Dropbear lags behind OpenSSH significantly in both support for modern
key formats like `ssh-ed25519`, let alone the recently-introduced
U2F/FIDO2-based `sk-ssh-ed25519@openssh.com` (as I found when I switched
my `authorizedKeys` over to it and promptly locked myself out of my
server's initrd SSH, breaking reboots), as well as security features
like multiprocess isolation. Using the same SSH daemon for stage-1 and
the main system ensures key formats will always remain compatible, as
well as more conveniently allowing the sharing of configuration and
host keys.
The main reason to use Dropbear over OpenSSH would be initrd space
concerns, but NixOS initrds are already large (17 MiB currently on my
server), and the size difference between the two isn't huge (the test's
initrd goes from 9.7 MiB to 12 MiB with this change). If the size is
still a problem, then it would be easy to shrink sshd down to a few
hundred kilobytes by using an initrd-specific build that uses musl and
disables things like Kerberos support.
This passes the test and works on my server, but more rigorous testing
and review from people who use initrd SSH would be appreciated!
Running the manual on a TTY is useless in the graphical ISOs and not
particularly useful in non-graphical ISOs (since you can also run
'nixos-help').
Fixes#83157.
* Removed the use of gnome-screensaver (https://gitlab.gnome.org/GNOME/gnome-flashback/issues/18)
* Flashback's menu-related environment variables are now set in the gnome3.nix module instead of gnome-panel to resolve dependency conflict.
While renaming `networking.defaultMailServer` directly to
`services.ssmtp` is shorter and probably clearer, it causes eval errors
due to the second rename (directDelivery -> enable) when using e.g. `lib.mkForce`.
For instance,
``` nix
{ lib, ... }: {
networking.defaultMailServer = {
hostName = "localhost";
directDelivery = lib.mkForce true;
domain = "example.org";
};
}
```
would break with the following (rather confusing) error:
```
error: The option value `services.ssmtp.enable' in `/home/ma27/Projects/nixpkgs/nixos/modules/programs/ssmtp.nix' is not of type `boolean'.
(use '--show-trace' to show detailed location information)
```
NixOS 20.03 is built on kernel 5.4 and 19.09 is on 4.19, so we should update
this option to the highest value possible, per linked upstream instructions from
Amazon.
* nixos/nixpkgs.nix: Allow just using config in system
This assertion requires system to work properly. We might not have
this in cases where the user just sets config and wants Nixpkgs to
infer system from that. This adds a default for when this happens,
using doubleFromSystem.
* parens
`$toplevel/system` of a system closure with `x86_64` kernel and `i686` userland should contain "x86_64-linux".
If `$toplevel/system` contains "i686-linux", the closure will be run using `qemu-system-i386`, which is able to run `x86_64` kernel on most Intel CPU, but fails on AMD.
So this fix is for a rare case of `x86_64` kernel + `i686` userland + AMD CPU
