前言：
一、DES加密
DES加密是对称加密算法，
对称加密算法的优点是速度快，缺点是密钥管理不方便，要求共享密钥
public class DesEncrypt
{
private readonly byte[] _rgbKey;
private readonly byte[] _rgbIV;
/// <summary>
/// Ctor
/// </summary>
/// <param name="rgbKey">用于对称算法的密钥</param>
/// <param name="rgbIV">用于对称算法的初始化向量</param>
public DesEncrypt(string rgbKey, string rgbIV)
{
_rgbKey = Encoding.ASCII.GetBytes(rgbKey.Substring(0, 8));
_rgbIV = Encoding.ASCII.GetBytes(rgbIV.Insert(0, "w").Substring(0, 8));
}
/// <summary>
/// DES加密
/// </summary>
/// <param name="text">需要加密的值</param>
/// <returns>加密后的结果</returns>
public string Encrypt(string text)
{
var desCrypto = new DESCryptoServiceProvider();
using (var memoryStream = new MemoryStream())
{
var crypStream = new CryptoStream(
memoryStream,
desCrypto.CreateEncryptor(_rgbKey, _rgbIV),
CryptoStreamMode.Write);
var sWriter = new StreamWriter(crypStream);
sWriter.Write(text);
sWriter.Flush();
crypStream.FlushFinalBlock();
memoryStream.Flush();
return Convert.ToBase64String(memoryStream.GetBuffer(), 0, (int)memoryStream.Length);
}
}
/// <summary>
/// DES解密
/// </summary>
/// <param name="encryptText">需要解密的值</param>
/// <returns>解密后的结果</returns>
public string Decrypt(string encryptText)
{
var desCrypto = new DESCryptoServiceProvider();
var buffer = Convert.FromBase64String(encryptText);
using (var memoryStream = new MemoryStream())
{
var crypStream = new CryptoStream(
memoryStream,
desCrypto.CreateDecryptor(_rgbKey, _rgbIV),
CryptoStreamMode.Write);
crypStream.Write(buffer, 0, buffer.Length);
crypStream.FlushFinalBlock();
return Encoding.UTF8.GetString(memoryStream.ToArray());
}
}
}
二、MD5加密
MD5加密是不可逆加密
防止被篡改 防止明文存储 防止抵赖，数字签名
public class MD5Encrypt
{
/// <summary>
/// 加密
/// </summary>
/// <param name="source">需要加密的字符串</param>
/// <param name="length">密文长度</param>
/// <returns>密文</returns>
public string Encrypt(string source, int length = 32)
{
if (string.IsNullOrEmpty(source))
return string.Empty;
var provider = CryptoConfig.CreateFromName("MD5") as HashAlgorithm;
// 这里需要区别编码的
var sourceBytes = Encoding.UTF8.GetBytes(source);
var hashValue = provider.ComputeHash(sourceBytes);
var cipher = new StringBuilder();
switch (length)
{
case 16:
for (int i = 4; i < 12; i++)
{
cipher.Append(hashValue[i].ToString("x2"));
}
break;
case 32:
for (int i = 0; i < 16; i++)
{
cipher.Append(hashValue[i].ToString("x2"));
}
break;
default:
for (int i = 0; i < hashValue.Length; i++)
{
cipher.Append(hashValue[i].ToString("x2"));
}
break;
}
return cipher.ToString();
}
}
也可以对文件进行加密，获得文件的MD5密文
根据MD5密码，可以判断文件是否被篡改，例如百度网盘的急速秒传。
/// <summary>
/// 获取文件的MD5摘要
/// </summary>
/// <param name="fileName"></param>
/// <returns></returns>
public string AbstractFile(string fileName)
{
using (var file = new FileStream(fileName, FileMode.Open))
{
return AbstractFile(file);
}
}
/// <summary>
/// 根据stream获取文件摘要
/// </summary>
/// <param name="stream"></param>
/// <returns></returns>
public static string AbstractFile(Stream stream)
{
var md5 = new MD5CryptoServiceProvider();
var computeHash = md5.ComputeHash(stream);
var cipher = new StringBuilder();
for (int i = 0; i < computeHash.Length; i++)
{
cipher.Append(computeHash[i].ToString("x2"));
}
return cipher.ToString();
}
}
三、RSA加密
RSA加密是可逆非对称加密
非对称加密算法的优点是密钥管理很方便，缺点是速度慢。
/// <summary>
/// 可逆非对称加密
/// 非对称加密算法的优点是密钥管理很方便，缺点是速度慢。
/// </summary>
public class RsaEncrypt
{
/// <summary>
/// 获取密钥对
/// </summary>
/// <returns></returns>
public KeyValuePair<string, string> GetKeyPair()
{
var rsaCryptoService = new RSACryptoServiceProvider();
var publicKey = rsaCryptoService.ToXmlString(false);
var privateKey = rsaCryptoService.ToXmlString(true);
return new KeyValuePair<string, string>(publicKey, privateKey);
}
/// <summary>
/// 加密
/// </summary>
/// <param name="content">需要加密的内容</param>
/// <param name="encryptKey">加密的密钥</param>
/// <returns></returns>
public string Encrypt(string content, string encryptKey)
{
var rsaCryptoService = new RSACryptoServiceProvider();
rsaCryptoService.FromXmlString(encryptKey);
byte[] dataToEncrypt = Encoding.UTF8.GetBytes(content);
byte[] resultBytes = rsaCryptoService.Encrypt(dataToEncrypt, false);
return Convert.ToBase64String(resultBytes);
}
/// <summary>
/// 解密
/// </summary>
/// <param name="content">需要解密的内容</param>
/// <param name="decryptKey">解密的密钥</param>
/// <returns></returns>
public string Decrypt(string content, string decryptKey)
{
var rsaCryptoService = new RSACryptoServiceProvider();
rsaCryptoService.FromXmlString(decryptKey);
byte[] dataToDecrypt = Convert.FromBase64String(content);
byte[] resultBytes = rsaCryptoService.Decrypt(dataToDecrypt, false);
return Encoding.UTF8.GetString(resultBytes);
}
}