let password = rpassword::read_password().unwrap();
println!("Your password is {}", password);

// It is recommended to secure clear your password if it's not needed anymore. 
// You can use crates like zeroize or secstr to achive this.
use zeroize::Zeroize;
password.zeroize();

use std::io::{Error, ErrorKind};
let res = rpassword::ask_password("Enter your password:", |password: &str| {
    // consume your password here, and make sure the code SHALL NOT PANIC here!

    if password.isEmpty() { // if password is wrong, return PermissionDenied to tell user to try again
        println!("Wrong password, please try again.");
        // This will cause password to be ask again automatically, and the wrong one will be securely zeroize too.
        Err(Error::from(ErrorKind::PermissionDenied)) 
    }

    Ok(()) // You can return any other thing you need other than the unit type ().
});
//Password has already securely zeroized here, no matter whether it is wrong or not, if nothing panic above.

match res {
    // if user has retried for 3 times, ask_password will not continue retrying and return this error.
    Err(error) if error.kind() == ErrorKind::PermissionDenied => { 
        panic!(); // now you can panic!() if needed.
    },
    Err(error) => {
        // Any other error will cause ask_password to exit without retry.
    }
    _ => {}
};