Hi Michael,
On Sat, 2017-11-11 at 14:48 -0500, Tom Rymes wrote:
Is it possible to put a warning in the text after an update, or perhaps in the text where "An update requires a reboot" appears?
Perhaps announce immediately and roll out two releases from now?
That would be an option, but people don't seem to be updating for each release. Some do it every second and some do it for every major or security release.
So it will need to be there for a while and then we still won't be able to tell the right people that they would be affected.
And to the pro-security people: Clearly that is a high priority. But I would like to say that the "conservative" option isn't really broken here. RSA isn't broken, the classic DH isn't broken and some of the server performance arguments are less important here because nobody has tens of thousands of people using the webUI at the same time...
I would agree here (actually, I wanted to write a similar text). Otherwise, I would not have suggested to stay with compatibility until next year. Nevertheless, I can live with the other option as well.
Best regards, Wolfgang
Best, -Michael
Tom
On Nov 11, 2017, at 2:33 PM, Peter Müller peter.mueller@link38.eu wrote:
Hello Peter, hello Wolfgang,
+1 for security, too.
However, it might be good to warn the users (planet post, etc.) some time before we release a new version which changes this.
In case we decide to change to the Modern SSL policy, I'll send in a second patch containing the Apache SSL directives Wolfgang told me (thanks for this again!).
Best regards, Peter Müller
Hi,
so how do we handle this?
We now have the argument for better security against the argument for better compatibility.
Indeed this is not an easy question. So please everybody else who has an opinion on this step forward and then I will just count the votes.
Best, -Michael
On Thu, 2017-11-09 at 22:35 +0100, Wolfgang Apolinarski wrote: Hi Peter,
Hello Wolfgang,
sorry for replying that late - at the moment I am quite busy. :-|
I can fully understand that - my reaction time is usually also a lot longer than what I want it to be...
> > > > Actually I proposed that in the discussion to another > > patch, but Wolfgang said that we would exclude too many systems. > > I still think that there might be too many clients, which do > not have support for TLS 1.2. > I would suggest postponing this step to next year.
To keep it short: I fear this is correct and there are networks - mostly they belong to companies, ironically - with very ancient client systems.
However, I would differ between several cases: (a) Public web sites such as https://www.ipfire.org - for these, I consider the 'Modern' policy OK since nobody wants to transmit sensitive data with 3DES or SHA1. If a user cannot connect, it is his/her/its fault. Further, the more SSL errors they get from big web sites, the more it hurts.
(b) Internal web sites - which is the case for IPFire's WebUI
- may be considered as less critical by some people since they
are located in the always trustworthy and super-safe internal network. Needless to say, I consider this being bullshit, but that explains why we still have WinXP & Co. systems running.
However, in my opinion, we also should apply the 'Modern' policy there since weak algorithms are weak, no matter in what network they are used. And in case this breaks internal systems, it is not our fault either: All you need is a system with FF >= 28 or something similar. TLS 1.2 is far from being brand new and as far as I am concerned, we _can_ expect that people move to this. Period.
They only thing I fear is that the apache configuration for the internal WebUI is also used for addons like owncloud which might be accessed with mobile clients - clients which cannot be updated that easily (this is why I cited the Android OS version usage statistics).
Service such as the Captive Portal or the Update Accelerator repo are using HTTP, so they should not make trouble. TLS 1.2 is "only" used for the administration web interface, which usually does not have to be accessible from all clients.
This is why I submitted this patch.
After the discussion with Michael, it was also on my personal todo list to submit an additional patch with the modern configuration, such that we can choose which we like best. So I am glad you did that.
(c) And there are mail servers, which must be treated differently since they fall back to plain text in case no common SSL/TLS ciphers were found. TLS on MX is meant as a protection layer against passive attackers in first place. This is why I'd never use the 'Modern' policy on MXs.
And there are still mail server that do not accept encrypted connections at all and/or do not check certificates for validity. I assume that the mail server world has improved, I still remember when it was not possible to connect securely to GMX' mail servers.
> > Also, for the modern configuration, we should edit the > SSLProtocol > value: > SSLProtocol all -SSLv2 -SSLv3 -TLSv1 -TLSv1.1 This allows > anyone to understand that only TLSv1.2+ is supported.
Yes, you are right. I forgot that. > > Regarding the re-ordering of the cipher suites: > ECDHE-ECDSA is not always faster than ECDHE-RSA. > It depends on the size of the EC and the RSA key. > Although I'm assuming that a 4096-bit key is quite slow...
Surprise! ;-) > I somewhere read that 2048-bit RSA is faster than 256-bit curve.
Really? I was unaware of this.
I think it was some slow Atom machine - I was just a little bit concerned, because the router machines are also constraint when it comes to CPU/RAM resources.
> We are using a 4096-bit RSA together with a 384-bit curve. > Did anyone perform some measurements?
