forked from Battelle/reductio
-
Notifications
You must be signed in to change notification settings - Fork 18
/
Copy pathaes.c
1362 lines (1214 loc) · 49.8 KB
/
aes.c
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
/*********************************************************************
* Filename: aes.c
* Author: Brad Conte (brad AT bradconte.com)
* Copyright:
* Disclaimer: This code is presented "as is" without any guarantees.
* Details: This code is the implementation of the AES algorithm and
the CTR, CBC, and CCM modes of operation it can be used in.
AES is, specified by the NIST in in publication FIPS PUB 197,
availible at:
* http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf .
The CBC and CTR modes of operation are specified by
NIST SP 800-38 A, available at:
* http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf .
The CCM mode of operation is specified by NIST SP80-38 C, available at:
* http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
*********************************************************************/
/*************************** HEADER FILES ***************************/
#include <stdlib.h>
#include <memory.h>
#include "aes.h"
#include <stdio.h>
/****************************** MACROS ******************************/
// The least significant byte of the word is rotated to the end.
#define KE_ROTWORD(x) (((x) << 8) | ((x) >> 24))
#define TRUE 1
#define FALSE 0
/**************************** DATA TYPES ****************************/
#define AES_128_ROUNDS 10
#define AES_192_ROUNDS 12
#define AES_256_ROUNDS 14
/*********************** FUNCTION DECLARATIONS **********************/
void ccm_prepare_first_ctr_blk(BYTE counter[], const BYTE nonce[], int nonce_len, int payload_len_store_size);
void ccm_prepare_first_format_blk(BYTE buf[], int assoc_len, int payload_len, int payload_len_store_size, int mac_len, const BYTE nonce[], int nonce_len);
void ccm_format_assoc_data(BYTE buf[], int *end_of_buf, const BYTE assoc[], int assoc_len);
void ccm_format_payload_data(BYTE buf[], int *end_of_buf, const BYTE payload[], int payload_len);
/**************************** VARIABLES *****************************/
// This is the specified AES SBox. To look up a substitution value, put the first
// nibble in the first index (row) and the second nibble in the second index (column).
static const BYTE aes_sbox[16][16] = {
{0x63,0x7C,0x77,0x7B,0xF2,0x6B,0x6F,0xC5,0x30,0x01,0x67,0x2B,0xFE,0xD7,0xAB,0x76},
{0xCA,0x82,0xC9,0x7D,0xFA,0x59,0x47,0xF0,0xAD,0xD4,0xA2,0xAF,0x9C,0xA4,0x72,0xC0},
{0xB7,0xFD,0x93,0x26,0x36,0x3F,0xF7,0xCC,0x34,0xA5,0xE5,0xF1,0x71,0xD8,0x31,0x15},
{0x04,0xC7,0x23,0xC3,0x18,0x96,0x05,0x9A,0x07,0x12,0x80,0xE2,0xEB,0x27,0xB2,0x75},
{0x09,0x83,0x2C,0x1A,0x1B,0x6E,0x5A,0xA0,0x52,0x3B,0xD6,0xB3,0x29,0xE3,0x2F,0x84},
{0x53,0xD1,0x00,0xED,0x20,0xFC,0xB1,0x5B,0x6A,0xCB,0xBE,0x39,0x4A,0x4C,0x58,0xCF},
{0xD0,0xEF,0xAA,0xFB,0x43,0x4D,0x33,0x85,0x45,0xF9,0x02,0x7F,0x50,0x3C,0x9F,0xA8},
{0x51,0xA3,0x40,0x8F,0x92,0x9D,0x38,0xF5,0xBC,0xB6,0xDA,0x21,0x10,0xFF,0xF3,0xD2},
{0xCD,0x0C,0x13,0xEC,0x5F,0x97,0x44,0x17,0xC4,0xA7,0x7E,0x3D,0x64,0x5D,0x19,0x73},
{0x60,0x81,0x4F,0xDC,0x22,0x2A,0x90,0x88,0x46,0xEE,0xB8,0x14,0xDE,0x5E,0x0B,0xDB},
{0xE0,0x32,0x3A,0x0A,0x49,0x06,0x24,0x5C,0xC2,0xD3,0xAC,0x62,0x91,0x95,0xE4,0x79},
{0xE7,0xC8,0x37,0x6D,0x8D,0xD5,0x4E,0xA9,0x6C,0x56,0xF4,0xEA,0x65,0x7A,0xAE,0x08},
{0xBA,0x78,0x25,0x2E,0x1C,0xA6,0xB4,0xC6,0xE8,0xDD,0x74,0x1F,0x4B,0xBD,0x8B,0x8A},
{0x70,0x3E,0xB5,0x66,0x48,0x03,0xF6,0x0E,0x61,0x35,0x57,0xB9,0x86,0xC1,0x1D,0x9E},
{0xE1,0xF8,0x98,0x11,0x69,0xD9,0x8E,0x94,0x9B,0x1E,0x87,0xE9,0xCE,0x55,0x28,0xDF},
{0x8C,0xA1,0x89,0x0D,0xBF,0xE6,0x42,0x68,0x41,0x99,0x2D,0x0F,0xB0,0x54,0xBB,0x16}
};
static const BYTE aes_invsbox[16][16] = {
{0x52,0x09,0x6A,0xD5,0x30,0x36,0xA5,0x38,0xBF,0x40,0xA3,0x9E,0x81,0xF3,0xD7,0xFB},
{0x7C,0xE3,0x39,0x82,0x9B,0x2F,0xFF,0x87,0x34,0x8E,0x43,0x44,0xC4,0xDE,0xE9,0xCB},
{0x54,0x7B,0x94,0x32,0xA6,0xC2,0x23,0x3D,0xEE,0x4C,0x95,0x0B,0x42,0xFA,0xC3,0x4E},
{0x08,0x2E,0xA1,0x66,0x28,0xD9,0x24,0xB2,0x76,0x5B,0xA2,0x49,0x6D,0x8B,0xD1,0x25},
{0x72,0xF8,0xF6,0x64,0x86,0x68,0x98,0x16,0xD4,0xA4,0x5C,0xCC,0x5D,0x65,0xB6,0x92},
{0x6C,0x70,0x48,0x50,0xFD,0xED,0xB9,0xDA,0x5E,0x15,0x46,0x57,0xA7,0x8D,0x9D,0x84},
{0x90,0xD8,0xAB,0x00,0x8C,0xBC,0xD3,0x0A,0xF7,0xE4,0x58,0x05,0xB8,0xB3,0x45,0x06},
{0xD0,0x2C,0x1E,0x8F,0xCA,0x3F,0x0F,0x02,0xC1,0xAF,0xBD,0x03,0x01,0x13,0x8A,0x6B},
{0x3A,0x91,0x11,0x41,0x4F,0x67,0xDC,0xEA,0x97,0xF2,0xCF,0xCE,0xF0,0xB4,0xE6,0x73},
{0x96,0xAC,0x74,0x22,0xE7,0xAD,0x35,0x85,0xE2,0xF9,0x37,0xE8,0x1C,0x75,0xDF,0x6E},
{0x47,0xF1,0x1A,0x71,0x1D,0x29,0xC5,0x89,0x6F,0xB7,0x62,0x0E,0xAA,0x18,0xBE,0x1B},
{0xFC,0x56,0x3E,0x4B,0xC6,0xD2,0x79,0x20,0x9A,0xDB,0xC0,0xFE,0x78,0xCD,0x5A,0xF4},
{0x1F,0xDD,0xA8,0x33,0x88,0x07,0xC7,0x31,0xB1,0x12,0x10,0x59,0x27,0x80,0xEC,0x5F},
{0x60,0x51,0x7F,0xA9,0x19,0xB5,0x4A,0x0D,0x2D,0xE5,0x7A,0x9F,0x93,0xC9,0x9C,0xEF},
{0xA0,0xE0,0x3B,0x4D,0xAE,0x2A,0xF5,0xB0,0xC8,0xEB,0xBB,0x3C,0x83,0x53,0x99,0x61},
{0x17,0x2B,0x04,0x7E,0xBA,0x77,0xD6,0x26,0xE1,0x69,0x14,0x63,0x55,0x21,0x0C,0x7D}
};
// This table stores pre-calculated values for all possible GF(2^8) calculations.This
// table is only used by the (Inv)MixColumns steps.
