,
    0x00010000L, 0x01010404L, 0x00000004L, 0x01010000L,
    0x01010400L, 0x01000000L, 0x01000000L, 0x00000400L,
    0x01010004L, 0x00010000L, 0x00010400L, 0x01000004L,
    0x00000400L, 0x00000004L, 0x01000404L, 0x00010404L,
    0x01010404L, 0x00010004L, 0x01010000L, 0x01000404L,
    0x01000004L, 0x00000404L, 0x00010404L, 0x01010400L,
    0x00000404L, 0x01000400L, 0x01000400L, 0x00000000L,
    0x00010004L, 0x00010400L, 0x00000000L, 0x01010004L };

static uint32_t SP2[64] = {
    0x80108020L, 0x80008000L, 0x00008000L, 0x00108020L,
    0x00100000L, 0x00000020L, 0x80100020L, 0x80008020L,
    0x80000020L, 0x80108020L, 0x80108000L, 0x80000000L,
    0x80008000L, 0x00100000L, 0x00000020L, 0x80100020L,
    0x00108000L, 0x00100020L, 0x80008020L, 0x00000000L,
    0x80000000L, 0x00008000L, 0x00108020L, 0x80100000L,
    0x00100020L, 0x80000020L, 0x00000000L, 0x00108000L,
    0x00008020L, 0x80108000L, 0x80100000L, 0x00008020L,
    0x00000000L, 0x00108020L, 0x80100020L, 0x00100000L,
    0x80008020L, 0x80100000L, 0x80108000L, 0x00008000L,
    0x80100000L, 0x80008000L, 0x00000020L, 0x80108020L,
    0x00108020L, 0x00000020L, 0x00008000L, 0x80000000L,
    0x00008020L, 0x80108000L, 0x00100000L, 0x80000020L,
    0x00100020L, 0x80008020L, 0x80000020L, 0x00100020L,
    0x00108000L, 0x00000000L, 0x80008000L, 0x00008020L,
    0x80000000L, 0x80100020L, 0x80108020L, 0x00108000L };

static uint32_t SP3[64] = {
    0x00000208L, 0x08020200L, 0x00000000L, 0x08020008L,
    0x08000200L, 0x00000000L, 0x00020208L, 0x08000200L,
    0x00020008L, 0x08000008L, 0x08000008L, 0x00020000L,
    0x08020208L, 0x00020008L, 0x08020000L, 0x00000208L,
    0x08000000L, 0x00000008L, 0x08020200L, 0x00000200L,
    0x00020200L, 0x08020000L, 0x08020008L, 0x00020208L,
    0x08000208L, 0x00020200L, 0x00020000L, 0x08000208L,
    0x00000008L, 0x08020208L, 0x00000200L, 0x08000000L,
    0x08020200L, 0x08000000L, 0x00020008L, 0x00000208L,
    0x00020000L, 0x08020200L, 0x08000200L, 0x00000000L,
    0x00000200L, 0x00020008L, 0x08020208L, 0x08000200L,
    0x08000008L, 0x00000200L, 0x00000000L, 0x08020008L,
    0x08000208L, 0x00020000L, 0x08000000L, 0x08020208L,
    0x00000008L, 0x00020208L, 0x00020200L, 0x08000008L,
    0x08020000L, 0x08000208L, 0x00000208L, 0x08020000L,
    0x00020208L, 0x00000008L, 0x08020008L, 0x00020200L };

static uint32_t SP4[64] = {
    0x00802001L, 0x00002081L, 0x00002081L, 0x00000080L,
    0x00802080L, 0x00800081L, 0x00800001L, 0x00002001L,
    0x00000000L, 0x00802000L, 0x00802000L, 0x00802081L,
    0x00000081L, 0x00000000L, 0x00800080L, 0x00800001L,
    0x00000001L, 0x00002000L, 0x00800000L, 0x00802001L,
    0x00000080L, 0x00800000L, 0x00002001L, 0x00002080L,
    0x00800081L, 0x00000001L, 0x00002080L, 0x00800080L,
    0x00002000L, 0x00802080L, 0x00802081L, 0x00000081L,
    0x00800080L, 0x00800001L, 0x00802000L, 0x00802081L,
    0x00000081L, 0x00000000L, 0x00000000L, 0x00802000L,
    0x00002080L, 0x00800080L, 0x00800081L, 0x00000001L,
    0x00802001L, 0x00002081L, 0x00002081L, 0x00000080L,
    0x00802081L, 0x00000081L, 0x00000001L, 0x00002000L,
    0x00800001L, 0x00002001L, 0x00802080L, 0x00800081L,
    0x00002001L, 0x00002080L, 0x00800000L, 0x00802001L,
    0x00000080L, 0x00800000L, 0x00002000L, 0x00802080L };

