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
|
/*
* Copyright (c) 2001, Dr Brian Gladman <brg@gladman.uk.net>, Worcester, UK.
* All rights reserved.
*
* LICENSE TERMS
*
* The free distribution and use of this software in both source and binary
* form is allowed (with or without changes) provided that:
*
* 1. distributions of this source code include the above copyright
* notice, this list of conditions and the following disclaimer;
*
* 2. distributions in binary form include the above copyright
* notice, this list of conditions and the following disclaimer
* in the documentation and/or other associated materials;
*
* 3. the copyright holder's name is not used to endorse products
* built using this software without specific written permission.
*
* DISCLAIMER
*
* This software is provided 'as is' with no explcit or implied warranties
* in respect of any properties, including, but not limited to, correctness
* and fitness for purpose.
*/
/*
* Issue Date: 21/01/2002
*
* This file contains the code for implementing the key schedule for AES
* (Rijndael) for block and key sizes of 16, 20, 24, 28 and 32 bytes.
*/
#include "aesopt.h"
/* Subroutine to set the block size (if variable) in bytes, legal
values being 16, 24 and 32.
*/
#if !defined(BLOCK_SIZE) && defined(SET_BLOCK_LENGTH)
/* Subroutine to set the block size (if variable) in bytes, legal
values being 16, 24 and 32.
*/
aes_rval aes_blk_len(unsigned int blen, aes_ctx cx[1])
{
#if !defined(FIXED_TABLES)
if(!tab_init) gen_tabs();
#endif
if((blen & 3) || blen < 16 || blen > 32)
{
cx->n_blk = 0; return aes_bad;
}
cx->n_blk = blen;
return aes_good;
}
#endif
/* Initialise the key schedule from the user supplied key. The key
length is now specified in bytes - 16, 24 or 32 as appropriate.
This corresponds to bit lengths of 128, 192 and 256 bits, and
to Nk values of 4, 6 and 8 respectively.
The following macros implement a single cycle in the key
schedule generation process. The number of cycles needed
for each cx->n_blk and nk value is:
nk = 4 5 6 7 8
------------------------------
cx->n_blk = 4 10 9 8 7 7
cx->n_blk = 5 14 11 10 9 9
cx->n_blk = 6 19 15 12 11 11
cx->n_blk = 7 21 19 16 13 14
cx->n_blk = 8 29 23 19 17 14
*/
/* Initialise the key schedule from the user supplied key. The key
length is now specified in bytes - 16, 20, 24, 28 or 32 as
appropriate. This corresponds to bit lengths of 128, 160, 192,
224 and 256 bits, and to Nk values of 4, 5, 6, 7 & 8 respectively.
*/
#define mx(t,f) (*t++ = inv_mcol(*f),f++)
#define cp(t,f) *t++ = *f++