// USAGE: The second index (column) is the coefficient of multiplication. Only 7 different
// coefficients are used: 0x01, 0x02, 0x03, 0x09, 0x0b, 0x0d, 0x0e, but multiplication by
// 1 is negligible leaving only 6 coefficients. Each column of the table is devoted to one
// of these coefficients, in the ascending order of value, from values 0x00 to 0xFF.
static const BYTE gf_mul[256][6] = {
{0x00,0x00,0x00,0x00,0x00,0x00},{0x02,0x03,0x09,0x0b,0x0d,0x0e},
{0x04,0x06,0x12,0x16,0x1a,0x1c},{0x06,0x05,0x1b,0x1d,0x17,0x12},
{0x08,0x0c,0x24,0x2c,0x34,0x38},{0x0a,0x0f,0x2d,0x27,0x39,0x36},
{0x0c,0x0a,0x36,0x3a,0x2e,0x24},{0x0e,0x09,0x3f,0x31,0x23,0x2a},
{0x10,0x18,0x48,0x58,0x68,0x70},{0x12,0x1b,0x41,0x53,0x65,0x7e},
{0x14,0x1e,0x5a,0x4e,0x72,0x6c},{0x16,0x1d,0x53,0x45,0x7f,0x62},
{0x18,0x14,0x6c,0x74,0x5c,0x48},{0x1a,0x17,0x65,0x7f,0x51,0x46},
{0x1c,0x12,0x7e,0x62,0x46,0x54},{0x1e,0x11,0x77,0x69,0x4b,0x5a},
{0x20,0x30,0x90,0xb0,0xd0,0xe0},{0x22,0x33,0x99,0xbb,0xdd,0xee},
{0x24,0x36,0x82,0xa6,0xca,0xfc},{0x26,0x35,0x8b,0xad,0xc7,0xf2},
{0x28,0x3c,0xb4,0x9c,0xe4,0xd8},{0x2a,0x3f,0xbd,0x97,0xe9,0xd6},
{0x2c,0x3a,0xa6,0x8a,0xfe,0xc4},{0x2e,0x39,0xaf,0x81,0xf3,0xca},
{0x30,0x28,0xd8,0xe8,0xb8,0x90},{0x32,0x2b,0xd1,0xe3,0xb5,0x9e},
{0x34,0x2e,0xca,0xfe,0xa2,0x8c},{0x36,0x2d,0xc3,0xf5,0xaf,0x82},
{0x38,0x24,0xfc,0xc4,0x8c,0xa8},{0x3a,0x27,0xf5,0xcf,0x81,0xa6},
{0x3c,0x22,0xee,0xd2,0x96,0xb4},{0x3e,0x21,0xe7,0xd9,0x9b,0xba},
{0x40,0x60,0x3b,0x7b,0xbb,0xdb},{0x42,0x63,0x32,0x70,0xb6,0xd5},
{0x44,0x66,0x29,0x6d,0xa1,0xc7},{0x46,0x65,0x20,0x66,0xac,0xc9},
{0x48,0x6c,0x1f,0x57,0x8f,0xe3},{0x4a,0x6f,0x16,0x5c,0x82,0xed},
{0x4c,0x6a,0x0d,0x41,0x95,0xff},{0x4e,0x69,0x04,0x4a,0x98,0xf1},
{0x50,0x78,0x73,0x23,0xd3,0xab},{0x52,0x7b,0x7a,0x28,0xde,0xa5},
{0x54,0x7e,0x61,0x35,0xc9,0xb7},{0x56,0x7d,0x68,0x3e,0xc4,0xb9},
{0x58,0x74,0x57,0x0f,0xe7,0x93},{0x5a,0x77,0x5e,0x04,0xea,0x9d},
{0x5c,0x72,0x45,0x19,0xfd,0x8f},{0x5e,0x71,0x4c,0x12,0xf0,0x81},
{0x60,0x50,0xab,0xcb,0x6b,0x3b},{0x62,0x53,0xa2,0xc0,0x66,0x35},
{0x64,0x56,0xb9,0xdd,0x71,0x27},{0x66,0x55,0xb0,0xd6,0x7c,0x29},
{0x68,0x5c,0x8f,0xe7,0x5f,0x03},{0x6a,0x5f,0x86,0xec,0x52,0x0d},
{0x6c,0x5a,0x9d,0xf1,0x45,0x1f},{0x6e,0x59,0x94,0xfa,0x48,0x11},
{0x70,0x48,0xe3,0x93,0x03,0x4b},{0x72,0x4b,0xea,0x98,0x0e,0x45},
{0x74,0x4e,0xf1,0x85,0x19,0x57},{0x76,0x4d,0xf8,0x8e,0x14,0x59},
{0x78,0x44,0xc7,0xbf,0x37,0x73},{0x7a,0x47,0xce,0xb4,0x3a,0x7d},
{0x7c,0x42,0xd5,0xa9,0x2d,0x6f},{0x7e,0x41,0xdc,0xa2,0x20,0x61},
{0x80,0xc0,0x76,0xf6,0x6d,0xad},{0x82,0xc3,0x7f,0xfd,0x60,0xa3},
{0x84,0xc6,0x64,0xe0,0x77,0xb1},{0x86,0xc5,0x6d,0xeb,0x7a,0xbf},
{0x88,0xcc,0x52,0xda,0x59,0x95},{0x8a,0xcf,0x5b,0xd1,0x54,0x9b},
{0x8c,0xca,0x40,0xcc,0x43,0x89},{0x8e,0xc9,0x49,0xc7,0x4e,0x87},
{0x90,0xd8,0x3e,0xae,0x05,0xdd},{0x92,0xdb,0x37,0xa5,0x08,0xd3},
{0x94,0xde,0x2c,0xb8,0x1f,0xc1},{0x96,0xdd,0x25,0xb3,0x12,0xcf},
{0x98,0xd4,0x1a,0x82,0x31,0xe5},{0x9a,0xd7,0x13,0x89,0x3c,0xeb},
{0x9c,0xd2,0x08,0x94,0x2b,0xf9},{0x9e,0xd1,0x01,0x9f,0x26,0xf7},
{0xa0,0xf0,0xe6,0x46,0xbd,0x4d},{0xa2,0xf3,0xef,0x4d,0xb0,0x43},
{0xa4,0xf6,0xf4,0x50,0xa7,0x51},{0xa6,0xf5,0xfd,0x5b,0xaa,0x5f},
{0xa8,0xfc,0xc2,0x6a,0x89,0x75},{0xaa,0xff,0xcb,0x61,0x84,0x7b},
{0xac,0xfa,0xd0,0x7c,0x93,0x69},{0xae,0xf9,0xd9,0x77,0x9e,0x67},
{0xb0,0xe8,0xae,0x1e,0xd5,0x3d},{0xb2,0xeb,0xa7,0x15,0xd8,0x33},
{0xb4,0xee,0xbc,0x08,0xcf,0x21},{0xb6,0xed,0xb5,0x03,0xc2,0x2f},
