(C#基础)各种加密学习

之前，一直想对这个做一个了解，但是总是坚持不下去，很急躁。最近看了几遍文章，很有感触，于是又来重新开始学习，从最最基础的开始——正所谓“慢就是快”。心态变了，继续吧！上代码！

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;

namespace dazilianxi.wenjian
{
public class RSACryptoHelper
{
//加密
public static string Encrypt(string publicKeyXml, string plainText)
{
RSACryptoServiceProvider provider = new RSACryptoServiceProvider();
provider.FromXmlString(publicKeyXml); //使用公匙初始化对象
byte[] plainData = Encoding.Default.GetBytes(plainText);
byte[] encryptedData = provider.Encrypt(plainData, true);
return Convert.ToBase64String(encryptedData);
}

//解密
public static string Decrypt(string privateKeyXml, string encryptedText)
{
RSACryptoServiceProvider provider = new RSACryptoServiceProvider();
provider.FromXmlString(privateKeyXml);
byte[] encryptedData = Convert.FromBase64String(encryptedText);
byte[] plainData = provider.Decrypt(encryptedData, true);
string plainText = Encoding.Default.GetString(plainData);
return plainText;
}
public static KeyValuePair<string, string> CreateRSAKey()
{
RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
string privateKey = RSA.ToXmlString(true);
string publicKey = RSA.ToXmlString(false);

return new KeyValuePair<string, string>(publicKey, privateKey);
}

public static string SignData(string plainText, string privateKeyXml)
{
RSACryptoServiceProvider provider = new RSACryptoServiceProvider();
provider.FromXmlString(privateKeyXml);

byte[] plainData = Encoding.Default.GetBytes(plainText);
//设置获取摘要的算法
HashAlgorithm sha1 = HashAlgorithm.Create("SHA1");
//获取签名过的摘要,是使用私匙加密过的摘要
byte[] signedDigest = provider.SignData(plainData, sha1);
return Convert.ToBase64String(signedDigest);
}

public static bool VerifyData(string plainText, string signature, string publicKeyXml)
{
RSACryptoServiceProvider provider = new RSACryptoServiceProvider();
provider.FromXmlString(publicKeyXml);

byte[] plainData = Encoding.Default.GetBytes(plainText);
byte[] signedDigest = Convert.FromBase64String(signature);

HashAlgorithm sha1 = HashAlgorithm.Create("SHA1");
bool isDataIntact = provider.VerifyData(plainData, sha1, signedDigest);
return isDataIntact;
}

//使用SingnHash
public static string SignData2(string plainText, string privateKeyXml)
{
RSACryptoServiceProvider provider = new RSACryptoServiceProvider();
provider.FromXmlString(privateKeyXml);
byte[] plainData = Encoding.Default.GetBytes(plainText);

//设置获取摘要的算法
HashAlgorithm sha1 = HashAlgorithm.Create("SHA1");
//获得原始摘要
byte[] digestData = sha1.ComputeHash(plainData);
//对元素摘要进行签名
byte[] signedDigest = provider.SignHash(digestData, "SHA1");
return Convert.ToBase64String(signedDigest);
}

//使用VerifyHash
public static bool VerifyData2(string plainText, string signedDigest, string publicKeyXml)
{
RSACryptoServiceProvider provider = new RSACryptoServiceProvider();
provider.FromXmlString(publicKeyXml);

byte[] plainData = Encoding.Default.GetBytes(plainText);
byte[] signedDigestData = Convert.FromBase64String(signedDigest);

//获得本地摘要
HashAlgorithm sha1 = HashAlgorithm.Create("SHA1");
byte[] digest = sha1.ComputeHash(plainData);

//解密签名
bool isDataIntact = provider.VerifyHash(digest, "SHA1", signedDigestData);
return isDataIntact;
}
}
}

RSACryptoServiceProvider provider = new RSACryptoServiceProvider();
string publicPrivate = provider.ToXmlString(true);//获得公/私匙对
// string publicOnly = provider.ToXmlString(false); //只获得公匙
// string key = "secret key";
string str = "hello world";
// string str2 = "hello world";
//加密
string encryptedText = RSACryptoHelper.Encrypt(publicPrivate, str);
Console.WriteLine(encryptedText);
//学到了重构，this 在构造函数中的灵活运用。不能直接满足条件，就要想方设法创造合适的。
//解密
string clearText = RSACryptoHelper.Decrypt(publicPrivate, encryptedText);
Console.WriteLine(clearText);

string originalData = "文章不错，这是我的签名：奥巴马！";
Console.WriteLine("签名数为：{0}", originalData);

KeyValuePair<string, string> keyPair =RSACryptoHelper.CreateRSAKey();
string privateKey = keyPair.Value;
string publicKey = keyPair.Key;
//1、生成签名，通过摘要算法
string signedData = RSACryptoHelper.SignData(originalData, privateKey);
Console.WriteLine("数字签名1:{0}", signedData);

//2、验证签名
bool verify = RSACryptoHelper.VerifyData(originalData, signedData, publicKey);
Console.WriteLine("签名验证结果：{0}", verify);

string signedData2 = RSACryptoHelper.SignData2(originalData, privateKey);
Console.WriteLine("数字签名2:{0}", signedData2);

//2、验证签名
bool verify2 = RSACryptoHelper.VerifyData2(originalData, signedData2, publicKey);
Console.WriteLine("签名验证结果2：{0}", verify2);

参考，延伸学习：

数据加密：http://www.cnblogs.com/yank/p/3528548.html

数字签名：http://www.cnblogs.com/yank/p/3533998.html

证书：http://www.cnblogs.com/Microshaoft/archive/2009/05/19/1460641.html

加密：http://www.cnblogs.com/Microshaoft/archive/2008/07/21/1247584.html

加密：http://www.cnblogs.com/darrenji/p/3677458.html