重定向到登录页面时，asp.net/iis 不附加 ReturnUrl

Question

Using Forms authentication in a traditional (not mvc) asp.net app, I can not get IIS or IIS-express (when debugging in VS2019) to append a ReturnUrl to the request querystring when it redirects to login.aspx. Thus Request["ReturnUrl"] is always null.

I've read many questions/answers over a few days regarding the Redirect not working but it's always in regards to after authentication and nobody that I've seen has had the problem where?ReturnUrl=/blah/blah/blah is not even getting appended to the url itself.

Also have read instances where users want ReturnUrl to NOT be appended which is maybe fixed by some code in Global.asax. Lucky them, I wish I had that problem instead of not getting the ReturnUrl in the first place!

I've tried every web.config possibility regarding the tag; specifiying/not specifying loginUrl and defaultUrl; specifiying allow/deny and all combinations thereof I do have a Global.asax but it is empty for the Request-related methods. I've also looked into various IIS settings to see if it is an option that it appends a returnUrl but I haven't found anything that suggests that option.

The latest basic entry I tried:

<authentication mode="Forms">
  <forms timeout="120" slidingExpiration="true" />
</authentication>
<authorization>
  <!--<deny users="?"/>-->
  <allow users="*"/>
</authorization>

I should also add that I am using a custom membership provider and not the default asp.net membership provider. Although not sure that would even matter in IIS appending/not appending a ReturnUrl but you never know...

<membership defaultProvider="LegacyDBMembershipProvider">
  <providers>
    <remove name="AspNetSqlMembershipProvider"/>
    <add name="LegacyDBMembershipProvider" someothertags... />
  </providers>
</membership>

I would like to have IIS redirect me to login.aspx (as it does) but have the Url look like: http://localhost:21542/MyWeb/Login.aspx?ReturnUrl=/MyWeb/RequestedPage.aspx instead of just: http://localhost:21542/MyWeb/Login.aspx

so that after authentication I can redirect the user to the originally requested page.

Thanks for your time and your consideration.

Answer 1

Thanks Brando, wazz and all that took time to read my question. Apparently it came down to the [allow users=" "/> tag itself. Whether or not I had [deny users> anywhere before or after it. I'm not sure why if I only have [allow users=" "/> (and no deny tag) that it even still forces to the login page (which I wanted) but it does and WITHOUT appending ReturnUrl. Hence my issue. But after removing any [allow> tags (I tried with individual users, groups, *, etc) the miracle happened and I got a ReturnUrl. It may also have something to do with not supplying a defaultUrl attribute in the [forms> tag. I thought I had tried every combo but apparently not.

Anyways, I'm going to do a little more research as to WHY it works this way and I'll post any info I can garner for posterity but right now I'm just giddy that I'm getting a ReturnUrl appended in the query string. Thanks again all.