ASP.NET Forms Authentication - Subsequent logins redirected to wrong page

Is there a ReturnURL set in the Querystring on the first request that isn't there on the second?  When a default URL isn't set, asp.net will redirect you to default.aspx in the root directory.

You might want to try setting defaultUrl in web.config (same place you set the logonUrl) and see what happens.

The DefaultURL is the same in both cases and I override the default with an explicit redirect.  As mentioned, the default.aspx file is present but is not accessed.

Can you post your web.config, specifically the <forms section, and the code that handles your Login?

Login ----------------------------------------------------------------------------------------------------------
System.Web.Security.FormsAuthentication.SetAuthCookie(name, li_Login.RememberMeSet);
Response.Redirect("~/General/Home.aspx", false);

Logout ----------------------------------------------------------------------------------------
Session.Abandon();
Session.Clear();
Session.Contents.RemoveAll();
System.Web.Security.FormsAuthentication.SignOut();
Response.Redirect("~/Public/Main.aspx"), true);

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/>
      <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.
        -->
            <compilation debug="true">
                  <assemblies>
                        <add assembly="System.Core, 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"/>
                        <add assembly="System.Data.DataSetExtensions, 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.
        -->
    <globalization
      culture="auto:en-US"
      uiCulture="auto:en-US"/>
            <authentication mode="Forms">
                  <forms loginUrl="Special/login.aspx" name=".EAGLEEYES" requireSSL="false" defaultUrl="General/Home.aspx" cookieless="AutoDetect" protection="All"/>
            </authentication>
            <authorization>
                  <allow users="?"/>
            </authorization>
            <!--
            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>
        -->
            <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>
                  <remove verb="*" path="*.asmx"/>
                  <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
                  <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
                  <add verb="GET,HEAD" path="ScriptResource.axd" validate="false" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/></httpHandlers>
            <httpModules>
                  <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/></httpModules></system.web>
      <location path="General">
            <system.web>
                  <authorization>
                        <deny users="?"/>
                  </authorization>
            </system.web>
      </location>
      <system.codedom>
                  <compilers>
                        <compiler language="c#;cs;csharp" extension=".cs" type="Microsoft.CSharp.CSharpCodeProvider,System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" warningLevel="4">
                              <providerOption name="CompilerVersion" value="v3.5"/>
                              <providerOption name="WarnAsError" value="false"/></compiler></compilers></system.codedom>
      <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"/></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" verb="GET,HEAD" path="ScriptResource.axd" preCondition="integratedMode" 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></configuration>

Interesting authorization section, typically I see this,

            <authorization>
                  <deny users="?" />
                  <allow users="*"/>
            </authorization>

This denies unauthenticated users, and allows anyone left.

My guess is the Login control is ultimately your problem, since it tries to do a lot of things automatically for you.  Have you tried to use a completely manual process?

Actually, the login control only handles data collection - the authenticate event is used if the Login button is clicked but, even in that case, it calls the same authentication code (the only difference is that the event's authenticate flag is set).  Regardless of the path, though, I get the same behavior.

The confusion on the auth section may be that there are two different ones.  The first is for the publicly accessible areas and the second is to protected the folder structure that contains the protected files.

And you're sure the Authenticate method is being called on the second login attempt?  Response.Redirect is a pretty solid method, and once you call it, there isn't a way to undo it, or for futher code to stop it.

Everything goes through my Authenticate() and, yes, I have verified that it is always called.  My guess is that either the authentication is not being recorded somewhere in the internals of FormsAuthentication, that there is some mechanism that is overriding the Redirect (my code terminates after this call so I'm not directly overiding it and, based on the call stack, the same chain of events occurs up to that point in both cases), or that some state is inconsistent after the logout.

After tracing the headers and not seeing anything unusual, I went back at looked at the entire process more closely and finally found the cause of the problem.  There are a set of cookies still being passed around that I thought were deleted.  These cookies direct the app to logout the user (go figure).

So, the question is now "how do I get rid of these dang cookies once I don't need them?"  I thought that Response.Cookies.RemoveAll() would do that but these, in effect, originate at the client (i.e. passed back) and so they are not in the Response list.  I also tried removing them from the Request assuming that this would prevent them from being populated back into the Response but that didn't work.

I can set a short expiration and work around the problem but I'd prefer not to play Russian Roulette with timing.  What is the correct way to get rid of cookies?

Use javascript, I've written javascript in a many logout pages to actually delete the cookies, because I noticed Response.Cookies.RemoveAll didn't work at all.

Would you happen to have JS handy to delete them?

It's as simple as setting the expiration to a past date.  This immediately deletes it.

function del_cookie(name) {
document.cookie = name +
'=; expires=Thu, 01-Jan-70 00:00:01 GMT;';
}

Thanks for the help.

Just to follow-up:  The final solution was not to set the expiration via javascript.  Using this technique in IE, the JS actually created a second cookie rather than setting the expiration on the first.  In Safari, it did nothing at all.

The final solution was to set the expiration on the server *after* processing the cookie (i.e. the final segment of the roundtrip from server->client->server) and then to manually add the cookie into the Response object.
   - if you set the expiration at the first step, it will not work if the client's and server's clocks are not synced.  I also added a server-side check to see if the cookie has expired incase the client's clock is out of sync enough that the cookie doesn't expire after another round trip.
   - if you do not manually add the cookie into the Response, the changes to the expiration will not propogate