对于 AES 256 位，在 Java 中加密并在 C# 中解密

Encrypt in java and Decrypt in C# For AES 256 bit

提问by Frank Myat Thu

1.I have java function which encrypt xml file and return encrypted String.

1.我有加密xml文件并返回加密字符串的java函数。

/// Java Class 
import java.security.Key;
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;

public class Crypt {

    public static String key = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
    public static byte[] key_Array = Base64.decodeBase64(key);

    public static String encrypt(String strToEncrypt)
    {       
        try
        {   
            //Cipher _Cipher = Cipher.getInstance("AES");
            //Cipher _Cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
            //Cipher _Cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");      

            Key SecretKey = new SecretKeySpec(key_Array, "AES");

            Cipher _Cipher = Cipher.getInstance("AES");     
            _Cipher.init(Cipher.ENCRYPT_MODE, SecretKey);       

            return Base64.encodeBase64String(_Cipher.doFinal(strToEncrypt.getBytes()));     
        }
        catch (Exception e)
        {
            System.out.println("[Exception]:"+e.getMessage());
        }
        return null;
    }

    public static void main(String[] args) {        
        StringBuilder sb = new StringBuilder();
        sb.append("xml file string ...");

        String EncryptedString = encrypt(sb.toString());        
        System.out.println("[EncryptedString]:"+EncryptedString);
    }
}

2.I have c# function which decrypt the message which is encrypted by java function.

2.我有解密由java函数加密的消息的c#函数。

/// C# Function
private static string Decrypt(string encryptedText)
{
    RijndaelManaged aesEncryption = new RijndaelManaged();            
    aesEncryption.BlockSize = 256;
    //aesEncryption.KeySize = 256;
    //aesEncryption.Mode = CipherMode.CBC;
    //aesEncryption.Padding = PaddingMode.PKCS7;

    string keyStr = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
    //string ivStr = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";        

    byte[] keyArr = Convert.FromBase64String(keyStr);
    //byte[] ivArr = Convert.FromBase64String(ivStr);

    aesEncryption.Key = keyArr;
    //aesEncryption.IV = ivArr;

    ICryptoTransform decrypto = aesEncryption.CreateDecryptor();

    byte[] encryptedBytes = Convert.FromBase64CharArray(encryptedText.ToCharArray(), 0, encryptedText.Length);  
    byte[] decryptedData = decrypto.TransformFinalBlock(encryptedBytes, 0, encryptedBytes.Length); /// CryptographicException: Length of the data to decrypt is invalid.    
    return ASCIIEncoding.UTF8.GetString(decryptedData); 
}

Java encrypt function is work well. But the problem is C# function,
when I decrypt I get below error message

Java 加密功能运行良好。但问题是 C# 函数，
当我解密时，我收到以下错误消息

CryptographicException: Length of the data to decrypt is invalid.

I searched solutions by using below ref

我使用以下参考搜索了解决方案

1. AES Encryption in Java and Decryption in C#
2. C# / Java | AES256 encrypt/decrypt
3. Encyption/Decryption in C# and Java

1. Java 中的 AES 加密和 C# 中的解密
2. C#/Java | AES256 加密/解密
3. C# 和 Java 中的加密/解密

but I still face the same error.Could anyone give me suggestion please.

但我仍然面临同样的错误。谁能给我建议。

Updated

更新

I Just change my C# crypto function. Below is my change lists

我只是更改了我的 C# 加密函数。以下是我的更改列表

1. Block Size to 128
2. Key Size to 256
3. IV Size to 16
4. Key Size to 32

1. 块大小为 128
2. 密钥大小为 256
3. IV 尺寸至 16
4. 密钥大小为 32

/// Updated decrypt function
private static string Decrypt(string encryptedText)
{
    RijndaelManaged aesEncryption = new RijndaelManaged();            
    aesEncryption.BlockSize = 128;
    aesEncryption.KeySize = 256;

    //aesEncryption.Mode = CipherMode.CBC;
    aesEncryption.Padding = PaddingMode.None;

    string keyStr = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
    string ivStr = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";           

    byte[] ivArr = Convert.FromBase64String(ivStr);
    byte[] IVkey16BytesValue = new byte[16];
    Array.Copy(ivArr, IVkey16BytesValue, 16);

    byte[] keyArr = Convert.FromBase64String(keyStr);
    byte[] KeyArr32BytesValue = new byte[32];
    Array.Copy(keyArr, KeyArr32BytesValue, 32);

    aesEncryption.IV = IVkey16BytesValue;
    aesEncryption.Key = KeyArr32BytesValue; 

    ICryptoTransform decrypto = aesEncryption.CreateDecryptor();

    byte[] encryptedBytes = Convert.FromBase64CharArray(encryptedText.ToCharArray(), 0, encryptedText.Length);
    byte[] decryptedData = decrypto.TransformFinalBlock(encryptedBytes, 0, encryptedBytes.Length); 
    return ASCIIEncoding.UTF8.GetString(decryptedData);
}

In this time, no error occur. But I get decrypted message which i cannot read.

