c# - 用 C# 加密 AES 以匹配 Java 加密

Question

我已经获得了用于加密的 Java 实现，但遗憾的是我们是一家 .net 商店，我无法将 Java 整合到我们的解决方案中。可悲的是，我也不是 Java 专家，所以我已经为此苦苦挣扎了几天，我想我终于可以来这里寻求帮助了。

我四处寻找一种方法来匹配 Java 加密的工作方式，并且我已经找到了我需要在 c# 中使用 RijndaelManaged 的​​解决方案。我真的很接近。我在 c# 中返回的字符串匹配前半部分，但后半部分不同。

这是 java 实现的一个片段:

private static String EncryptBy16( String str, String theKey) throws Exception
{

    if ( str == null || str.length() > 16)
    {
        throw new NullPointerException();
    }
    int len = str.length();
    byte[] pidBytes = str.getBytes();
    byte[] pidPaddedBytes = new byte[16];

    for ( int x=0; x<16; x++ )
    {
        if ( x<len )
        {
            pidPaddedBytes[x] = pidBytes[x];
        }
        else
        {
            pidPaddedBytes[x] = (byte) 0x0;
        }

    }

    byte[] raw = asBinary( theKey );
    SecretKeySpec myKeySpec = new SecretKeySpec( raw, "AES" );
    Cipher myCipher = Cipher.getInstance( "AES/ECB/NoPadding" );
    cipher.init( Cipher.ENCRYPT_MODE, myKeySpec );
    byte[] encrypted = myCipher.doFinal( pidPaddedBytes );
    return( ByteToString( encrypted ) );
}

public static String Encrypt(String stringToEncrypt, String key) throws Exception
{

    if ( stringToEncrypt == null ){
        throw new NullPointerException();
    }
    String str = stringToEncrypt;

    StringBuffer result = new StringBuffer();
    do{
        String s = str;
        if(s.length() > 16){
            str = s.substring(16);
            s = s.substring(0,16);
        }else {
            str = null;
        }
        result.append(EncryptBy16(s,key));
    }while(str != null);

    return result.toString();
}

我不完全确定为什么他们一次只传递 16 个字符，但是 w/e。我使用字符串生成器对我的 C# 实现进行了同样的尝试，一次只发送 16 个字符，得到的结果与我一次传递整个字符串时得到的结果相同。

这是我的 C# 实现的一个片段，主要是从 MS 的 RijndaelManaged 站点复制和粘贴:

public static string Encrypt(string stringToEncrypt, string key)
        {
            using (RijndaelManaged myRijndael = new RijndaelManaged())
            {
                myRijndael.Key = StringToByte(key);
                myRijndael.IV = new byte[16];
                return EncryptStringToBytes(stringToEncrypt, myRijndael.Key, myRijndael.IV);
            }
        }

static string EncryptStringToBytes(string plainText, byte[] Key, byte[] IV)
        {
            if (plainText == null || plainText.Length <= 0)
                throw new ArgumentNullException("plainText");
            if (Key == null || Key.Length <= 0)
                throw new ArgumentNullException("Key");
            if (IV == null || IV.Length <= 0)
                throw new ArgumentNullException("Key");
            byte[] encrypted;
            using (RijndaelManaged rijAlg = new RijndaelManaged())
            {
                rijAlg.Key = Key;
                rijAlg.IV = IV;
                ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);
                using (MemoryStream msEncrypt = new MemoryStream())
                {
                    using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                    {
                        using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                        {
                            swEncrypt.Write(plainText);
                        }
                        encrypted = msEncrypt.ToArray();
                    }
                }
            }
            return ByteToString(encrypted);
        }

正如我上面所说，加密字符串的前半部分是相同的(见下面的示例)，但后半部分是关闭的。我在下面的输出中添加了空格，以更好地说明差异所在。我对加密和 Java 的了解都不够，不知道下一步该去哪里。任何指导将不胜感激

Java 输出:

49a85367ec8bc387bb44963b54528c97 8026d7eaeff9e4cb7cf74f8227f80752

C# 输出:

49a85367ec8bc387bb44963b54528c97 718f574341593be65034627a6505f13c

根据以下 Chris 的建议进行更新:

static string EncryptStringToBytes(string plainText, byte[] Key, byte[] IV)
{
    if (plainText == null || plainText.Length <= 0)
        throw new ArgumentNullException("plainText");
    if (Key == null || Key.Length <= 0)
        throw new ArgumentNullException("Key");
    if (IV == null || IV.Length <= 0)
        throw new ArgumentNullException("Key");
    byte[] encrypted;
    using (RijndaelManaged rijAlg = new RijndaelManaged())
    {
        rijAlg.Key = Key;
        rijAlg.IV = IV;
        rijAlg.Padding = PaddingMode.None;
        rijAlg.Mode = CipherMode.ECB;
        ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);
        using (MemoryStream msEncrypt = new MemoryStream())
        {
            using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
            {
                using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                {

                    swEncrypt.Write(plainText);
                    if (plainText.Length < 16)
                    {
                        for (int i = plainText.Length; i < 16; i++)
                        {
                            swEncrypt.Write((byte)0x0);
                        }
                    }
                }
                encrypted = msEncrypt.ToArray();
            }
        }
    }
    return ByteToString(encrypted);
}

