即使数据正确，AES-GCM 256解密也失败

Question

我有一个给定的加密消息（解密，它是“加密的秘密消息”），我正在尝试从AES-GCM 256加密的一个中检索这个原始字符串。我使用AES-GCM板条箱来执行以下操作：

use aes_gcm::Aes256Gcm;
use aead::{Aead, NewAead, generic_array::GenericArray};

fn main() {
    let key_bytes = hex::decode("ce265dbc38bb25ef29fade77a4b88fe07b6063215f6526a4623cf810a3d611c9").unwrap();
    let nonce_bytes = hex::decode("ce77357fe7b2401400408f44").unwrap();
    let ciphertext_bytes = hex::decode("fd77fae68fa27ea00afbe474f4fcd47248a19b3cbf2a6d7e").unwrap();

    let key = GenericArray::clone_from_slice(key_bytes.as_slice());
    let nonce = GenericArray::from_slice(nonce_bytes.as_slice());

    let cipher = Aes256Gcm::new(key);
    let plaintext = cipher.decrypt(nonce, ciphertext_bytes.as_slice()).unwrap(); // panic on a decryption failure

    println!("{:?}", plaintext);
}

这是my Cargo.toml的dependencies部分：

[dependencies]
aes-gcm = "0.5.0"
aead = "0.2.0"
hex = "0.4.2"

thread 'main' panicked at 'called Result::unwrap() on an Err value: Error', src\main.rs:13:21

看起来像是加密消息无效的错误，加密消息、密钥或随机数无效的错误，但事实并非如此。我写了一个Python程序，它做完全相同的事情，它工作；输出的确实是加密的秘密消息！

from Crypto.Cipher import AES

key = bytes.fromhex("ce265dbc38bb25ef29fade77a4b88fe07b6063215f6526a4623cf810a3d611c9")

nonce = bytes.fromhex("ce77357fe7b2401400408f44")
cipher_text = bytes.fromhex("fd77fae68fa27ea00afbe474f4fcd47248a19b3cbf2a6d7e")

cipher = AES.new(key, AES.MODE_GCM, nonce=nonce)
plaintext = cipher.decrypt(cipher_text)

print(plaintext.decode("utf-8"))

我希望能够在Rust中解密这些加密消息，而不是在Python中。我不知道为什么我会出错。我错过什么了吗？

Answer 1

从encrypt，强调我的：

默认实现假定一个后缀标记（ala AES-GCM、AES-GCM-SIV、ChaCha20Poly1305)。不使用后缀标记的Aead实现将需要重写该标记以正确组合密文消息。

既然你说你有标签：

use aead::{generic_array::GenericArray, Aead, NewAead};
use aes_gcm::Aes256Gcm;

fn main() {
    let key_hex = "ce265dbc38bb25ef29fade77a4b88fe07b6063215f6526a4623cf810a3d611c9";
    let nonce_hex = "ce77357fe7b2401400408f44";
    let ciphertext_hex = "fd77fae68fa27ea00afbe474f4fcd47248a19b3cbf2a6d7e";

    // Append the tag data to the encrypted data
    let tag_hex = "2ef2a9d27909df90bcb45606067148a6";
    let ciphertext_and_tag_hex = format!("{}{}", ciphertext_hex, tag_hex);
    let ciphertext_bytes = hex::decode(ciphertext_and_tag_hex).unwrap();

    let key_bytes = hex::decode(key_hex).unwrap();
    let nonce_bytes = hex::decode(nonce_hex).unwrap();

    let key = GenericArray::clone_from_slice(&key_bytes);
    let nonce = GenericArray::from_slice(&nonce_bytes);

    let cipher = Aes256Gcm::new(key);

    let plaintext = cipher.decrypt(nonce, &*ciphertext_bytes).unwrap();
    println!("{}", String::from_utf8_lossy(&plaintext));
}

您还可以研究decrypt_in_place_detached方法，该方法更复杂，但允许单独指定标记。