c# 实现MD5，SHA1，SHA256，SHA512等常用加密算法

using
System;



using
System.IO;



using
System.Data;



using
System.Text;



using
System.Diagnostics;



using
System.Security;



using
System.Security.Cryptography;







/**/
/*


* .Net框架由于拥有CLR提供的丰富库支持，只需很少的代码即可实现先前使用C等旧式语言很难实现的加密算法。本类实现一些常用机密算法，供参考。其中MD5算法返回Int的ToString字串。返回数字字母型结果的算法参见之前Blog文章


*/



namespace
档案数字化加工







{




/**//// <summary>


/// 类名：HashEncrypt


/// 作用：对传入的字符串进行Hash运算，返回通过Hash算法加密过的字串。


/// 属性：［无］


/// 构造函数额参数：


/// IsReturnNum:是否返回为加密后字符的Byte代码


/// IsCaseSensitive：是否区分大小写。


/// 方法：此类提供MD5，SHA1，SHA256，SHA512等四种算法，加密字串的长度依次增大。


/// </summary>


public class HashEncrypt






{


//private string strIN;


private bool isReturnNum;


private bool isCaseSensitive;






/**//// <summary>


/// 类初始化，此类提供MD5，SHA1，SHA256，SHA512等四种算法，加密字串的长度依次增大。


/// </summary>


/// <param name="IsCaseSensitive">是否区分大小写</param>


/// <param name="IsReturnNum">是否返回为加密后字符的Byte代码</param>


public HashEncrypt(bool IsCaseSensitive, bool IsReturnNum)






{


this.isReturnNum = IsReturnNum;


this.isCaseSensitive = IsCaseSensitive;


}




private string getstrIN(string strIN)






{


//string strIN = strIN;


if (strIN.Length == 0)






{


strIN = "~NULL~";


}


if (isCaseSensitive == false)






{


strIN = strIN.ToUpper();


}


return strIN;


}




public string MD5Encrypt(string strIN)






{


//string strIN = getstrIN(strIN);


byte[] tmpByte;


MD5 md5 = new MD5CryptoServiceProvider();


tmpByte = md5.ComputeHash(GetKeyByteArray(getstrIN(strIN)));


md5.Clear();




return GetStringValue(tmpByte);




}




public string SHA1Encrypt(string strIN)






{


//string strIN = getstrIN(strIN);


byte[] tmpByte;


SHA1 sha1 = new SHA1CryptoServiceProvider();




tmpByte = sha1.ComputeHash(GetKeyByteArray(strIN));


sha1.Clear();




return GetStringValue(tmpByte);




}




public string SHA256Encrypt(string strIN)






{


//string strIN = getstrIN(strIN);


byte[] tmpByte;


SHA256 sha256 = new SHA256Managed();




tmpByte = sha256.ComputeHash(GetKeyByteArray(strIN));


sha256.Clear();




return GetStringValue(tmpByte);




}




public string SHA512Encrypt(string strIN)






{


//string strIN = getstrIN(strIN);


byte[] tmpByte;


SHA512 sha512 = new SHA512Managed();




tmpByte = sha512.ComputeHash(GetKeyByteArray(strIN));


sha512.Clear();




return GetStringValue(tmpByte);




}






/**//// <summary>


/// 使用DES加密（Added by niehl 2005-4-6）


/// </summary>


/// <param name="originalValue">待加密的字符串</param>


/// <param name="key">密钥(最大长度8)</param>


/// <param name="IV">初始化向量(最大长度8)</param>


/// <returns>加密后的字符串</returns>


public string DESEncrypt(string originalValue, string key, string IV)






{


//将key和IV处理成8个字符


key += "12345678";


IV += "12345678";


key = key.Substring(0, 8);


IV = IV.Substring(0, 8);




SymmetricAlgorithm sa;


ICryptoTransform ct;


MemoryStream ms;


CryptoStream cs;


byte[] byt;




sa = new DESCryptoServiceProvider();


sa.Key = Encoding.UTF8.GetBytes(key);


sa.IV = Encoding.UTF8.GetBytes(IV);


ct = sa.CreateEncryptor();




byt = Encoding.UTF8.GetBytes(originalValue);




ms = new MemoryStream();


cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);


cs.Write(byt, 0, byt.Length);


cs.FlushFinalBlock();




cs.Close();




return Convert.ToBase64String(ms.ToArray());


}




public string DESEncrypt(string originalValue, string key)






{


return DESEncrypt(originalValue, key, key);


}






/**//// <summary>


/// 使用DES解密（Added by niehl 2005-4-6）


/// </summary>


/// <param name="encryptedValue">待解密的字符串</param>


/// <param name="key">密钥(最大长度8)</param>


/// <param name="IV">m初始化向量(最大长度8)</param>


/// <returns>解密后的字符串</returns>


public string DESDecrypt(string encryptedValue, string key, string IV)






{


//将key和IV处理成8个字符


key += "12345678";


IV += "12345678";


key = key.Substring(0, 8);


IV = IV.Substring(0, 8);




SymmetricAlgorithm sa;


ICryptoTransform ct;


MemoryStream ms;


CryptoStream cs;


byte[] byt;




sa = new DESCryptoServiceProvider();


sa.Key = Encoding.UTF8.GetBytes(key);


sa.IV = Encoding.UTF8.GetBytes(IV);


ct = sa.CreateDecryptor();




byt = Convert.FromBase64String(encryptedValue);




ms = new MemoryStream();


cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);


cs.Write(byt, 0, byt.Length);


cs.FlushFinalBlock();




cs.Close();




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




}




public string DESDecrypt(string encryptedValue, string key)






{


return DESDecrypt(encryptedValue, key, key);


}




private string GetStringValue(byte[] Byte)






{


string tmpString = "";


if (this.isReturnNum == false)






{


ASCIIEncoding Asc = new ASCIIEncoding();


tmpString = Asc.GetString(Byte);


}


else






{


int iCounter;


for (iCounter = 0; iCounter < Byte.Length; iCounter++)






{


tmpString = tmpString + Byte[iCounter].ToString();


}


}


return tmpString;


}




private byte[] GetKeyByteArray(string strKey)






{




ASCIIEncoding Asc = new ASCIIEncoding();




int tmpStrLen = strKey.Length;


byte[] tmpByte = new byte[tmpStrLen - 1];




tmpByte = Asc.GetBytes(strKey);




return tmpByte;




}




}


}