SSH-KEYSIGN(8)                     BSD System Manager's Manual                     SSH-KEYSIGN(8)

NAME
     ssh-keysign — ssh helper program for host-based authentication

SYNOPSIS
     ssh-keysign

DESCRIPTION
     ssh-keysign is used by ssh(1) to access the local host keys and generate the digital signa‐
     ture required during host-based authentication with SSH protocol version 2.

     ssh-keysign is disabled by default and can only be enabled in the global client configura‐
     tion file /etc/ssh/ssh_config by setting EnableSSHKeysign to “yes”.

     ssh-keysign is not intended to be invoked by the user, but from ssh(1).  See ssh(1) and
     sshd(8) for more information about host-based authentication.

FILES
     /etc/ssh/ssh_config
             Controls whether ssh-keysign is enabled.

     /etc/ssh/ssh_host_dsa_key
     /etc/ssh/ssh_host_ecdsa_key
     /etc/ssh/ssh_host_ed25519_key
     /etc/ssh/ssh_host_rsa_key
             These files contain the private parts of the host keys used to generate the digital
             signature.  They should be owned by root, readable only by root, and not accessible
             to others.  Since they are readable only by root, ssh-keysign must be set-uid root
             if host-based authentication is used.

     /etc/ssh/ssh_host_dsa_key-cert.pub
     /etc/ssh/ssh_host_ecdsa_key-cert.pub
     /etc/ssh/ssh_host_ed25519_key-cert.pub
     /etc/ssh/ssh_host_rsa_key-cert.pub
             If these files exist they are assumed to contain public certificate information cor‐
             responding with the private keys above.

SEE ALSO
     ssh(1), ssh-keygen(1), ssh_config(5), sshd(8)

HISTORY
     ssh-keysign first appeared in OpenBSD 3.2.

AUTHORS
     Markus Friedl <markus AT openbsd.org>

BSD                                       April 30, 2025                                      BSD