net core体系-web应用程序-4asp.net core2.0 项目实战（1）-8项目加密解密方案

本文目录
1. 摘要
2. MD5加密封装
3. AES的加密、解密
4. DES加密/解密
5. 总结

1.  摘要

　　C#中常用的一些加密和解密方案，如：md5加密、RSA加密与解密和DES加密等，Asp.Net Core 2.0下该如何调整与使用我们以前常用的解加密算法类呢，下面是我整理的MD5加密、AES&DES对称加解密、Encrypt&Decrypt加解密完整实例。希望能给大家提供一些参考和帮助。

　　

2.  MD5加密封装

　　MD5常用加密FormsAuthentication.HashPasswordForStoringInConfigFile在Net Freamwork4.5以后就不在支持，下面整理了32位或16位下的几个方法，以及不同写法，最后一个由从老版本迁移过来，后续淘汰不用。

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

namespace NC.Common
{
    /// <summary>
    /// 此类获取md5加密值均为大写，如果要获取小写：MD5Comm.Get32MD5One(xx).ToLower();或完善此类。
    /// </summary>
    public class MD5Comm
    {
        #region --Expired code--
        ///// <summary>
        ///// MD5加密
        ///// </summary>
        //public string Md5(string txt)
        //{
        //    //return FormsAuthentication.HashPasswordForStoringInConfigFile(txt, "MD5");//此方法nf4.5后不再支持
        //}
        //public string Md5Pass(string pwd)
        //{
        //    return Md5(pwd + "Jiahao");
        //} 
        #endregion

        /// <summary>
        /// 此代码示例通过创建哈希字符串适用于任何 MD5 哈希函数 （在任何平台） 上创建 32 个字符的十六进制格式哈希字符串
        /// 官网案例改编
        /// </summary>
        /// <param name="source"></param>
        /// <returns></returns>
        public static string Get32MD5One(string source)
        {
            using (MD5 md5Hash = MD5.Create())
            {
                byte[] data = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(source));
                StringBuilder sBuilder = new StringBuilder();
                for (int i = 0; i < data.Length; i++)
                {
                    sBuilder.Append(data[i].ToString("x2"));
                }

                string hash = sBuilder.ToString();
                return hash.ToUpper();
            }
        }
        /// <summary>
        /// 获取16位md5加密
        /// </summary>
        /// <param name="source"></param>
        /// <returns></returns>
        public static string Get16MD5One(string source)
        {
            using (MD5 md5Hash = MD5.Create())
            {
                byte[] data = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(source));
                //转换成字符串，并取9到25位
                string sBuilder = BitConverter.ToString(data, 4, 8);
                //BitConverter转换出来的字符串会在每个字符中间产生一个分隔符，需要去除掉
                sBuilder = sBuilder.Replace("-", "");
                return sBuilder.ToString().ToUpper();
            }
        }
        //// <summary>
        /// </summary>
        /// <param name="strSource">需要加密的明文</param>
        /// <returns>返回32位加密结果，该结果取32位加密结果的第9位到25位</returns>
        public static string Get32MD5Two(string source)
        {
            System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
            //获取密文字节数组
            byte[] bytResult = md5.ComputeHash(System.Text.Encoding.Default.GetBytes(source));
            //转换成字符串，32位
            string strResult = BitConverter.ToString(bytResult);
            //BitConverter转换出来的字符串会在每个字符中间产生一个分隔符，需要去除掉
            strResult = strResult.Replace("-", "");
            return strResult.ToUpper();
        }
        //// <summary>
        /// </summary>
        /// <param name="strSource">需要加密的明文</param>
        /// <returns>返回16位加密结果，该结果取32位加密结果的第9位到25位</returns>
        public static string Get16MD5Two(string source)
        {
            System.Security.Cryptography.MD5 md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
            //获取密文字节数组
            byte[] bytResult = md5.ComputeHash(System.Text.Encoding.Default.GetBytes(source));
            //转换成字符串，并取9到25位
            string strResult = BitConverter.ToString(bytResult, 4, 8);
            //BitConverter转换出来的字符串会在每个字符中间产生一个分隔符，需要去除掉
            strResult = strResult.Replace("-", "");
            return strResult.ToUpper();
        }
        /// <summary>
        /// 自定义MD5函数,32位,从老版本迁移过来，后续淘汰不用。与Get32MD5One重复
        /// </summary>
        public static string Get32MD5Old(string str)
        {
            byte[] b = Encoding.UTF8.GetBytes(str);
            b = new MD5CryptoServiceProvider().ComputeHash(b);
            string ret = "";
            for (int i = 0; i < b.Length; i++)
                ret += b[i].ToString("x").PadLeft(2, '0');

