Repeating Key XOR

gistfile1.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char result[512];
void char_to_hex(char char_input, int should_copy)
{
	char *result_char;
	switch(char_input)
	{
		case '\v': result_char = "0b"; break;
		case ' ': result_char = "20"; break;
		case '!': result_char = "21"; break;
		case '\"': result_char = "22"; break;
		case '#': result_char = "23"; break;
		case '$': result_char = "24"; break;
		case '%': result_char = "25"; break;
		case '&': result_char = "26"; break;
		case '\'': result_char = "27"; break;
		case '(': result_char = "28"; break;
		case ')': result_char = "29"; break;
		case '*': result_char = "2A"; break;
		case '+': result_char = "2B"; break;
		case ',': result_char = "2C"; break;
		case '-': result_char = "2D"; break;
		case '.': result_char = "2E"; break;
		case '/': result_char = "2F"; break;
		case '0': result_char = "30"; break;
		case '1': result_char = "31"; break;
		case '2': result_char = "32"; break;
		case '3': result_char = "33"; break;
		case '4': result_char = "34"; break;
		case '5': result_char = "35"; break;
		case '6': result_char = "36"; break;
		case '7': result_char = "37"; break;
		case '8': result_char = "38"; break;
		case '9': result_char = "39"; break;
		case ':': result_char = "3A"; break;
		case ';': result_char = "3B"; break;
		case '<': result_char = "3C"; break;
		case '=': result_char = "3D"; break;
		case '>': result_char = "3E"; break;
		case '?': result_char = "3F"; break;
		case '@': result_char = "40"; break;
		case 'A': result_char = "41"; break;
		case 'B': result_char = "42"; break;
		case 'C': result_char = "43"; break;
		case 'D': result_char = "44"; break;
		case 'E': result_char = "45"; break;
		case 'F': result_char = "46"; break;
		case 'G': result_char = "47"; break;
		case 'H': result_char = "48"; break;
		case 'I': result_char = "49"; break;
		case 'J': result_char = "4A"; break;
		case 'K': result_char = "4B"; break;
		case 'L': result_char = "4C"; break;
		case 'M': result_char = "4D"; break;
		case 'N': result_char = "4E"; break;
		case 'O': result_char = "4F"; break;
		case 'P': result_char = "50"; break;
		case 'Q': result_char = "51"; break;
		case 'R': result_char = "52"; break;
		case 'S': result_char = "53"; break;
		case 'T': result_char = "54"; break;
		case 'U': result_char = "55"; break;
		case 'V': result_char = "56"; break;
		case 'W': result_char = "57"; break;
		case 'X': result_char = "58"; break;
		case 'Y': result_char = "59"; break;
		case 'Z': result_char = "5A"; break;
		case '[': result_char = "5B"; break;
		case '\\': result_char = "5C"; break;
		case ']': result_char = "5D"; break;
		case '^': result_char = "5E"; break;
		case '_': result_char = "5F"; break;
		case '`': result_char = "60"; break;
		case 'a': result_char = "61"; break;
		case 'b': result_char = "62"; break;
		case 'c': result_char = "63"; break;
		case 'd': result_char = "64"; break;
		case 'e': result_char = "65"; break;
		case 'f': result_char = "66"; break;
		case 'g': result_char = "67"; break;
		case 'h': result_char = "68"; break;
		case 'i': result_char = "69"; break;
		case 'j': result_char = "6A"; break;
		case 'k': result_char = "6B"; break;
		case 'l': result_char = "6C"; break;
		case 'm': result_char = "6D"; break;
		case 'n': result_char = "6E"; break;
		case 'o': result_char = "6F"; break;
		case 'p': result_char = "70"; break;
		case 'q': result_char = "71"; break;
		case 'r': result_char = "72"; break;
		case 's': result_char = "73"; break;
		case 't': result_char = "74"; break;
		case 'u': result_char = "75"; break;
		case 'v': result_char = "76"; break;
		case 'w': result_char = "77"; break;
		case 'x': result_char = "78"; break;
		case 'y': result_char = "79"; break;
		case 'z': result_char = "7A"; break;
		case '{': result_char = "7B"; break;
		case '|': result_char = "7C"; break;
		case '}': result_char = "7D"; break;
		case '~': result_char = "7E"; break;
	}
	if (should_copy == 0)
	{
		strcpy(result, result_char);
	}
	else
	{
		strcat(result, result_char);
	}
}

int main(int argc, char *argv[])
{
	int i = 0;
	int j = 0;
	int k = 0;
	int l = 0;
	int I = 'I';
	int C = 'C';
	int E = 'E';
	char temp[512];
	for (i = 0; i < strlen(argv[1]); i+=3)
	{
		temp[i] = argv[1][i] ^ I;
	}
	for (j = 1; j < strlen(argv[1]); j+=3)
	{
		temp[j] = argv[1][j] ^ C;
	}
	for (k = 2; k < strlen(argv[1]); k+=3)
	{
		temp[k] = argv[1][k] ^ E;
	}
	for (l = 0; l < strlen(temp); l++)
	{
		char_to_hex(temp[l], l);
	}
	printf("%s\n", result);
	return 0;
}