此时，不会发生错误。但是我收到了无法阅读的解密消息。

g:?
    aesEncryption.Padding = PaddingMode.None; 
?\td??Y\符O????\rL??W?wHm?>f?\au????%??0??\ ..........

Please let me get your suggestion again.

请让我再次得到您的建议。

采纳答案by deathismyfriend

I believe the blockSize should be 128 and the keysize be 256. The keyStr should be 32 characters long and the IVstr should be 16 characters long. This may help as it describes why 128 bits have to be used for block size and what the key sizes can be. csrc.nist.gov/publications/fips/fips197/fips-197.pdf

我相信 blockSize 应该是 128，keysize 应该是 256。keyStr 应该是 32 个字符长，IVstr 应该是 16 个字符长。这可能会有所帮助，因为它描述了为什么 128 位必须用于块大小以及密钥大小可以是多少。csrc.nist.gov/publications/fips/fips197/fips-197.pdf

You have this in the decrypt method.

你在解密方法中有这个。

    aes.Key = ASCIIEncoding.ASCII.GetBytes(keyStr); 
    aes.IV = ASCIIEncoding.ASCII.GetBytes(ivStr);

I believe you need to put that in the encrypt method also.

我相信你也需要把它放在加密方法中。

Also why not use this method for the key and IV.

另外，为什么不将这种方法用于密钥和 IV。

/// C# Error Fixed Version - CipherMode.ECB
public static string keyStr = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";

private static string Encrypt(string PlainText)
{
    RijndaelManaged aes = new RijndaelManaged();
    aes.BlockSize = 128;
    aes.KeySize = 256;

    /// In Java, Same with below code
    /// Cipher _Cipher = Cipher.getInstance("AES");  // Java Code
    aes.Mode = CipherMode.ECB; 

    byte[] keyArr = Convert.FromBase64String(keyStr);
    byte[] KeyArrBytes32Value = new byte[32];
    Array.Copy(keyArr, KeyArrBytes32Value, 32);

    aes.Key = KeyArrBytes32Value;

    ICryptoTransform encrypto = aes.CreateEncryptor();

    byte[] plainTextByte = ASCIIEncoding.UTF8.GetBytes(PlainText);
    byte[] CipherText = encrypto.TransformFinalBlock(plainTextByte, 0, plainTextByte.Length);
    return Convert.ToBase64String(CipherText);
}

private static string Decrypt(string CipherText)
{  
    RijndaelManaged aes = new RijndaelManaged();
    aes.BlockSize = 128;
    aes.KeySize = 256;

    /// In Java, Same with below code
    /// Cipher _Cipher = Cipher.getInstance("AES");  // Java Code
    aes.Mode = CipherMode.ECB;

    byte[] keyArr = Convert.FromBase64String(keyStr);
    byte[] KeyArrBytes32Value = new byte[32];
    Array.Copy(keyArr, KeyArrBytes32Value, 32);

    aes.Key = KeyArrBytes32Value;

    ICryptoTransform decrypto = aes.CreateDecryptor();

    byte[] encryptedBytes = Convert.FromBase64CharArray(CipherText.ToCharArray(), 0, CipherText.Length);
    byte[] decryptedData = decrypto.TransformFinalBlock(encryptedBytes, 0, encryptedBytes.Length);
    return ASCIIEncoding.UTF8.GetString(decryptedData);
}

回答by Frank Myat Thu

After I got very helpful suggestions from @deathismyfriend and other, I found out what I am missing in my C# Decrypt function.So I change my function as below.

在我从@deathismyfriend 和其他人那里得到非常有用的建议后，我发现了我在 C# Decrypt 函数中缺少的东西。所以我改变了我的函数如下。

CryptographicException: Padding is invalid and cannot be removed.

 Solution:  
_RijndaelManaged.Padding = CipherMode.xxx;    ///should toggle here
_RijndaelManaged.Padding = PaddingMode.xxx;   ///should toggle here 


CryptographicException: Length of the data to decrypt is invalid. 
CryptographicException: Specified initialization vector (IV) does not match the block size for this algorithm.

