encrypt_decrypt.c

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


void encrypt(char *str_in, char *str_out, int base)
{	
	for (size_t i = 0; str_in[i] != 0; i++) {
		sprintf(str_out + i * 2, "%02x", str_in[i] ^ base);  
	}
}

void decrypt(char *str_in, char *str_out, int base)
{
	char buffer[3];
	
	for (size_t i = 0; str_in[i] != 0; i += 2) {
		strncpy(buffer, str_in + i, 2);
		sprintf(str_out + strlen(str_out),"%c", strtol(buffer, NULL, 16) ^ base);
	}
}
 

int main(int argc, char ** argv) {  
	// 

	return 0;
}