loginform.cs

清华大学出版社出版的 移动应用开发宝典 张大威（2008）的附书源代码

using System;
using System.Collections.Generic;
using System.Data;
using System.Windows.Forms;
using Microsoft.Practices.Mobile.PasswordAuthentication;
using Microsoft.Practices.Mobile.Configuration;
using System.Security.Cryptography;

namespace MobileDevelopersHandbook
{
    public partial class LoginForm : Form
    {
        private DataSet users;

        private Dictionary<string, string> configSettings = null;

        public LoginForm(Dictionary<string, string> settings)
        {
            InitializeComponent();

            configSettings = settings;
        }

        private void LoginForm_Load(object sender, EventArgs e)
        {
            Cursor.Current = Cursors.WaitCursor;
            try
            {
                // Get the user details
                users = new DataSet();
                users.ReadXml(GetApplicationDirectory() + @"\Users.xml");
            }
            finally
            {
                Cursor.Current = Cursors.Default;
            }
        }
        
        private void menuItemSubmit_Click(object sender, EventArgs e)
        {
            for(int rowidx = 0; rowidx < users.Tables[0].Rows.Count; rowidx++ )
            {
                DataRow userRow = users.Tables[0].Rows[rowidx];
                if ((string)userRow["Name"] == textBoxUsername.Text)
                {
                    Cursor.Current = Cursors.WaitCursor;

                    try
                    {
                        PasswordIdentity identity = AuthenticateUser((string)userRow["Token"]);
                        if (identity != null && identity.IsAuthenticated)
                        {
                            // Success!! Decrypt the config file
                            DecryptSettings(identity, (string)userRow["encKey"]);

                            //Close the modal dialog
                            this.DialogResult = DialogResult.OK;
                        }
                    }
                    finally
                    {
                        Cursor.Current = Cursors.Default;
                    }
                }
            }

            // Show the login failed message
            labelIncorrect.Visible = true;
        }

        private PasswordIdentity AuthenticateUser(string userToken)
        {
            using (RsaAesCryptographyProvider provider = new RsaAesCryptographyProvider("MobileDevelopersHandbook"))
            {
                // Create AuthenticationToken using existing token
                AuthenticationToken token = new AuthenticationToken(userToken);
                PasswordIdentity identity = token.Authenticate(textBoxUsername.Text, textBoxPassword.Text, provider);
                // return result - caller checks Authenticated property to see authentication result
                return identity;
            }
        }

        private void DecryptSettings(PasswordIdentity identity, string userEncryptedConfigurationKey)
        {
            // Obtain the user's key
            byte[] userKeyBytes = identity.CryptoKey;

            // Create an instance of the CryptographyBlock class
            SymmetricAlgorithm symmetric = Rijndael.Create();
            CryptographyBlock block = new CryptographyBlock(symmetric, userKeyBytes);

            // Get the user's encrypted configuration key
            byte[] configKeyBytes = Convert.FromBase64String(userEncryptedConfigurationKey);

            // Decrypt the key
            byte[] configurationKey = block.Decrypt(configKeyBytes);

            // Create a configuration provider to decrypt the config file
            RijndaelConfigurationProvider configProvider = new RijndaelConfigurationProvider(configurationKey);

            // Assign the new instance of the RijndaelConfigurationProvider class to the ConfigurationManager.
            ConfigurationManager.ProtectedConfigurationProvider = configProvider;

            // Finally, use the GetSection method of the ConfigurationManager to retrieve the section we want
            String sectionName = "SystemSettings";
            SystemSettingsSection configSection = ConfigurationManager.GetSection(sectionName) as SystemSettingsSection;

            // Store the decrypted data in the settings collection
            foreach (SystemSettingsItemElement item in configSection.SystemSettingsItems)
            {
                configSettings.Add(item.Name, item.Value);
            }
        }

        private string GetApplicationDirectory()
        {
            return System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().GetModules()[0].FullyQualifiedName);
        }

        private void textBoxPassword_GotFocus(object sender, EventArgs e)
        {
            Microsoft.WindowsCE.Forms.InputModeEditor.SetInputMode(textBoxPassword, Microsoft.WindowsCE.Forms.InputMode.Numeric);
        }
    }
}