OpenSSL加密无法解密C# [英] OpenSSL encryption failing to decrypt C#

问题描述

我一直在努力解密通过SSL在Unix机器上加密的某些数据，我不断收到填充错误，并且不确定我丢失了什么.

I have been struggling with decrypting some data that is being encrypted on a Unix machine via SSL, I keep getting padding errors, and am unsure what it is that I am missing.

加密文件是一个简单的文本文件，只显示"Hello World".

The encrypted file is a simple text file just saying "Hello World".

unix中使用的加密命令为:

The encryption command used in unix is:

openssl enc -base64 -aes-256-cbc  -k 12345678901234567890123456789012 -in test.txt -out cbc64.txt

我有2种解密方法:

private static CipherMode sCipherMode = CipherMode.CBC;
private static PaddingMode sPaddingMode = PaddingMode.PKCS7;
private const int HigKeyLen = 32;
private const int HigKeySiz = 256;

public static string decrypt(string text, //the text to be decrypt                
    int cipherindex// the strength of the original encryption
    )
{
    byte[] plainText = null;
    try
    {
        string tempText = Regex.Replace(text, @"\n", "");
        //get the cipher strength--from cipherindex            
        CipherKey Key = CipherKey.getCipherKey(cipherindex);
        //build and init the Decryptor
        RijndaelManaged rijndaelCipher = new RijndaelManaged();
        rijndaelCipher.Mode = sCipherMode;
        rijndaelCipher.Padding = sPaddingMode;
        rijndaelCipher.KeySize = Key.Size;
        rijndaelCipher.BlockSize = Key.Size;
        byte[] encryptedData = Convert.FromBase64String(tempText);
        byte[] pwdBytes = System.Text.Encoding.UTF8.GetBytes(pass);
        byte[] keyBytes = new byte[Key.Len];


        int len = pwdBytes.Length;
        if (len > keyBytes.Length)
        {
            len = keyBytes.Length;
        }
        Array.Copy(pwdBytes, keyBytes, len);

        rijndaelCipher.Key = keyBytes;
        rijndaelCipher.IV = keyBytes;
        ICryptoTransform transform = rijndaelCipher.CreateDecryptor();
        plainText = transform.TransformFinalBlock(encryptedData, 0, encryptedData.Length);

    }
    catch (Exception e)
    {
        // test code, do nothing
    }
    return System.Text.Encoding.UTF8.GetString(plainText);
}

这将返回以下错误:填充无效，无法删除.

This returns the following error: Padding is invalid and cannot be removed.

第二种方法:

public static string Decryptor(string TextToDecrypt)
    {

        byte[] EncryptedBytes = Convert.FromBase64String(Regex.Replace(TextToDecrypt, @"\n", ""));

        //Setup the AES provider for decrypting.            
        AesCryptoServiceProvider aesProvider = new AesCryptoServiceProvider();
        //aesProvider.Key = System.Text.Encoding.ASCII.GetBytes(strKey);
        //aesProvider.IV = System.Text.Encoding.ASCII.GetBytes(strIV);
        aesProvider.BlockSize = 128;
        aesProvider.KeySize = 256;
        //My key and iv that i have used in openssl
        aesProvider.Key = System.Text.Encoding.UTF8.GetBytes(pass);
        aesProvider.IV = System.Text.Encoding.UTF8.GetBytes(pass);
        aesProvider.Padding = PaddingMode.PKCS7;
        aesProvider.Mode = CipherMode.CBC;

        ICryptoTransform cryptoTransform = aesProvider.CreateDecryptor(aesProvider.Key, aesProvider.IV);
        byte[] DecryptedBytes = cryptoTransform.TransformFinalBlock(EncryptedBytes, 0, EncryptedBytes.Length);
        return System.Text.Encoding.ASCII.GetString(DecryptedBytes);
    }

第二种方法由于密码的长度不适合块大小而出现问题.

The second method gives an issue due to the password not being the right length for the blocksize.

我做错了什么?

推荐答案

您的openssl命令错误，我认为应该是:
openssl enc -base64 -aes-256-cbc -k 12345678901234567890123456789012 -in test.txt -out cbc64.txt

You openssl command is wrong, I assume it should be:
openssl enc -base64 -aes-256-cbc -k 12345678901234567890123456789012 -in test.txt -out cbc64.txt

阅读代码，我发现您做出了一些错误的假设:

reading your code I see you made a few wrong assumptions:

• 您正在使用密码作为密钥和IV(您从哪里得到的?) 密码不是关键
• 您已假定输出为纯密文

• You are using the password as a key and as IV (where did you get that?) Password is not key
• you've assumed the output is pure ciphertext

尝试将-p参数添加到openssl enc命令，它将同时显示salt和派生密钥以及iv

try to add -p parameter to the openssl enc command and it will display as well salt and derived key and iv

因此，请解决此问题:

1. OpenSSL生成随机的8字节盐
2. OpenSSL使用其魔术"函数EVP_BytesToKey从密码和盐中导出密钥和IV， 查看全文