java - C#和Java之间的加密/解密

Question

C# 上有一个加密密码的服务器(方法encryptCSharp)，android 应用程序接收加密密码、salt、passPhrase 和initVector。 我必须用 Java 解密该密码。 服务器人员在 C# 中向我发送了一个加密方法，我需要创建 encryptJava 和 decryptJava 方法，它们在 Java 中的工作方式与在 C# 中的工作方式相同。 要创建 Java 中不存在的 PasswordDeriveBytes，我使用此处的示例 Encryption Diff Between Java and C#

那么，我的问题是，我的 Java 方法出了什么问题？两者都不起作用

更新:我对代码 fragment 进行了一些更改，现在一切正常!!

我调用该方法:

String encryptedText = encryptJava("12345", "100", "@.erf.net34", "@gugnet@gugnet77");//it works!!
String decryptedText = decryptJava(encryptedText, "100", "@.erf.net34", "@gugnet@gugnet77");//it doesn't work!!

这是我使用的 Java 方法和来自服务器的 C# 方法。

C#(我无法更改)

public static String encryptCSharp(String plainText, String saltValue, String passPhrase, String initVector) {
    String hashAlgorithm = "SHA1";
    int passwordIterations = 1;
    int keySize = 256;
    // Convert strings into byte arrays.
    // Let us assume that strings only contain ASCII codes.
    // If strings include Unicode characters, use Unicode, UTF7, or UTF8
    // encoding.
    byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector);
    byte[] saltValueBytes = Encoding.ASCII.GetBytes(saltValue);

    // Convert our plaintext into a byte array.
    // Let us assume that plaintext contains UTF8-encoded characters.
    byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);

    // First, we must create a password, from which the key will be derived.
    // This password will be generated from the specified passphrase and
    // salt value. The password will be created using the specified hash
    // algorithm. Password creation can be done in several iterations.
    PasswordDeriveBytes password = new PasswordDeriveBytes(
            passPhrase,
            saltValueBytes,
            hashAlgorithm,
            passwordIterations);

    // Use the password to generate pseudo-random bytes for the encryption
    // key. Specify the size of the key in bytes (instead of bits).
    byte[] keyBytes = password.GetBytes(keySize / 8);

    // Create uninitialized Rijndael encryption object.
    RijndaelManaged symmetricKey = new RijndaelManaged();

    // It is reasonable to set encryption mode to Cipher Block Chaining
    // (CBC). Use default options for other symmetric key parameters.
    symmetricKey.Mode = CipherMode.CBC;

    // Generate encryptor from the existing key bytes and initialization
    // vector. Key size will be defined based on the number of the key
    // bytes.
    ICryptoTransform encryptor = symmetricKey.CreateEncryptor(
            keyBytes,
            initVectorBytes);

    // Define memory stream which will be used to hold encrypted data.
    MemoryStream memoryStream = new MemoryStream();

    // Define cryptographic stream (always use Write mode for encryption).
    CryptoStream cryptoStream = new CryptoStream(memoryStream,
            encryptor,
            CryptoStreamMode.Write);
    // Start encrypting.
    cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);

    // Finish encrypting.
    cryptoStream.FlushFinalBlock();

    // Convert our encrypted data from a memory stream into a byte array.
    byte[] cipherTextBytes = memoryStream.ToArray();

    // Close both streams.
    memoryStream.Close();
    cryptoStream.Close();

    // Convert encrypted data into a base64-encoded string.

    String cipherText = Convert.ToBase64String(cipherTextBytes);

    // Return encrypted string.
    return cipherText;
}

Java 加密消息，它有效，我得到了与 C# 中的方法相同的结果

private String encryptJava(String plainText, String saltValue, String passPhrase, String initVector) {//working!!!
    String result = "";

    byte[] initVectorBytes = initVector.getBytes(US_ASCII);
    byte[] saltValueBytes = saltValue.getBytes(US_ASCII);
    byte[] plainTextBytes = plainText.getBytes(UTF_8);

