On Wed, Jan 5, 2022 at 10:38 AM Jochen Bern <Jochen.Bern@xxxxxxxxx> wrote: > The hashing is meant to obscure info about what host it matches, so the > relevant failure mode is if the hash algo would become *reversible*. And normally, it's the opposite of helpful. The known_hosts is useful for casual review and for tuning .ssh/config as desired for more specific uses, and the hashing obscures the commonly used SSH targets. > One question about the real-world use cases, however: How many people > are there hashing known_hosts entries *autogenerated by client use out > of the very same account*? If I were to find that someone got ahold of Many simply turn off known_hosts, because it is a burden to approve new hostkeys and very awkward if there is an IP address overlap in a DHCP or externally configured target. The .ssh/config settings for this are quite old, and well documented: Host * UserKnownHostsFile /dev/null StrictHostKeyChecking no LogLevel ERROR > A much more understandable use case would be if an organization > distributes a centrally administered/collected known_hosts file to users > but doesn't want marginally-trusted users to immediately see where to > find the company LAN's crown jewels. However, in order to make a > successful algo migration in *that* scenario, we'd have to address the > possibility that users and the central repository could end up > supporting *different* sets of algos for some length of time ... The burden is why I disable it in setups like, say, ansible server setups to control wide varieties of VM's in a multi-purpose VLAN. _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev