Re: authz's inverted group access rules are only effective for users mentioned in authz

[Branko Čibej <br...@apache.org>]

On 28.11.2018 01:49, Branko Čibej wrote:
> On 27.11.2018 22:33, Branko Čibej wrote:
>> On 27.11.2018 10:41, Branko Čibej wrote:
>>> On 26.11.2018 18:32, Pavel Goran wrote:
>>>> Hello mailing list,
>>>>
>>>> I'm migrating a repository from an ancient Subversion installation:
>>>>
>>>> svn, version 1.6.17 (r1128011)
>>>> compiled Jun  2 2011, 23:35:08
>>>> (on Windows)
>>>>
>>>> to a recent version:
>>>>
>>>> svn, version 1.11.0 (r1845130)
>>>>    compiled Oct 29 2018, 14:33:24 on x86_64-unknown-linux-gnu
>>>> (on NixOS Linux)
>>>>
>>>> And I'm encountering a regression in handling of the authz file by svnserve.
>>>>
>>>> Steps to reproduce:
>>> [...]
>>>> # svnserve -r /data/svn -d
>>>>
>>>> # svn --username myuser --password mypassword --no-auth-cache ls svn://localhost/myrepo
>>>> svn: E170001: Authorization failed
>>>>
>>>> The user "myuser" is not included in group "readonly", so I expect the rule
>>>> "~@readonly = rw" to take effect, but apparently this doesn't happen.
>>>>
>>>> This setup worked fine in the old installation (version 1.6.17). Also, it
>>>> starts working if I add the user "myuser" to any other group:
>>>>
>>>> # in authz, [groups] section
>>>> unrelatedgroup = myuser
>>>>
>>>> or use it in any access rule (even if the rule specifies no access):
>>>>
>>>> # in authz, [/] section
>>>> myuser =
>>>>
>>>> I looked at the sources (subversion/libsvn_repos/authz_parse.c), and my
>>>> guess is that this behaviour results from not setting up user's rights with
>>>> a call to prepare_global_rights(). When a user is mentioned in authz, this
>>>> function gets called, and authorization starts working for the user.
>>>>
>>>> Possibly correction of this problem could involve adding the new field
>>>> "unkn_rights" (and "has_unkn_rights") to struct authz_full_t, so that this
>>>> field would receive access rights from all inverted user-related access
>>>> rules (~user, ~&alias, ~@group). Then, svn_authz__get_global_rights() would
>>>> combine authz->has_unkn_rights with authz->has_authn_rights (instead of just
>>>> returning authz->has_authn_rights) when user_rights is NULL.
>>>>
>>>> Pavel Goran
>>>>
>>>> P.S. I'm not subscribed to the mailing list; please CC me directly when
>>>> replying.
>>> Thanks for the detailed report! Yes, this is indeed a bug. I see that
>>> you've taken time to analyse the code; could you prepare a patch with
>>> the fix you propose?
>>>
>>> Also can you please create an issue in Jira:
>>> https://issues.apache.org/jira/projects/SVN/
>> I added a test case for this in r1847598, using the reproduction steps
>> described above.
> https://issues.apache.org/jira/browse/SVN-4793

Fixed: http://svn.apache.org/r1847922

-- Brane