c# - 用于加密图像文件的简单加密/解密方法

Question

我的要求是我需要C#中的简单加密/解密方法来加密和解密图像(可能是 gif/jpeg)。原因很简单，我必须将它存储在数据库中的 BLOB 字段中，而其他一些使用其他编程语言(如 java)的开发人员可能需要提取并显示该图像。我不需要许多安全性导致它只是一个“通过模糊实现安全”(生活)的问题。

Gulp..有人可以帮忙吗...

Answer 1

由于您“不需要太多安全性”，您可能可以通过类似 AES (Rijndael) 的方式来解决问题.它使用对称 key ，并且在 .NET 框架中提供了大量帮助，使其易于实现。 MSDN on the Rijndael class 中有很多信息你可能会觉得有帮助。

这是一个非常精简的加密/解密方法示例，可用于处理字节数组(二进制内容)...

using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;

public class RijndaelHelper
{
    // Example usage: EncryptBytes(someFileBytes, "SensitivePhrase", "SodiumChloride");
    public static byte[] EncryptBytes(byte[] inputBytes, string passPhrase, string saltValue)
    {
        RijndaelManaged RijndaelCipher = new RijndaelManaged();

        RijndaelCipher.Mode = CipherMode.CBC;
        byte[] salt = Encoding.ASCII.GetBytes(saltValue);
        PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, salt, "SHA1", 2);

        ICryptoTransform Encryptor = RijndaelCipher.CreateEncryptor(password.GetBytes(32), password.GetBytes(16));

        MemoryStream memoryStream = new MemoryStream();
        CryptoStream cryptoStream = new CryptoStream(memoryStream, Encryptor, CryptoStreamMode.Write);
        cryptoStream.Write(inputBytes, 0, inputBytes.Length);
        cryptoStream.FlushFinalBlock();
        byte[] CipherBytes = memoryStream.ToArray();

        memoryStream.Close();
        cryptoStream.Close();

        return CipherBytes;
    }

    // Example usage: DecryptBytes(encryptedBytes, "SensitivePhrase", "SodiumChloride");
    public static byte[] DecryptBytes(byte[] encryptedBytes, string passPhrase, string saltValue)
    {
        RijndaelManaged RijndaelCipher = new RijndaelManaged();

        RijndaelCipher.Mode = CipherMode.CBC;
        byte[] salt = Encoding.ASCII.GetBytes(saltValue);
        PasswordDeriveBytes password = new PasswordDeriveBytes(passPhrase, salt, "SHA1", 2);

        ICryptoTransform Decryptor = RijndaelCipher.CreateDecryptor(password.GetBytes(32), password.GetBytes(16));

        MemoryStream memoryStream = new MemoryStream(encryptedBytes);
        CryptoStream cryptoStream = new CryptoStream(memoryStream, Decryptor, CryptoStreamMode.Read);
        byte[] plainBytes = new byte[encryptedBytes.Length];

        int DecryptedCount = cryptoStream.Read(plainBytes, 0, plainBytes.Length);

        memoryStream.Close();
        cryptoStream.Close();

        return plainBytes;
    }
}