Re: OpenVPN - DEPRECATED OPTION: --tls-remote

[ummeegge <ummeegge@ipfire.org>]

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Hi Michael,

Am 11.08.2014 um 11:36 schrieb Michael Tremer:

> Hi Erik,
> 
> On Tue, 2014-07-29 at 20:05 +0200, ummeegge wrote:
>> Hi all,
>> since the update to OpenVPN version 2.3 on IPFire the client log
>> message "DEPRECATED OPTION: --tls-remote, please update your
>> configuration" appears. so the clientside directive "--tls-remote"
>> will be removed from OpenVPN in one of the comming versions -->
>> https://community.openvpn.net/openvpn/wiki/Openvpn23ManPage . For
>> future updates of OpenVPN on IPFire (2.4+) it will be important to
>> modify existing client.ovpn´s and replace the "--tls-remote name" with
>> the new "--verify-x509-name name type" directive.
> 
> Yes, we should do this at some point. The question that is currently on
> my mind is if that is completely backwards-compatible with all
> installations that we do have out there.

Have tested the "--verify-x509-name" directive positive only with 2.3.2 and above. =< 2.3.1 have had problems with this. Causing the heartbleed bug it might be probably a good time and chance for may ~ 90% of the clients out there which have no problems with this. But you are right there are a couple of other clients which are using nevertheless older (may patched) versions. Have seen this e.g. in the Snom forum that they have problems with this directive. 
> 
>> Since OpenVPN client/server version 2.3.2 the new verify option can be
>> used in client configs whereby "type" includes the possibilty of 3
>> different kinds of verification --> "subject", "name" and
>> "name-prefix" . This leads to a question which one of the "types"
>> should be used for future versions on IPFire. 
>> At this time IPFire handles "--tls-remote" automatically and it can´t
>> be configured over the WUI, this is handy cause the user doesn´t need
>> to bother around with all that kind of settings, but should this
>> remain in that way also for the new verification method ?
> 
> This should not be configurable for the user, because I cannot see the
> point right now. It should stay compatible to what we are doing at the
> moment.

I think so. There is also some time left until OpenVPN throws this directive away. An exact time aren´t known at this time.

> 
>> Also, to use "--verify-x509-name" the clients needs to have a version
>>> = 2.3.2 otherwise the connection won´t come up so there is no
>> backwards compatibility with the new directive and version =< 2.3.1 .
> 
> This is my biggest concern as there might be many systems that run old
> versions.
> 
>> May some people out there have some ideas, informations, ...., for
>> this topic ?
> 
> Not really as far as we can see. Would you please update the code for
> this and send patches when you have the time for it?

We could possibly do it in that way: We leave "--tls-remote" in the client.ovpn configuration file but add also the "--verify-x509-name" directive out commented with a little hint when it could be used, like it is done now for the usage of different interfaces --> "#Coment the above line and uncoment the next line, if you want to connect on the Blue interface" <-- or someting like that...

> 
>> Anyway a discussion about that might be interesting.
> 
> -Michael
> 
> 

As a first idea.


Greetings,

Erik