常用的加密解密（DES，RSA）

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

/// <summary>
/// DES加密
/// </summary>
/// <param name="input">待加密的字符串</param>
/// <param name="key">加密密钥</param>
/// <returns></returns>
public static string Encrypt(string EncryptString, byte[] Key, byte[] IV)
{
//byte[] rgbKey = Encoding.UTF8.GetBytes(key.Substring(0, 8));
byte[] inputByteArray = Encoding.UTF8.GetBytes(EncryptString);
DESCryptoServiceProvider des = new DESCryptoServiceProvider();
MemoryStream mStream = new MemoryStream();
CryptoStream cStream = new CryptoStream(mStream, des.CreateEncryptor(Key, IV), CryptoStreamMode.Write);
cStream.Write(inputByteArray, 0, inputByteArray.Length);
cStream.FlushFinalBlock();
return Convert.ToBase64String(mStream.ToArray());
}
/// <summary>
/// DES解密
/// </summary>
/// <param name="input">待解密的字符串</param>
/// <param name="key">解密密钥,要求为8位,和加密密钥相同</param>
/// <returns>解密成功返回解密后的字符串,失败返源串</returns>
public static string Decrypt(string DecryptString, byte[] Key, byte[] IV)
{
try
{
//byte[] rgbKey = Encoding.UTF8.GetBytes(Key);
byte[] inputByteArray = Convert.FromBase64String(DecryptString);
DESCryptoServiceProvider des = new DESCryptoServiceProvider();

MemoryStream mStream = new MemoryStream();
CryptoStream cStream = new CryptoStream(mStream, des.CreateDecryptor(Key, IV), CryptoStreamMode.Write);
cStream.Write(inputByteArray, 0, inputByteArray.Length);
cStream.FlushFinalBlock();
return Encoding.UTF8.GetString(mStream.ToArray());
}
catch
{
return "";
}
}
}
/// <summary>
/// RSA加解密算法
/// </summary>
public class RSA
{
/// <summary>
/// RSA加密函数
/// </summary>
/// <param name="xmlPublicKey">说明KEY必须是XML的行式,返回的是字符串</param>
/// <param name="EncryptString"></param>
/// <returns></returns>
public string Encrypt(string xmlPublicKey, string EncryptString)
{
byte[] PlainTextBArray;
byte[] CypherTextBArray;
string Result;
RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
rsa.FromXmlString(xmlPublicKey);
PlainTextBArray = (new UnicodeEncoding()).GetBytes(EncryptString);
CypherTextBArray = rsa.Encrypt(PlainTextBArray, false);
Result = Convert.ToBase64String(CypherTextBArray);
return Result;
}
/// <summary>
/// RSA解密函数
/// </summary>
/// <param name="xmlPrivateKey"></param>
/// <param name="DecryptString"></param>
/// <returns></returns>
public string Decrypt(string xmlPrivateKey, string DecryptString)
{
byte[] PlainTextBArray;
byte[] DypherTextBArray;
string Result;
RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
rsa.FromXmlString(xmlPrivateKey);
PlainTextBArray = Convert.FromBase64String(DecryptString);
DypherTextBArray = rsa.Decrypt(PlainTextBArray, false);
Result = (new UnicodeEncoding()).GetString(DypherTextBArray);
return Result;
}

/// <summary>
/// 产生RSA的密钥
/// </summary>
/// <param name="xmlKeys">私钥</param>
/// <param name="xmlPublicKey">公钥</param>
public void RSAKey(out string xmlKeys, out string xmlPublicKey)
{
RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
xmlKeys = rsa.ToXmlString(true);
xmlPublicKey = rsa.ToXmlString(false);
}