C＃AES解密 [英] c# AES Decryption

问题描述

我与SagePay形式的工作，目前转换他们有VB例子为C＃。我已经取得了良好进展，所以我的项目的加密部分工作正常（SagePay可以将其解密）。

我遇到的问题是，当我试图对字符串进行解密，它变成垃圾。如果有人这样做之前我真的很感激一些帮助，我的解密代码。我已经包括加密代码，工作和前两行是从另一种方法进行设置和调用。

我还没有添加VB代码，但如果这是必需的，我可以添加它。 。不想，如果不需要一个巨大的后

实用方法：

 公共字符串byteArrayToHexString（字节[] BA）
 {
返回BitConverter.ToString（BA）.Replace（ - ，）; 
} 
 
公共静态的byte [] StringToByteArray（十六进制字符串）
 {
返回Enumerable.Range（0，hex.Length）
。凡（ X =&X的催化剂％2 == 0）
。选择（X => Convert.ToByte（hex.Substring（X，2），16））
 .ToArray（）; 
} 
  

主要加密与第一对夫妇行是调用它从提取的方法更大的方法。

 字符串隐窝=blahblahblah
串EncryptAndEncode =@+ byteArrayToHexString（aesEncrypt（地下室） ）; 
 
 
私人字节[] aesEncrypt（字符串inputText的）
 {
 
 RijndaelManaged的AES =新RijndaelManaged的（）; 
 
 //设置为重点
 AES.Padding = PaddingMode.PKCS7模式，填充和块的大小; 
 AES.Mode = CipherMode.CBC; 
 AES.KeySize = 128; 
 AES.BlockSize = 128; 
 
 //转换键和文字输入字节数组
字节[] = keyAndIvBytes UTF8Encoding.UTF8.GetBytes（tR7nR6wZHGjYMCuV）; 
字节[] = inputBytes UTF8Encoding.UTF8.GetBytes（inputText的）; // AbHLlc5uLone0D1q 
 
 //创建流和加密对象
的MemoryStream MemoryStream的=新的MemoryStream（）; 
的CryptoStream的CryptoStream =新的CryptoStream（的MemoryStream，AES.CreateEncryptor（keyAndIvBytes，keyAndIvBytes），CryptoStreamMode.Write）; 
 
 //执行加密
 cryptoStream.Write（inputBytes，0，inputBytes.Length）; 
 cryptoStream.FlushFinalBlock（）; 
 
 //获取加密流成字节数组
字节[] = outBytes memoryStream.ToArray（）; 
 
 //关闭流
 memoryStream.Close（）; 
 cryptoStream.Close（）; 
 AES.Clear（）; 
 
返回outBytes; 
} 
  

解码和解密方法

 公共字符串DecodeAndDecrypt（字符串〜应变）
 {
 // ** HEX解码那么AES解密，CBC与PKCS5填充阻断 - 默认** 
 
 
串DecodeAndDecrypt = aesDecrypt（StringToByteArray（strIn.Substring（1）））; 
回报（DecodeAndDecrypt）; 
} 
 
私人字符串aesDecrypt（字节[] inputBytes）
 {
 RijndaelManaged的AES =新RijndaelManaged的（）; 
字节[] = keyAndIvBytes UTF8Encoding.UTF8.GetBytes（tR7nR6wZHGjYMCuV）; 
字节[] = outputBytes inputBytes; // Convert.FromBase64String（inputBytes）; 
 
 //设置的模式，填充和块大小
 AES.Padding = PaddingMode.PKCS7; 
 AES.Mode = CipherMode.CBC; 
 AES.KeySize = 128; 
 AES.BlockSize = 128; 
 
 //创建流，并解密对象
的MemoryStream MemoryStream的=新的MemoryStream（outputBytes）; 
的CryptoStream的CryptoStream =新的CryptoStream（的MemoryStream，AES.CreateEncryptor（keyAndIvBytes，keyAndIvBytes），CryptoStreamMode.Read）; 
 //执行解密
 cryptoStream.Read（outputBytes，0，outputBytes.Length）; 
 Trace.WriteLine（outputBytes）; 
 //关闭流
 memoryStream.Close（）; 
 cryptoStream.Close（）; 
 AES.Clear（）; 
 //返回System.Text.Encoding.UTF8.GetString（outputBytes）; 
 
