Both managed authorized_keys files lacked a trailing newline. sshd reads
the final key fine on its own, but any subsequent append (tooling, a
follow-up key, or the validation harness) concatenated onto the last key
line, fusing two keys into one unparseable blob and silently breaking
public-key auth for both.
Add the trailing newline so the files concatenate safely.
🤖 Generated with [Crush](https://github.com/charmassociates/crush)
Assisted-by: GLM-5 via Crush <crush@charm.land>
The KexAlgorithms line in ssh-audit-hardening.conf began with a space.
In sshd_config a leading whitespace marks a line continuation, so the
entire directive was absorbed as arguments to the (non-existent)
previous directive. The effective kexalgorithms collapsed to only the
two trailing GSSAPI entries (gss-curve25519-sha256-, gss-group16-sha512-),
which no normal OpenSSH client can negotiate.
Result: after secharden-ssh deployed this file, every SSH connection to
the host died in [preauth] with no usable key exchange algorithm. sshd -t
still returned 0, so the breakage was completely silent.
Drop the leading space so the directive is parsed as intended. This
restores normal client compatibility while keeping the hardened
algorithm set.
🤖 Generated with [Crush](https://github.com/charmassociates/crush)
Assisted-by: GLM-5 via Crush <crush@charm.land>
mrcharles