加密，解密码，签名，验证签名

using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Security;

using System.Security.Cryptography;

using System.Text;

namespace Cryption

{

public class Cryption

{

#region 解释Convert.ToBase64String 与 Encoding.GetString 区别

/*

*

二者都是将 byte[] 转换成字符串，一个区别在于 Convert.ToBase64String 使用 base 64 数字编码，所以它生成的全部是 ASCII 字符。

而 Encoding.GetString 就是转换成我们平常所认识的字符串。

一些加密方法返回 byte[]，此时我们要转换成字符串用哪个呢？

利用 Encoding.GetString 转换，可能得到很多方块或问号，这是由于某些整数序列无法对应于我们现实生活中的文字的原因，只能用方块或问号来代替。

所以我们一般还是用 Convert.ToBase64String 来进行。

那么从另一方面，字符串转换成 byte[] 用哪个呢？是不是一定要用 FromBase64String 呢？

不是的，我们普通的文字(如String类型)并不是 base 64 编码的，不能使用 FromBase64String 转换成 byte[]，比如：FromBase64String("千一网络") 就会出错，因为“千一网络”并不是 base 64 编码的,此时应该用Encoding.GetBytes()。

*/

#endregion

/// <summary>

/// 得到公钥和私钥

/// </summary>

/// <param name="publicKEY"></param>

/// <param name="PrivateKEY"></param>

public static void GetKey(out string publicKEY, out string PrivateKEY)

{

RSACryptoServiceProvider rsaProvider = new RSACryptoServiceProvider();

publicKEY = rsaProvider.ToXmlString(false);

PrivateKEY = rsaProvider.ToXmlString(true);

}

/// <summary>

/// 加密码

/// </summary>

/// <param name="publicKEY"></param>

/// <param name="encryptText"></param>

/// <returns></returns>

public static string Encrypt(string publicKEY, string encryptText)

{

byte[] byteencryptText = new UnicodeEncoding().GetBytes(encryptText);

RSACryptoServiceProvider rsProvider = new RSACryptoServiceProvider();

rsProvider.FromXmlString(publicKEY);

return Convert.ToBase64String(rsProvider.Encrypt(byteencryptText, false));

}

/// <summary>

/// 解密

/// </summary>

/// <param name="PrivateKEY"></param>

/// <param name="decryptText"></param>

/// <returns></returns>

public static string Decrypt(string PrivateKEY, string decryptText)

{

UnicodeEncoding uni = new UnicodeEncoding();

byte[] byteencryptText = Convert.FromBase64String(decryptText);

RSACryptoServiceProvider rsProvider = new RSACryptoServiceProvider();

rsProvider.FromXmlString(PrivateKEY);

return uni.GetString(rsProvider.Decrypt(byteencryptText, false));

}

/// <summary>

/// 计算指定字节数组的哈希值

/// </summary>

/// <param name="text"></param>

/// <returns></returns>

public static string Gethash(string text)

{

byte[] bytetext = new UnicodeEncoding().GetBytes(text);

HashAlgorithm ha = HashAlgorithm.Create("md5");

return Convert.ToBase64String(ha.ComputeHash(bytetext));

}

/// <summary>

/// 创建签名

/// </summary>

/// <param name="publicKEY"></param>

/// <param name="text"></param>

/// <param name="signatureText">签名后的数据</param>

/// <returns></returns>

public static void SignatureFormatter(string privatekey, string text, ref string signatureText)

{

byte[] byteText = Convert.FromBase64String(text);

RSACryptoServiceProvider rsaProvider = new RSACryptoServiceProvider();

rsaProvider.FromXmlString(privatekey);

RSAPKCS1SignatureFormatter rsaSignatureFormatter = new RSAPKCS1SignatureFormatter(rsaProvider);

rsaSignatureFormatter.SetHashAlgorithm("MD5");

byte[] bytesignatureText = rsaSignatureFormatter.CreateSignature(byteText);

signatureText = Convert.ToBase64String(bytesignatureText);

}

/// <summary>

/// 验证签名

/// </summary>

/// <param name="key"></param>

/// <param name="text">原文本</param>

/// <param name="SignatureText">签名后文本</param>

/// <returns>true：正确，false:错误</returns>

public static bool SignatureDeFormatter(string publickey, string text, string SignatureText)

{

byte[] byteText = Convert.FromBase64String(text);

byte[] byteSignatureText = Convert.FromBase64String(SignatureText);

RSACryptoServiceProvider rsaProvider = new RSACryptoServiceProvider();

rsaProvider.FromXmlString(publickey);

RSAPKCS1SignatureDeformatter rsaSignatureDeFormatter = new RSAPKCS1SignatureDeformatter(rsaProvider);

rsaSignatureDeFormatter.SetHashAlgorithm("MD5");

return rsaSignatureDeFormatter.VerifySignature(byteText, byteSignatureText);

}

}

}