No, not yet. The only numbers I have are from Ivan Ristic, who says:
algorithm strength CPU time (client) CPU time (server) ECDHE-ECDSA 256/256 bits 1.09s 0.74s ECDHE-RSA 256/2048 bits 0.81s 2.06s
Ah, interesting. I executed the following command on my Ipfire machine (Intel NUC): "openssl speed aes rsa ecdsa ecdh" the results are: Method ; Sign ; Verify ; Sign/s ; Verify/s 384 bit ecdsa (nistp384) ; 0.0007s ; 0.0030s ; 1356.3 ; 335.3 rsa 2048 bits; 0.004814s 0.000141s ; 207.7 ; 7075.8 rsa 4096 bits; 0.034930s 0.000531s ; 28.6 ; 1882.1 Method ; op ; op/s 384 bit ecdh (nistp384) ; 0.0025s ; 400.8
RSA is really fast in verification, but I assume that the server (WebUI) signs and the client then verifies. So ECDSA is more resource intensive for clients, but RSA is a lot slower on servers.
Also, I now recognized that secp384r1 is an NIST curve. Well, maybe this is more a political issue and not that relevant for a WebUI-Frontend...
Thereof I assume ECDSA keys perform usually better than RSA ones, especially when it comes to server CPU time.
Depends on the usage as can be seen above, but in general this is true for servers, especially with increasing key sizes.
> > > > > Did you see that conversation? > > And I really thought that maybe my mail did not make it > through after reading the patch...
I am sorry, but I really did not notice it. Did you say which systems you expect to cause problems with TLS 1.2 only?
Yes, according to Mozilla: Oldest compatible clients: Firefox 27, Chrome 30, IE 11 on Windows 7, Edge, Opera 17, Safari 9, Android 5.0, and Java 8
Android < 5.0 has still a market share of > 25%. https://en.wikipedia.org/wiki/Android_version_history#/media/Fil e:Androi d_historical_version_distribution_-_vector.svg
Actually all my clients would be compatible. ;-)
Nevertheless, the following additional changes would be a good idea: SSLProtocol all -SSLv2 -SSLv3 -TLSv1 -TLSv1.1 SSLCompression off SSLSessionTickets off (the last parameter improves PFS). The apache docs: "TLS session tickets are enabled by default. Using them without restarting the web server with an appropriate frequency (e.g. daily) compromises perfect forward secrecy."
Best regards, Wolfgang
> > > > > > On Tue, 2017-11-07 at 20:51 +0100, Peter Müller wrote: > > > Change the TLS cipher list of Apache to "Mozilla Modern". > > > > > > ECDSA is preferred over RSA to save CPU time on both > > > server and client. Clients without support for TLS 1.2 > > > and AES will experience connection failures. > > > > > > Signed-off-by: Peter Müller peter.mueller@link38.eu > > > --- > > > config/httpd/vhosts.d/ipfire-interface-ssl.conf | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git > > > a/config/httpd/vhosts.d/ipfire-interface-ssl.conf > > > b/config/httpd/vhosts.d/ipfire-interface-ssl.conf > > > index c9ccd5be5..d08d3d2bb 100644 > > > --- a/config/httpd/vhosts.d/ipfire-interface-ssl.conf > > > +++ b/config/httpd/vhosts.d/ipfire-interface-ssl.conf > > > @@ -9,7 +9,7 @@ > > > TransferLog /var/log/httpd/access_log > > > SSLEngine on > > > SSLProtocol all -SSLv2 -SSLv3 > > > - SSLCipherSuite ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-ECDSA- > > > AES128-SHA256:ECDHE-ECDSA > > > -AES128-SHA:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-ECDSA-AE > > > S256- > > > SHA38 > > > 4:EC > > > DHE-ECDSA-AES256-SHA:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-R > > > SA- > > > AES128- > > > SHA2 > > > 56:ECDHE-RSA-AES128-SHA:ECDHE-RSA-AES256-GCM-SHA384:ECDH > > > E-RSA- > > > AES2 > > > 56-S > > > HA384:ECDHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES128- > > > SHA256:AES128-SHA: > > > CAMELLIA128-SHA:AES256-GCM-SHA384:AES256-SHA256:AES256- > > > SHA:CAMELLI > > > A256 > > > -SHA > > > + SSLCipherSuite > > > + ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20- > > > POLY1305:ECDH > > > + E-EC > > > + DSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE- > > > + ECDSA- > > > AES1 > > > + 28-S > > > + HA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-CHACHA20- > > > POLY1305:EC > > > + DHE- > > > + RSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-SHA384:ECDHE-RS > > > + A- > > > AES128-S > > > + HA25 > > > + 6 > > > SSLHonorCipherOrder on > > > SSLCertificateFile /etc/httpd/server.crt > > > SSLCertificateKeyFile /etc/httpd/server.key