{0xb8,0xe4,0x8a,0x32,0xe1,0x05},{0xba,0xe7,0x83,0x39,0xec,0x0b},
{0xbc,0xe2,0x98,0x24,0xfb,0x19},{0xbe,0xe1,0x91,0x2f,0xf6,0x17},
{0xc0,0xa0,0x4d,0x8d,0xd6,0x76},{0xc2,0xa3,0x44,0x86,0xdb,0x78},
{0xc4,0xa6,0x5f,0x9b,0xcc,0x6a},{0xc6,0xa5,0x56,0x90,0xc1,0x64},
{0xc8,0xac,0x69,0xa1,0xe2,0x4e},{0xca,0xaf,0x60,0xaa,0xef,0x40},
{0xcc,0xaa,0x7b,0xb7,0xf8,0x52},{0xce,0xa9,0x72,0xbc,0xf5,0x5c},
{0xd0,0xb8,0x05,0xd5,0xbe,0x06},{0xd2,0xbb,0x0c,0xde,0xb3,0x08},
{0xd4,0xbe,0x17,0xc3,0xa4,0x1a},{0xd6,0xbd,0x1e,0xc8,0xa9,0x14},
{0xd8,0xb4,0x21,0xf9,0x8a,0x3e},{0xda,0xb7,0x28,0xf2,0x87,0x30},
{0xdc,0xb2,0x33,0xef,0x90,0x22},{0xde,0xb1,0x3a,0xe4,0x9d,0x2c},
{0xe0,0x90,0xdd,0x3d,0x06,0x96},{0xe2,0x93,0xd4,0x36,0x0b,0x98},
{0xe4,0x96,0xcf,0x2b,0x1c,0x8a},{0xe6,0x95,0xc6,0x20,0x11,0x84},
{0xe8,0x9c,0xf9,0x11,0x32,0xae},{0xea,0x9f,0xf0,0x1a,0x3f,0xa0},
{0xec,0x9a,0xeb,0x07,0x28,0xb2},{0xee,0x99,0xe2,0x0c,0x25,0xbc},
{0xf0,0x88,0x95,0x65,0x6e,0xe6},{0xf2,0x8b,0x9c,0x6e,0x63,0xe8},
{0xf4,0x8e,0x87,0x73,0x74,0xfa},{0xf6,0x8d,0x8e,0x78,0x79,0xf4},
{0xf8,0x84,0xb1,0x49,0x5a,0xde},{0xfa,0x87,0xb8,0x42,0x57,0xd0},
{0xfc,0x82,0xa3,0x5f,0x40,0xc2},{0xfe,0x81,0xaa,0x54,0x4d,0xcc},
{0x1b,0x9b,0xec,0xf7,0xda,0x41},{0x19,0x98,0xe5,0xfc,0xd7,0x4f},
{0x1f,0x9d,0xfe,0xe1,0xc0,0x5d},{0x1d,0x9e,0xf7,0xea,0xcd,0x53},
{0x13,0x97,0xc8,0xdb,0xee,0x79},{0x11,0x94,0xc1,0xd0,0xe3,0x77},
{0x17,0x91,0xda,0xcd,0xf4,0x65},{0x15,0x92,0xd3,0xc6,0xf9,0x6b},
{0x0b,0x83,0xa4,0xaf,0xb2,0x31},{0x09,0x80,0xad,0xa4,0xbf,0x3f},
{0x0f,0x85,0xb6,0xb9,0xa8,0x2d},{0x0d,0x86,0xbf,0xb2,0xa5,0x23},
{0x03,0x8f,0x80,0x83,0x86,0x09},{0x01,0x8c,0x89,0x88,0x8b,0x07},
{0x07,0x89,0x92,0x95,0x9c,0x15},{0x05,0x8a,0x9b,0x9e,0x91,0x1b},
{0x3b,0xab,0x7c,0x47,0x0a,0xa1},{0x39,0xa8,0x75,0x4c,0x07,0xaf},
{0x3f,0xad,0x6e,0x51,0x10,0xbd},{0x3d,0xae,0x67,0x5a,0x1d,0xb3},
{0x33,0xa7,0x58,0x6b,0x3e,0x99},{0x31,0xa4,0x51,0x60,0x33,0x97},
{0x37,0xa1,0x4a,0x7d,0x24,0x85},{0x35,0xa2,0x43,0x76,0x29,0x8b},
{0x2b,0xb3,0x34,0x1f,0x62,0xd1},{0x29,0xb0,0x3d,0x14,0x6f,0xdf},
{0x2f,0xb5,0x26,0x09,0x78,0xcd},{0x2d,0xb6,0x2f,0x02,0x75,0xc3},
{0x23,0xbf,0x10,0x33,0x56,0xe9},{0x21,0xbc,0x19,0x38,0x5b,0xe7},
{0x27,0xb9,0x02,0x25,0x4c,0xf5},{0x25,0xba,0x0b,0x2e,0x41,0xfb},
{0x5b,0xfb,0xd7,0x8c,0x61,0x9a},{0x59,0xf8,0xde,0x87,0x6c,0x94},
{0x5f,0xfd,0xc5,0x9a,0x7b,0x86},{0x5d,0xfe,0xcc,0x91,0x76,0x88},
{0x53,0xf7,0xf3,0xa0,0x55,0xa2},{0x51,0xf4,0xfa,0xab,0x58,0xac},
{0x57,0xf1,0xe1,0xb6,0x4f,0xbe},{0x55,0xf2,0xe8,0xbd,0x42,0xb0},
{0x4b,0xe3,0x9f,0xd4,0x09,0xea},{0x49,0xe0,0x96,0xdf,0x04,0xe4},
{0x4f,0xe5,0x8d,0xc2,0x13,0xf6},{0x4d,0xe6,0x84,0xc9,0x1e,0xf8},
{0x43,0xef,0xbb,0xf8,0x3d,0xd2},{0x41,0xec,0xb2,0xf3,0x30,0xdc},
{0x47,0xe9,0xa9,0xee,0x27,0xce},{0x45,0xea,0xa0,0xe5,0x2a,0xc0},
{0x7b,0xcb,0x47,0x3c,0xb1,0x7a},{0x79,0xc8,0x4e,0x37,0xbc,0x74},
{0x7f,0xcd,0x55,0x2a,0xab,0x66},{0x7d,0xce,0x5c,0x21,0xa6,0x68},
{0x73,0xc7,0x63,0x10,0x85,0x42},{0x71,0xc4,0x6a,0x1b,0x88,0x4c},
{0x77,0xc1,0x71,0x06,0x9f,0x5e},{0x75,0xc2,0x78,0x0d,0x92,0x50},
{0x6b,0xd3,0x0f,0x64,0xd9,0x0a},{0x69,0xd0,0x06,0x6f,0xd4,0x04},
{0x6f,0xd5,0x1d,0x72,0xc3,0x16},{0x6d,0xd6,0x14,0x79,0xce,0x18},
{0x63,0xdf,0x2b,0x48,0xed,0x32},{0x61,0xdc,0x22,0x43,0xe0,0x3c},
{0x67,0xd9,0x39,0x5e,0xf7,0x2e},{0x65,0xda,0x30,0x55,0xfa,0x20},
{0x9b,0x5b,0x9a,0x01,0xb7,0xec},{0x99,0x58,0x93,0x0a,0xba,0xe2},
{0x9f,0x5d,0x88,0x17,0xad,0xf0},{0x9d,0x5e,0x81,0x1c,0xa0,0xfe},
