密码加密模式不安全，如何解决？

Question

我正在加密登录密码firebase，它运行良好，但我在 google play 控制台中收到一条警告，your app contains unsafe cryptographic encryption patterns我该如何摆脱它？

我正在 android studio 上尝试。

public static class AESCrypt
{
    private static final String ALGORITHM = "AES";
    private static final String KEY = "1Hbfh667adfDEJ78";

    public static String encrypt(String value) throws Exception
    {
        Key key = generateKey();
        Cipher cipher = Cipher.getInstance(AESCrypt.ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, key);
        byte [] encryptedByteValue = cipher.doFinal(value.getBytes("utf-8"));
        String encryptedValue64 = Base64.encodeToString(encryptedByteValue, Base64.DEFAULT);
        return encryptedValue64;

    }

    public static String decrypt(String value) throws Exception
    {
        Key key = generateKey();
        Cipher cipher = Cipher.getInstance(AESCrypt.ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, key);
        byte[] decryptedValue64 = Base64.decode(value, Base64.DEFAULT);
        byte [] decryptedByteValue = cipher.doFinal(decryptedValue64);
        String decryptedValue = new String(decryptedByteValue,"utf-8");
        return decryptedValue;

    }

    private static Key generateKey() throws Exception
    {
        Key key = new SecretKeySpec(AESCrypt.KEY.getBytes(),AESCrypt.ALGORITHM);
        return key;
    }

Answer 1

主要问题是您使用没有完整性的密码和硬编码的加密密钥。如果您使用Find Security Bugs分析源代码，您会收到CIPHER_INTEGRITY和HARD_CODE_KEY警告：

The cipher does not provide data integrity [com.lloyds.keystorage.AESCrypt] At AESCrypt.java:[line 25] CIPHER_INTEGRITY
The cipher does not provide data integrity [com.lloyds.keystorage.AESCrypt] At AESCrypt.java:[line 15] CIPHER_INTEGRITY
Hard coded cryptographic key found [com.lloyds.keystorage.AESCrypt] At AESCrypt.java:[line 35] HARD_CODE_KEY

解决方案是使用包含基于哈希的消息身份验证代码 (HMAC) 的密码来对数据进行签名：

Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");

并将密钥存储在单独的配置文件或密钥库中。

下面是完整重构后的整个类：

The cipher does not provide data integrity [com.lloyds.keystorage.AESCrypt] At AESCrypt.java:[line 25] CIPHER_INTEGRITY
The cipher does not provide data integrity [com.lloyds.keystorage.AESCrypt] At AESCrypt.java:[line 15] CIPHER_INTEGRITY
Hard coded cryptographic key found [com.lloyds.keystorage.AESCrypt] At AESCrypt.java:[line 35] HARD_CODE_KEY