This reverts commit a8eb2a6a81. OpenSSH
7.0 is causing too many interoperability problems so soon before the
15.08 release.
For instance, it causes NixOps EC2 initial deployments to fail with
"REMOTE HOST IDENTIFICATION HAS CHANGED". This is because the client
knows the server's ssh-dss host key, but this key is no longer
accepted by default. Setting "HostKeyAlgorithms" to "+ssh-dss" does
not work because it causes ssh-dss to be ordered after
"ecdsa-sha2-nistp521", which the server also offers. (Normally, ssh
prioritizes host key algorithms for which the client has a known host
key, but not if you set HostKeyAlgorithms.)
The man page for ssh-keygen(1) has a section "MODULI GENERATION" that describes
how to generate your own moduli file. The following script might also be helpful:
| #! /usr/bin/env bash
|
| moduliFiles=()
|
| generateModuli()
| {
| ssh-keygen -G "moduli-$1.candidates" -b "$1"
| ssh-keygen -T "moduli-$1" -f "moduli-$1.candidates"
| rm "moduli-$1.candidates"
| }
|
| for (( i=0 ; i <= 16 ; ++i )); do
| let bitSize="2048 + i * 128"
| generateModuli "$bitSize" &
| moduliFiles+=( "moduli-$bitSize" )
| done
| wait
|
| echo >moduli "# Time Type Tests Tries Size Generator Modulus"
| cat >>moduli "${moduliFiles[@]}"
| rm "${moduliFiles[@]}"
Note that generating moduli takes a long time, i.e. several hours on a fast
machine!
This patch resolves https://github.com/NixOS/nixpkgs/pull/5870.
These services don't create files on disk, let alone on a network
filesystem, so they don't really need a fixed uid. And this also gets
rid of a warning coming from <= 14.12 systems.
Generating the file was refactored to be completely in nix.
Functionally it should create the same content as before,
only adding the newlines.
CC recent updaters: @aszlig, @rickynils.
This reverts commit a3331eb87b.
See https://github.com/NixOS/nixpkgs/issues/2559#issuecomment-47313334
for a description why this is not a good idea.
I guess it's better to implement a sane way to remove all files in
authorized_keys.d, especially because it is also backwards-compatible.
Reopens #2559.
Signed-off-by: aszlig <aszlig@redmoonstudios.org>
By enabling ‘services.openssh.startWhenNeeded’, sshd is started
on-demand by systemd using socket activation. This is particularly
useful if you have a zillion containers and don't want to have sshd
running permanently. Note that socket activation is not noticeable
slower, contrary to what the manpage for ‘sshd -i’ says, so we might
want to make this the default one day.
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
- Make dhcp work, use dhcpcd without udev in container
- Make login shell work, patch getty to not wait for /dev/tty0
- Make ssh work, sshd/pam do not start session
Sshd *must* use PAM because we depend on it for proper session
management. The original goal of this option (disabling password
logins) can also be implemented by removing pam_auth authentication
from sshd's PAM service.
That is, you can say
security.pam.services.sshd = { options... };
instead of
security.pam.services = [ { name = "sshd"; options... } ];
making it easier to override PAM settings from other modules.
