I am creating a Silverlight 3 application that must work with a database that is used by a legacy ASP .net 1.0 system. The database contains tables for users and roles. The Silverlight 3 application should use forms authentication and use the “User” and “Role” table in the database.

First I tried to change the uthenticationService : AuthenticationBase<UserWeb> to inherit my “LINQ to SQL” domainservice, but then I got a exception:

The entity type ‘Ada.Tts.Toggle.Silverlight.Web.Company’ is exposed by multiple DomainService types. Entity types cannot be shared across DomainServices

I solved this problem by implementing a custom membership provider, the custom membership provider uses the Linq to SQL domainservice.

TTSMembershipProvider.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Security;

namespace Ada.Tts.Toggle.Web.BC
{
    public class TTSMembershipProvider : MembershipProvider
    {
        public override string ApplicationName
        {
            get
            {
                throw new NotImplementedException();
            }
            set
            {
                throw new NotImplementedException();
            }
        }
        public override bool ChangePassword(string username, string oldPassword, string newPassword)
        {
            throw new NotImplementedException();
        }
        public override bool ChangePasswordQuestionAndAnswer(string username, string password, string newPasswordQuestion, string newPasswordAnswer)
        {
            throw new NotImplementedException();
        }
        public override MembershipUser CreateUser(string username, string password, string email, string passwordQuestion, string passwordAnswer, bool isApproved, object providerUserKey, out MembershipCreateStatus status)
        {
            throw new NotImplementedException();
        }
        public override bool DeleteUser(string username, bool deleteAllRelatedData)
        {
            throw new NotImplementedException();
        }
        public override bool EnablePasswordReset
        {
            get { throw new NotImplementedException(); }
        }
        public override bool EnablePasswordRetrieval
        {
            get { throw new NotImplementedException(); }
        }
        public override MembershipUserCollection FindUsersByEmail(string emailToMatch, int pageIndex, int pageSize, out int totalRecords)
        {
            throw new NotImplementedException();
        }
        public override MembershipUserCollection FindUsersByName(string usernameToMatch, int pageIndex, int pageSize, out int totalRecords)
        {
            throw new NotImplementedException();
        }
        public override MembershipUserCollection GetAllUsers(int pageIndex, int pageSize, out int totalRecords)
        {
            throw new NotImplementedException();
        }
        public override int GetNumberOfUsersOnline()
        {
            throw new NotImplementedException();
        }
        public override string GetPassword(string username, string answer)
        {
            throw new NotImplementedException();
        }
        public override MembershipUser GetUser(object providerUserKey, bool userIsOnline)
        {
            throw new NotImplementedException();
        }
        public override MembershipUser GetUser(string username, bool userIsOnline)
        {
            throw new NotImplementedException();
        }
        public override string GetUserNameByEmail(string email)
        {
            throw new NotImplementedException();
        }
        public override int MaxInvalidPasswordAttempts
        {
            get { throw new NotImplementedException(); }
        }
        public override int MinRequiredNonAlphanumericCharacters
        {
            get { throw new NotImplementedException(); }
        }
        public override int MinRequiredPasswordLength
        {
            get { throw new NotImplementedException(); }
        }
        public override int PasswordAttemptWindow
        {
            get { throw new NotImplementedException(); }
        }
        public override MembershipPasswordFormat PasswordFormat
        {
            get { throw new NotImplementedException(); }
        }
        public override string PasswordStrengthRegularExpression
        {
            get { throw new NotImplementedException(); }
        }
        public override bool RequiresQuestionAndAnswer
        {
            get { throw new NotImplementedException(); }
        }
        public override bool RequiresUniqueEmail
        {
            get { throw new NotImplementedException(); }
        }
        public override string ResetPassword(string username, string answer)
        {
            throw new NotImplementedException();
        }
        public override bool UnlockUser(string userName)
        {
            throw new NotImplementedException();
        }
        public override void UpdateUser(MembershipUser user)
        {
            throw new NotImplementedException();
        }
        public override bool ValidateUser(string username, string password)
        {
            bool result = false;
            TimeTrackerDataContext context = new TimeTrackerDataContext();
            var users = from u in context.TTUsers
                                    where u.UserName == username && u.Password == Protector.Encrypt(password)
                                    select u;

            if (users != null && users.ToList<TTUser>().Count > 0)
            {
                    result = true;
            }
            