{0x93,0x57,0xbe,0x2d,0x83,0xd4},{0x91,0x54,0xb7,0x26,0x8e,0xda},
{0x97,0x51,0xac,0x3b,0x99,0xc8},{0x95,0x52,0xa5,0x30,0x94,0xc6},
{0x8b,0x43,0xd2,0x59,0xdf,0x9c},{0x89,0x40,0xdb,0x52,0xd2,0x92},
{0x8f,0x45,0xc0,0x4f,0xc5,0x80},{0x8d,0x46,0xc9,0x44,0xc8,0x8e},
{0x83,0x4f,0xf6,0x75,0xeb,0xa4},{0x81,0x4c,0xff,0x7e,0xe6,0xaa},
{0x87,0x49,0xe4,0x63,0xf1,0xb8},{0x85,0x4a,0xed,0x68,0xfc,0xb6},
{0xbb,0x6b,0x0a,0xb1,0x67,0x0c},{0xb9,0x68,0x03,0xba,0x6a,0x02},
{0xbf,0x6d,0x18,0xa7,0x7d,0x10},{0xbd,0x6e,0x11,0xac,0x70,0x1e},
{0xb3,0x67,0x2e,0x9d,0x53,0x34},{0xb1,0x64,0x27,0x96,0x5e,0x3a},
{0xb7,0x61,0x3c,0x8b,0x49,0x28},{0xb5,0x62,0x35,0x80,0x44,0x26},
{0xab,0x73,0x42,0xe9,0x0f,0x7c},{0xa9,0x70,0x4b,0xe2,0x02,0x72},
{0xaf,0x75,0x50,0xff,0x15,0x60},{0xad,0x76,0x59,0xf4,0x18,0x6e},
{0xa3,0x7f,0x66,0xc5,0x3b,0x44},{0xa1,0x7c,0x6f,0xce,0x36,0x4a},
{0xa7,0x79,0x74,0xd3,0x21,0x58},{0xa5,0x7a,0x7d,0xd8,0x2c,0x56},
{0xdb,0x3b,0xa1,0x7a,0x0c,0x37},{0xd9,0x38,0xa8,0x71,0x01,0x39},
{0xdf,0x3d,0xb3,0x6c,0x16,0x2b},{0xdd,0x3e,0xba,0x67,0x1b,0x25},
{0xd3,0x37,0x85,0x56,0x38,0x0f},{0xd1,0x34,0x8c,0x5d,0x35,0x01},
{0xd7,0x31,0x97,0x40,0x22,0x13},{0xd5,0x32,0x9e,0x4b,0x2f,0x1d},
{0xcb,0x23,0xe9,0x22,0x64,0x47},{0xc9,0x20,0xe0,0x29,0x69,0x49},
{0xcf,0x25,0xfb,0x34,0x7e,0x5b},{0xcd,0x26,0xf2,0x3f,0x73,0x55},
{0xc3,0x2f,0xcd,0x0e,0x50,0x7f},{0xc1,0x2c,0xc4,0x05,0x5d,0x71},
{0xc7,0x29,0xdf,0x18,0x4a,0x63},{0xc5,0x2a,0xd6,0x13,0x47,0x6d},
{0xfb,0x0b,0x31,0xca,0xdc,0xd7},{0xf9,0x08,0x38,0xc1,0xd1,0xd9},
{0xff,0x0d,0x23,0xdc,0xc6,0xcb},{0xfd,0x0e,0x2a,0xd7,0xcb,0xc5},
{0xf3,0x07,0x15,0xe6,0xe8,0xef},{0xf1,0x04,0x1c,0xed,0xe5,0xe1},
{0xf7,0x01,0x07,0xf0,0xf2,0xf3},{0xf5,0x02,0x0e,0xfb,0xff,0xfd},
{0xeb,0x13,0x79,0x92,0xb4,0xa7},{0xe9,0x10,0x70,0x99,0xb9,0xa9},
{0xef,0x15,0x6b,0x84,0xae,0xbb},{0xed,0x16,0x62,0x8f,0xa3,0xb5},
{0xe3,0x1f,0x5d,0xbe,0x80,0x9f},{0xe1,0x1c,0x54,0xb5,0x8d,0x91},
{0xe7,0x19,0x4f,0xa8,0x9a,0x83},{0xe5,0x1a,0x46,0xa3,0x97,0x8d}
};
/*********************** FUNCTION DEFINITIONS ***********************/
// XORs the in and out buffers, storing the result in out. Length is in bytes.
void xor_buf(const BYTE in[], BYTE out[], size_t len)
{
size_t idx;
for (idx = 0; idx < len; idx++)
out[idx] ^= in[idx];
}
/*******************
* AES - CBC
*******************/
int aes_encrypt_cbc(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
{
BYTE buf_in[AES_BLOCK_SIZE], buf_out[AES_BLOCK_SIZE], iv_buf[AES_BLOCK_SIZE];
int blocks, idx;
if (in_len % AES_BLOCK_SIZE != 0)
return(FALSE);
blocks = in_len / AES_BLOCK_SIZE;
memcpy(iv_buf, iv, AES_BLOCK_SIZE);
for (idx = 0; idx < blocks; idx++) {
memcpy(buf_in, &in[idx * AES_BLOCK_SIZE], AES_BLOCK_SIZE);
xor_buf(iv_buf, buf_in, AES_BLOCK_SIZE);
aes_encrypt(buf_in, buf_out, key, keysize);
memcpy(&out[idx * AES_BLOCK_SIZE], buf_out, AES_BLOCK_SIZE);
memcpy(iv_buf, buf_out, AES_BLOCK_SIZE);
}
return(TRUE);
}
int aes_encrypt_cbc_mac(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
{
BYTE buf_in[AES_BLOCK_SIZE], buf_out[AES_BLOCK_SIZE], iv_buf[AES_BLOCK_SIZE];
int blocks, idx;
if (in_len % AES_BLOCK_SIZE != 0)
return(FALSE);
blocks = in_len / AES_BLOCK_SIZE;
memcpy(iv_buf, iv, AES_BLOCK_SIZE);
for (idx = 0; idx < blocks; idx++) {
memcpy(buf_in, &in[idx * AES_BLOCK_SIZE], AES_BLOCK_SIZE);
xor_buf(iv_buf, buf_in, AES_BLOCK_SIZE);
aes_encrypt(buf_in, buf_out, key, keysize);
memcpy(iv_buf, buf_out, AES_BLOCK_SIZE);
// Do not output all encrypted blocks.
