C#中RSA加密解密和签名与验证的实现 (转）

RSA加密算法是一种非对称加密算法。在公钥加密标准和电子商业中RSA被广泛使用。RSA是1977年由罗纳德•李维斯特（Ron Rivest）、阿迪•萨莫尔（Adi Shamir）和伦纳德•阿德曼（Leonard Adleman）一起提出的。当时他们三人都在麻省理工学院工作。RSA就是他们三人姓氏开头字母拼在一起组成的。.Net的推出，我们能够利用.Net Framework中的类提供的加密服务来保证数据安全。目前应用较为广泛的加密方法是使用RSA算法进行加密。在.Net Framework中与RSA加密算法相关的类主要有两个：RSA 类和RSACryptoServiceProvider 类。按照MSDN的说法RSA 类是“表示 RSA 算法的所有实现均从中继承的基类”，而RSACryptoServiceProvider 类是“使用加密服务提供程序 (CSP) 提供的 RSA 算法的实现执行不对称加密和解密”。另外，“表示 RSA 算法的标准参数”的RSAParameters 结构也是很重要的，它保存了RSA算法的参数。
这里具体讲述一下在C#中如何使用框架提供的RSA算法来对我们的信息加密、签名、验证签名、解密的这个几个步骤的实现

代码

using System.Security.Cryptography;

using System.Management;

using Microsoft.Win32;

/// <summary>

/// 生成公私钥

/// </summary>

/// <param name="PrivateKeyPath"></param>

/// <param name="PublicKeyPath"></param>

public void RSAKey(string PrivateKeyPath, string PublicKeyPath)

{

try

{

RSACryptoServiceProvider provider = new RSACryptoServiceProvider();

this.CreatePrivateKeyXML(PrivateKeyPath, provider.ToXmlString(true));

this.CreatePublicKeyXML(PublicKeyPath, provider.ToXmlString(false));

}

catch (Exception exception)

{

throw exception;

}

}

/// <summary>

/// 对原始数据进行MD5加密

/// </summary>

/// <param name="m_strSource">待加密数据</param>

/// <returns>返回机密后的数据</returns>

public string GetHash(string m_strSource)

{

HashAlgorithm algorithm = HashAlgorithm.Create("MD5");

byte[] bytes = Encoding.GetEncoding("GB2312").GetBytes(m_strSource);

byte[] inArray = algorithm.ComputeHash(bytes);

return Convert.ToBase64String(inArray);

}

/// <summary>

/// RSA加密

/// </summary>

/// <param name="xmlPublicKey">公钥</param>

/// <param name="m_strEncryptString">MD5加密后的数据</param>

/// <returns>RSA公钥加密后的数据</returns>

public string RSAEncrypt(string xmlPublicKey, string m_strEncryptString)

{

string str2;

try

{

RSACryptoServiceProvider provider = new RSACryptoServiceProvider();

provider.FromXmlString(xmlPublicKey);

byte[] bytes = new UnicodeEncoding().GetBytes(m_strEncryptString);

str2 = Convert.ToBase64String(provider.Encrypt(bytes, false));

}

catch (Exception exception)

{

throw exception;

}

return str2;

}

/// <summary>

/// RSA解密

/// </summary>

/// <param name="xmlPrivateKey">私钥</param>

/// <param name="m_strDecryptString">待解密的数据</param>

/// <returns>解密后的结果</returns>

public string RSADecrypt(string xmlPrivateKey, string m_strDecryptString)

{

string str2;

try

{

RSACryptoServiceProvider provider = new RSACryptoServiceProvider();

provider.FromXmlString(xmlPrivateKey);

byte[] rgb = Convert.FromBase64String(m_strDecryptString);

byte[] buffer2 = provider.Decrypt(rgb, false);

str2 = new UnicodeEncoding().GetString(buffer2);

}

catch (Exception exception)

{

throw exception;

}

return str2;

}

/// <summary>

/// 对MD5加密后的密文进行签名

/// </summary>

/// <param name="p_strKeyPrivate">私钥</param>

/// <param name="m_strHashbyteSignature">MD5加密后的密文</param>

/// <returns></returns>

public string SignatureFormatter(string p_strKeyPrivate, string m_strHashbyteSignature)

{

byte[] rgbHash = Convert.FromBase64String(m_strHashbyteSignature);

RSACryptoServiceProvider key = new RSACryptoServiceProvider();

key.FromXmlString(p_strKeyPrivate);

RSAPKCS1SignatureFormatter formatter = new RSAPKCS1SignatureFormatter(key);

formatter.SetHashAlgorithm("MD5");

byte[] inArray = formatter.CreateSignature(rgbHash);

return Convert.ToBase64String(inArray);

}

/// <summary>

/// 签名验证

/// </summary>

/// <param name="p_strKeyPublic">公钥</param>

/// <param name="p_strHashbyteDeformatter">待验证的用户名</param>

/// <param name="p_strDeformatterData">注册码</param>

/// <returns></returns>

public bool SignatureDeformatter(string p_strKeyPublic, string p_strHashbyteDeformatter, string p_strDeformatterData)

