decode.c

#include <stdio.h>

#define MAX_FILE_SIZE (1024*1024*4)



int main( int argc, char *argv[] ) {

	char key[64];
	
	if( argc == 2 ) {		
		FILE *fptr;
		unsigned char* data = (char*)malloc(MAX_FILE_SIZE);
		
		fptr = fopen(argv[1], "rb");
		unsigned char original_hex[] = "\x35\x51\x9D\x36\xE0\x80\x3F\x0A\xF4\x29\x6A\x8E\x69\xE8\xCA\xF3\x49\xBD\x76\x81\x81\x50\x18\xB0\x06\x2A\x7D\x87\x34\x87\x8A\xEC\x5A\x18\x32\x12\x9E\xB4\xCC\x0C\x75\xA7\xB9\x23"; 
		
		int i = 0;
		while (!feof(fptr)) {
			data[i++] = fgetc(fptr);
		}
		
		fclose(fptr);
		
		int z;
		for(z=880 ; z<924 ; z++)
			key[z-880] = (data[z] ^ (original_hex[z-880]));
			
		
	}
	else if( argc > 2 ) {
		printf("Too many arguments supplied.\n");
	}
	else {
		printf("One argument expected.\n");
	}
	
	
	printf("Key: ");
	
	int j;
	for(j=0 ; j<44 ; j++)
		printf("%c", key[j]);
	printf("\n");
	
	return 0;
}