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
|
#include <stdint.h>
#include <stdlib.h>
#include "twofish.h"
void Twofish_cfb128_encrypt(Twofish_key* keyCtx, Twofish_Byte* in,
Twofish_Byte* out, size_t len,
Twofish_Byte* ivec, int32_t *num)
{
uint32_t n;
n = *num;
do {
while (n && len) {
*(out++) = ivec[n] ^= *(in++);
--len;
n = (n+1) % 16;
}
while (len>=16) {
Twofish_encrypt(keyCtx, ivec, ivec);
for (n=0; n<16; n+=sizeof(size_t)) {
*(size_t*)(out+n) =
*(size_t*)(ivec+n) ^= *(size_t*)(in+n);
}
len -= 16;
out += 16;
in += 16;
}
n = 0;
if (len) {
Twofish_encrypt(keyCtx, ivec, ivec);
while (len--) {
out[n] = ivec[n] ^= in[n];
++n;
}
}
*num = n;
return;
} while (0);
}
void Twofish_cfb128_decrypt(Twofish_key* keyCtx, Twofish_Byte* in,
Twofish_Byte* out, size_t len,
Twofish_Byte* ivec, int32_t *num)
{
uint32_t n;
n = *num;
do {
while (n && len) {
unsigned char c;
*(out++) = ivec[n] ^ (c = *(in++)); ivec[n] = c;
--len;
n = (n+1) % 16;
}
while (len>=16) {
Twofish_encrypt(keyCtx, ivec, ivec);
for (n=0; n<16; n+=sizeof(size_t)) {
size_t t = *(size_t*)(in+n);
*(size_t*)(out+n) = *(size_t*)(ivec+n) ^ t;
*(size_t*)(ivec+n) = t;
}
len -= 16;
out += 16;
in += 16;
}
n = 0;
if (len) {
Twofish_encrypt(keyCtx, ivec, ivec);
while (len--) {
unsigned char c;
out[n] = ivec[n] ^ (c = in[n]); ivec[n] = c;
++n;
}
}
*num = n;
return;
} while (0);
}
|