}
memcpy(out, buf_out, AES_BLOCK_SIZE); // Only output the last block.
return(TRUE);
}
int aes_decrypt_cbc(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
{
BYTE buf_in[AES_BLOCK_SIZE], buf_out[AES_BLOCK_SIZE], iv_buf[AES_BLOCK_SIZE];
int blocks, idx;
if (in_len % AES_BLOCK_SIZE != 0)
return(FALSE);
blocks = in_len / AES_BLOCK_SIZE;
memcpy(iv_buf, iv, AES_BLOCK_SIZE);
for (idx = 0; idx < blocks; idx++) {
memcpy(buf_in, &in[idx * AES_BLOCK_SIZE], AES_BLOCK_SIZE);
aes_decrypt(buf_in, buf_out, key, keysize);
xor_buf(iv_buf, buf_out, AES_BLOCK_SIZE);
memcpy(&out[idx * AES_BLOCK_SIZE], buf_out, AES_BLOCK_SIZE);
memcpy(iv_buf, buf_in, AES_BLOCK_SIZE);
}
return(TRUE);
}
/*******************
* AES - CTR
*******************/
void increment_iv(BYTE iv[], int counter_size)
{
int idx;
// Use counter_size bytes at the end of the IV as the big-endian integer to increment.
for (idx = AES_BLOCK_SIZE - 1; idx >= AES_BLOCK_SIZE - counter_size; idx--) {
iv[idx]++;
if (iv[idx] != 0 || idx == AES_BLOCK_SIZE - counter_size)
break;
}
}
// Performs the encryption in-place, the input and output buffers may be the same.
// Input may be an arbitrary length (in bytes).
void aes_encrypt_ctr(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
{
size_t idx = 0, last_block_length;
BYTE iv_buf[AES_BLOCK_SIZE], out_buf[AES_BLOCK_SIZE];
if (in != out)
memcpy(out, in, in_len);
memcpy(iv_buf, iv, AES_BLOCK_SIZE);
last_block_length = in_len - AES_BLOCK_SIZE;
if (in_len > AES_BLOCK_SIZE) {
for (idx = 0; idx < last_block_length; idx += AES_BLOCK_SIZE) {
aes_encrypt(iv_buf, out_buf, key, keysize);
xor_buf(out_buf, &out[idx], AES_BLOCK_SIZE);
increment_iv(iv_buf, AES_BLOCK_SIZE);
}
}
aes_encrypt(iv_buf, out_buf, key, keysize);
xor_buf(out_buf, &out[idx], in_len - idx); // Use the Most Significant bytes.
}
void aes_decrypt_ctr(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
{
// CTR encryption is its own inverse function.
aes_encrypt_ctr(in, in_len, out, key, keysize, iv);
}
/*******************
* AES - CCM
*******************/
// out_len = payload_len + assoc_len
int aes_encrypt_ccm(const BYTE payload[], WORD payload_len, const BYTE assoc[], unsigned short assoc_len,
const BYTE nonce[], unsigned short nonce_len, BYTE out[], WORD *out_len,
WORD mac_len, const BYTE key_str[], int keysize)
{
BYTE temp_iv[AES_BLOCK_SIZE], counter[AES_BLOCK_SIZE], mac[16], *buf;
int end_of_buf, payload_len_store_size;
WORD key[60];
if (mac_len != 4 && mac_len != 6 && mac_len != 8 && mac_len != 10 &&
mac_len != 12 && mac_len != 14 && mac_len != 16)
return(FALSE);
if (nonce_len < 7 || nonce_len > 13)
return(FALSE);
if (assoc_len > 32768 /* = 2^15 */)
return(FALSE);
buf = (BYTE*)malloc(payload_len + assoc_len + 48 /*Round both payload and associated data up a block size and add an extra block.*/);
if (! buf)
return(FALSE);
// Prepare the key for usage.
aes_key_setup(key_str, key, keysize);
// Format the first block of the formatted data.
payload_len_store_size = AES_BLOCK_SIZE - 1 - nonce_len;
ccm_prepare_first_format_blk(buf, assoc_len, payload_len, payload_len_store_size, mac_len, nonce, nonce_len);
end_of_buf = AES_BLOCK_SIZE;
// Format the Associated Data, aka, assoc[].
ccm_format_assoc_data(buf, &end_of_buf, assoc, assoc_len);
// Format the Payload, aka payload[].
ccm_format_payload_data(buf, &end_of_buf, payload, payload_len);
// Create the first counter block.
ccm_prepare_first_ctr_blk(counter, nonce, nonce_len, payload_len_store_size);
// Perform the CBC operation with an IV of zeros on the formatted buffer to calculate the MAC.
memset(temp_iv, 0, AES_BLOCK_SIZE);
aes_encrypt_cbc_mac(buf, end_of_buf, mac, key, keysize, temp_iv);
// Copy the Payload and MAC to the output buffer.
memcpy(out, payload, payload_len);
memcpy(&out[payload_len], mac, mac_len);
// Encrypt the Payload with CTR mode with a counter starting at 1.
memcpy(temp_iv, counter, AES_BLOCK_SIZE);
increment_iv(temp_iv, AES_BLOCK_SIZE - 1 - mac_len); // Last argument is the byte size of the counting portion of the counter block. /*BUG?*/
aes_encrypt_ctr(out, payload_len, out, key, keysize, temp_iv);
// Encrypt the MAC with CTR mode with a counter starting at 0.
aes_encrypt_ctr(&out[payload_len], mac_len, &out[payload_len], key, keysize, counter);
free(buf);
*out_len = payload_len + mac_len;
return(TRUE);
}
// plaintext_len = ciphertext_len - mac_len
// Needs a flag for whether the MAC matches.
int aes_decrypt_ccm(const BYTE ciphertext[], WORD ciphertext_len, const BYTE assoc[], unsigned short assoc_len,
const BYTE nonce[], unsigned short nonce_len, BYTE plaintext[], WORD *plaintext_len,
WORD mac_len, int *mac_auth, const BYTE key_str[], int keysize)
{
BYTE temp_iv[AES_BLOCK_SIZE], counter[AES_BLOCK_SIZE], mac[16], mac_buf[16], *buf;
int end_of_buf, plaintext_len_store_size;
WORD key[60];
if (ciphertext_len <= mac_len)
return(FALSE);
buf = (BYTE*)malloc(assoc_len + ciphertext_len /*ciphertext_len = plaintext_len + mac_len*/ + 48);
if (! buf)
return(FALSE);
// Prepare the key for usage.
aes_key_setup(key_str, key, keysize);
// Copy the plaintext and MAC to the output buffers.
*plaintext_len = ciphertext_len - mac_len;
plaintext_len_store_size = AES_BLOCK_SIZE - 1 - nonce_len;
memcpy(plaintext, ciphertext, *plaintext_len);
memcpy(mac, &ciphertext[*plaintext_len], mac_len);
// Prepare the first counter block for use in decryption.
ccm_prepare_first_ctr_blk(counter, nonce, nonce_len, plaintext_len_store_size);
// Decrypt the Payload with CTR mode with a counter starting at 1.
memcpy(temp_iv, counter, AES_BLOCK_SIZE);
increment_iv(temp_iv, AES_BLOCK_SIZE - 1 - mac_len); // (AES_BLOCK_SIZE - 1 - mac_len) is the byte size of the counting portion of the counter block.
aes_decrypt_ctr(plaintext, *plaintext_len, plaintext, key, keysize, temp_iv);
// Setting mac_auth to NULL disables the authentication check.
if (mac_auth != NULL) {
// Decrypt the MAC with CTR mode with a counter starting at 0.
aes_decrypt_ctr(mac, mac_len, mac, key, keysize, counter);
// Format the first block of the formatted data.
