Arch Linux: describe ed25519 support

[ejiektpobehuk]

ed25519 support: mkj/dropbear#91

[rlaager]

@ejiek Could you add a Signed-off-by to the commit, please?

@ne9z Is this support now available in Arch?

[ghost]

@ejiek Have you tested this though? Last time I checked, mkinitcpio-dropbear hook complains a lot for not being able to read ed25519 host key generated with ssh-keygen -Am pem. For now I would just stick with good ol' RSA 3072 keys.

[ejiektpobehuk]

@ne9z @rlaager this setup works a fresh install of AL (as of 07.03.2021).

I've experienced no problems with ed25519 key in /etc/dropbear/root_key.
As for host keys dropbearconvert openssh dropbear /etc/ssh/ssh_host_ed25519_key dropbear_ed25519_host_key has succesfully converted a host key, but it's not done by mkinitcpio-dropbear hook yet.

[ghost]

Thanks for testing this out. So it means that ed25519 still does not work with mkinitcpio-dropbear without manually converting the host key first.

Please add this instruction and note to the pull request.

[ejiektpobehuk]

I'd argue that this PR was about /etc/dropbear/root_key not a host key.
But I think that it can be expanded to ed25519 support =]

[ghost]

Latest commit looks good to me. However Arch guide has significantly changed since this notice was proposed. "This branch has conflicts that must be resolved"

Maybe rebase on the latest version?

[ejiektpobehuk]

Done!

I'm not sure how correct it is in English but I've added two commas to make reading a bit easier.

Thanks for all the support during this PR!

[ghost]

I've opened a pull request in your repo to address the issues.

[ghost]

@rlaager I think it's ready for merging.