：MD5 不可逆加密
2：Des对称可逆加密
3：RSA非对称可逆加密
4：数字证书 SSL
Anker_张（博客园）http://www.cnblogs.com/AnkerZhang/
1：MD5 不可逆加密
using System.IO; using System.Security.Cryptography; using System.Text; namespace EncryptDemo { /// <summary> /// 不可逆加密 /// 1 防止被篡改 /// 2 防止明文存储 /// 3 防止抵赖，数字签名 /// </summary> public class MD5Encrypt { #region MD5 /// <summary> /// MD5加密,和动网上的16/32位MD5加密结果相同, /// 使用的UTF8编码 /// </summary> /// <param name="strSource">待加密的字符串</param> /// <param name="length">16或32值之一,其它则采用.net默认MD5加密算法</param> /// <returns>加密后的字串</returns> public static string Encrypt(string source, int length = 32)//默认参数 { HashAlgorithm provider = CryptoConfig.CreateFromName("MD5") as HashAlgorithm; if (string.IsNullOrEmpty(source)) return string.Empty; byte[] bytes = Encoding.UTF8.GetBytes(source);// Encoding.ASCII.GetBytes(source); byte[] hashValue = provider.ComputeHash(bytes); StringBuilder sb = new StringBuilder(); switch (length) { case 16://16位密文是32位密文的9到24位字符 for (int i = 4; i < 12; i++) sb.Append(hashValue[i].ToString("x2")); break; case 32: for (int i = 0; i < 16; i++) { sb.Append(hashValue[i].ToString("x2")); } break; default: for (int i = 0; i < hashValue.Length; i++) { sb.Append(hashValue[i].ToString("x2")); } break; } return sb.ToString(); } /// <summary> /// MD5加密,和动网上的16/32位MD5加密结果相同, /// 使用的UTF8编码 /// 为文件加密方法 /// </summary> /// <param name="strSource">待加密的文件路径</param> /// <param name="length">16或32值之一,其它则采用.net默认MD5加密算法</param> /// <returns>加密后的字串</returns> public static string EncryptFile(string pathFile, int length = 32)//默认参数 { using (FileStream fsRead = new FileStream(pathFile, FileMode.Open)) { int fsLen = (int)fsRead.Length; byte[] heByte = new byte[fsLen]; int r = fsRead.Read(heByte, 0, heByte.Length); string myStr = System.Text.Encoding.UTF8.GetString(heByte); return Encrypt(myStr, length); } } #endregion MD5 } }
2：Des对称可逆加密
using System; using System.IO; using System.Security.Cryptography; using System.Text; namespace EncryptDemo { /// <summary> /// DES AES Blowfish /// 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。 /// 可逆对称加密 密钥长度8 /// </summary> public class DesEncrypt { //8位长度 private static string KEY = "Anker_张1"; private static byte[] rgbKey = ASCIIEncoding.ASCII.GetBytes(KEY.Substring(0, 8)); private static byte[] rgbIV = ASCIIEncoding.ASCII.GetBytes(KEY.Insert(0, "Z").Substring(0, 8)); /// <summary> /// DES 加密 /// </summary> /// <param name="strValue"></param> /// <returns></returns> public static string Encrypt(string strValue) { DESCryptoServiceProvider dsp = new DESCryptoServiceProvider(); using (MemoryStream memStream = new MemoryStream()) { CryptoStream crypStream = new CryptoStream(memStream, dsp.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write); StreamWriter sWriter = new StreamWriter(crypStream); sWriter.Write(strValue); sWriter.Flush(); crypStream.FlushFinalBlock(); memStream.Flush(); return Convert.ToBase64String(memStream.GetBuffer(), 0, (int)memStream.Length); } } /// <summary> /// DES解密 /// </summary> /// <param name="EncValue"></param> /// <returns></returns> public static string Decrypt(string EncValue) { DESCryptoServiceProvider dsp = new DESCryptoServiceProvider(); byte[] buffer = Convert.FromBase64String(EncValue); using (MemoryStream memStream = new MemoryStream()) { CryptoStream crypStream = new CryptoStream(memStream, dsp.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write); crypStream.Write(buffer, 0, buffer.Length); crypStream.FlushFinalBlock(); return ASCIIEncoding.UTF8.GetString(memStream.ToArray()); } } } }
3：RSA非对称可逆加密
using System; using System.Collections.Generic; using System.Security.Cryptography; using System.Text; namespace EncryptDemo { /// <summary> /// RSA ECC /// 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> /// publicKey:加密,privateKey解密 /// </summary> /// <returns></returns> public static KeyValuePair<string, string> GetKeyPair() { RSACryptoServiceProvider RSA = new RSACryptoServiceProvider(); string publicKey = RSA.ToXmlString(false); string privateKey = RSA.ToXmlString(true); return new KeyValuePair<string, string>(publicKey, privateKey); } /// <summary> /// 加密 /// </summary> /// <param name="content"></param> /// <param name="publicKey">返还公钥</param> /// <param name="privateKey">返回密钥</param> /// <returns>加密后结果</returns> 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：内容+公钥 /// </summary> /// <param name="content"></param> /// <param name="publicKey"></param> /// <returns></returns> public static string Encrypt(string content, string publicKey) { RSACryptoServiceProvider rsa = new RSACryptoServiceProvider(); rsa.FromXmlString(publicKey); UnicodeEncoding ByteConverter = new UnicodeEncoding(); byte[] DataToEncrypt = ByteConverter.GetBytes(content); byte[] resultBytes = rsa.Encrypt(DataToEncrypt, false); return Convert.ToBase64String(resultBytes); } /// <summary> /// 解密 内容+私钥 /// </summary> /// <param name="content"></param> /// <param name="privateKey"></param> /// <returns></returns> public static string Decrypt(string content, string privateKey) { byte[] dataToDecrypt = Convert.FromBase64String(content); RSACryptoServiceProvider RSA = new RSACryptoServiceProvider(); RSA.FromXmlString(privateKey); byte[] resultBytes = RSA.Decrypt(dataToDecrypt, false); UnicodeEncoding ByteConverter = new UnicodeEncoding(); return ByteConverter.GetString(resultBytes); } } }
RSA非对称可逆加密原理
4：数字证书 SSL
.Net中的加密解密：http://www.cnblogs.com/JimmyZhang/archive/2008/10/02/Cryptograph.html
MD5算法原理：http://blog.csdn.net/forgotaboutgirl/article/details/7258109
详情Des加密: http://www.iplaysoft.com/encrypt-arithmetic.html
详情RSA加密:http://www.iplaysoft.com/encrypt-arithmetic.html
SSL 与 数字证书 的基本概念和工作原理:http://blog.csdn.net/jhonguy/article/details/7577729