#if BLOCK_SIZE == 16
#define cpy(d,s) cp(d,s); cp(d,s); cp(d,s); cp(d,s)
#define mix(d,s) mx(d,s); mx(d,s); mx(d,s); mx(d,s)
#elif BLOCK_SIZE == 20
#define cpy(d,s) cp(d,s); cp(d,s); cp(d,s); cp(d,s); \
cp(d,s)
#define mix(d,s) mx(d,s); mx(d,s); mx(d,s); mx(d,s); \
mx(d,s)
#elif BLOCK_SIZE == 24
#define cpy(d,s) cp(d,s); cp(d,s); cp(d,s); cp(d,s); \
cp(d,s); cp(d,s)
#define mix(d,s) mx(d,s); mx(d,s); mx(d,s); mx(d,s); \
mx(d,s); mx(d,s)
#elif BLOCK_SIZE == 28
#define cpy(d,s) cp(d,s); cp(d,s); cp(d,s); cp(d,s); \
cp(d,s); cp(d,s); cp(d,s)
#define mix(d,s) mx(d,s); mx(d,s); mx(d,s); mx(d,s); \
mx(d,s); mx(d,s); mx(d,s)
#elif BLOCK_SIZE == 32
#define cpy(d,s) cp(d,s); cp(d,s); cp(d,s); cp(d,s); \
cp(d,s); cp(d,s); cp(d,s); cp(d,s)
#define mix(d,s) mx(d,s); mx(d,s); mx(d,s); mx(d,s); \
mx(d,s); mx(d,s); mx(d,s); mx(d,s)
#else
#define cpy(d,s) \
switch(nc) \
{ case 8: cp(d,s); \
case 7: cp(d,s); \
case 6: cp(d,s); \
case 5: cp(d,s); \
case 4: cp(d,s); cp(d,s); \
cp(d,s); cp(d,s); \
}
#define mix(d,s) \
switch(nc) \
{ case 8: mx(d,s); \
case 7: mx(d,s); \
case 6: mx(d,s); \
case 5: mx(d,s); \
case 4: mx(d,s); mx(d,s); \
mx(d,s); mx(d,s); \
}
#endif
/* The following macros implement a single cycle in the key
schedule generation process. The number of cycles needed
for each cx->n_blk and nk value is:
nk = 4 5 6 7 8
-----------------------
cx->n_blk = 4 10 9 8 7 7
cx->n_blk = 5 14 11 10 9 9
cx->n_blk = 6 19 15 12 11 11
cx->n_blk = 7 21 19 16 13 14
cx->n_blk = 8 29 23 19 17 14
*/
#define ks4(i) \
{ p ^= ls_box(s,3) ^ rcon_tab[i]; q ^= p; r ^= q; s ^= r; \
cx->k_sch[4*(i)+4] = p; \
cx->k_sch[4*(i)+5] = q; \
cx->k_sch[4*(i)+6] = r; \
cx->k_sch[4*(i)+7] = s; \
}
#define ks5(i) \
{ p ^= ls_box(t,3) ^ rcon_tab[i]; q ^= p; \
r ^= q; s ^= r; t ^= s; \
cx->k_sch[5*(i)+ 5] = p; \
cx->k_sch[5*(i)+ 6] = q; \
cx->k_sch[5*(i)+ 7] = r; \
cx->k_sch[5*(i)+ 8] = s; \
cx->k_sch[5*(i)+ 9] = t; \
}
#define ks6(i) \
{ p ^= ls_box(u,3) ^ rcon_tab[i]; q ^= p; \
r ^= q; s ^= r; t ^= s; u ^= t; \
cx->k_sch[6*(i)+ 6] = p; \
cx->k_sch[6*(i)+ 7] = q; \
cx->k_sch[6*(i)+ 8] = r; \
cx->k_sch[6*(i)+ 9] = s; \
cx->k_sch[6*(i)+10] = t; \
cx->k_sch[6*(i)+11] = u; \
}
#define ks7(i) \
{ p ^= ls_box(v,3) ^ rcon_tab[i]; q ^= p; r ^= q; s ^= r; \
t ^= ls_box(s,0); u ^= t; v ^= u; \
cx->k_sch[7*(i)+ 7] = p; \
cx->k_sch[7*(i)+ 8] = q; \
cx->k_sch[7*(i)+ 9] = r; \
cx->k_sch[7*(i)+10] = s; \
cx->k_sch[7*(i)+11] = t; \
cx->k_sch[7*(i)+12] = u; \
cx->k_sch[7*(i)+13] = v; \
}
#define ks8(i) \
{ p ^= ls_box(w,3) ^ rcon_tab[i]; q ^= p; r ^= q; s ^= r; \
