C#.NET 加密解密：AES/DES/Base64/RSA/MD5/SHA256

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
using System.Data;
using System.Data.Common;
using System.Web.Script.Serialization;
using System.IO;
using System.Security.Cryptography;

namespace Pub.Class
{
public static class EncryptExtensions
{

private static byte[] AESKeys = { 0x41, 0x72, 0x65, 0x79, 0x6F, 0x75, 0x6D, 0x79, 0x53, 0x6E, 0x6F, 0x77, 0x6D, 0x61, 0x6E, 0x3F };
public static string AESEncode(this string encryptString, string encryptKey)
{
encryptKey = encryptKey.SubString(32, "");
encryptKey = encryptKey.PadRight(32, ' ');

RijndaelManaged rijndaelProvider = new RijndaelManaged();
rijndaelProvider.Key = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 32));
rijndaelProvider.IV = AESKeys;
ICryptoTransform rijndaelEncrypt = rijndaelProvider.CreateEncryptor();

byte[] inputData = Encoding.UTF8.GetBytes(encryptString);
byte[] encryptedData = rijndaelEncrypt.TransformFinalBlock(inputData, 0, inputData.Length);

return Convert.ToBase64String(encryptedData);
}
public static string AESDecode(this string decryptString, string decryptKey)
{
try
{
decryptKey = decryptKey.SubString(32, "");
decryptKey = decryptKey.PadRight(32, ' ');

RijndaelManaged rijndaelProvider = new RijndaelManaged();
rijndaelProvider.Key = Encoding.UTF8.GetBytes(decryptKey);
rijndaelProvider.IV = AESKeys;
ICryptoTransform rijndaelDecrypt = rijndaelProvider.CreateDecryptor();

byte[] inputData = Convert.FromBase64String(decryptString);
byte[] decryptedData = rijndaelDecrypt.TransformFinalBlock(inputData, 0, inputData.Length);

return Encoding.UTF8.GetString(decryptedData);
}
catch { return string.Empty; }
}

private static byte[] DESKeys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
public static string DESEncode(this string encryptString, string encryptKey)
{
encryptKey = encryptKey.SubString(8, "");
encryptKey = encryptKey.PadRight(8, ' ');
byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
byte[] rgbIV = DESKeys;
byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
MemoryStream mStream = new MemoryStream();
CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
cStream.Write(inputByteArray, 0, inputByteArray.Length);
cStream.FlushFinalBlock();
return Convert.ToBase64String(mStream.ToArray());
}
public static string DESDecode(this string decryptString, string decryptKey)
{
try
{
decryptKey = decryptKey.SubString(8, "");
decryptKey = decryptKey.PadRight(8, ' ');
byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
byte[] rgbIV = DESKeys;
byte[] inputByteArray = Convert.FromBase64String(decryptString);
DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();

MemoryStream mStream = new MemoryStream();
CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
cStream.Write(inputByteArray, 0, inputByteArray.Length);
cStream.FlushFinalBlock();
return Encoding.UTF8.GetString(mStream.ToArray());
}
catch { return string.Empty; }
}

public static string Base64Encode(this string encryptString)
{
byte[] encbuff = System.Text.Encoding.UTF8.GetBytes(encryptString);
return Convert.ToBase64String(encbuff);
}
public static string Base64Decode(this string decryptString)
{
byte[] decbuff = Convert.FromBase64String(decryptString);
return System.Text.Encoding.UTF8.GetString(decbuff);
}

public static string RSADecrypt(this string s, string key)
{
string result = null;

if (string.IsNullOrEmpty(s)) throw new ArgumentException("An empty string value cannot be encrypted.");

if (string.IsNullOrEmpty(key)) throw new ArgumentException("Cannot decrypt using an empty key. Please supply a decryption key.");

CspParameters cspp = new CspParameters();
cspp.KeyContainerName = key;

RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(cspp);
rsa.PersistKeyInCsp = true;

string[] decryptArray = s.Split(new string[] { "-" }, StringSplitOptions.None);
byte[] decryptByteArray = Array.ConvertAll<string, byte>(decryptArray, (a => Convert.ToByte(byte.Parse(a, System.Globalization.NumberStyles.HexNumber))));

byte[] bytes = rsa.Decrypt(decryptByteArray, true);

result = System.Text.UTF8Encoding.UTF8.GetString(bytes);

return result;
}
public static string RSAEncrypt(this string s, string key)
{
if (string.IsNullOrEmpty(s)) throw new ArgumentException("An empty string value cannot be encrypted.");

if (string.IsNullOrEmpty(key)) throw new ArgumentException("Cannot encrypt using an empty key. Please supply an encryption key.");

CspParameters cspp = new CspParameters();
cspp.KeyContainerName = key;

RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(cspp);
rsa.PersistKeyInCsp = true;

byte[] bytes = rsa.Encrypt(System.Text.UTF8Encoding.UTF8.GetBytes(s), true);

return BitConverter.ToString(bytes);
}

public static string MD5(this string str)
{
string cl1 = str;
string pwd = "";
System.Security.Cryptography.MD5 md5 = System.Security.Cryptography.MD5.Create();// 加密后是一个字节类型的数组
byte[] s = md5.ComputeHash(Encoding.Unicode.GetBytes(cl1));
for (int i = 0; i < s.Length; i++)
{// 通过使用循环，将字节类型的数组转换为字符串，此字符串是常规字符格式化所得
pwd = pwd + s[i].ToString("x");// 将得到的字符串使用十六进制类型格式。格式后的字符是小写的字母，如果使用大写（X）则格式后的字符是大写字符
}
return pwd;
}
public static string MD5CSP(this string encypStr)
{
string retStr;
MD5CryptoServiceProvider m5 = new MD5CryptoServiceProvider();

//创建md5对象
byte[] inputBye;
byte[] outputBye;

//使用GB2312编码方式把字符串转化为字节数组．
inputBye = Encoding.GetEncoding("GB2312").GetBytes(encypStr);

outputBye = m5.ComputeHash(inputBye);

retStr = System.BitConverter.ToString(outputBye);
retStr = retStr.Replace("-", "").ToLower();
return retStr;
}

public static string SHA256(this string str)
{
byte[] SHA256Data = Encoding.UTF8.GetBytes(str);
SHA256Managed Sha256 = new SHA256Managed();
byte[] Result = Sha256.ComputeHash(SHA256Data);
return Convert.ToBase64String(Result);  //返回长度为44字节的字符串
}

}
}