Mailing List Archive

question on Apache2_4::AuthCookie
Hi.
I have (a long time ago) created an AAA module based originally on Apache2::AuthCookie (a
copy and rewrite, not a sub-class). Now I need to adapt this to Apache 2.4.
I have read all the docs at
https://metacpan.org/source/MSCHOUT/Apache-AuthCookie-3.24/lib/Apache2_4/AuthCookie.pm,
and followed the related correspondence on this list.
My problem is that I would like to keep a single perl source, for both Apache 2.2 and
Apache 2.4.
As far as I can tell so far, this should not be a big problem, except for the following
difference :

In the Apache 2.2 version, I have this statement :

use Apache2::Const -compile => qw(:common :http :methods :override :proxy);

and in the Apache 2.4 version, I must have this statement or it will not compile :

use Apache2::Const -compile => qw(:common :http :methods :override :proxy AUTHZ_GRANTED
AUTHZ_DENIED AUTHZ_DENIED_NO_USER);

(That is because these new AUTHZ_* constants must be used in the new "AuthzProvider" subs).

I could of course hack the values of these constants under 2.4, and use their values
directly in my module, but that is rather "inelegant".

My question is thus : would there be a way to make the import of these constants
conditional on the Apache version the module is running under ?
(In other words e.g. define them with value 0 initially (for Apache 2.2, since they are
never used there), and override them if under Apache 2.4 ?

Or, to put this another way : imagining that there are already some servers, currently
running Apache 2.2 with, say, mod_perl 2.0.7, and on which the current (2.2-only) version
of my Auth module is running.
If I ever update these servers with the latest (2.4-compatible) version of my module,
including the above extra imported constants, that updated module will not compile anymore
on those systems (because these constants are not defined there).
Is there a way to avoid this incompatibility ?

I tried to phrase the above as clearly as possible, but if it is still confusing, I can
try again..

Thanks
Re: question on Apache2_4::AuthCookie [ In reply to ]
On 4/6/16 11:51 AM, A. Warnier wrote:
> I could of course hack the values of these constants under 2.4, and use
> their values directly in my module, but that is rather "inelegant".

If you insist on using the same module/source for both 2.4 and 2.2 I do
not see any other option.

The AUTHZ_GRANTED (and friends) constants simply do not exist in
previous versions of apache.

Regards,
Michael Schout
Re: question on Apache2_4::AuthCookie [ In reply to ]
>
> Hi.
> I have (a long time ago) created an AAA module based originally on
> Apache2::AuthCookie (a copy and rewrite, not a sub-class). Now I need to
> adapt this to Apache 2.4.
> I have read all the docs at
> https://metacpan.org/source/MSCHOUT/Apache-AuthCookie-3.24/lib/Apache2_4/AuthCookie.pm,
> and followed the related correspondence on this list.
> My problem is that I would like to keep a single perl source, for both
> Apache 2.2 and Apache 2.4.
> As far as I can tell so far, this should not be a big problem, except for
> the following difference :
>
> In the Apache 2.2 version, I have this statement :
>
> use Apache2::Const -compile => qw(:common :http :methods :override :proxy);
>
> and in the Apache 2.4 version, I must have this statement or it will not
> compile :
>
> use Apache2::Const -compile => qw(:common :http :methods :override :proxy
> AUTHZ_GRANTED AUTHZ_DENIED AUTHZ_DENIED_NO_USER);
>
>
I'm not very familiar with require vs use, but could you use a begin
block, Apache2::ServerUtil::get_server_version()
and then if/else based on the version number?

Lathan Bidwell



> (That is because these new AUTHZ_* constants must be used in the new
> "AuthzProvider" subs).
>
> I could of course hack the values of these constants under 2.4, and use
> their values directly in my module, but that is rather "inelegant".
>
> My question is thus : would there be a way to make the import of these
> constants conditional on the Apache version the module is running under ?
> (In other words e.g. define them with value 0 initially (for Apache 2.2,
> since they are never used there), and override them if under Apache 2.4 ?
>
> Or, to put this another way : imagining that there are already some
> servers, currently running Apache 2.2 with, say, mod_perl 2.0.7, and on
> which the current (2.2-only) version of my Auth module is running.
> If I ever update these servers with the latest (2.4-compatible) version of
> my module, including the above extra imported constants, that updated
> module will not compile anymore on those systems (because these constants
> are not defined there).
> Is there a way to avoid this incompatibility ?
>
> I tried to phrase the above as clearly as possible, but if it is still
> confusing, I can try again..
>
> Thanks
>
>
Re: question on Apache2_4::AuthCookie [ In reply to ]
On 07.04.2016 21:12, Lathan Bidwell wrote:
>>
>> Hi.
>> I have (a long time ago) created an AAA module based originally on
>> Apache2::AuthCookie (a copy and rewrite, not a sub-class). Now I need to
>> adapt this to Apache 2.4.
>> I have read all the docs at
>> https://metacpan.org/source/MSCHOUT/Apache-AuthCookie-3.24/lib/Apache2_4/AuthCookie.pm,
>> and followed the related correspondence on this list.
>> My problem is that I would like to keep a single perl source, for both
>> Apache 2.2 and Apache 2.4.
>> As far as I can tell so far, this should not be a big problem, except for
>> the following difference :
>>
>> In the Apache 2.2 version, I have this statement :
>>
>> use Apache2::Const -compile => qw(:common :http :methods :override :proxy);
>>
>> and in the Apache 2.4 version, I must have this statement or it will not
>> compile :
>>
>> use Apache2::Const -compile => qw(:common :http :methods :override :proxy
>> AUTHZ_GRANTED AUTHZ_DENIED AUTHZ_DENIED_NO_USER);
>>
>>
> I'm not very familiar with require vs use, but could you use a begin
> block, Apache2::ServerUtil::get_server_version()
> and then if/else based on the version number?
>

I was kind of thinking in that direction also, but as I recall BEGIN blocks can be kind of
iffy in an Apache/mod_perl module context. I'm not an expert either, so I guess I'll have
to go review some docs about this.
Thanks for the reference to Apache2::ServerUtil::get_server_version(), saves me some digging.



>
>
>
>> (That is because these new AUTHZ_* constants must be used in the new
>> "AuthzProvider" subs).
>>
>> I could of course hack the values of these constants under 2.4, and use
>> their values directly in my module, but that is rather "inelegant".
>>
>> My question is thus : would there be a way to make the import of these
>> constants conditional on the Apache version the module is running under ?
>> (In other words e.g. define them with value 0 initially (for Apache 2.2,
>> since they are never used there), and override them if under Apache 2.4 ?
>>
>> Or, to put this another way : imagining that there are already some
>> servers, currently running Apache 2.2 with, say, mod_perl 2.0.7, and on
>> which the current (2.2-only) version of my Auth module is running.
>> If I ever update these servers with the latest (2.4-compatible) version of
>> my module, including the above extra imported constants, that updated
>> module will not compile anymore on those systems (because these constants
>> are not defined there).
>> Is there a way to avoid this incompatibility ?
>>
>> I tried to phrase the above as clearly as possible, but if it is still
>> confusing, I can try again..
>>
>> Thanks
>>
>>
>