plaintext_len_store_size = AES_BLOCK_SIZE - 1 - nonce_len;
ccm_prepare_first_format_blk(buf, assoc_len, *plaintext_len, plaintext_len_store_size, mac_len, nonce, nonce_len);
end_of_buf = AES_BLOCK_SIZE;
// Format the Associated Data into the authentication buffer.
ccm_format_assoc_data(buf, &end_of_buf, assoc, assoc_len);
// Format the Payload into the authentication buffer.
ccm_format_payload_data(buf, &end_of_buf, plaintext, *plaintext_len);
// Perform the CBC operation with an IV of zeros on the formatted buffer to calculate the MAC.
memset(temp_iv, 0, AES_BLOCK_SIZE);
aes_encrypt_cbc_mac(buf, end_of_buf, mac_buf, key, keysize, temp_iv);
// Compare the calculated MAC against the MAC embedded in the ciphertext to see if they are the same.
if (! memcmp(mac, mac_buf, mac_len)) {
*mac_auth = TRUE;
}
else {
*mac_auth = FALSE;
memset(plaintext, 0, *plaintext_len);
}
}
free(buf);
return(TRUE);
}
// Creates the first counter block. First byte is flags, then the nonce, then the incremented part.
void ccm_prepare_first_ctr_blk(BYTE counter[], const BYTE nonce[], int nonce_len, int payload_len_store_size)
{
memset(counter, 0, AES_BLOCK_SIZE);
counter[0] = (payload_len_store_size - 1) & 0x07;
memcpy(&counter[1], nonce, nonce_len);
}
void ccm_prepare_first_format_blk(BYTE buf[], int assoc_len, int payload_len, int payload_len_store_size, int mac_len, const BYTE nonce[], int nonce_len)
{
// Set the flags for the first byte of the first block.
buf[0] = ((((mac_len - 2) / 2) & 0x07) << 3) | ((payload_len_store_size - 1) & 0x07);
if (assoc_len > 0)
buf[0] += 0x40;
// Format the rest of the first block, storing the nonce and the size of the payload.
memcpy(&buf[1], nonce, nonce_len);
memset(&buf[1 + nonce_len], 0, AES_BLOCK_SIZE - 1 - nonce_len);
buf[15] = payload_len & 0x000000FF;
buf[14] = (payload_len >> 8) & 0x000000FF;
}
void ccm_format_assoc_data(BYTE buf[], int *end_of_buf, const BYTE assoc[], int assoc_len)
{
int pad;
buf[*end_of_buf + 1] = assoc_len & 0x00FF;
buf[*end_of_buf] = (assoc_len >> 8) & 0x00FF;
*end_of_buf += 2;
memcpy(&buf[*end_of_buf], assoc, assoc_len);
*end_of_buf += assoc_len;
pad = AES_BLOCK_SIZE - (*end_of_buf % AES_BLOCK_SIZE); /*BUG?*/
memset(&buf[*end_of_buf], 0, pad);
*end_of_buf += pad;
}
void ccm_format_payload_data(BYTE buf[], int *end_of_buf, const BYTE payload[], int payload_len)
{
int pad;
memcpy(&buf[*end_of_buf], payload, payload_len);
*end_of_buf += payload_len;
pad = *end_of_buf % AES_BLOCK_SIZE;
if (pad != 0)
pad = AES_BLOCK_SIZE - pad;
memset(&buf[*end_of_buf], 0, pad);
*end_of_buf += pad;
}
/*******************
* AES
*******************/
/////////////////
// KEY EXPANSION
/////////////////
// Substitutes a word using the AES S-Box.
WORD SubWord(WORD word)
{
unsigned int result;
result = (int)aes_sbox[(word >> 4) & 0x0000000F][word & 0x0000000F];
result += (int)aes_sbox[(word >> 12) & 0x0000000F][(word >> 8) & 0x0000000F] << 8;
result += (int)aes_sbox[(word >> 20) & 0x0000000F][(word >> 16) & 0x0000000F] << 16;
result += (int)aes_sbox[(word >> 28) & 0x0000000F][(word >> 24) & 0x0000000F] << 24;
return(result);
}
// Performs the action of generating the keys that will be used in every round of
// encryption. "key" is the user-supplied input key, "w" is the output key schedule,
// "keysize" is the length in bits of "key", must be 128, 192, or 256.
void aes_key_setup(const BYTE key[], WORD w[], int keysize)
{
int Nb=4,Nr,Nk,idx;
WORD temp,Rcon[]={0x01000000,0x02000000,0x04000000,0x08000000,0x10000000,0x20000000,
0x40000000,0x80000000,0x1b000000,0x36000000,0x6c000000,0xd8000000,
0xab000000,0x4d000000,0x9a000000};
switch (keysize) {
case 128: Nr = 10; Nk = 4; break;
case 192: Nr = 12; Nk = 6; break;
case 256: Nr = 14; Nk = 8; break;
default: return;
}
for (idx=0; idx < Nk; ++idx) {
w[idx] = ((key[4 * idx]) << 24) | ((key[4 * idx + 1]) << 16) |
((key[4 * idx + 2]) << 8) | ((key[4 * idx + 3]));
}
for (idx = Nk; idx < Nb * (Nr+1); ++idx) {
temp = w[idx - 1];
if ((idx % Nk) == 0)
temp = SubWord(KE_ROTWORD(temp)) ^ Rcon[(idx-1)/Nk];
else if (Nk > 6 && (idx % Nk) == 4)
temp = SubWord(temp);
w[idx] = w[idx-Nk] ^ temp;
}
}
/////////////////
// ADD ROUND KEY
/////////////////
// Performs the AddRoundKey step. Each round has its own pre-generated 16-byte key in the
// form of 4 integers (the "w" array). Each integer is XOR'd by one column of the state.
// Also performs the job of InvAddRoundKey(); since the function is a simple XOR process,
// it is its own inverse.
void AddRoundKey(BYTE state[][4], const WORD w[])
{
BYTE subkey[4];
// memcpy(subkey,&w[idx],4); // Not accurate for big endian machines
// Subkey 1
subkey[0] = w[0] >> 24;
subkey[1] = w[0] >> 16;
subkey[2] = w[0] >> 8;
subkey[3] = w[0];
state[0][0] ^= subkey[0];
state[1][0] ^= subkey[1];
state[2][0] ^= subkey[2];
state[3][0] ^= subkey[3];
// Subkey 2
subkey[0] = w[1] >> 24;
subkey[1] = w[1] >> 16;
subkey[2] = w[1] >> 8;
subkey[3] = w[1];
state[0][1] ^= subkey[0];
state[1][1] ^= subkey[1];
state[2][1] ^= subkey[2];
state[3][1] ^= subkey[3];
// Subkey 3
subkey[0] = w[2] >> 24;
subkey[1] = w[2] >> 16;
subkey[2] = w[2] >> 8;
subkey[3] = w[2];
state[0][2] ^= subkey[0];
state[1][2] ^= subkey[1];
state[2][2] ^= subkey[2];
state[3][2] ^= subkey[3];
// Subkey 4
subkey[0] = w[3] >> 24;
subkey[1] = w[3] >> 16;
subkey[2] = w[3] >> 8;
subkey[3] = w[3];
state[0][3] ^= subkey[0];
state[1][3] ^= subkey[1];
state[2][3] ^= subkey[2];
state[3][3] ^= subkey[3];
}
/////////////////
// (Inv)SubBytes
/////////////////
// Performs the SubBytes step. All bytes in the state are substituted with a
// pre-calculated value from a lookup table.
