C#安全加密类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.IO;
using System.Data;
using System.Data.SQLite;
using System.Web;
using System.Runtime.InteropServices;

namespace AiXinTang.User
{
    public static class DbSafe
    {
        public static DataTable GetNewDataTable(DataTable dt, string condition, string sortstr)
        {
            DataTable newdt = new DataTable();
            newdt = dt.Clone();
            DataRow[] dr = dt.Select(condition, sortstr);
            for (int i = 0; i < dr.Length; i++)
            {
                newdt.ImportRow((DataRow)dr[i]);
            }
            return newdt;//返回的查询结果
        }

        public static string md5(string str, int code)
        {
            string mymd5 = string.Empty;
            if (code == 16) //16位MD5加密（取32位加密的9~25字符） 
            {
                mymd5 = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(str, "MD5").ToLower().Substring(8, 16);
            }
            if (code == 32) //32位加密 
            {
                mymd5 = System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(str, "MD5").ToLower();
            }
            return mymd5;
        }

        public static string myChar = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789~!@#$%^&*()_+,./;'|:?-={}";

        /// <summary>
        /// 根据制定位数获取不同随机字符串
        /// </summary>
        /// <param name="num"></param>
        /// <returns></returns>
        public static string GetStr(int num)
        {
            int n = myChar.Length;
            string str = string.Empty;
            if (num < n)
            {
                Random _currenRandom = new Random(Guid.NewGuid().GetHashCode());
                for (int i = 0; i < num; i++)
                {
                    int _n = _currenRandom.Next(0, n - 1);
                    str += myChar.Substring(_n, 1);
                }
            }
            return str;
        }

        /// <summary>
        /// 生成AES密钥32位
        /// </summary>
        public static string GetAESKey
        {
            get
            {
                return GetStr(32);
            }
        }

        /// <summary>
        /// 生成AES常量16位
        /// </summary>
        public static string GetAESIV
        {
            get
            {
                return GetStr(16);
            }
        }

        /// <summary>
        /// 生成DES密钥32位
        /// </summary>
        public static string GetDESKey
        {
            get
            {
                return GetStr(8);
            }
        }

        /// <summary>
        /// 生成DES常量16位
        /// </summary>
        public static string GetDESIV
        {
            get
            {
                return GetStr(16);
            }
        }

    }

    /// <summary>
    /// DES加密解密 KEY-8 IV-16
    /// </summary>
    public static class DES
    {

        /// <summary>
        /// DES加密 KEY-8 IV-16
        /// </summary>
        /// <param name="plainStr">明文字符串</param>
        /// <returns>密文</returns>
        public static string DESEncrypt(string Key, string IV, string plainStr)
        {
            byte[] bKey = Encoding.UTF8.GetBytes(Key);
            byte[] bIV = Encoding.UTF8.GetBytes(IV);
            byte[] byteArray = Encoding.UTF8.GetBytes(plainStr);

            string encrypt = null;
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            try
            {
                using (MemoryStream mStream = new MemoryStream())
                {
                    using (CryptoStream cStream = new CryptoStream(mStream, des.CreateEncryptor(bKey, bIV), CryptoStreamMode.Write))
                    {
                        cStream.Write(byteArray, 0, byteArray.Length);
                        cStream.FlushFinalBlock();
                        encrypt = Convert.ToBase64String(mStream.ToArray());
                    }
                }
            }
            catch { }
            des.Clear();

            return encrypt;
        }

        /// <summary>
        /// DES解密 KEY-8 IV-16
        /// </summary>
        /// <param name="encryptStr">密文字符串</param>
        /// <returns>明文</returns>
        public static string DESDecrypt(string Key, string IV, string encryptStr)
        {
            byte[] bKey = Encoding.UTF8.GetBytes(Key);
            byte[] bIV = Encoding.UTF8.GetBytes(IV);
            byte[] byteArray = Convert.FromBase64String(encryptStr);

            string decrypt = null;
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            try
            {
                using (MemoryStream mStream = new MemoryStream())
                {
                    using (CryptoStream cStream = new CryptoStream(mStream, des.CreateDecryptor(bKey, bIV), CryptoStreamMode.Write))
                    {
                        cStream.Write(byteArray, 0, byteArray.Length);
                        cStream.FlushFinalBlock();
                        decrypt = Encoding.UTF8.GetString(mStream.ToArray());
                    }
                }
            }
            catch { }
            des.Clear();

            return decrypt;
        }
    }

    /// <summary>
    /// AES加密解密 KEY-32 IV-16
    /// </summary>
    public static class AES
    {

