-
Notifications
You must be signed in to change notification settings - Fork 0
/
key_gen_aes.c
51 lines (40 loc) · 1.32 KB
/
key_gen_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
#include <stdio.h>
int main(int before_gen_k[4][4], int round){ /*get key into before_gen_k, get the round of encryption*/
int r_con[4][10] = {{0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36},
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}};
/*Just a tested matrix*/
/*int mat[4][4] = {{0x2b, 0x28, 0xab, 0x09},
{0x7e, 0xae, 0xf7, 0xcf},
{0x15, 0xd2, 0x15, 0x4f},
{0x16, 0xa6, 0x88, 0x3c}};*/
int i, j, temp, after_gen_k[4][4], k_sub_byte[4][1];
/*rot word
[a] ----- [b]
[b] | [c]
[c] | [d]
[d] -----> [a] */
temp = before_gen_k[0][3];
before_gen_k[0][3] = before_gen_k[1][3];
before_gen_k[1][3] = before_gen_k[2][3];
before_gen_k[2][3] = before_gen_k[3][3];
before_gen_k[3][3] = temp;
/*s_box*/
k_sub_byte = sub_byte(before_gen_k); /*sub_byte only last column*/
for(i=0; i<4; i++){
for(j=0; j<4; j++){
if (i==0)
{
after_gen_k[j][i] = before_gen_k[j][i] ^ k_sub_byte[j][0] ^ r_con[j][round];
/*put the generated key to after_gen_k*/
}
else
{
after_gen_k[j][i] = before_gen_k[j][i] ^ after_gen_k[j][i-1];
/*put the generated key to after_gen_k*/
}
}
}
return after_gen_k;
}