t ^= ls_box(s,0); u ^= t; v ^= u; w ^= v; \
cx->k_sch[8*(i)+ 8] = p; \
cx->k_sch[8*(i)+ 9] = q; \
cx->k_sch[8*(i)+10] = r; \
cx->k_sch[8*(i)+11] = s; \
cx->k_sch[8*(i)+12] = t; \
cx->k_sch[8*(i)+13] = u; \
cx->k_sch[8*(i)+14] = v; \
cx->k_sch[8*(i)+15] = w; \
}
#if defined(ENCRYPTION_KEY_SCHEDULE)
aes_rval aes_enc_key(const unsigned char in_key[], unsigned int klen, aes_ctx cx[1])
{ uint32_t i,p,q,r,s,t,u,v,w;
#if !defined(FIXED_TABLES)
if(!tab_init) gen_tabs();
#endif
#if !defined(BLOCK_SIZE)
if(!cx->n_blk) cx->n_blk = 16;
#else
cx->n_blk = BLOCK_SIZE;
#endif
cx->n_blk = (cx->n_blk & ~3) | 1;
cx->n_rnd = ((klen >> 2) > nc ? (klen >> 2) : nc) + 6;
cx->k_sch[0] = p = word_in(in_key );
cx->k_sch[1] = q = word_in(in_key + 4);
cx->k_sch[2] = r = word_in(in_key + 8);
cx->k_sch[3] = s = word_in(in_key + 12);
#if BLOCK_SIZE == 16 && defined(UNROLL)
switch(klen >> 2)
{
case 4: ks4(0); ks4(1); ks4(2); ks4(3);
ks4(4); ks4(5); ks4(6); ks4(7);
ks4(8); ks4(9);
cx->n_rnd = 10; break;
case 5: cx->k_sch[4] = t = word_in(in_key + 16);
ks5(0); ks5(1); ks5(2); ks5(3);
ks5(4); ks5(5); ks5(6); ks5(7);
ks5(8);
cx->n_rnd = 11; break;
case 6: cx->k_sch[4] = t = word_in(in_key + 16);
cx->k_sch[5] = u = word_in(in_key + 20);
ks6(0); ks6(1); ks6(2); ks6(3);
ks6(4); ks6(5); ks6(6); ks6(7);
cx->n_rnd = 12; break;
case 7: cx->k_sch[4] = t = word_in(in_key + 16);
cx->k_sch[5] = u = word_in(in_key + 20);
cx->k_sch[6] = v = word_in(in_key + 24);
ks7(0); ks7(1); ks7(2); ks7(3);
ks7(4); ks7(5); ks7(6);
cx->n_rnd = 13; break;
case 8: cx->k_sch[4] = t = word_in(in_key + 16);
cx->k_sch[5] = u = word_in(in_key + 20);
cx->k_sch[6] = v = word_in(in_key + 24);
cx->k_sch[7] = w = word_in(in_key + 28);
ks8(0); ks8(1); ks8(2); ks8(3);
ks8(4); ks8(5); ks8(6);
cx->n_rnd = 14; break;
default:cx->n_rnd = 0; return aes_bad;
}
#else
cx->n_rnd = ((klen >> 2) > nc ? (klen >> 2) : nc) + 6;
{
uint32_t l = (nc * (cx->n_rnd + 1) - 1) / (klen >> 2);
switch(klen >> 2)
{
case 4: for(i = 0; i < l; ++i)
ks4(i);
break;
case 5: cx->k_sch[4] = t = word_in(in_key + 16);
for(i = 0; i < l; ++i)
ks5(i);
break;
case 6: cx->k_sch[4] = t = word_in(in_key + 16);
cx->k_sch[5] = u = word_in(in_key + 20);
for(i = 0; i < l; ++i)
ks6(i);
break;
case 7: cx->k_sch[4] = t = word_in(in_key + 16);
cx->k_sch[5] = u = word_in(in_key + 20);
cx->k_sch[6] = v = word_in(in_key + 24);
for(i = 0; i < l; ++i)
ks7(i);
break;
case 8: cx->k_sch[4] = t = word_in(in_key + 16);
cx->k_sch[5] = u = word_in(in_key + 20);
cx->k_sch[6] = v = word_in(in_key + 24);
cx->k_sch[7] = w = word_in(in_key + 28);
for(i = 0; i < l; ++i)