            return ret.ToUpper();
        }
    }
}

3.  AES的加密、解密

　　上面我们介绍了MD5加密封装，接下来分享给大家供大家参考一下AES加密、解密，AES要注意的是32位密匙。AES 加密解密(高级加密标准，是下一代的加密算法标准，速度快，安全级别高，目前 AES 标准的一个实现是 Rijndael 算法)

using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;

namespace NC.Common
{
    /// <summary> 
    /// 加密
    /// </summary> 
    public class AES
    {
        //默认密钥向量
        private static byte[] Keys = { 0x41, 0x72, 0x65, 0x79, 0x6F, 0x75, 0x6D, 0x79, 0x53, 0x6E, 0x6F, 0x77, 0x6D, 0x61, 0x6E, 0x3F };

        public static string Encode(string encryptString, string encryptKey)
        {
            encryptKey = GetSubString(encryptKey,0, 32, "");
            encryptKey = encryptKey.PadRight(32, ' ');

            RijndaelManaged rijndaelProvider = new RijndaelManaged();
            rijndaelProvider.Key = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 32));
            rijndaelProvider.IV = Keys;
            ICryptoTransform rijndaelEncrypt = rijndaelProvider.CreateEncryptor();

            byte[] inputData = Encoding.UTF8.GetBytes(encryptString);
            byte[] encryptedData = rijndaelEncrypt.TransformFinalBlock(inputData, 0, inputData.Length);

            return Convert.ToBase64String(encryptedData);
        }

        public static string Decode(string decryptString, string decryptKey)
        {
            try
            {
                decryptKey = GetSubString(decryptKey,0, 32, "");
                decryptKey = decryptKey.PadRight(32, ' ');

                RijndaelManaged rijndaelProvider = new RijndaelManaged();
                rijndaelProvider.Key = Encoding.UTF8.GetBytes(decryptKey);
                rijndaelProvider.IV = Keys;
                ICryptoTransform rijndaelDecrypt = rijndaelProvider.CreateDecryptor();

                byte[] inputData = Convert.FromBase64String(decryptString);
                byte[] decryptedData = rijndaelDecrypt.TransformFinalBlock(inputData, 0, inputData.Length);

                return Encoding.UTF8.GetString(decryptedData);
            }
            catch
            {
                return "";
            }

        }

        public static string GetSubString(string p_SrcString, int p_StartIndex, int p_Length, string p_TailString)
        {
            string myResult = p_SrcString;

            Byte[] bComments = Encoding.UTF8.GetBytes(p_SrcString);
            foreach (char c in Encoding.UTF8.GetChars(bComments))
            {    //当是日文或韩文时(注:中文的范围:u4e00 - u9fa5, 日文在u0800 - u4e00, 韩文为xAC00-xD7A3)
                if ((c > 'u0800' && c < 'u4e00') || (c > 'xAC00' && c < 'xD7A3'))
                {
                    //if (System.Text.RegularExpressions.Regex.IsMatch(p_SrcString, "[u0800-u4e00]+") || System.Text.RegularExpressions.Regex.IsMatch(p_SrcString, "[xAC00-xD7A3]+"))
                    //当截取的起始位置超出字段串长度时
                    if (p_StartIndex >= p_SrcString.Length)
                        return "";
                    else
                        return p_SrcString.Substring(p_StartIndex,
                                                       ((p_Length + p_StartIndex) > p_SrcString.Length) ? (p_SrcString.Length - p_StartIndex) : p_Length);
                }
            }

            if (p_Length >= 0)
            {
                byte[] bsSrcString = Encoding.Default.GetBytes(p_SrcString);

                //当字符串长度大于起始位置
                if (bsSrcString.Length > p_StartIndex)
                {
                    int p_EndIndex = bsSrcString.Length;