void SubBytes(BYTE state[][4])
{
state[0][0] = aes_sbox[state[0][0] >> 4][state[0][0] & 0x0F];
state[0][1] = aes_sbox[state[0][1] >> 4][state[0][1] & 0x0F];
state[0][2] = aes_sbox[state[0][2] >> 4][state[0][2] & 0x0F];
state[0][3] = aes_sbox[state[0][3] >> 4][state[0][3] & 0x0F];
state[1][0] = aes_sbox[state[1][0] >> 4][state[1][0] & 0x0F];
state[1][1] = aes_sbox[state[1][1] >> 4][state[1][1] & 0x0F];
state[1][2] = aes_sbox[state[1][2] >> 4][state[1][2] & 0x0F];
state[1][3] = aes_sbox[state[1][3] >> 4][state[1][3] & 0x0F];
state[2][0] = aes_sbox[state[2][0] >> 4][state[2][0] & 0x0F];
state[2][1] = aes_sbox[state[2][1] >> 4][state[2][1] & 0x0F];
state[2][2] = aes_sbox[state[2][2] >> 4][state[2][2] & 0x0F];
state[2][3] = aes_sbox[state[2][3] >> 4][state[2][3] & 0x0F];
state[3][0] = aes_sbox[state[3][0] >> 4][state[3][0] & 0x0F];
state[3][1] = aes_sbox[state[3][1] >> 4][state[3][1] & 0x0F];
state[3][2] = aes_sbox[state[3][2] >> 4][state[3][2] & 0x0F];
state[3][3] = aes_sbox[state[3][3] >> 4][state[3][3] & 0x0F];
}
void InvSubBytes(BYTE state[][4])
{
state[0][0] = aes_invsbox[state[0][0] >> 4][state[0][0] & 0x0F];
state[0][1] = aes_invsbox[state[0][1] >> 4][state[0][1] & 0x0F];
state[0][2] = aes_invsbox[state[0][2] >> 4][state[0][2] & 0x0F];
state[0][3] = aes_invsbox[state[0][3] >> 4][state[0][3] & 0x0F];
state[1][0] = aes_invsbox[state[1][0] >> 4][state[1][0] & 0x0F];
state[1][1] = aes_invsbox[state[1][1] >> 4][state[1][1] & 0x0F];
state[1][2] = aes_invsbox[state[1][2] >> 4][state[1][2] & 0x0F];
state[1][3] = aes_invsbox[state[1][3] >> 4][state[1][3] & 0x0F];
state[2][0] = aes_invsbox[state[2][0] >> 4][state[2][0] & 0x0F];
state[2][1] = aes_invsbox[state[2][1] >> 4][state[2][1] & 0x0F];
state[2][2] = aes_invsbox[state[2][2] >> 4][state[2][2] & 0x0F];
state[2][3] = aes_invsbox[state[2][3] >> 4][state[2][3] & 0x0F];
state[3][0] = aes_invsbox[state[3][0] >> 4][state[3][0] & 0x0F];
state[3][1] = aes_invsbox[state[3][1] >> 4][state[3][1] & 0x0F];
state[3][2] = aes_invsbox[state[3][2] >> 4][state[3][2] & 0x0F];
state[3][3] = aes_invsbox[state[3][3] >> 4][state[3][3] & 0x0F];
}
/////////////////
// (Inv)ShiftRows
/////////////////
// Performs the ShiftRows step. All rows are shifted cylindrically to the left.
void ShiftRows(BYTE state[][4])
{
int t;
// Shift left by 1
t = state[1][0];
state[1][0] = state[1][1];
state[1][1] = state[1][2];
state[1][2] = state[1][3];
state[1][3] = t;
// Shift left by 2
t = state[2][0];
state[2][0] = state[2][2];
state[2][2] = t;
t = state[2][1];
state[2][1] = state[2][3];
state[2][3] = t;
// Shift left by 3
t = state[3][0];
state[3][0] = state[3][3];
state[3][3] = state[3][2];
state[3][2] = state[3][1];
state[3][1] = t;
}
// All rows are shifted cylindrically to the right.
void InvShiftRows(BYTE state[][4])
{
int t;
// Shift right by 1
t = state[1][3];
state[1][3] = state[1][2];
state[1][2] = state[1][1];
state[1][1] = state[1][0];
state[1][0] = t;
// Shift right by 2
t = state[2][3];
state[2][3] = state[2][1];
state[2][1] = t;
t = state[2][2];
state[2][2] = state[2][0];
state[2][0] = t;
// Shift right by 3
t = state[3][3];
state[3][3] = state[3][0];
state[3][0] = state[3][1];
state[3][1] = state[3][2];
state[3][2] = t;
}
/////////////////
// (Inv)MixColumns
/////////////////
// Performs the MixColums step. The state is multiplied by itself using matrix
// multiplication in a Galios Field 2^8. All multiplication is pre-computed in a table.
// Addition is equivilent to XOR. (Must always make a copy of the column as the original
// values will be destoyed.)
void MixColumns(BYTE state[][4])
{
BYTE col[4];
// Column 1
col[0] = state[0][0];
col[1] = state[1][0];
col[2] = state[2][0];
col[3] = state[3][0];
state[0][0] = gf_mul[col[0]][0];
state[0][0] ^= gf_mul[col[1]][1];
state[0][0] ^= col[2];
state[0][0] ^= col[3];
state[1][0] = col[0];
state[1][0] ^= gf_mul[col[1]][0];
state[1][0] ^= gf_mul[col[2]][1];
state[1][0] ^= col[3];
state[2][0] = col[0];
state[2][0] ^= col[1];
state[2][0] ^= gf_mul[col[2]][0];
state[2][0] ^= gf_mul[col[3]][1];
state[3][0] = gf_mul[col[0]][1];
state[3][0] ^= col[1];
state[3][0] ^= col[2];
state[3][0] ^= gf_mul[col[3]][0];
// Column 2
col[0] = state[0][1];
col[1] = state[1][1];
col[2] = state[2][1];
col[3] = state[3][1];
state[0][1] = gf_mul[col[0]][0];
state[0][1] ^= gf_mul[col[1]][1];
state[0][1] ^= col[2];
state[0][1] ^= col[3];
state[1][1] = col[0];
state[1][1] ^= gf_mul[col[1]][0];
state[1][1] ^= gf_mul[col[2]][1];
state[1][1] ^= col[3];
state[2][1] = col[0];
state[2][1] ^= col[1];
state[2][1] ^= gf_mul[col[2]][0];
state[2][1] ^= gf_mul[col[3]][1];
state[3][1] = gf_mul[col[0]][1];
state[3][1] ^= col[1];
state[3][1] ^= col[2];
state[3][1] ^= gf_mul[col[3]][0];
// Column 3
col[0] = state[0][2];
col[1] = state[1][2];
col[2] = state[2][2];
col[3] = state[3][2];
state[0][2] = gf_mul[col[0]][0];
state[0][2] ^= gf_mul[col[1]][1];
state[0][2] ^= col[2];
state[0][2] ^= col[3];
state[1][2] = col[0];
state[1][2] ^= gf_mul[col[1]][0];
state[1][2] ^= gf_mul[col[2]][1];
state[1][2] ^= col[3];
state[2][2] = col[0];
state[2][2] ^= col[1];
state[2][2] ^= gf_mul[col[2]][0];
state[2][2] ^= gf_mul[col[3]][1];
state[3][2] = gf_mul[col[0]][1];
state[3][2] ^= col[1];
state[3][2] ^= col[2];
state[3][2] ^= gf_mul[col[3]][0];
// Column 4
col[0] = state[0][3];
col[1] = state[1][3];
col[2] = state[2][3];
col[3] = state[3][3];
state[0][3] = gf_mul[col[0]][0];
state[0][3] ^= gf_mul[col[1]][1];
state[0][3] ^= col[2];
state[0][3] ^= col[3];
