Rust实现AES加解密详解

[dependencies]
rust-crypto = "0.2.36"

/// Encrypt a buffer with the given key and iv using AES256/CBC/Pkcs encryption.
fn aes256_cbc_encrypt(
    data: &[u8],
    key: &[u8; 32],
    iv: &[u8; 16],
) -> Result<Vec<u8>, SymmetricCipherError> {
    let mut encryptor = aes::cbc_encryptor(
        KeySize256,
        key, iv,
        PkcsPadding,
    );

    let mut buffer = [0; 4096];
    let mut write_buffer = RefWriteBuffer::new(&mut buffer);
    let mut read_buffer = RefReadBuffer::new(data);
    let mut final_result = Vec::new();

    loop {
        let result = encryptor.encrypt(&mut read_buffer, &mut write_buffer, true)?;
        final_result.extend(write_buffer.take_read_buffer().take_remaining().iter().map(|&i| i));
        match result {
            BufferUnderflow => break,
            _ => continue,
        }
    }

    Ok(final_result)
}

/// Decrypt a buffer with the given key and iv using AES256/CBC/Pkcs encryption.
fn aes256_cbc_decrypt(
    data: &[u8],
    key: &[u8; 32],
    iv: &[u8; 16],
) -> Result<Vec<u8>, SymmetricCipherError> {
    let mut decryptor = aes::cbc_decryptor(
        KeySize256,
        key, iv,
        PkcsPadding,
    );

    let mut buffer = [0; 4096];
    let mut write_buffer = RefWriteBuffer::new(&mut buffer);
    let mut read_buffer = RefReadBuffer::new(data);
    let mut final_result = Vec::new();

    loop {
        let result = decryptor.decrypt(&mut read_buffer, &mut write_buffer, true)?;
        final_result.extend(write_buffer.take_read_buffer().take_remaining().iter().map(|&i| i));
        match result {
            BufferUnderflow => break,
            _ => continue,
        }
    }

    Ok(final_result)
}

[dependencies]
rand = "0.8.4"

#[test]
fn test_aes256_cbc() {
    use rand::{RngCore, rngs::OsRng};

    let mut rng = OsRng::default();
    let mut key = [0; 32];
    let mut iv = [0; 16];
    rng.fill_bytes(&mut key);
    rng.fill_bytes(&mut iv);

    let data = "Hello, world!";
    let encrypted_data = aes256_cbc_encrypt(data.as_bytes(), &key, &iv).unwrap();
    let decrypted_data = aes256_cbc_decrypt(encrypted_data.as_slice(), &key, &iv).unwrap();

    let result = str::from_utf8(decrypted_data.as_slice()).unwrap();

    assert_eq!(data, result);
    println!("{}", result);
}