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

{

///

/// 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。

///

public class HashEncrypt

{

//private string strIN;

private bool isReturnNum;

private bool isCaseSensitive;

///

/// 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。

///

/// 是否区分大小写

/// 是否返回为加密后字符的Byte代码

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);

}

///

/// 使用DES加密(Added by niehl 2005-4-6)

///

/// 待加密的字符串

/// 密钥(最大长度8)

/// 初始化向量(最大长度8)

/// 加密后的字符串

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);

}

///

/// 使用DES解密(Added by niehl 2005-4-6)

///

/// 待解密的字符串

/// 密钥(最大长度8)

/// m初始化向量(最大长度8)

/// 解密后的字符串

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;

}

}

}