svn commit: r303716 - head/crypto/openssh

[Andrey Chernov]

On 07.08.2016 19:14, Bruce Simpson wrote:
> On 07/08/16 15:40, Warner Losh wrote:
>> That’s a cop-out answer. We, as a project, need to articulate to our
>> users, whom we care about, why this rather obnoxious hit to usability
>> was taken. The answer must be more complete than “We just disabled
>> it because upstream disabled it for reasons we’re too lazy to explain
>> or document how to work around"
> 
> Alcatel-Lucent OmniSwitch 6800 login broken (pfSense 2.3.2 which
> accepted the upstream change, workaround no-go)
> 
> [2.3.2-RELEASE][root at gw.lab]/root: ssh -l admin
> -oKexAlgorithms=+diffie-hellman-group1-sha1 192.168.1.XXX
> Fssh_ssh_dispatch_run_fatal: Connection to 192.168.1.XXX port 22: DH GEX
> group out of range
> 

DH prime size must be at least 2048, openssh now refuse lower values.
Commonly used DH size 1024 can be easily broken. See https://weakdh.org