state[1][3] = col[0];
state[1][3] ^= gf_mul[col[1]][0];
state[1][3] ^= gf_mul[col[2]][1];
state[1][3] ^= col[3];
state[2][3] = col[0];
state[2][3] ^= col[1];
state[2][3] ^= gf_mul[col[2]][0];
state[2][3] ^= gf_mul[col[3]][1];
state[3][3] = gf_mul[col[0]][1];
state[3][3] ^= col[1];
state[3][3] ^= col[2];
state[3][3] ^= gf_mul[col[3]][0];
}
void InvMixColumns(BYTE state[][4])
{
BYTE col[4];
// Column 1
col[0] = state[0][0];
col[1] = state[1][0];
col[2] = state[2][0];
col[3] = state[3][0];
state[0][0] = gf_mul[col[0]][5];
state[0][0] ^= gf_mul[col[1]][3];
state[0][0] ^= gf_mul[col[2]][4];
state[0][0] ^= gf_mul[col[3]][2];
state[1][0] = gf_mul[col[0]][2];
state[1][0] ^= gf_mul[col[1]][5];
state[1][0] ^= gf_mul[col[2]][3];
state[1][0] ^= gf_mul[col[3]][4];
state[2][0] = gf_mul[col[0]][4];
state[2][0] ^= gf_mul[col[1]][2];
state[2][0] ^= gf_mul[col[2]][5];
state[2][0] ^= gf_mul[col[3]][3];
state[3][0] = gf_mul[col[0]][3];
state[3][0] ^= gf_mul[col[1]][4];
state[3][0] ^= gf_mul[col[2]][2];
state[3][0] ^= gf_mul[col[3]][5];
// Column 2
col[0] = state[0][1];
col[1] = state[1][1];
col[2] = state[2][1];
col[3] = state[3][1];
state[0][1] = gf_mul[col[0]][5];
state[0][1] ^= gf_mul[col[1]][3];
state[0][1] ^= gf_mul[col[2]][4];
state[0][1] ^= gf_mul[col[3]][2];
state[1][1] = gf_mul[col[0]][2];
state[1][1] ^= gf_mul[col[1]][5];
state[1][1] ^= gf_mul[col[2]][3];
state[1][1] ^= gf_mul[col[3]][4];
state[2][1] = gf_mul[col[0]][4];
state[2][1] ^= gf_mul[col[1]][2];
state[2][1] ^= gf_mul[col[2]][5];
state[2][1] ^= gf_mul[col[3]][3];
state[3][1] = gf_mul[col[0]][3];
state[3][1] ^= gf_mul[col[1]][4];
state[3][1] ^= gf_mul[col[2]][2];
state[3][1] ^= gf_mul[col[3]][5];
// Column 3
col[0] = state[0][2];
col[1] = state[1][2];
col[2] = state[2][2];
col[3] = state[3][2];
state[0][2] = gf_mul[col[0]][5];
state[0][2] ^= gf_mul[col[1]][3];
state[0][2] ^= gf_mul[col[2]][4];
state[0][2] ^= gf_mul[col[3]][2];
state[1][2] = gf_mul[col[0]][2];
state[1][2] ^= gf_mul[col[1]][5];
state[1][2] ^= gf_mul[col[2]][3];
state[1][2] ^= gf_mul[col[3]][4];
state[2][2] = gf_mul[col[0]][4];
state[2][2] ^= gf_mul[col[1]][2];
state[2][2] ^= gf_mul[col[2]][5];
state[2][2] ^= gf_mul[col[3]][3];
state[3][2] = gf_mul[col[0]][3];
state[3][2] ^= gf_mul[col[1]][4];
state[3][2] ^= gf_mul[col[2]][2];
state[3][2] ^= gf_mul[col[3]][5];
// Column 4
col[0] = state[0][3];
col[1] = state[1][3];
col[2] = state[2][3];
col[3] = state[3][3];
state[0][3] = gf_mul[col[0]][5];
state[0][3] ^= gf_mul[col[1]][3];
state[0][3] ^= gf_mul[col[2]][4];
state[0][3] ^= gf_mul[col[3]][2];
state[1][3] = gf_mul[col[0]][2];
state[1][3] ^= gf_mul[col[1]][5];
state[1][3] ^= gf_mul[col[2]][3];
state[1][3] ^= gf_mul[col[3]][4];
state[2][3] = gf_mul[col[0]][4];
state[2][3] ^= gf_mul[col[1]][2];
state[2][3] ^= gf_mul[col[2]][5];
state[2][3] ^= gf_mul[col[3]][3];
state[3][3] = gf_mul[col[0]][3];
state[3][3] ^= gf_mul[col[1]][4];
state[3][3] ^= gf_mul[col[2]][2];
state[3][3] ^= gf_mul[col[3]][5];
}
/////////////////
// (En/De)Crypt
/////////////////
void aes_encrypt(const BYTE in[], BYTE out[], const WORD key[], int keysize)
{
BYTE state[4][4];
// Copy input array (should be 16 bytes long) to a matrix (sequential bytes are ordered
// by row, not col) called "state" for processing.
// *** Implementation note: The official AES documentation references the state by
// column, then row. Accessing an element in C requires row then column. Thus, all state
// references in AES must have the column and row indexes reversed for C implementation.
state[0][0] = in[0];
state[1][0] = in[1];
state[2][0] = in[2];
state[3][0] = in[3];
state[0][1] = in[4];
state[1][1] = in[5];
state[2][1] = in[6];
state[3][1] = in[7];
state[0][2] = in[8];
state[1][2] = in[9];
state[2][2] = in[10];
state[3][2] = in[11];
state[0][3] = in[12];
state[1][3] = in[13];
state[2][3] = in[14];
state[3][3] = in[15];
// Perform the necessary number of rounds. The round key is added first.
// The last round does not perform the MixColumns step.
AddRoundKey(state,&key[0]);
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[4]);
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[8]);
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[12]);
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[16]);
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[20]);
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[24]);
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[28]);
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[32]);
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[36]);
if (keysize != 128) {
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[40]);
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[44]);
if (keysize != 192) {
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[48]);
SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[52]);
SubBytes(state); ShiftRows(state); AddRoundKey(state,&key[56]);
}
else {
SubBytes(state); ShiftRows(state); AddRoundKey(state,&key[48]);
}
}
else {
SubBytes(state); ShiftRows(state); AddRoundKey(state,&key[40]);
}
// Copy the state to the output array.
out[0] = state[0][0];
out[1] = state[1][0];
out[2] = state[2][0];
out[3] = state[3][0];
out[4] = state[0][1];
out[5] = state[1][1];
out[6] = state[2][1];
out[7] = state[3][1];
out[8] = state[0][2];
out[9] = state[1][2];
out[10] = state[2][2];
out[11] = state[3][2];
out[12] = state[0][3];
out[13] = state[1][3];
out[14] = state[2][3];
out[15] = state[3][3];
}