bof2.c

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

int login(char *password) {
	int secret = 0;
	char buffer[16]; 
	strcpy(buffer, password); 

	if (secret == 0x231da6e1){
		printf("Welcome! ;)\n");
		secret = 1;
	} else {
		printf("Access Denied.\n");
	}
}

int main(int argc, char *argv[]) {
	if (argc > 1)
		login(argv[1]);
	return 0;
}