字符串明文= Encoding.UTF8.GetString（outputBytes，
 0，
 outputBytes.Length）; 
 
返回明文; 
} 
  

解决方案

实际上有多个问题你的代码。首先在你的解密方法，你要创建一个加密，这应该是一个解密。其次，你正在阅读的整个街区，包括你的算法的填充到缓冲区中，当你做解密。下面是固定的项目类，并应返回正确的结果。然而，我建议你找存储密钥，把你的代码和生成的方式找你edoing一个更好的方式，它是一种没有没有。你应该产生具有RNG（RNGCryptoServiceProvider）的键，然后用安全散列算法散列它如SHA512，使用输出的关键。然后，你需要找到一个好地方来存储的话，我会去了解一下加密你的web.config文件。

 公共静态类EncryptionHelper 
 {
私人静态的byte [] keyAndIvBytes; 
 
静态EncryptionHelper（）
 {
 //你需要这个存储的更安全的方式，我希望这不是
 //真正的关键
 keyAndIvBytes = UTF8Encoding.UTF8.GetBytes（tR7nR6wZHGjYMCuV）; 
} 
 
公共静态字符串ByteArrayToHexString（字节[] BA）
 {
返回BitConverter.ToString（BA）.Replace（ - ，）; 
} 
 
公共静态的byte [] StringToByteArray（十六进制字符串）
 {
返回Enumerable.Range（0，hex.Length）
。凡（ X =&X的催化剂％2 == 0）
。选择（X => Convert.ToByte（hex.Substring（X，2），16））
 .ToArray（）; 
} 
 
公共静态字符串DecodeAndDecrypt（字符串密文）
 {
串DecodeAndDecrypt = AesDecrypt（StringToByteArray（密文））; 
回报（DecodeAndDecrypt）; 
} 
 
公共静态字符串EncryptAndEncode（字符串明文）
 {
返回ByteArrayToHexString（AesEncrypt（明文））; 
} 
 
公共静态字符串AesDecrypt（字节[] inputBytes）
 {
字节[] = outputBytes inputBytes; 
 
字符串明文=的String.Empty;使用（MemoryStream的MemoryStream的=新的MemoryStream（outputBytes））
 {使用（CryptoStream的CryptoStream的=新的CryptoStream（的MemoryStream，GetCryptoAlgorithm（）
。CreateDecryptor的（keyAndIvBytes，keyAndIvBytes），CryptoStreamMode 
 
 .Read））
 {使用
（StreamReader的srDecrypt =新的StreamReader（CryptoStream的））
 {
明文= srDecrypt.ReadToEnd（）; 
} 
} 
} 
 
返回明文; 
} 
 
公共静态的byte [] AesEncrypt（字符串inputText的）
 {
字节[] = inputBytes UTF8Encoding.UTF8.GetBytes（inputText的）; // AbHLlc5uLone0D1q 
 
字节[]的结果= NULL;使用（MemoryStream的MemoryStream的=新的MemoryStream（））
 {$ B $使用B 
（CryptoStream的CryptoStream的=新的CryptoStream（的MemoryStream，GetCryptoAlgorithm（）。CreateEncryptor（keyAndIvBytes，keyAndIvBytes），CryptoStreamMode.Write））
 {
 cryptoStream.Write（inputBytes，0，inputBytes.Length）; 
 cryptoStream.FlushFinalBlock（）; 
 
结果= memoryStream.ToArray（）; 
} 
} 
 
返回结果; 
} 
 
 
私有静态RijndaelManaged的GetCryptoAlgorithm（）
 {
 RijndaelManaged的算法=新RijndaelManaged的（）; 
 //设置的模式，填充和块大小
 algorithm.Padding = PaddingMode.PKCS7; 
 algorithm.Mode = CipherMode.CBC; 
 algorithm.KeySize = 128; 
 algorithm.BlockSize = 128; 
返回算法; 
} 
} 
  

调用很容易：

 字符串隐窝=blahblahblah; 
串EncryptAndEncode = EncryptionHelper.EncryptAndEncode（地下室）; 
 Console.WriteLine（EncryptAndEncode）; 
 
 Console.WriteLine（EncryptionHelper.DecodeAndDecrypt（EncryptAndEncode））; 
 
到Console.ReadLine（）; 
  

I am working with SagePay Forms and currently converting the VB examples they have to c#. I have made good progress so the encryption part of my project works fine (SagePay can decrypt it).

