C# DES加密，KEY和IV不同设置的写法

1、KEY和IV分别赋值

//默认密钥向量
        private static byte[] Iv= { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
        /// <summary>
        /// DES加密字符串
        /// </summary>
        /// <param name="encryptString">待加密的字符串</param>
        /// <param name="encryptKey">加密密钥,要求为8位</param>
        /// <returns>加密成功返回加密后的字符串，失败返回源串</returns>
        public static string EncryptDES(string encryptString, string encryptKey)
        {
            try
            {
                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(, ));
                byte[] rgbIV = Iv;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
                var mStream = new MemoryStream();
                var cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey,rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, , inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Convert.ToBase64String(mStream.ToArray());
            }
            catch
            {
                return encryptString;
            }
        }

2、根据8位密钥，建立KEY和IV

public static string Encrypt(string pToEncrypt, string sKey)
        {
            var des = new DESCryptoServiceProvider();
            //把字符串放到byte数组中
            byte[] inputByteArray = Encoding.Default.GetBytes(pToEncrypt);

            //建立加密对象的密钥和偏移量
            des.Key = Encoding.ASCII.GetBytes(sKey);
            des.IV = Encoding.ASCII.GetBytes(sKey);

            var ms = new MemoryStream();
            var cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, , inputByteArray.Length);
            cs.FlushFinalBlock();

            return Encoding.UTF8.GetString(ms.ToArray());
        }

3、KEY和IV为空，调用 GenerateKey 方法以创建新的随机key ，调用 GenerateIV 方法以创建新的随机 IV

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

class EncryptorExample
{
     private static string quote =
         "Things may come to those who wait, but only the " +
         "things left by those who hustle. -- Abraham Lincoln";

     public static void Main()
     {
         AesCryptoServiceProvider aesCSP = new AesCryptoServiceProvider();

         aesCSP.GenerateKey();
         aesCSP.GenerateIV();
         byte[] encQuote = EncryptString(aesCSP, quote);

         Console.WriteLine("Encrypted Quote:\n");
         Console.WriteLine(Convert.ToBase64String(encQuote));

         Console.WriteLine("\nDecrypted Quote:\n");
         Console.WriteLine(DecryptBytes(aesCSP, encQuote));
     }

     public static byte[] EncryptString(SymmetricAlgorithm symAlg, string inString)
     {
         byte[] inBlock = UnicodeEncoding.Unicode.GetBytes(inString);
         ICryptoTransform xfrm = symAlg.CreateEncryptor();
         byte[] outBlock = xfrm.TransformFinalBlock(inBlock, 0, inBlock.Length);

         return outBlock;
     }

     public static string DecryptBytes(SymmetricAlgorithm symAlg, byte[] inBytes)
     {
         ICryptoTransform xfrm = symAlg.CreateDecryptor();
         byte[] outBlock = xfrm.TransformFinalBlock(inBytes, 0, inBytes.Length);

         return UnicodeEncoding.Unicode.GetString(outBlock);
     }
}

另外：一般DES加密完的字符串大概长这样：U2FsdGVkX1+PX0/VZiqtq/fOMdgdX7mTQh3RNACgods=

因为有一些特殊符号，如果拼在querystring中不便于传输，可以考虑这样写：

 var str= new StringBuilder();
 foreach (byte b in ms.ToArray())
 {
     str.AppendFormat("{0:X2}", b);
 }
 return str.ToString();

来代替直接返回 return Encoding.UTF8.GetString(ms.ToArray());

这样加密后的字符串长这样：4BD2B330AA45FFAD57109EE56D34E21B7E3858BA45A096220EB6634A5B779E80