            return result;
        }
    }
}

Web.config

<?xml version="1.0"?>
<configuration>
  <configSections>
    <sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
      <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
        <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
        <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35">
          <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="Everywhere"/>
          <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
          <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
          <section name="roleService" type="System.Web.Configuration.ScriptingRoleServiceSection, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" requirePermission="false" allowDefinition="MachineToApplication"/>
        </sectionGroup>
      </sectionGroup>
    </sectionGroup>
  </configSections>
  <appSettings/>
    <connectionStrings>
  <remove name="LocalSqlServer" />
  <add name="LocalSqlServer" connectionString="Data Source=.;Initial Catalog=TimeTracker;Integrated Security=True"
   providerName="System.Data.SqlClient" />
 </connectionStrings>
  <system.web>
    <!-- 
            Set compilation debug="true" to insert debugging 
            symbols into the compiled page. Because this 
            affects performance, set this value to true only 
            during development.
        -->
    <roleManager enabled="true"/>
    <globalization culture="auto"/>
        <membership defaultProvider="TTSMembershipProvider">
            <providers>
                <clear/>
                <add
     name="TTSMembershipProvider"
     type=" Ada.Tts.Toggle.Web.BC.TTSMembershipProvider, Ada.Tts.Toggle.Web"/>
            </providers>
        </membership>
        <compilation debug="true">
      <assemblies>
        <add assembly="System.Core, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
        <add assembly="System.Data.DataSetExtensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
        <add assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
        <add assembly="System.Xml.Linq, Version=3.5.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
      </assemblies>
    </compilation>
    <!--
            The <authentication> section enables configuration 
            of the security authentication mode used by 
            ASP.NET to identify an incoming user. 
        -->
    <authentication mode="Forms">
      <forms name=".Ada.Tts.Toggle_ASPXAUTH" />
    </authentication>
    <!--
            The <customErrors> section enables configuration 
            of what to do if/when an unhandled error occurs 
            during the execution of a request. Specifically, 
            it enables developers to configure html error pages 
            to be displayed in place of a error stack trace.

        <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
            <error statusCode="403" redirect="NoAccess.htm" />
            <error statusCode="404" redirect="FileNotFound.htm" />
        </customErrors>
        -->
    <profile>
      <properties>
        <add name="FriendlyName"/>
      </properties>
    </profile>
    <pages>
      <controls>
        <add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
        <add tagPrefix="asp" namespace="System.Web.UI.WebControls" assembly="System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
      </controls>
    </pages>
    <httpHandlers>
      <add path="*.asmx" verb="*" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" validate="false"/>
      <add path="*_AppService.axd" verb="*" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" validate="false"/>
      <add path="ScriptResource.axd" verb="GET,HEAD" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" validate="false"/>
    </httpHandlers>
    <httpModules>
      <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
      <add name="DomainServiceModule" type="System.Web.Ria.Services.DomainServiceHttpModule, System.Web.Ria, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    </httpModules>
  </system.web>
  <system.codedom>
    <compilers>
      <compiler language="c#;cs;csharp" extension=".cs" warningLevel="4" type="Microsoft.CSharp.CSharpCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
        <providerOption name="CompilerVersion" value="v3.5"/>
        <providerOption name="WarnAsError" value="false"/>
      </compiler>
    </compilers>
  </system.codedom>
  <!-- 
        The system.webServer section is required for running ASP.NET AJAX under Internet
        Information Services 7.0.  It is not necessary for previous version of IIS.
  -->
  <system.webServer>
    <validation validateIntegratedModeConfiguration="false"/>
    <modules>
      <remove name="ScriptModule"/>
      <add name="ScriptModule" preCondition="managedHandler" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
      <add name="DomainServiceModule" preCondition="managedHandler" type="System.Web.Ria.Services.DomainServiceHttpModule, System.Web.Ria, Version=2.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    </modules>
    <handlers>
      <remove name="WebServiceHandlerFactory-Integrated"/>
      <remove name="ScriptHandlerFactory"/>
      <remove name="ScriptHandlerFactoryAppServices"/>
      <remove name="ScriptResource"/>
      <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
      <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
      <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    </handlers>
  </system.webServer>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Extensions" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Extensions.Design" publicKeyToken="31bf3856ad364e35"/>
        <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0"/>
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
  <system.serviceModel>
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true"/>
  </system.serviceModel>
</configuration>

For more information on implementing a custom roleprovider, see:

http://davidhayden.com/blog/dave/archive/2007/10/17/CreateCustomRoleProviderASPNETRolePermissionsSecurity.aspx