ks8(i);
break;
}
}
#endif
return aes_good;
}
#endif
#if defined(DECRYPTION_KEY_SCHEDULE)
aes_rval aes_dec_key(const unsigned char in_key[], unsigned int klen, aes_ctx cx[1])
{ uint32_t i,p,q,r,s,t,u,v,w;
dec_imvars
#if !defined(FIXED_TABLES)
if(!tab_init) gen_tabs();
#endif
#if !defined(BLOCK_SIZE)
if(!cx->n_blk) cx->n_blk = 16;
#else
cx->n_blk = BLOCK_SIZE;
#endif
cx->n_blk = (cx->n_blk & ~3) | 2;
cx->n_rnd = ((klen >> 2) > nc ? (klen >> 2) : nc) + 6;
cx->k_sch[0] = p = word_in(in_key );
cx->k_sch[1] = q = word_in(in_key + 4);
cx->k_sch[2] = r = word_in(in_key + 8);
cx->k_sch[3] = s = word_in(in_key + 12);
#if BLOCK_SIZE == 16 && defined(UNROLL)
switch(klen >> 2)
{
case 4: ks4(0); ks4(1); ks4(2); ks4(3);
ks4(4); ks4(5); ks4(6); ks4(7);
ks4(8); ks4(9);
cx->n_rnd = 10; break;
case 5: cx->k_sch[4] = t = word_in(in_key + 16);
ks5(0); ks5(1); ks5(2); ks5(3);
ks5(4); ks5(5); ks5(6); ks5(7);
ks5(8);
cx->n_rnd = 11; break;
case 6: cx->k_sch[4] = t = word_in(in_key + 16);
cx->k_sch[5] = u = word_in(in_key + 20);
ks6(0); ks6(1); ks6(2); ks6(3);
ks6(4); ks6(5); ks6(6); ks6(7);
cx->n_rnd = 12; break;
case 7: cx->k_sch[4] = t = word_in(in_key + 16);
cx->k_sch[5] = u = word_in(in_key + 20);
cx->k_sch[6] = v = word_in(in_key + 24);
ks7(0); ks7(1); ks7(2); ks7(3);
ks7(4); ks7(5); ks7(6);
cx->n_rnd = 13; break;
case 8: cx->k_sch[4] = t = word_in(in_key + 16);
cx->k_sch[5] = u = word_in(in_key + 20);
cx->k_sch[6] = v = word_in(in_key + 24);
cx->k_sch[7] = w = word_in(in_key + 28);
ks8(0); ks8(1); ks8(2); ks8(3);
ks8(4); ks8(5); ks8(6);
cx->n_rnd = 14; break;
default:cx->n_rnd = 0; return aes_bad;
}
#else
cx->n_rnd = ((klen >> 2) > nc ? (klen >> 2) : nc) + 6;
{
uint32_t l = (nc * (cx->n_rnd + 1) - 1) / (klen >> 2);
switch(klen >> 2)
{
case 4: for(i = 0; i < l; ++i)
ks4(i);
break;
case 5: cx->k_sch[4] = t = word_in(in_key + 16);
for(i = 0; i < l; ++i)
ks5(i);
break;
case 6: cx->k_sch[4] = t = word_in(in_key + 16);
cx->k_sch[5] = u = word_in(in_key + 20);
for(i = 0; i < l; ++i)
ks6(i);
break;
case 7: cx->k_sch[4] = t = word_in(in_key + 16);
cx->k_sch[5] = u = word_in(in_key + 20);
cx->k_sch[6] = v = word_in(in_key + 24);
for(i = 0; i < l; ++i)
ks7(i);
break;
case 8: cx->k_sch[4] = t = word_in(in_key + 16);
cx->k_sch[5] = u = word_in(in_key + 20);
cx->k_sch[6] = v = word_in(in_key + 24);
cx->k_sch[7] = w = word_in(in_key + 28);
for(i = 0; i < l; ++i)
ks8(i);
break;
}
}
#endif
#if (DEC_ROUND != NO_TABLES)
for(i = nc; i < nc * cx->n_rnd; ++i)
cx->k_sch[i] = inv_mcol(cx->k_sch[i]);
#endif
return aes_good;
}
#endif
|
