encode.cs

C#写的加密解密程序

private const string key="lyfhednc";
        private const string iv="sikechtf";
        public static void Main() 
        {
            string str="hello,world!";
            do
            {
                Console.WriteLine("原始-->{0}",str);
                DESCryptoServiceProvider DES=new DESCryptoServiceProvider();
                //Console.WriteLine(Encoding.ASCII.GetString(DES.IV));
                //Console.WriteLine(Encoding.ASCII.GetString(DES.Key));
                //DES.IV=Encoding.ASCII.GetBytes(iv);
                //DES.Key=Encoding.ASCII.GetBytes(key);  // 這裡可以指定使用的key與iv  沒有指定則是隨機的 所
                                                                                     //  以每 次 都 不一樣
                byte[] b=Encrypt(str,DES);
                str=Encoding.UTF8.GetString(b);
                Console.WriteLine("加密-->{0}",str);

                Console.WriteLine("解密-->{0}",Decrypt(b,DES));
                 

            }while((str=Console.ReadLine())!="a");

            
        } 

        public static string Decrypt(byte[] CypherText, SymmetricAlgorithm key)
        {
            // Create a memory stream to the passed buffer.
            MemoryStream ms = new MemoryStream(CypherText);

            // Create a CryptoStream using the memory stream and the 
            // CSP DES key. 
            CryptoStream encStream = new CryptoStream(ms, key.CreateDecryptor(), CryptoStreamMode.Read);

            // Create a StreamReader for reading the stream.
            StreamReader sr = new StreamReader(encStream);

            // Read the stream as a string.
            string val = sr.ReadLine();

            // Close the streams.
            sr.Close();
            encStream.Close();
            ms.Close();
            
            return val;
        }


        public static byte[] Encrypt(string PlainText, SymmetricAlgorithm key)
        {
            // Create a memory stream.
            MemoryStream ms = new MemoryStream();

            // Create a CryptoStream using the memory stream and the 
            // CSP DES key.  
            CryptoStream encStream = new CryptoStream(ms, key.CreateEncryptor(), CryptoStreamMode.Write);

            // Create a StreamWriter to write a string
            // to the stream.
            StreamWriter sw = new StreamWriter(encStream);

            // Write the plaintext to the stream.
            sw.WriteLine(PlainText);

            // Close the StreamWriter and CryptoStream.
            sw.Close();
            encStream.Close();

            // Get an array of bytes that represents
            // the memory stream.
            byte[] buffer = ms.ToArray();

            // Close the memory stream.
            ms.Close();

            // Return the encrypted byte array.
            return buffer;
        }