Am Samstag, dem 14.10.2023 um 13:10 +0100 schrieb Michael Tremer: > Hi Erik, > > Long time no see :) May it will become in the next time a little more often ;-) (a project has been canceled)... > > > On 11 Oct 2023, at 15:20, ummeegge wrote: > > > > Hi Adolf, > > > > Am Montag, dem 09.10.2023 um 19:26 +0200 schrieb Adolf Belka: > > > Hi All, > > > > > > I thought it was too good to be true. > > > > > > Before creating a client connection with something like BlowFish > > > I > > > thought I would just test the server settings with selecting BF > > > in > > > the data-ciphers-fallback selection box. > > Have disabled all the 64 bit block cipher in my previouse patches > > since > > the cipher negotiaton managed the whole thing. I think AEAD ciphers > > are > > since OpenSSL-1.0.1 available so if AES-GCM is available in --data- > > ciphers, the clients will use them even BF-CBC is set in > > client.ovpn . > > We have had a conversation about this also with some tests which > > you > > can find in here --> > > https://community.ipfire.org/t/openvpn-2-6-development-version/8603/3 > > > > > > > > Then pressed Start OpenVPN Server and nothing happened. Checked > > > the > > > logs and there is the openssl error > > > > > > OpenSSL: error:0308010C:digital envelope routines::unsupported > > > > > > which occurs because Openssl-3.x doesn't support the older > > > ciphers > > > like BF unless legacy is selected. In this case I think it is the > > > OpenVPN server conf file that requires the > > > > > > providers legacy default > > > > > > to be included, rather than the client conf file. > > > > > > Still it does feel like two steps forward and one backwards so > > > overall still making progress. > > > > > > > > > Regards, > > > > > > Adolf. > > > > Best, > > > > Erik > > > > > > > > > On 09/10/2023 14:05, Adolf Belka wrote: > > > > Hi All, > > > > > > > > > > > > Over the last week I have been working on the openvpn update > > > > using > > > > Erik's previous patches as my starting point. > > > > > > > > My first attempt to try and be able to understand the changes > > > > from > > > > each patch to figure out what I needed to do proved difficult > > > > for > > > > me to work with. > > > > > > > > What I then did was take the current ovpnmain.cgi and apply all > > > > of > > > > Erik's patches to it. > > > > > > > > Then I have gone through that new version of ovpnmain.cgi and > > > > made > > > > the changes based on previous discussions with Michael. > > > > > > > > So I have removed the b2sum options that were present for the > > > > Data > > > > and Channel Authentication. > > > > > > > > I also moved all the cryptographic options from an additional > > > > advanced cryptographic options button into the Advanced Server > > > > options button. > > > > > > > > I was successful in doing all the above and then tested the > > > > ovpnmain.cgi out with a vm using the existing openvpn-2.5.9 > > > > version > > > > for openvpn. > > > > > > > > My old profile for my laptop which had a ciphers entry worked > > > > without any problem. My laptop was working withy openvpn-2.6.6 > > > > > > > > I then created a new profile using the new ovpnmain.cgi using > > > > the > > > > negotiation option which ended up with a data-ciphers line. > > > > That > > > > also worked in making a successful openvpn tunnel with my > > > > laptop > > > > without any issues. > > > > > > > > I then downgraded my laptop to openvpn-2.4.8 and had to install > > > > openvpn-1.1.1 to make that work. > > > > > > > > With that client version on my laptop both the old and new > > > > profiles > > > > connected with a tunnel with no problems. > > > > > > > > I then tried downgrading my laptop to openvpn-2.3.14 but to > > > > make > > > > this work I would have had to downgrade the laptop to openssl- > > > > 1.0.0 > > > > which I was not willing to do as that is very old and very > > > > insecure. > > > > > > > > The oldest openvpn version working with openssl-1.1.1 is 2.4.0 > > > > which is nearly 7 years old. > > > > > > > > That version also worked with both the old and new laptop > > > > profiles. > > > > > > > > I then tested out the openvpn server on my IPFire vm with a > > > > 2.6.0 > > > > and 2.6.6 version of openvpn. > > > > > > > > Both these openvpn versions worked with both the old and new > > > > laptop > > > > connection profiles with my laptop on version 2.4.0 and on > > > > 2.6.6 > > > > > > > > All the above was using network manager with its openvpn plugin > > > > option on the laptop for making the openvpn tunnel connections. > > > > > > > > As far as I can tell everything is working fine when > > > > negotiation is > > > > specified on the server. Old profiles that just use the cipher > > > > option also work fine. Therefore my plan is to only use the > > > > negotiation option and not make it selectable for older > > > > clients. > > > > The data-ciphers-fallback option in the server seems to be > > > > doing > > > > its job. > > > > > > > > The negotiation option on the server was able to connect to a > > > > 2.4.0 > > > > client on my laptop. > > > > > > > > According to the OpenVPN wiki on cipher negotiation the data- > > > > ciphers-fallback option will work with 2.4.x and 2.3.x clients. > > > > As > > > > the 2.3.x clients need to be using openssl-1.0.0 then I think > > > > if > > > > those clients work then fine but nothing further back. > > > > > > > > Overall, I am very happy with what I have succeeded in doing so > > > > far. I achieved things much quicker than I had expected. > > > > > > > > I will now try and see about creating a profile on a CU 179 > > > > based > > > > system that uses one of the old insecure ciphers such as Blow > > > > Fish > > > > and restore that into my evaluation vm and see how that works > > > > with > > > > my laptop when I have it downgraded to openvpn-2.4.0 > > > > > > > > I already know that if the laptop is at openvpn-2.6.6 then it > > > > will > > > > not accept a blowfish cipher (or another weak cipher such as > > > > DES) > > > > as that is something I tested in the past. > > > > > > > > If that also works then my plan will be to take the updated > > > > ovpnmain.cgi and split the changes into a new range of patches > > > > and > > > > then submit them for consideration. > > > > > > > > That will probably end up later in November as I will be busy > > > > with > > > > personal things at the end of October / beginning of November. > > > > > > > > > > > > Regards, > > > > > > > > Adolf. > >