Answer 1

好问题，这是使用相同加密算法但使用不同语言时的常见错误。算法细节的实现需要注意。我没有测试过代码，但在您的情况下，两种实现的填充选项不同，请尝试使用 same padding options对于 c# 和 java 实现。您可以从 here 中阅读有关实现的评论和更多信息。 .请注意填充默认值。

• Padding = PaddingMode.PKCS7,
• private final String cipherTransformation = "AES/CBC/PKCS5Padding";

C# 实现:

public RijndaelManaged GetRijndaelManaged(String secretKey)
    {
        var keyBytes = new byte[16];
        var secretKeyBytes = Encoding.UTF8.GetBytes(secretKey);
        Array.Copy(secretKeyBytes, keyBytes, Math.Min(keyBytes.Length, secretKeyBytes.Length));
        return new RijndaelManaged
        {
            Mode = CipherMode.CBC,
            Padding = PaddingMode.PKCS7,
            KeySize = 128,
            BlockSize = 128,
            Key = keyBytes,
            IV = keyBytes
        };
    }

    public byte[] Encrypt(byte[] plainBytes, RijndaelManaged rijndaelManaged)
    {
        return rijndaelManaged.CreateEncryptor()
            .TransformFinalBlock(plainBytes, 0, plainBytes.Length);
    }

    public byte[] Decrypt(byte[] encryptedData, RijndaelManaged rijndaelManaged)
    {
        return rijndaelManaged.CreateDecryptor()
            .TransformFinalBlock(encryptedData, 0, encryptedData.Length);
    }


    // Encrypts plaintext using AES 128bit key and a Chain Block Cipher and returns a base64 encoded string

    public String Encrypt(String plainText, String key)
    {
        var plainBytes = Encoding.UTF8.GetBytes(plainText);
        return Convert.ToBase64String(Encrypt(plainBytes, GetRijndaelManaged(key)));
    }


    public String Decrypt(String encryptedText, String key)
    {
        var encryptedBytes = Convert.FromBase64String(encryptedText);
        return Encoding.UTF8.GetString(Decrypt(encryptedBytes, GetRijndaelManaged(key)));
    }

Java 实现:

private final String characterEncoding = "UTF-8";
private final String cipherTransformation = "AES/CBC/PKCS5Padding";
private final String aesEncryptionAlgorithm = "AES";

public  byte[] decrypt(byte[] cipherText, byte[] key, byte [] initialVector) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException
{
    Cipher cipher = Cipher.getInstance(cipherTransformation);
    SecretKeySpec secretKeySpecy = new SecretKeySpec(key, aesEncryptionAlgorithm);
    IvParameterSpec ivParameterSpec = new IvParameterSpec(initialVector);
    cipher.init(Cipher.DECRYPT_MODE, secretKeySpecy, ivParameterSpec);
    cipherText = cipher.doFinal(cipherText);
    return cipherText;
}

public byte[] encrypt(byte[] plainText, byte[] key, byte [] initialVector) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException
{
    Cipher cipher = Cipher.getInstance(cipherTransformation);
    SecretKeySpec secretKeySpec = new SecretKeySpec(key, aesEncryptionAlgorithm);
    IvParameterSpec ivParameterSpec = new IvParameterSpec(initialVector);
    cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivParameterSpec);
    plainText = cipher.doFinal(plainText);
    return plainText;
}

private byte[] getKeyBytes(String key) throws UnsupportedEncodingException{
    byte[] keyBytes= new byte[16];
    byte[] parameterKeyBytes= key.getBytes(characterEncoding);
    System.arraycopy(parameterKeyBytes, 0, keyBytes, 0, Math.min(parameterKeyBytes.length, keyBytes.length));
    return keyBytes;
}


public String encrypt(String plainText, String key) throws UnsupportedEncodingException, InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException{
    byte[] plainTextbytes = plainText.getBytes(characterEncoding);
    byte[] keyBytes = getKeyBytes(key);
    return Base64.encodeToString(encrypt(plainTextbytes,keyBytes, keyBytes), Base64.DEFAULT);
}


public String decrypt(String encryptedText, String key) throws KeyException, GeneralSecurityException, GeneralSecurityException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException, IOException{
    byte[] cipheredBytes = Base64.decode(encryptedText, Base64.DEFAULT);
    byte[] keyBytes = getKeyBytes(key);
    return new String(decrypt(cipheredBytes, keyBytes, keyBytes), characterEncoding);
}