Password input from stdin using curse getch()

stdin-password.c

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

int getch();

const char ENTER_KEY = '\n';
const char BACKSPACE_KEY = (char) 127;

char *get_password() {
	char buffer[160];
	char read;
	int index = 0;

	read = (char) getch();
	while (ENTER_KEY != read) {
		if (BACKSPACE_KEY == read) {
			if (index > 0) {
				printf("%s", "\b \b");
				index--;
			}
		} else {
			buffer[index] = read;
			index++;
			printf("*");
		}

		read = (char) getch();
	}

	printf("\n");
	buffer[index] = '\0';
	return strdup(buffer);
}

int main() {
	char *correct_password = "@(abcd123)";
	char *input_password;

	int attempts = 0;
	int max_attempts = 3;

	int valid_password = 0;

	while (attempts < max_attempts) {
		printf("Enter password: ");
		input_password = get_password();

		if (strcmp(correct_password, input_password) == 0) {
			valid_password = 1;
			break;
		}
		attempts++;
	}

	if (valid_password == 1) {
		printf("PASSWORD CORRECT!");
	} else {
		printf("%d INCORRECT PASSWORD ATTEMPTS", attempts);
	}
	printf("\n");
	return 0;
}

int getch() {
  /*
   * Copied from:
   * https://stackoverflow.com/questions/3276546/how-to-implement-getch-function-of-c-in-linux#23035044
   */
	struct termios oldattr, newattr;
	int ch;
	tcgetattr(STDIN_FILENO, &oldattr);
	newattr = oldattr;
	newattr.c_lflag &= ~(ICANON | ECHO);
	tcsetattr(STDIN_FILENO, TCSANOW, &newattr);
	ch = getchar();
	tcsetattr(STDIN_FILENO, TCSANOW, &oldattr);
	return ch;
}