                    //当要截取的长度在字符串的有效长度范围内
                    if (bsSrcString.Length > (p_StartIndex + p_Length))
                    {
                        p_EndIndex = p_Length + p_StartIndex;
                    }
                    else
                    {   //当不在有效范围内时,只取到字符串的结尾

                        p_Length = bsSrcString.Length - p_StartIndex;
                        p_TailString = "";
                    }

                    int nRealLength = p_Length;
                    int[] anResultFlag = new int[p_Length];
                    byte[] bsResult = null;

                    int nFlag = 0;
                    for (int i = p_StartIndex; i < p_EndIndex; i++)
                    {
                        if (bsSrcString[i] > 127)
                        {
                            nFlag++;
                            if (nFlag == 3)
                                nFlag = 1;
                        }
                        else
                            nFlag = 0;

                        anResultFlag[i] = nFlag;
                    }

                    if ((bsSrcString[p_EndIndex - 1] > 127) && (anResultFlag[p_Length - 1] == 1))
                        nRealLength = p_Length + 1;

                    bsResult = new byte[nRealLength];

                    Array.Copy(bsSrcString, p_StartIndex, bsResult, 0, nRealLength);

                    myResult = Encoding.Default.GetString(bsResult);
                    myResult = myResult + p_TailString;
                }
            }

            return myResult;
        }

    }
}

4.  DES加密/解密

　　除了MD5加密、AES加密/解密之外还经常用到DES加密、解密，注意的是DES的密匙是8位的，这里有家婆MD5加密一起使用。

using System;
using System.Security.Cryptography;
using System.Text;

namespace NC.Common
{
    /// <summary>
    /// DES加密/解密类。
    /// </summary>
    public class DESEncrypt
    {

        #region --加密--

        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="Text"></param>
        /// <returns></returns>
        public static string Encrypt(string Text)
        {
            return Encrypt(Text, "ncmvc");
        }
        /// <summary> 
        /// 加密数据 
        /// </summary> 
        /// <param name="Text"></param> 
        /// <param name="sKey"></param> 
        /// <returns></returns> 
        public static string Encrypt(string Text, string sKey)
        {
            try
            {
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                byte[] inputByteArray;
                inputByteArray = Encoding.Default.GetBytes(Text);
                string md5SKey = MD5Comm.Get32MD5One(sKey).Substring(0, 8);
                des.Key = ASCIIEncoding.ASCII.GetBytes(md5SKey);
                des.IV = ASCIIEncoding.ASCII.GetBytes(md5SKey);
                System.IO.MemoryStream ms = new System.IO.MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                StringBuilder ret = new StringBuilder();
                foreach (byte b in ms.ToArray())
                {
                    ret.AppendFormat("{0:X2}", b);
                }
                return ret.ToString();
            }
            catch { return "error"; }
        }

        #endregion

        #region --解密--

        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="Text"></param>
        /// <returns></returns>
        public static string Decrypt(string Text)
        {
            return Decrypt(Text, "ncmvc");
        }
        /// <summary> 
        /// 解密数据 
        /// </summary> 
        /// <param name="Text"></param> 
        /// <param name="sKey"></param> 
        /// <returns></returns> 
        public static string Decrypt(string Text, string sKey)
        {
            try
            {
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                int len;
                len = Text.Length / 2;
                byte[] inputByteArray = new byte[len];
                int x, i;
                for (x = 0; x < len; x++)
                {
                    i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
                    inputByteArray[x] = (byte)i;
                }
                string md5SKey = MD5Comm.Get32MD5One(sKey).Substring(0, 8);
                des.Key = ASCIIEncoding.ASCII.GetBytes(md5SKey);
                des.IV = ASCIIEncoding.ASCII.GetBytes(md5SKey);
                System.IO.MemoryStream ms = new System.IO.MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                return Encoding.Default.GetString(ms.ToArray());
            }
            catch { return "error"; }
        }

        #endregion

    }
}

5.  总结

　　Asp.Net Core 2.0下加解密封装类分享给大家，供参考！文中有不合理之处望告知，欢迎批评指正。以前做项目常用的几种加密方式，在Net Core2.0下经过重新整理，好的延续，不合理方法弃用。相关案例使用方法欢迎大家继续关注《Asp.Net Core 2.0项目实战》系列。