Hello

This contribution has not met an enthousiast reaction. No comment, anyone?

On Wed, Mar 29, 2017 at 01:05:48PM +0000, Emmanuel Dreyfus wrote:
> Hello
> 
> If you tried to use mod_dav_fs with recent MS Office on Windows,
> you probably had the unpleaseant experience of being prompted for
> authentication on every time an MS Office program is started. This
> is because it has its own WebDAV client and it does not use the
> Windows network drive.
> 
> There are various workarounds [1], one of them being to implement
> MS-OFBA [2] which stands for Office Forms Based Authentication. It
> works this way:
> 
> - An OFBA-capable client sends an unauthenticated OPTIONS request. 
>   OFBA capability is advertised either by a specific HTTP header, or 
>   through a list of specified User-Agent strings.
> 
> - The serveur replies with HTTP status 403 FORBIDDEN with OFBA-specific
>   headers pointing to a form where authentication should happen
> 
> - The client invokes MS Internet Explorer or Edge and display the form. 
>   Once authentication is done, it obtains a session cookie which is shared
>   among all OFBA capable clients, until it expires.
> 
> - MS Office now access the WebDAV share using the session cookie, and it
>   does not prompt for authentication anymore.
> 
> I crafted a patch that implements MS-OFBA in mod_auth_form [3]. It
> depends on 4 previously filed changes [4, 5, 6, 7]. I have not yet
> filled a bug report in bugzilla for the mod_auth_form.c [3] patch
> because it probably needs to be improved a bit.
> 
> Here is the problem: if OFBA is enabled and mod_auth_form detected
> an unauthenticated OFBA-capable client, it must reply with an HTTP
> status 403, with OFBA headers. For now I do that by registering an
> output filter so that I can regain control after authentication
> and detect that the client was not authenticated. Is there a better
> suited hook for that?
> 
> Any other comment on the patches? An Apache WebDAV server playing
> better with MS Office would be a great benefit, hence I hope this
> will get some interest.
> 
> 
> [1] 
> https://support.microsoft.com/en-us/help/2019105/authentication-requests-when-you-open-office-documents
> [2] https://msdn.microsoft.com/en-us/library/office/cc313069(v=office.12).aspx
> [3] https://ftp.espci.fr/shadow/manu/patch20170329-modules_aaa_mod_auth_form.c
> [4] https://bz.apache.org/bugzilla/show_bug.cgi?id=60908
> [5] https://bz.apache.org/bugzilla/show_bug.cgi?id=60909
> [6] https://bz.apache.org/bugzilla/show_bug.cgi?id=60708
> [7] https://bz.apache.org/bugzilla/show_bug.cgi?id=60910
> 
> -- 
> Emmanuel Dreyfus
> [email protected]

-- 
Emmanuel Dreyfus
[email protected]

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