{

try

{

byte[] rgbHash = Convert.FromBase64String(p_strHashbyteDeformatter);

RSACryptoServiceProvider key = new RSACryptoServiceProvider();

key.FromXmlString(p_strKeyPublic);

RSAPKCS1SignatureDeformatter deformatter = new RSAPKCS1SignatureDeformatter(key);

deformatter.SetHashAlgorithm("MD5");

byte[] rgbSignature = Convert.FromBase64String(p_strDeformatterData);

if (deformatter.VerifySignature(rgbHash, rgbSignature))

{

return true;

}

return false;

}

catch

{

return false;

}

}

/// <summary>

/// 获取硬盘ID

/// </summary>

/// <returns>硬盘ID</returns>

public string GetHardID()

{

string HDInfo = "";

ManagementClass cimobject1 = new ManagementClass("Win32_DiskDrive");

ManagementObjectCollection moc1 = cimobject1.GetInstances();

foreach (ManagementObject mo in moc1)

{

HDInfo = (string)mo.Properties["Model"].Value;

}

return HDInfo;

}

/// <summary>

/// 读注册表中指定键的值

/// </summary>

/// <param name="key">键名</param>

/// <returns>返回键值</returns>

private string ReadReg(string key)

{

string temp = "";

try

{

RegistryKey myKey = Registry.LocalMachine;

RegistryKey subKey = myKey.OpenSubKey(@"SOFTWARE\JX\Register");

temp = subKey.GetValue(key).ToString();

subKey.Close();

myKey.Close();

return temp;

}

catch (Exception)

{

throw;//可能没有此注册项;

}

}

/// <summary>

/// 创建注册表中指定的键和值

/// </summary>

/// <param name="key">键名</param>

/// <param name="value">键值</param>

private void WriteReg(string key, string value)

{

try

{

RegistryKey rootKey = Registry.LocalMachine.CreateSubKey(@"SOFTWARE\JX\Register");

rootKey.SetValue(key, value);

rootKey.Close();

}

catch (Exception)

{

throw;

}

}

/// <summary>

/// 创建公钥文件

/// </summary>

/// <param name="path"></param>

/// <param name="publickey"></param>

public void CreatePublicKeyXML(string path, string publickey)

{

try

{

FileStream publickeyxml = new FileStream(path, FileMode.Create);

StreamWriter sw = new StreamWriter(publickeyxml);

sw.WriteLine(publickey);

sw.Close();

publickeyxml.Close();

}

catch

{

throw;

}

}

/// <summary>

/// 创建私钥文件

/// </summary>

/// <param name="path"></param>

/// <param name="privatekey"></param>

public void CreatePrivateKeyXML(string path, string privatekey)

{

try

{

FileStream privatekeyxml = new FileStream(path, FileMode.Create);

StreamWriter sw = new StreamWriter(privatekeyxml);

sw.WriteLine(privatekey);

sw.Close();

privatekeyxml.Close();

}

catch

{

throw;

}

}

/// <summary>

/// 读取公钥

/// </summary>

/// <param name="path"></param>

/// <returns></returns>

public string ReadPublicKey(string path)

{

StreamReader reader = new StreamReader(path);

string publickey = reader.ReadToEnd();

reader.Close();

return publickey;

}

/// <summary>

/// 读取私钥

/// </summary>

/// <param name="path"></param>

/// <returns></returns>

public string ReadPrivateKey(string path)

{

StreamReader reader = new StreamReader(path);

string privatekey = reader.ReadToEnd();

reader.Close();

return privatekey;

}

/// <summary>

/// 初始化注册表，程序运行时调用，在调用之前更新公钥xml

/// </summary>

/// <param name="path">公钥路径</param>

public void InitialReg(string path)

{

Registry.LocalMachine.CreateSubKey(@"SOFTWARE\JX\Register");

Random ra = new Random();

string publickey = this.ReadPublicKey(path);

if (Registry.LocalMachine.OpenSubKey(@"SOFTWARE\JX\Register").ValueCount <= 0)

{

this.WriteReg("RegisterRandom", ra.Next(1,100000).ToString());

this.WriteReg("RegisterPublicKey", publickey);

}

else

{

this.WriteReg("RegisterPublicKey", publickey);

}

}

如果是要对发送的消息进行加密和解密，加密时用公钥，解密时用私钥，即使密文被窃取也无法破解。

如果是要对软件进行注册，生成注册码，则服务端将用户的硬盘号用私钥加密，客户端用公钥解密，解密后将客户端的硬盘号进行MD5加密，将得到的结果和解密后的结果进行比较，如果相同，说明是注册用户，否则为非注册用户。

本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/llwinnner/archive/2009/03/21/4011936.aspx