Sequoia symmetric encryption example

Cargo.toml

[package]
name = "sequoia-test"
version = "0.1.0"
edition = "2021"

[[bin]]
name = "sequoia-test-password"
path = "password.rs"

[[bin]]
name = "sequoia-test-recipient"
path = "recipient.rs"

[dependencies]
sequoia-openpgp = "1.22"

password.rs

//use openpgp::serialize::stream::padding::Padder;
use openpgp::serialize::stream::{Encryptor2, LiteralWriter, Message};
use sequoia_openpgp as openpgp;
use std::fs;
use std::io::Write;

fn main() {
    let mut file = fs::OpenOptions::new()
        .create(true)
        .write(true)
        .truncate(true)
        .open("test.gpg")
        .unwrap();

    let message = Encryptor2::with_passwords(Message::new(&mut file), Some("password"))
        .build()
        .unwrap();
    //let message = Padder::new(message).build().unwrap();
    let mut w = LiteralWriter::new(message).build().unwrap();
    w.write_all(b"").unwrap();
    w.finalize().unwrap();
}

recipient.rs

use openpgp::cert::prelude::*;
use openpgp::parse::Parse;
use openpgp::policy::StandardPolicy;
//use openpgp::serialize::stream::padding::Padder;
use openpgp::serialize::stream::{Encryptor2, LiteralWriter, Message};
use sequoia_openpgp as openpgp;
use std::fs;
use std::io::Write;

fn main() {
    // mkdir gnupg-test-dir
    // gpg --homedir gnupg-test-dir --generate-key
    // gpg --homedir gnupg-test-dir --export --armour > pub.key
    let cert = Cert::from_file("pub.key").unwrap();
    //println!("{:?}", cert);

    let p = &StandardPolicy::new();
    let recipients = cert
        .keys()
        .with_policy(p, None)
        .supported()
        .alive()
        .revoked(false)
        .for_storage_encryption();

    let mut file = fs::OpenOptions::new()
        .create(true)
        .write(true)
        .truncate(true)
        .open("test.gpg")
        .unwrap();

    let message = Message::new(&mut file);
    let message = Encryptor2::for_recipients(message, recipients)
        .build()
        .unwrap();
    //let message = Padder::new(message).build().unwrap();
    let mut w = LiteralWriter::new(message).build().unwrap();
    w.write_all(b"Hello world.").unwrap();
    w.finalize().unwrap();
}