tari_wallet 0.8.1

// Copyright 2020. The Tari Project
//
// Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
// following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
// disclaimer.
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// 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
// following disclaimer in the documentation and/or other materials provided with the distribution.
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// 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote
// products derived from this software without specific prior written permission.
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// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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use aes_gcm::{
    aead::{generic_array::GenericArray, Aead, Error as AeadError},
    Aes256Gcm,
};
use rand::{rngs::OsRng, RngCore};

pub const AES_NONCE_BYTES: usize = 12;
pub const AES_KEY_BYTES: usize = 32;

pub trait Encryptable<C> {
    fn encrypt(&mut self, cipher: &C) -> Result<(), AeadError>;
    fn decrypt(&mut self, cipher: &C) -> Result<(), AeadError>;
}

pub fn decrypt_bytes_integral_nonce(cipher: &Aes256Gcm, ciphertext: Vec<u8>) -> Result<Vec<u8>, AeadError> {
    if ciphertext.len() < AES_NONCE_BYTES {
        return Err(AeadError);
    }
    let (nonce, cipher_text) = ciphertext.split_at(AES_NONCE_BYTES);
    let nonce = GenericArray::from_slice(nonce);
    cipher.decrypt(nonce, cipher_text.as_ref())
}

pub fn encrypt_bytes_integral_nonce(cipher: &Aes256Gcm, plaintext: Vec<u8>) -> Result<Vec<u8>, AeadError> {
    let mut nonce = [0u8; AES_NONCE_BYTES];
    OsRng.fill_bytes(&mut nonce);
    let nonce_ga = GenericArray::from_slice(&nonce);
    let mut ciphertext = cipher.encrypt(nonce_ga, plaintext.as_ref())?;
    let mut ciphertext_integral_nonce = nonce.to_vec();
    ciphertext_integral_nonce.append(&mut ciphertext);
    Ok(ciphertext_integral_nonce)
}

#[cfg(test)]
mod test {
    use crate::util::encryption::{decrypt_bytes_integral_nonce, encrypt_bytes_integral_nonce};
    use aes_gcm::{
        aead::{generic_array::GenericArray, NewAead},
        Aes256Gcm,
    };
    #[test]
    fn test_encrypt_decrypt() {
        let plaintext = b"The quick brown fox was annoying".to_vec();
        let key = GenericArray::from_slice(b"an example very very secret key.");
        let cipher = Aes256Gcm::new(key);

        let cipher_text = encrypt_bytes_integral_nonce(&cipher, plaintext.clone()).unwrap();
        let decrypted_text = decrypt_bytes_integral_nonce(&cipher, cipher_text).unwrap();
        assert_eq!(decrypted_text, plaintext);
    }
}