Solution
1. _RijndaelManaged.BlockSize = 128; /// Must be
2. _RijndaelManaged.KeySize = 256; /// Must be
3. _RijndaelManaged.Key = Byte Array Size must be 32 in length ( more detail 32*8 = 256 KeySize )
4. _RijndaelManaged.IV = Byte Array Size must be 16 in length ( more detail 16*8 = 128 BlockSize)

By using upper c# function , now I can decrypt and read cipher text.
Below is what I found out after I getting error again and again.

通过使用上层c#函数，现在我可以解密和读取密文了。
以下是我一次又一次出错后发现的内容。

// Java code - Cipher mode CBC version.
// CBC version need Initialization vector IV.
// Reference from https://stackoverflow.com/questions/6669181/why-does-my-aes-encryption-throws-an-invalidkeyexception/6669812#6669812

import java.security.Key;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import org.apache.commons.codec.binary.Base64;

public class CryptoSecurity {

    public static String key = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
    public static byte[] key_Array = Base64.decodeBase64(key);

    public static String encrypt(String strToEncrypt)
    {       
        try
        {   
            //Cipher _Cipher = Cipher.getInstance("AES");
            //Cipher _Cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
            Cipher _Cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");        

            // Initialization vector.   
            // It could be any value or generated using a random number generator.
            byte[] iv = { 1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1, 7, 7, 7, 7 };
            IvParameterSpec ivspec = new IvParameterSpec(iv);

            Key SecretKey = new SecretKeySpec(key_Array, "AES");    
            _Cipher.init(Cipher.ENCRYPT_MODE, SecretKey, ivspec);       

            return Base64.encodeBase64String(_Cipher.doFinal(strToEncrypt.getBytes()));     
        }
        catch (Exception e)
        {
            System.out.println("[Exception]:"+e.getMessage());
        }
        return null;
    }

    public static String decrypt(String EncryptedMessage)
    {
        try
        {
            //Cipher _Cipher = Cipher.getInstance("AES");
            //Cipher _Cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
            Cipher _Cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");            

            // Initialization vector.   
            // It could be any value or generated using a random number generator.
            byte[] iv = { 1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1, 7, 7, 7, 7 };
            IvParameterSpec ivspec = new IvParameterSpec(iv);

            Key SecretKey = new SecretKeySpec(key_Array, "AES");
            _Cipher.init(Cipher.DECRYPT_MODE, SecretKey, ivspec);           

            byte DecodedMessage[] = Base64.decodeBase64(EncryptedMessage);
            return new String(_Cipher.doFinal(DecodedMessage));

        }
        catch (Exception e)
        {
            System.out.println("[Exception]:"+e.getMessage());          

        }
        return null;
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        StringBuilder sb = new StringBuilder();

        sb.append("xml file string ...");

        String outputOfEncrypt = encrypt(sb.toString());        
        System.out.println("[CryptoSecurity.outputOfEncrypt]:"+outputOfEncrypt);

        String outputOfDecrypt = decrypt(outputOfEncrypt);        
        //String outputOfDecrypt = decrypt(sb.toString());        
        System.out.println("[CryptoSecurity.outputOfDecrypt]:"+outputOfDecrypt);
    }

}

But when it come to security reason, I think I should not use ECB mode.
According to

但是说到安全原因，我认为我不应该使用ECB模式。
根据

1. ECB mode is not secure
2. StackOverFlow link

1. 欧洲央行模式不安全
2. StackOverFlow 链接

So I Modify it again in Java and C#.

所以我在Java和C#中再次修改它。

// C# Code, CipherMode.CBC
// CBC version need Initialization vector IV.

public static string keyStr = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
private static string Encrypt(string PlainText)
{
    RijndaelManaged aes = new RijndaelManaged();
    aes.BlockSize = 128;
    aes.KeySize = 256;

    // It is equal in java 
    /// Cipher _Cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");    
    aes.Mode = CipherMode.CBC;  
    aes.Padding = PaddingMode.PKCS7; 

    byte[] keyArr = Convert.FromBase64String(keyStr);
    byte[] KeyArrBytes32Value = new byte[32];
    Array.Copy(keyArr, KeyArrBytes32Value, 32);

    // Initialization vector.   
    // It could be any value or generated using a random number generator.
    byte[] ivArr = { 1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1, 7, 7, 7, 7 };
    byte[] IVBytes16Value = new byte[16];
    Array.Copy(ivArr, IVBytes16Value, 16);

    aes.Key = KeyArrBytes32Value;
    aes.IV = IVBytes16Value;

    ICryptoTransform encrypto = aes.CreateEncryptor();

    byte[] plainTextByte = ASCIIEncoding.UTF8.GetBytes(PlainText);
    byte[] CipherText = encrypto.TransformFinalBlock(plainTextByte, 0, plainTextByte.Length);
    return Convert.ToBase64String(CipherText);