    Cipher cipher;
    try {
        final com.gmail.example.PasswordDeriveBytes password = new com.gmail.example.PasswordDeriveBytes(passPhrase, saltValueBytes);
        final byte[] keyBytes = password.getBytes(256 / Byte.SIZE);
        SecretKeySpec secretKey = new SecretKeySpec(keyBytes, "AES");

        cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        try {
            cipher.init(Cipher.ENCRYPT_MODE, secretKey, new IvParameterSpec(initVectorBytes));
        } catch (InvalidAlgorithmParameterException e) {
            e.printStackTrace();
        }

        final byte[] ct = cipher.doFinal(plainTextBytes);
        result = Base64.encodeToString(ct, Base64.DEFAULT);//**added this line!** 
        //result = new String(ct, "US-ASCII");**-- deleted this line!** 
    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
    } catch (NoSuchPaddingException e) {
        e.printStackTrace();
    } catch (InvalidKeyException e) {
        e.printStackTrace();
    } catch (BadPaddingException e) {
        e.printStackTrace();
    } catch (IllegalBlockSizeException e) {
        e.printStackTrace();
    }
    return result;
}

在 C# 中模拟相同方法的 Java 方法

public class PasswordDeriveBytes {

    private final MessageDigest hash;

    private final byte[] firstToLastDigest;
    private final byte[] outputBuffer;

    private int position = 0;

    public PasswordDeriveBytes(String password, byte[] salt) {
        try {
            this.hash = MessageDigest.getInstance("SHA-1");

            this.hash.update(password.getBytes(UTF_8));
            this.hash.update(salt);
            this.firstToLastDigest = this.hash.digest();

            final int iterations = 1;//**changed from 100**
            for (int i = 1; i < iterations - 1; i++) {
                hash.update(firstToLastDigest);
                hash.digest(firstToLastDigest, 0, firstToLastDigest.length);
            }

            this.outputBuffer = hash.digest(firstToLastDigest);

        } catch (NoSuchAlgorithmException | DigestException e) {
            throw new IllegalStateException("SHA-1 digest should always be available", e);
        }
    }

    public byte[] getBytes(int requested) {
        if (requested < 1) {
            throw new IllegalArgumentException(
                    "You should at least request 1 byte");
        }

        byte[] result = new byte[requested];

        int generated = 0;

        try {
            while (generated < requested) {
                final int outputOffset = position % outputBuffer.length;
                if (outputOffset == 0 && position != 0) {
                    final String counter = String.valueOf(position / outputBuffer.length);
                    hash.update(counter.getBytes(US_ASCII));
                    hash.update(firstToLastDigest);
                    hash.digest(outputBuffer, 0, outputBuffer.length);
                }

                final int left = outputBuffer.length - outputOffset;
                final int required = requested - generated;
                final int copy = Math.min(left, required);

                System.arraycopy(outputBuffer, outputOffset, result, generated, copy);

                generated += copy;
                position += copy;
            }
        } catch (final DigestException e) {
            throw new IllegalStateException(e);
        }
        return result;
    }
}

最后是不起作用的 Java 方法，并尝试理解我做错了什么

private String decryptJava(String encryptedText, String saltValue, String passPhrase, String initVector) {
    String result = "";
    byte[] initVectorBytes = initVector.getBytes(US_ASCII);
    byte[] saltValueBytes = saltValue.getBytes(US_ASCII);
    byte[] encryptedTexttBytes = Base64.decode(encryptedText, Base64.DEFAULT);
    Cipher cipher;
    try {
        final PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, saltValueBytes);
        final byte[] keyBytes = password.getBytes(256 / Byte.SIZE);
        SecretKeySpec secretKey = new SecretKeySpec(keyBytes, "AES");

        cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        try {
            cipher.init(Cipher.DECRYPT_MODE, secretKey, new IvParameterSpec(initVectorBytes));
        } catch (InvalidAlgorithmParameterException e) {
            e.printStackTrace();
        }
        final byte[] ct = cipher.doFinal(encryptedTexttBytes);
        //result = Base64.encodeToString(ct, Base64.DEFAULT); - **deleted this line**
        try {
            result = new String(ct, "US-ASCII");//** added this line**
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
    } catch (NoSuchPaddingException e) {
        e.printStackTrace();
    } catch (InvalidKeyException e) {
        e.printStackTrace();
    } catch (BadPaddingException e) {
        e.printStackTrace();
    } catch (IllegalBlockSizeException e) {
        e.printStackTrace();
    }
    return result;
}

Answer 1

使用 PasswordDeriveBytes 永远不会曾经要求比底层哈希函数更多的字节。此函数实现 PBKDF1，它不能输出超过该位数的位数(在您的示例中，SHA-1 为 160)。

Microsoft 的实现允许更多的输出，但是实现被破坏到了极致(甚至可能重复输出!)。使用 Rfc2898DeriveBytes 代替，它实现了 PBKDF2，在 Java 中也可用。使用更大的散列，PBKDF2 可以生成比散列输出更多的字节，但代价是安全性。