using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;
namespace Sp.Common
{
public class EncryptHelper
{
private static string so = "1234567890abcdefghijklmnopqrstuvwxyzQWERTYUIOPASDFGHJKLZXCVBNM";
/// <summary>
/// 生成内容随机key
/// </summary>
/// <returns></returns>
private static string GetContent()
{
Random rand = new Random();
string str = null;
for (int i = 0; i < 8; i++)
{
str += so.Substring(rand.Next(62), 1);
}
return str;
}
private static byte[] Keys = { 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>
/// <returns>加密成功返回加密后的字符串，失败返回源串</returns>
public static string Encrypt(string encryptString)
{
try
{
Random rand = new Random();
int r = rand.Next(9);
string encryptKey = GetContent();
string first = encryptKey.Substring(0, r);
string last = encryptKey.Substring(r);
byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
byte[] rgbIV = Keys;
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();
string str = Convert.ToBase64String(mStream.ToArray());
int i = 0;
for (int j = str.Length - 1; j > 0; j--)
{
if (str[j] != '=')
{
break;
}
else
{
i++;
}
}
str = str.Substring(0, str.Length - i);
return string.Format("{0}{1}{2}{3}{4}", i.ToString(), r.ToString(), first, str, last);
}
catch
{
return encryptString;
}
}
/// <summary>
/// DES解密字符串
/// </summary>
/// <param name="decryptString">待解密的字符串</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)
{
try
{
int code = Int32.Parse(decryptString.Substring(1, 1));
int i = Int32.Parse(decryptString.Substring(0, 1));
string first = decryptString.Substring(2, code);
string last = decryptString.Substring(decryptString.Length - 8 + code);
string encryptKey = first + last;
decryptString = decryptString.Substring(code + 2, decryptString.Length - 10);
for (int j = 0; j < i; j++)
{
decryptString += "=";
}
byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey);
byte[] rgbIV = Keys;
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 decryptString;
}
}
const string AES_IV = "1234567890000000";//16位
/// <summary>
/// AES加密算法
/// </summary>
///<param name="input">明文字符串
///<param name="key">密钥（32位）
/// <returns>字符串</returns>
public static string EncryptByAES(string input, string key)
{
byte[] keyBytes = Encoding.UTF8.GetBytes(key.Substring(0, 32));
using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
{
ICryptoTransform encryptor = aesAlg.CreateEncryptor(keyBytes, Encoding.UTF8.GetBytes(AES_IV));
using (MemoryStream msEncrypt = new MemoryStream())
{
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
swEncrypt.Write(input);
}
return Convert.ToBase64String(msEncrypt.ToArray());
}
}
}
}
/// <summary>
/// AES解密
/// </summary>
///<param name="input">密文字节数组
///<param name="key">密钥（32位）
/// <returns>返回解密后的字符串</returns>
public static string DecryptByAES(string input, string key)
{
byte[] inputBytes = Convert.FromBase64String(input);
byte[] keyBytes = Encoding.UTF8.GetBytes(key.Substring(0, 32));
using (AesCryptoServiceProvider aesAlg = new AesCryptoServiceProvider())
{
ICryptoTransform decryptor = aesAlg.CreateDecryptor(keyBytes, Encoding.UTF8.GetBytes(AES_IV));
using (MemoryStream msEncrypt = new MemoryStream(inputBytes))
{
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srEncrypt = new StreamReader(csEncrypt))
{
return srEncrypt.ReadToEnd();
}
}
}
}
}
}
}
