CLASS POUR LES LOGIN

using System.IO;
using System;
using System.Text;
using System.Data;
using System.Windows.Forms;
using System.Xml;
using System.Xml.XPath;
using System.Security.Cryptography;

namespace Login1
{
    class users
    {
        public string UName = "admin";
        public string UPassword = "admin";

        public void CreateNewPWD()
        {
            XmlDocument docUserLogin = new XmlDocument();
            string strFilename = Application.ProductName + ".xml";
            string UserName = "admin";
            string UPassword = Encrypt("admin");
            //crée le fichier XML
            docUserLogin.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\"?>" + "<!-- Copyright Daniel Morais 2009 -->" + "<" + Application.ProductName + "> <Users><Name>" + UserName + "</Name> <Password>" + UPassword + "</Password> </Users> </" + Application.ProductName + ">");
            docUserLogin.Save(strFilename);
            MessageBox.Show("Utilisateur  'admin'  et Mot de passe  'admin' " + "\r\n" +
             "ont été créer pour permettre un premier accès au programme " + "\r\n" +
             "Vous devriez les changés après l'ouverture du programme en cliquand sur " + "\r\n" +
             "Changer le mot de passe.", Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Information);
            //Récupération des attributs d'un fichier                  
            File.SetAttributes(strFilename, FileAttributes.Hidden);
        }

        public void SaveUPWord(string strUser, string strPassword)
        {
            XmlDocument docUserLogin = new XmlDocument();
            string strFilename = Application.ProductName + ".xml";
            try
            {
                File.Delete(strFilename);
                //create the xml file
                docUserLogin.LoadXml("<?xml version=\"1.0\" encoding=\"utf-8\"?>" + "<!-- Copyright Daniel Morais 2009 -->" + "<" + Application.ProductName + "> <Users><Name>" + strUser + "</Name> <Password>" + Encrypt(strPassword) + "</Password> </Users> </" + Application.ProductName + ">");
                docUserLogin.Save(strFilename);
                File.SetAttributes(strFilename, FileAttributes.Hidden);
            }
            catch
            {
                MessageBox.Show("Une erreur s'est produite dans le programme, impossible de connecter a " + strFilename, Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Information);
                return;
            }
            finally
            {
                MessageBox.Show("L'utilisateur et le mot de passe ont été changé avec succès.", Application.ProductName, MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }

        public void ReadUPWord()
        {
            string FILE_NAME = Application.ProductName + ".xml";
            XPathDocument doc;
            XPathNavigator nav;
            XPathExpression expr;
            XPathNodeIterator iterator;

            //LoadXml(FILE_NAME);
            doc = new XPathDocument(FILE_NAME);
            nav = doc.CreateNavigator();

            // Compile a standard XPath expression

            expr = nav.Compile("/" + Application.ProductName + "/Users/Name");
            iterator = nav.Select(expr);
            while (iterator.MoveNext())
            {
                XPathNavigator nav1 = iterator.Current.Clone();
                UName = nav1.Value;
            }
            expr = nav.Compile("/" + Application.ProductName + "/Users/Password");
            iterator = nav.Select(expr);
            while (iterator.MoveNext())
            {
                XPathNavigator nav2 = iterator.Current.Clone();
                UPassword = nav2.Value;
            }
        }

        public string Encrypt(string pwd)
        {
            UTF8Encoding encoder = new UTF8Encoding();
            SHA1CryptoServiceProvider sha1hasher = new SHA1CryptoServiceProvider();
            byte[] hashedDataBytes = sha1hasher.ComputeHash(encoder.GetBytes(pwd));
            return byteArrayToString(hashedDataBytes);
        }

        private string byteArrayToString(byte[] inputArray)
        {
            StringBuilder output = new StringBuilder("");
            for (int i = 0; i < inputArray.Length; i++)
            {
                output.Append(inputArray[i].ToString("X2"));
            }
            return output.ToString();
        }

        ///'******* Encrypt the Data *******
        private string GetEncryptedData(string Data)
        {
            SHA512Managed shaM = new SHA512Managed();
            Convert.ToBase64String(shaM.ComputeHash(Encoding.ASCII.GetBytes(Data)));
            byte[] eNC_data = ASCIIEncoding.ASCII.GetBytes(Data);
            string eNC_str = Convert.ToBase64String(eNC_data);
            //GetEncryptedData = eNC_str;
            return eNC_str;
        }

        ///'******* Decrypt the Data *******
        private string GetDecryptedData(string Data)
        {
            byte[] dEC_data = Convert.FromBase64String(Data);
            string dEC_Str = ASCIIEncoding.ASCII.GetString(dEC_data);
            //GetDecryptedData = dEC_Str;
            return dEC_Str;
        }


    }

}