密码学-远程SQL Server +桌面应用程序

复制这段代码并进行测试。WPF控制台应用程序等。

using System;
using System.Security.Cryptography;
using System.Text;
public static class DataEncryption
{
   public static string Encrypt(string input, string key)
   {
      byte[] inputArray = UTF8Encoding.UTF8.GetBytes(input);
      TripleDESCryptoServiceProvider tripleDES = new TripleDESCryptoServiceProvider();
      tripleDES.Key = UTF8Encoding.UTF8.GetBytes(key);
      tripleDES.Mode = CipherMode.ECB;
      tripleDES.Padding = PaddingMode.PKCS7;
      ICryptoTransform cTransform = tripleDES.CreateEncryptor();
      byte[] resultArray = cTransform.TransformFinalBlock(inputArray, 0, inputArray.Length);
      tripleDES.Clear();
      return Convert.ToBase64String(resultArray, 0, resultArray.Length);
   }
   public static string Decrypt(string input, string key)
   {
      byte[] inputArray = Convert.FromBase64String(input);
      TripleDESCryptoServiceProvider tripleDES = new TripleDESCryptoServiceProvider();
      tripleDES.Key = UTF8Encoding.UTF8.GetBytes(key);
      tripleDES.Mode = CipherMode.ECB;
      tripleDES.Padding = PaddingMode.PKCS7;
      ICryptoTransform cTransform = tripleDES.CreateDecryptor();
      byte[] resultArray = cTransform.TransformFinalBlock(inputArray, 0, inputArray.Length);
      tripleDES.Clear();
      return UTF8Encoding.UTF8.GetString(resultArray);
   }
}

这应该能让你明白我在说什么。

应该通过Internet工作并与远程DB通信

这是SSL/TLS中发生的事情之一。服务器端和客户端建立了一个窃听者无法拦截的安全通道。我建议阅读《应用密码学》这本书，了解这个协议以及其他类似协议是如何工作的。PGP是一个相当熟悉的应用程序，您可能希望学习它。

开发人员在应用程序中需要动态加密时该如何操作?

一般来说，以前的雇主都使用自生成的公钥证书。根据业务需求，软件的每个版本要么获得不同的证书，要么每个用户获得不同的证书(这最终成为每个用户获得的许可密钥的一部分)。如果其中一个证书泄露，则可以撤销该证书。

如果您只需要为传输加密数据，那么您应该使用加密(即SSL/TLS)连接。MS SQL Server支持:

加密到SQL Server的连接

如何进行简单加密

试试这个代码，它也工作得很好…基本上，无论你想要加密的字符串是什么，只要将该字符串传递给方法，你可能需要修改代码来为你的项目工作，你可以随心所欲地使用代码。

using System;
using System.Text;
using System.Security.Cryptography;
namespace EncryptStringSample
{
    class MainClass
    {
        public static string EncryptString(string Message, string Passphrase)
        {
            byte[] Results;
            System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
            // Step 1. We hash the passphrase using MD5
            // We use the MD5 hash generator as the result is a 128 bit byte array
            // which is a valid length for the TripleDES encoder we use below
            MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider();
            byte[] TDESKey = HashProvider.ComputeHash(UTF8.GetBytes(Passphrase));
            // Step 2. Create a new TripleDESCryptoServiceProvider object
            TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider();
            // Step 3. Setup the encoder
            TDESAlgorithm.Key = TDESKey;
            TDESAlgorithm.Mode = CipherMode.ECB;
            TDESAlgorithm.Padding = PaddingMode.PKCS7;
            // Step 4. Convert the input string to a byte[]
            byte[] DataToEncrypt = UTF8.GetBytes(Message);
            // Step 5. Attempt to encrypt the string
            try
            {
                ICryptoTransform Encryptor = TDESAlgorithm.CreateEncryptor();
                Results = Encryptor.TransformFinalBlock(DataToEncrypt, 0, DataToEncrypt.Length);
            }
            finally
            {
                // Clear the TripleDes and Hashprovider services of any sensitive information
                TDESAlgorithm.Clear();
                HashProvider.Clear();
            }
            // Step 6. Return the encrypted string as a base64 encoded string
            return Convert.ToBase64String(Results);
        }
        public static string DecryptString(string Message, string Passphrase)
        {
            byte[] Results;
            System.Text.UTF8Encoding UTF8 = new System.Text.UTF8Encoding();
            // Step 1. We hash the passphrase using MD5
            // We use the MD5 hash generator as the result is a 128 bit byte array
            // which is a valid length for the TripleDES encoder we use below
            MD5CryptoServiceProvider HashProvider = new MD5CryptoServiceProvider();
            byte[] TDESKey = HashProvider.ComputeHash(UTF8.GetBytes(Passphrase));
            // Step 2. Create a new TripleDESCryptoServiceProvider object
            TripleDESCryptoServiceProvider TDESAlgorithm = new TripleDESCryptoServiceProvider();
            // Step 3. Setup the decoder
            TDESAlgorithm.Key = TDESKey;
            TDESAlgorithm.Mode = CipherMode.ECB;
            TDESAlgorithm.Padding = PaddingMode.PKCS7;
            // Step 4. Convert the input string to a byte[]
            byte[] DataToDecrypt = Convert.FromBase64String(Message);
            // Step 5. Attempt to decrypt the string
            try
            {
                ICryptoTransform Decryptor = TDESAlgorithm.CreateDecryptor();
                Results = Decryptor.TransformFinalBlock(DataToDecrypt, 0, DataToDecrypt.Length);
            }
            finally
            {
                // Clear the TripleDes and Hashprovider services of any sensitive information
                TDESAlgorithm.Clear();
                HashProvider.Clear();
            }
            // Step 6. Return the decrypted string in UTF8 format
            return UTF8.GetString( Results );
        }
        public static void Main(string[] args)
        {
            // The message to encrypt.
            string Msg = "This world is round, not flat, don't believe them!";
            string Password = "secret";
            string EncryptedString = EncryptString(Msg, Password);
            string DecryptedString = DecryptString(EncryptedString, Password);
            Console.WriteLine("Message: {0}",Msg);
            Console.WriteLine("Password: {0}",Password);
            Console.WriteLine("Encrypted string: {0}",EncryptedString);
            Console.WriteLine("Decrypted string: {0}",DecryptedString);
        }
    }
}