1. #include <iostream>
2. #include <fstream>
3. #include <iomanip>
4. #include <stdio.h>
5.  
6. using namespace std;
7.  
8.  
9.  
10. void swap ( unsigned char* S, unsigned char* B ){
11.  
12.         char temp = *S;
13.         *S = *B;
14.         *B = temp;
15. }
16.  
17. unsigned char* KeyInit ( char* key, int key_length ){
18.  
19.         unsigned char* s = ( unsigned char* ) calloc ( 256, sizeof ( unsigned char ) );
20.  
21.         for ( int k = 0; k < 256; k++ )
22.         {
23.                 s[k] = k;
24.         }
25.  
26.         int j = 0;
27.  
28.         for ( int i = 0; i < 256; i++ )
29.         {
30.                 j = ( j + s[i] + key[i % key_length] ) % 256;
31.                 swap ( s[i], s[j] );
32.         }
33.  
34.         return s;
35.  
36. }
37.  
38. void RandomGen ( unsigned char* S, int len, unsigned char* w ){
39.  
40.         int i = 0;
41.         int j = 0;
42.  
43.         for ( int k = 0; k < len; k++ ){
44.                 i = ( i + 1 ) % 256;
45.                 j = ( j + S[i] ) % 256;
46.                 swap ( S[i], S[j] );
47.                 w[k] = ( S[( S[i] + S[j] ) % 256] );
48.         }
49.  
50. }
51.  
52. void Encrypt ( char* S, int len, unsigned char* w, unsigned char* X ){
53.  
54.         for ( int k = 0; k < len; k++ )
55.                 X[k] = S[k] ^ w[k];
56. }
57.  
58. int main ()
59. {
60.         char key[] = "Secret";
61.  
62.         /*ifstream file;
63.         file.open ( "message.txt", ios::binary );
64.         if ( !file ){
65.  
66.                 perror ( "file not found" );
67.                 return 1;
68.         }*/
69.         FILE* fin = NULL;
70.         fpos_t length = 0;
71.         fin = fopen ( "message.txt", "rb" );
72.         if ( !fin ){
73.                 perror ( "file not found" );
74.                 return 1;
75.  
76.         }
77.         fseek ( fin, 0, SEEK_END );
78.         fgetpos ( fin, &length );
79.  
80.         char* message = ( char* ) calloc ( length, sizeof ( char ) );
81.         rewind ( fin );
82.  
83.         for ( int i = 0; i < length; i++ )
84.                 fscanf ( fin, "%c", &message[i] );
85.  
86.         fclose ( fin );
87.  
88.         unsigned char* w = ( unsigned char* ) calloc ( length, sizeof ( unsigned char ) );
89.  
90.         unsigned char* S = KeyInit ( key, ( sizeof ( key ) / sizeof ( char ) ) - 1 );
91.  
92.         RandomGen ( S, length, w );
93.  
94.         unsigned char* X = ( unsigned char* ) calloc ( length, sizeof ( unsigned char ) );
95.  
96.         Encrypt ( message, length, w, X );
97.  
98.  
99.         FILE* fout = NULL;
100.         fout = fopen ( "result.txt", "w" );
101.         if ( !fout ){
102.                 perror ( "file not found" );
103.                 return 2;
104.         }
105.  
106.  
107.  
108.         for ( size_t i = 0; i < length; i++ )
109.                 //fputc ((int)i, fout );
110.                 //fwrite ( (int)5, sizeof ( char ), length, fout ) ;
111.                 fprintf ( fout, "%02x", X[i] );
112.                 //printf ( "%02x\n", X[i] );
113.  
114.                 fclose ( fout );
115.  
116.  
117.  
118.  
119.         return 0;
120.  
121. }