bug#24490: 25.1; restclient no longer sends auth header upon redirect

[Thomas Fitzsimmons]

Lars Ingebrigtsen <larsi@gnus.org> writes:

> Alain Picard <alain@gocatch.com> writes:
>
>> Dear Maintainers,
>>
>> In emacs 25.1,
>> the code in url-http.el, line 638, states:
>>
>>   ;; Do not automatically include an authorization header in the
>>   ;; redirect.  If needed it will be regenerated by the relevant
>>   ;; auth scheme when the new request happens.
>>   (setq url-http-extra-headers
>> (cl-remove "Authorization"
>>    url-http-extra-headers :key 'car :test 'equal))
>>
>> I suspect this automatic regenration does not occur.
>
> I think this code is basically correct -- if the auth scheme has added
> something to url-http-extra-headers, then that has to be removed when
> doing the redirect, because otherwise we might be sending the auth to a
> completely wrong server, with the security implications of that.
>
>> Problem: I am using restclient.el, and hitting a server which
>> issues a redirect, and I receive a 400 Forbidden response because
>> the redirected call does not receive the authentication header
>> (I can see this from the log of my server).
>
> I think this must be a bug in restclient.el -- it should instead use an
> auth scheme that re-adds the Authorization header.

It looks like restclient.el uses advice to skip
url-http-handle-authentication if it (restclient) is in the middle of a
request.

Alain, to rule out that advice as being responsible, can you do:

M-: (ad-deactivate  'url-http-handle-authentication)

then try the API call again?

Thomas