static uint32_t SP5[64] = {
    0x00000100L, 0x02080100L, 0x02080000L, 0x42000100L,
    0x00080000L, 0x00000100L, 0x40000000L, 0x02080000L,
    0x40080100L, 0x00080000L, 0x02000100L, 0x40080100L,
    0x42000100L, 0x42080000L, 0x00080100L, 0x40000000L,
    0x02000000L, 0x40080000L, 0x40080000L, 0x00000000L,
    0x40000100L, 0x42080100L, 0x42080100L, 0x02000100L,
    0x42080000L, 0x40000100L, 0x00000000L, 0x42000000L,
    0x02080100L, 0x02000000L, 0x42000000L, 0x00080100L,
    0x00080000L, 0x42000100L, 0x00000100L, 0x02000000L,
    0x40000000L, 0x02080000L, 0x42000100L, 0x40080100L,
    0x02000100L, 0x40000000L, 0x42080000L, 0x02080100L,
    0x40080100L, 0x00000100L, 0x02000000L, 0x42080000L,
    0x42080100L, 0x00080100L, 0x42000000L, 0x42080100L,
    0x02080000L, 0x00000000L, 0x40080000L, 0x42000000L,
    0x00080100L, 0x02000100L, 0x40000100L, 0x00080000L,
    0x00000000L, 0x40080000L, 0x02080100L, 0x40000100L };

static uint32_t SP6[64] = {
    0x20000010L, 0x20400000L, 0x00004000L, 0x20404010L,
    0x20400000L, 0x00000010L, 0x20404010L, 0x00400000L,
    0x20004000L, 0x00404010L, 0x00400000L, 0x20000010L,
    0x00400010L, 0x20004000L, 0x20000000L, 0x00004010L,
    0x00000000L, 0x00400010L, 0x20004010L, 0x00004000L,
    0x00404000L, 0x20004010L, 0x00000010L, 0x20400010L,
    0x20400010L, 0x00000000L, 0x00404010L, 0x20404000L,
    0x00004010L, 0x00404000L, 0x20404000L, 0x20000000L,
    0x20004000L, 0x00000010L, 0x20400010L, 0x00404000L,
    0x20404010L, 0x00400000L, 0x00004010L, 0x20000010L,
    0x00400000L, 0x20004000L, 0x20000000L, 0x00004010L,
    0x20000010L, 0x20404010L, 0x00404000L, 0x20400000L,
    0x00404010L, 0x20404000L, 0x00000000L, 0x20400010L,
    0x00000010L, 0x00004000L, 0x20400000L, 0x00404010L,
    0x00004000L, 0x00400010L, 0x20004010L, 0x00000000L,
    0x20404000L, 0x20000000L, 0x00400010L, 0x20004010L };

static uint32_t SP7[64] = {
    0x00200000L, 0x04200002L, 0x04000802L, 0x00000000L,
    0x00000800L, 0x04000802L, 0x00200802L, 0x04200800L,
    0x04200802L, 0x00200000L, 0x00000000L, 0x04000002L,
    0x00000002L, 0x04000000L, 0x04200002L, 0x00000802L,
    0x04000800L, 0x00200802L, 0x00200002L, 0x04000800L,
    0x04000002L, 0x04200000L, 0x04200800L, 0x00200002L,
    0x04200000L, 0x00000800L, 0x00000802L, 0x04200802L,
    0x00200800L, 0x00000002L, 0x04000000L, 0x00200800L,
    0x04000000L, 0x00200800L, 0x00200000L, 0x04000802L,
    0x04000802L, 0x04200002L, 0x04200002L, 0x00000002L,
    0x00200002L, 0x04000000L, 0x04000800L, 0x00200000L,
    0x04200800L, 0x00000802L, 0x00200802L, 0x04200800L,
    0x00000802L, 0x04000002L, 0x04200802L, 0x04200000L,
    0x00200800L, 0x00000000L, 0x00000002L, 0x04200802L,
    0x00000000L, 0x00200802L, 0x04200000L, 0x00000800L,
    0x04000002L, 0x04000800L, 0x00000800L, 0x00200002L };

static uint32_t SP8[64] = {
    0x10001040L, 0x00001000L, 0x00040000L, 0x10041040L,
    0x10000000L, 0x10001040L, 0x00000040L, 0x10000000L,
    0x00040040L, 0x10040000L, 0x10041040L, 0x00041000L,
    0x10041000L, 0x00041040L, 0x00001000L, 0x00000040L,
    0x10040000L, 0x10000040L, 0x10001000L, 0x00001040L,
    0x00041000L, 0x00040040L, 0x10040040L, 0x10041000L,
    0x00001040L, 0x00000000L, 0x00000000L, 0x10040040L,
    0x10000040L, 0x10001000L, 0x00041040L, 0x00040000L,
    0x00041040L, 0x00040000L, 0x10041000L, 0x00001000L,
    0x00000040L, 0x10040040L, 0x00001000L, 0x00041040L,
    0x10001000L, 0x00000040L, 0x10000040L, 0x10040000L,
    0x10040040L, 0x10000000L, 0x00040000L, 0x10001040L,
    0x00000000L, 0x10041040L, 0x00040040L, 0x10000040L,
    0x10040000L, 0x10001000L, 0x10001040L, 0x00000000L,
    0x10041040L, 0x00041000L, 0x00041000L, 0x00001040L,
    0x00001040L, 0x00040040L, 0x10000000L, 0x10041000L };

