rgp 0.5.2

Enabling E2EE for a range of applications.
Documentation 
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/*
Copyright (c) 2026 Ordinary Labs, LLC

SPDX-License-Identifier: AGPL-3.0-only
*/

use std::error::Error;
use std::fs::{File, OpenOptions, remove_file};
use std::io::Write;

use rgp::{
    Components, Decrypt, Encrypt, KemKeyReader, decrypt, encrypt, extract_components_mut,
    generate_fingerprint, generate_kem_keys,
};

pub fn main() -> Result<(), Box<dyn Error>> {
    let (fingerprint, verifier) = generate_fingerprint();

    let (recipient_secret_key, recipient_pub_key) = generate_kem_keys();

    // 5mb
    let content = vec![0u8; 5_000_000];

    // create pub key file and open in append mode
    let mut pub_keys_file = OpenOptions::new()
        .create(true)
        .write(true)
        .append(true)
        .open("example_kem_pub_keys")?;

    // write first recipient's pub key to pub key file
    pub_keys_file.write_all(&recipient_pub_key)?;
    pub_keys_file.flush()?;

    // write additional 50 recipient keys to file
    for _ in 0..50 {
        let (_, pub_key) = generate_kem_keys();

        pub_keys_file.write_all(&pub_key)?;
        pub_keys_file.flush()?;
    }

    // initialize public key reader for McEliece pub key file
    let key_reader = KemKeyReader::new(File::open("example_kem_pub_keys")?);

    // encrypt message for all recipients
    let (mut encrypted_content, content_key) =
        encrypt(fingerprint, content.clone(), Encrypt::Kem(key_reader))?;

    // extract encrypted content key and ciphertext at position 0
    if let Components::Kem(encrypted_key, ciphertext, _) =
        extract_components_mut(0, &mut encrypted_content)
    {
        // decrypt message with encrypted content key ciphertext
        let (decrypted_content, decrypted_content_key) = decrypt(
            Some(&verifier),
            &encrypted_content,
            Decrypt::Kem(
                encrypted_key,
                ciphertext,
                Box::new(recipient_secret_key),
                None,
            ),
        )?;

        assert_eq!(decrypted_content, content);
        assert_eq!(decrypted_content_key, content_key);
    };

    remove_file("example_kem_pub_keys")?;

    Ok(())
}