在Android中生成具有16个字符的初始化矢量的32个字符的AES字符串

Question

我正在使用下面的类在android中生成AES 256密钥，初始化向量，加密和解密。我面临的几个问题

1）当我调用getInitializationVector（）时，它返回24个字符而不是16个字符。（例如：WoiUFsQpizjG705OXja1Jw ==]2）当我调用generateKey（）时，它返回44个字符而不是32个字符。（例如：tEf + dcrzI4x + kSMS8UZxjwziGySMMkDxO0aVgsj0oBs =）3）下面的类是对称方法，如何使其不对称。

您可以看到textKey和testIV为默认值。但是我无法创建它。我已经在堆栈溢出中搜索了解决方案，但是，所有人都给我发了相同长度的文本。有谁知道如何做到这一点？我做错了吗？感谢您宝贵的时间。

public class CryptoDataHandler {

    //32 characters
    String testKey = "82a645babc5cd41c9a2cb4d0d3ba17ad";
    //16 characters
    String testIV = "acf30ad32b693849";

    String edType = "AES";
    String chiperInstanceType = "AES/CBC/PKCS5PADDING";

    private static CryptoDataHandler instance = null;

    public static CryptoDataHandler getInstance() {

        if (instance == null) {
            Security.setProperty("crypto.policy", "unlimited");
            instance = new CryptoDataHandler();
        }
        return instance;
    }

    public String encrypt(String message) throws NoSuchAlgorithmException,
            NoSuchPaddingException, IllegalBlockSizeException,
            BadPaddingException, InvalidKeyException,
            UnsupportedEncodingException, InvalidAlgorithmParameterException {

        byte[] srcBuff = message.getBytes(StandardCharsets.UTF_8);
        //here using substring because AES takes only 16 or 24 or 32 byte of key
        SecretKeySpec skeySpec = new
                SecretKeySpec(testKey.substring(0, 32).getBytes(), edType);
        IvParameterSpec ivSpec = new
                IvParameterSpec(testIV.substring(0, 16).getBytes());
        Cipher ecipher = Cipher.getInstance(chiperInstanceType);
        ecipher.init(Cipher.ENCRYPT_MODE, skeySpec, ivSpec);
        byte[] dstBuff = ecipher.doFinal(srcBuff);
        return Base64.encodeToString(dstBuff, Base64.DEFAULT);
    }

    public String decrypt(String encrypted) throws NoSuchAlgorithmException,
            NoSuchPaddingException, InvalidKeyException,
            InvalidAlgorithmParameterException, IllegalBlockSizeException,
            BadPaddingException, UnsupportedEncodingException {

        SecretKeySpec skeySpec = new
                SecretKeySpec(testKey.substring(0, 32).getBytes(), edType);
        IvParameterSpec ivSpec = new
                IvParameterSpec(testIV.substring(0, 16).getBytes());
        Cipher ecipher = Cipher.getInstance(chiperInstanceType);
        ecipher.init(Cipher.DECRYPT_MODE, skeySpec, ivSpec);
        byte[] raw = Base64.decode(encrypted, Base64.DEFAULT);
        byte[] originalBytes = ecipher.doFinal(raw);
        return new String(originalBytes, StandardCharsets.UTF_8);
    }

    public String generateKey() {

        try {
            Key key;
            SecureRandom rand = new SecureRandom();
            KeyGenerator generator = KeyGenerator.getInstance(edType);
            generator.init(256, rand);
            key = generator.generateKey();
            return Base64.encodeToString(key.getEncoded(), Base64.DEFAULT);
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }

        return null;
    }


    public String getInitializationVector() {
        byte[] IV = new byte[16];
        SecureRandom random = new SecureRandom();
        random.nextBytes(IV);
        return Base64.encodeToString(IV, Base64.DEFAULT);
    }
}

我正在使用下面的类在android中生成AES 256密钥，初始化向量，加密和解密。我面临的问题很少：1）当我调用getInitializationVector（）时...

Answer 1

嗯，我找到了解决方案。在这里发布。如果这对其他人有帮助。