-
Notifications
You must be signed in to change notification settings - Fork 0
/
decrypt.c
46 lines (42 loc) · 1.1 KB
/
decrypt.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
#include <stdio.h>
#include <string.h>
#define BYTE unsigned char
int main(int argc, char **argv)
{
char *f1=argv[1], *f2=argv[2];
// strncmp(f1, argv[0], strchr(argv[0], '.')-argv[0]);
// strncmp(f2, argv[1], strchr(argv[1], '.')-argv[1]);
FILE *fp1=fopen(f1,"rb");
FILE *fp2=fopen(f2,"wb");
BYTE buffer[16]={};
BYTE hByte[2]={};
fread(hByte, sizeof(BYTE), 2, fp1);
fseek(fp1, 0, SEEK_SET);
BYTE header[2]={0xff, 0xd8};
for (int i=0; i < 2; i++)
{
hByte[i]=hByte[i] ^ header[i];
}
if (hByte[0] != hByte[1])
{
printf("Not valid WeChat data!\nExiting...\n");
fclose(fp1);
fclose(fp2);
return -1;
}
BYTE wd=hByte[0];
int i=0;
while (16==(i=fread(buffer, sizeof(BYTE), 16, fp1)))
{
for (int i=0; i < 16; i++)
{
buffer[i]=buffer[i] ^ wd;
}
fwrite(buffer, sizeof(BYTE), 16, fp2);
}
fwrite(buffer, sizeof(BYTE), i, fp2);
printf("Successfully decrypted!\n");
fclose(fp1);
fclose(fp2);
return 0;
}