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 signature required during host-based authentication.
ssh-keysign is disabled by default and can only be enabled in the global
client configuration 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 authentica-
tion.
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 certifi-
cate information corresponding with the private keys above.
ENVIRONMENT
SSH_USE_STRONG_RNG
The reseeding of the OpenSSL random generator is usually done
from /dev/urandom. If the SSH_USE_STRONG_RNG environment vari-
able is set to value other than 0 the OpenSSL random generator is
reseeded from /dev/random. The number of bytes read is defined
by the SSH_USE_STRONG_RNG value. Minimum is 14 bytes. This set-
ting is not recommended on the computers without the hardware
random generator because insufficient entropy causes the connec-
tion to be blocked until enough entropy is available.
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 November 25, 2024 BSD