The issue I am having is that when I attempt to decrypt the string, it turns to garbage. If anyone has done this before I would really appreciate some help with my decryption code. I have included the encryption code which works and the first two lines are the setup and call from another method.

I haven't added the VB code but if this is required I could add it. Didn't want a huge post if not required.

Utility Methods:

public string byteArrayToHexString(byte[] ba)
    {
    return BitConverter.ToString(ba).Replace("-", "");
    }

public static byte[] StringToByteArray(string hex)
    {
        return Enumerable.Range(0, hex.Length)
                         .Where(x => x % 2 == 0)
                         .Select(x => Convert.ToByte(hex.Substring(x, 2), 16))
                         .ToArray();
    }

Main Encryption Method with first couple of lines being the calling of it extracted from a larger method.

string crypt = "blahblahblah"
string EncryptAndEncode = "@" + byteArrayToHexString(aesEncrypt(crypt));


        private byte[] aesEncrypt(string inputText)
    {

        RijndaelManaged AES = new RijndaelManaged();

        //set the mode, padding and block size for the key
        AES.Padding = PaddingMode.PKCS7;
        AES.Mode = CipherMode.CBC;
        AES.KeySize = 128;
        AES.BlockSize = 128;

        //convert key and plain text input into byte arrays
        Byte[] keyAndIvBytes = UTF8Encoding.UTF8.GetBytes("tR7nR6wZHGjYMCuV");
        Byte[] inputBytes = UTF8Encoding.UTF8.GetBytes(inputText);//AbHLlc5uLone0D1q

        //create streams and encryptor object
        MemoryStream memoryStream = new MemoryStream();
        CryptoStream cryptoStream = new CryptoStream(memoryStream, AES.CreateEncryptor(keyAndIvBytes, keyAndIvBytes), CryptoStreamMode.Write);

        //perform encryption
        cryptoStream.Write(inputBytes, 0, inputBytes.Length);
        cryptoStream.FlushFinalBlock();

        //get encrypted stream into byte array
        Byte[] outBytes = memoryStream.ToArray();

        //close streams
        memoryStream.Close();
        cryptoStream.Close();
        AES.Clear();

        return outBytes;
    }

Decoding and Decrypting methods

public string DecodeAndDecrypt(string strIn)
    {
        //** HEX decoding then AES decryption, CBC blocking with PKCS5 padding - DEFAULT **


        string DecodeAndDecrypt = aesDecrypt(StringToByteArray(strIn.Substring(1)));
        return (DecodeAndDecrypt);
    }

    private string aesDecrypt(Byte[] inputBytes)
    {
    RijndaelManaged AES = new RijndaelManaged();
    Byte[] keyAndIvBytes = UTF8Encoding.UTF8.GetBytes("tR7nR6wZHGjYMCuV");
    Byte[] outputBytes = inputBytes;//Convert.FromBase64String(inputBytes);

    //set the mode, padding and block size
    AES.Padding = PaddingMode.PKCS7;
    AES.Mode = CipherMode.CBC;
    AES.KeySize = 128;
    AES.BlockSize = 128;