        /// <summary>
        /// AES加密 KEY-32 IV-16
        /// </summary>
        /// <param name="plainStr">明文字符串</param>
        /// <returns>密文</returns>
        public static string AESEncrypt(string Key, string IV, string plainStr)
        {
            byte[] bKey = Encoding.UTF8.GetBytes(Key);
            byte[] bIV = Encoding.UTF8.GetBytes(IV);
            byte[] byteArray = Encoding.UTF8.GetBytes(plainStr);

            string encrypt = null;
            Rijndael aes = Rijndael.Create();
            try
            {
                using (MemoryStream mStream = new MemoryStream())
                {
                    using (CryptoStream cStream = new CryptoStream(mStream, aes.CreateEncryptor(bKey, bIV), CryptoStreamMode.Write))
                    {
                        cStream.Write(byteArray, 0, byteArray.Length);
                        cStream.FlushFinalBlock();
                        encrypt = Convert.ToBase64String(mStream.ToArray());
                    }
                }
            }
            catch { }
            aes.Clear();

            return encrypt;
        }


        /// <summary>
        /// AES解密 KEY-32 VI-IV
        /// </summary>
        /// <param name="encryptStr">密文字符串</param>
        /// <returns>明文</returns>
        public static string AESDecrypt(string Key, string IV, string encryptStr)
        {
            byte[] bKey = Encoding.UTF8.GetBytes(Key);
            byte[] bIV = Encoding.UTF8.GetBytes(IV);
            byte[] byteArray = Convert.FromBase64String(encryptStr);

            string decrypt = null;
            Rijndael aes = Rijndael.Create();
            try
            {
                using (MemoryStream mStream = new MemoryStream())
                {
                    using (CryptoStream cStream = new CryptoStream(mStream, aes.CreateDecryptor(bKey, bIV), CryptoStreamMode.Write))
                    {
                        cStream.Write(byteArray, 0, byteArray.Length);
                        cStream.FlushFinalBlock();
                        decrypt = Encoding.UTF8.GetString(mStream.ToArray());
                    }
                }
            }
            catch { }
            aes.Clear();

            return decrypt;
        }

    }

    /// <summary>
    /// SQLITE操作
    /// </summary>
    public static class Sqlite
    {
        /// <summary>
        /// 是否链接成功
        /// </summary>
        /// <param name="path"></param>
        /// <param name="pwd"></param>
        /// <returns></returns>
        public static bool IfConn(string path, string pwd)
        {
            bool r = false;
            if (!string.IsNullOrEmpty(path))
            {
                var con = new SQLiteConnection();
                if (!string.IsNullOrEmpty(pwd))
                {
                    con.ConnectionString = String.Format("Data Source={0};Version=3;Password={1}", path.Trim(), pwd.Trim());
                }
                else
                {
                    con.ConnectionString = String.Format("Data Source={0};Version=3;", path.Trim());
                }
                try
                {
                    con.Open();
                    r = true;

                }
                catch
                {
                    r = false;
                }
                finally
                {

                    con.Close();
                }
            }
            return r;
        }

        /// <summary>
        /// 重置数据库链接密码
        /// </summary>
        /// <param name="path"></param>
        /// <param name="pwdold"></param>
        /// <param name="pwdnew"></param>
        /// <returns></returns>
        public static bool SetPwd(string path, string pwdold, string pwdnew)
        {
            bool r = false;
            var con = new SQLiteConnection();
            if (!string.IsNullOrEmpty(pwdold))
            {
                con.ConnectionString = String.Format("Data Source={0};Version=3;Password={1}", path.Trim(), pwdold.Trim());
            }
            else
            {
                con.ConnectionString = String.Format("Data Source={0};Version=3;", path.Trim());
            }
            try
            {
                con.Open();
                if (!string.IsNullOrEmpty(pwdnew.Trim()))
                {
                    con.ChangePassword(pwdnew.Trim());
                }
                r = true;

            }
            catch
            {
                r = false;
            }
            finally
            {

                con.Close();
            }
            return r;
        }

        [DllImport("kernel32.dll")]
        public static extern IntPtr _lopen(string lpPathName, int iReadWrite);

        [DllImport("kernel32.dll")]
        public static extern bool CloseHandle(IntPtr hObject);
        /// <summary>
        /// 创建新的用户数据库
        /// </summary>
        /// <param name="name"></param>
        /// <returns></returns>
        public static bool DbNew(string name,string pwd)
        {
            bool r = false;
            string path = HttpContext.Current.Server.MapPath(HttpContext.Current.Request.ApplicationPath.TrimEnd('\')+@"app_data");
            if (File.Exists(path + "AXT.User.Demo.config") && !File.Exists(path + name + ".config"))
            {
                File.Copy(path + "AXT.User.Demo.config", path + name+".config");
                if (File.Exists(path + name + ".config"))
                {
                    const int OF_READWRITE = 2;
                    const int OF_SHARE_DENY_NONE = 0x40;
                    IntPtr HFILE_ERROR = new IntPtr(-1);
                    IntPtr vHandle = _lopen(path + name + ".config", OF_READWRITE | OF_SHARE_DENY_NONE);
                    CloseHandle(vHandle);
                    if (SetPwd(path + name + ".config", "", pwd))
                    {
                        r = true;
                    }
                }
            }
            return r;
        }

        public static bool IsFileInUse(string fileName)
        {
            bool inUse = true;

            FileStream fs = null;
            try
            {
                fs = new FileStream(fileName, FileMode.Open, FileAccess.Read,

                FileShare.None);

                inUse = false;
            }
            catch
            {

            }
            finally
            {
                if (fs != null)

                    fs.Close();
            }
            return inUse;
        }

    }
}