}

private static string Decrypt(string CipherText)
{
    RijndaelManaged aes = new RijndaelManaged();
    aes.BlockSize = 128;
    aes.KeySize = 256;

    aes.Mode = CipherMode.CBC;
    aes.Padding = PaddingMode.PKCS7;

    byte[] keyArr = Convert.FromBase64String(keyStr);
    byte[] KeyArrBytes32Value = new byte[32];
    Array.Copy(keyArr, KeyArrBytes32Value, 32);

    // Initialization vector.   
    // It could be any value or generated using a random number generator.
    byte[] ivArr = { 1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1, 7, 7, 7, 7 };            
    byte[] IVBytes16Value = new byte[16];
    Array.Copy(ivArr, IVBytes16Value, 16);

    aes.Key = KeyArrBytes32Value;
    aes.IV = IVBytes16Value;

    ICryptoTransform decrypto = aes.CreateDecryptor();

    byte[] encryptedBytes = Convert.FromBase64CharArray(CipherText.ToCharArray(), 0, CipherText.Length);
    byte[] decryptedData = decrypto.TransformFinalBlock(encryptedBytes, 0, encryptedBytes.Length);
    return ASCIIEncoding.UTF8.GetString(decryptedData);
}

In C#, I modify it like below.

在 C# 中，我像下面那样修改它。

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

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

        };
    }

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

Now it all work.
For more detail about AES, click this linkwhich I was given by @deathismyfriend.
It is also very useful.

现在一切正常。
有关 AES 的更多详细信息，请单击@deathismyfriend 提供的此链接。
它也非常有用。

回答by A Kimmel

On one of my recent projects I was tasked with building up a url with an encrypted portion to pass to another website. They ran java on their server, whereas we developed in c#.

在我最近的一个项目中，我的任务是构建一个带有加密部分的 url 以传递到另一个网站。他们在他们的服务器上运行 java，而我们用 c# 开发。

I know this isn't an exact match to what you were tasked to create, but hopefully this can help out others that are trying to find answers :)

我知道这与您的任务不完全匹配，但希望这可以帮助其他试图找到答案的人:)

I received the following from their developers to build our encryption off from

我从他们的开发人员那里收到了以下内容来构建我们的加密

To accomplish this in c# I did the following:

为了在 C# 中完成此操作，我执行了以下操作：

// Java code - Cipher mode CBC version.
// CBC version need Initialization vector IV.
// Reference from https://stackoverflow.com/questions/6669181/why-does-my-aes-encryption-throws-an-invalidkeyexception/6669812#6669812
public static String key = "FFClY170hLrhsDnKUEhJ4FhVOnrpNNFFClY170hLrhsDnKUE";
public static byte[] key_Array = Base64.decodeBase64(key);

public static String encrypt(String strToEncrypt) {
    try {
        //Cipher _Cipher = Cipher.getInstance("AES");
        //Cipher _Cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
        Cipher _Cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");

        // Initialization vector.   
        // It could be any value or generated using a random number generator.
        byte[] iv = {1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1, 7, 7, 7, 7};
        IvParameterSpec ivspec = new IvParameterSpec(iv);

        key_Array = Arrays.copyOf(key_Array, 32);

        Key SecretKey = new SecretKeySpec(key_Array, "AES");
        _Cipher.init(Cipher.ENCRYPT_MODE, SecretKey, ivspec);

        return Base64.encodeBase64String(_Cipher.doFinal(strToEncrypt.getBytes()));
    } catch (Exception e) {
        System.out.println("[Exception]:" + e.getMessage());
    }
    return null;
}

public static String decrypt(String EncryptedMessage) {
    try {
        //Cipher _Cipher = Cipher.getInstance("AES");
        //Cipher _Cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
        Cipher _Cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");

        // Initialization vector.   
        // It could be any value or generated using a random number generator.
        byte[] iv = {1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1, 7, 7, 7, 7};
        IvParameterSpec ivspec = new IvParameterSpec(iv);

        key_Array = Arrays.copyOf(key_Array, 32);

        Key SecretKey = new SecretKeySpec(key_Array, "AES");
        _Cipher.init(Cipher.DECRYPT_MODE, SecretKey, ivspec);

        byte DecodedMessage[] = Base64.decodeBase64(EncryptedMessage);
        return new String(_Cipher.doFinal(DecodedMessage));

    } catch (Exception e) {
        System.out.println("[Exception]:" + e.getMessage());

    }
    return null;
}

回答by Allan Jacques Neves de Oliveir

I had a problem with this algorithm (in Java only) and I did a litle changes.

我对这个算法有一个问题（仅在 Java 中），我做了一些改动。

Diff Image

差异图像

##代码##