    //create streams and decryptor object
    MemoryStream memoryStream = new MemoryStream(outputBytes);
    CryptoStream cryptoStream = new CryptoStream(memoryStream, AES.CreateEncryptor(keyAndIvBytes, keyAndIvBytes), CryptoStreamMode.Read);
    //perform decryption
    cryptoStream.Read(outputBytes, 0, outputBytes.Length);
    Trace.WriteLine(outputBytes);
    //close streams
    memoryStream.Close();
    cryptoStream.Close();
    AES.Clear();
    //return System.Text.Encoding.UTF8.GetString(outputBytes);

    string plainText = Encoding.UTF8.GetString(outputBytes,
                                   0,
                                   outputBytes.Length);

    return plainText;
    }

解决方案

There are actually multiple problems with your code. First in your decrypt method you're creating an encryptor, that should be a decryptor. Secondly you're reading the entire block including the padding of your algorithm into the buffer when you do the decryption. Below is a class with the items fixed and should be returning the proper result. I do however suggest you find a better way of storing the key, putting in your code and generating it the way you'r edoing it is a no no. You should generate your key with an RNG (RNGCryptoServiceProvider) then hash it with a secure hashing algorithm such as SHA512, use that output for your key. You then need to find a good place to store it, I would look into encrypting your web.config file.

public static class EncryptionHelper
{
    private static byte[] keyAndIvBytes;

    static EncryptionHelper()
    {
        // You'll need a more secure way of storing this, I hope this isn't
        // the real key
        keyAndIvBytes = UTF8Encoding.UTF8.GetBytes("tR7nR6wZHGjYMCuV");
    }

    public static string ByteArrayToHexString(byte[] ba)
    {
        return BitConverter.ToString(ba).Replace("-", "");
    }

    public static byte[] StringToByteArray(string hex)
    {
        return Enumerable.Range(0, hex.Length)
                         .Where(x => x % 2 == 0)
                         .Select(x => Convert.ToByte(hex.Substring(x, 2), 16))
                         .ToArray();
    }

    public static string DecodeAndDecrypt(string cipherText)
    {
        string DecodeAndDecrypt = AesDecrypt(StringToByteArray(cipherText));
        return (DecodeAndDecrypt);
    }

    public static string EncryptAndEncode(string plaintext)
    {
        return ByteArrayToHexString(AesEncrypt(plaintext));
    }

    public static string AesDecrypt(Byte[] inputBytes)
    {
        Byte[] outputBytes = inputBytes;

        string plaintext = string.Empty;

        using (MemoryStream memoryStream = new MemoryStream(outputBytes))
        {
            using (CryptoStream cryptoStream = new CryptoStream(memoryStream, GetCryptoAlgorithm().CreateDecryptor(keyAndIvBytes, keyAndIvBytes), CryptoStreamMode.Read))
            {
                using (StreamReader srDecrypt = new StreamReader(cryptoStream))
                {
                    plaintext = srDecrypt.ReadToEnd();
                }
            }
        }

        return plaintext;
    }

    public static byte[] AesEncrypt(string inputText)
    {
        byte[] inputBytes = UTF8Encoding.UTF8.GetBytes(inputText);//AbHLlc5uLone0D1q

        byte[] result = null;
        using (MemoryStream memoryStream = new MemoryStream())
        {
            using (CryptoStream cryptoStream = new CryptoStream(memoryStream, GetCryptoAlgorithm().CreateEncryptor(keyAndIvBytes, keyAndIvBytes), CryptoStreamMode.Write))
            {
                cryptoStream.Write(inputBytes, 0, inputBytes.Length);
                cryptoStream.FlushFinalBlock();

                result = memoryStream.ToArray();
            }
        }

        return result;
    }


    private static RijndaelManaged GetCryptoAlgorithm()
    {
        RijndaelManaged algorithm = new RijndaelManaged();
        //set the mode, padding and block size
        algorithm.Padding = PaddingMode.PKCS7;
        algorithm.Mode = CipherMode.CBC;
        algorithm.KeySize = 128;
        algorithm.BlockSize = 128;
        return algorithm;
    }
}

Calling it is easy:

string crypt = "blahblahblah";
string EncryptAndEncode = EncryptionHelper.EncryptAndEncode(crypt);            
Console.WriteLine(EncryptAndEncode);

Console.WriteLine(EncryptionHelper.DecodeAndDecrypt(EncryptAndEncode));

Console.ReadLine();

这篇关于C＃AES解密的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！