static void
IP(uint32_t v[2])
{
    uint32_t work;

    work = ((v[0] >> 4) ^ v[1]) & 0x0f0f0f0fL;
    v[1] ^= work;
    v[0] ^= (work << 4);
    work = ((v[0] >> 16) ^ v[1]) & 0x0000ffffL;
    v[1] ^= work;
    v[0] ^= (work << 16);
    work = ((v[1] >> 2) ^ v[0]) & 0x33333333L;
    v[0] ^= work;
    v[1] ^= (work << 2);
    work = ((v[1] >> 8) ^ v[0]) & 0x00ff00ffL;
    v[0] ^= work;
    v[1] ^= (work << 8);
    v[1] = ((v[1] << 1) | ((v[1] >> 31) & 1L)) & 0xffffffffL;
    work = (v[0] ^ v[1]) & 0xaaaaaaaaL;
    v[0] ^= work;
    v[1] ^= work;
    v[0] = ((v[0] << 1) | ((v[0] >> 31) & 1L)) & 0xffffffffL;
}

static void
FP(uint32_t v[2])
{
    uint32_t work;

    v[0] = (v[0] << 31) | (v[0] >> 1);
    work = (v[1] ^ v[0]) & 0xaaaaaaaaL;
    v[1] ^= work;
    v[0] ^= work;
    v[1] = (v[1] << 31) | (v[1] >> 1);
    work = ((v[1] >> 8) ^ v[0]) & 0x00ff00ffL;
    v[0] ^= work;
    v[1] ^= (work << 8);
    work = ((v[1] >> 2) ^ v[0]) & 0x33333333L;
    v[0] ^= work;
    v[1] ^= (work << 2);
    work = ((v[0] >> 16) ^ v[1]) & 0x0000ffffL;
    v[1] ^= work;
    v[0] ^= (work << 16);
    work = ((v[0] >> 4) ^ v[1]) & 0x0f0f0f0fL;
    v[1] ^= work;
    v[0] ^= (work << 4);
}

static void
desx(uint32_t block[2], DES_key_schedule *ks, int encp)
{
    uint32_t *keys;
    uint32_t fval, work, right, left;
    int round;

    left = block[0];
    right = block[1];

    if (encp) {
	keys = &ks->ks[0];

	for( round = 0; round < 8; round++ ) {
	    work  = (right << 28) | (right >> 4);
	    work ^= *keys++;
	    fval  = SP7[ work     & 0x3fL];
	    fval |= SP5[(work >>  8) & 0x3fL];
	    fval |= SP3[(work >> 16) & 0x3fL];
	    fval |= SP1[(work >> 24) & 0x3fL];
	    work  = right ^ *keys++;
	    fval |= SP8[ work     & 0x3fL];
	    fval |= SP6[(work >>  8) & 0x3fL];
	    fval |= SP4[(work >> 16) & 0x3fL];
	    fval |= SP2[(work >> 24) & 0x3fL];
	    left ^= fval;
	    work  = (left << 28) | (left >> 4);
	    work ^= *keys++;
	    fval  = SP7[ work     & 0x3fL];
	    fval |= SP5[(work >>  8) & 0x3fL];
	    fval |= SP3[(work >> 16) & 0x3fL];
	    fval |= SP1[(work >> 24) & 0x3fL];
	    work  = left ^ *keys++;
	    fval |= SP8[ work     & 0x3fL];
	    fval |= SP6[(work >>  8) & 0x3fL];
	    fval |= SP4[(work >> 16) & 0x3fL];
	    fval |= SP2[(work >> 24) & 0x3fL];
	    right ^= fval;
	}
    } else {
	keys = &ks->ks[30];

	for( round = 0; round < 8; round++ ) {
	    work  = (right << 28) | (right >> 4);
	    work ^= *keys++;
	    fval  = SP7[ work     & 0x3fL];
	    fval |= SP5[(work >>  8) & 0x3fL];
	    fval |= SP3[(work >> 16) & 0x3fL];
	    fval |= SP1[(work >> 24) & 0x3fL];
	    work  = right ^ *keys++;
	    fval |= SP8[ work     & 0x3fL];
	    fval |= SP6[(work >>  8) & 0x3fL];
	    fval |= SP4[(work >> 16) & 0x3fL];
	    fval |= SP2[(work >> 24) & 0x3fL];
	    left ^= fval;
	    work  = (left << 28) | (left >> 4);
	    keys -= 4;
	    work ^= *keys++;
	    fval  = SP7[ work     & 0x3fL];
	    fval |= SP5[(work >>  8) & 0x3fL];
	    fval |= SP3[(work >> 16) & 0x3fL];
	    fval |= SP1[(work >> 24) & 0x3fL];
	    work  = left ^ *keys++;
	    fval |= SP8[ work     & 0x3fL];
	    fval |= SP6[(work >>  8) & 0x3fL];
	    fval |= SP4[(work >> 16) & 0x3fL];
	    fval |= SP2[(work >> 24) & 0x3fL];
	    right ^= fval;
	    keys -= 4;
	}
    }
    block[0] = right;
    block[1] = left;
}