freebsd-nq/crypto/openssh/ssh-keysign.8
Ed Maste 19261079b7 openssh: update to OpenSSH v8.7p1
Some notable changes, from upstream's release notes:

- sshd(8): Remove support for obsolete "host/port" syntax.
- ssh(1): When prompting whether to record a new host key, accept the key
  fingerprint as a synonym for "yes".
- ssh-keygen(1): when acting as a CA and signing certificates with an RSA
  key, default to using the rsa-sha2-512 signature algorithm.
- ssh(1), sshd(8), ssh-keygen(1): this release removes the "ssh-rsa"
  (RSA/SHA1) algorithm from those accepted for certificate signatures.
- ssh-sk-helper(8): this is a new binary. It is used by the FIDO/U2F
  support to provide address-space isolation for token middleware
  libraries (including the internal one).
- ssh(1): this release enables UpdateHostkeys by default subject to some
  conservative preconditions.
- scp(1): this release changes the behaviour of remote to remote copies
  (e.g. "scp host-a:/path host-b:") to transfer through the local host
  by default.
- scp(1): experimental support for transfers using the SFTP protocol as
  a replacement for the venerable SCP/RCP protocol that it has
  traditionally used.

Additional integration work is needed to support FIDO/U2F in the base
system.

Deprecation Notice
------------------

OpenSSH will disable the ssh-rsa signature scheme by default in the
next release.

Reviewed by:	imp
MFC after:	1 month
Relnotes:	Yes
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D29985
2021-09-07 21:05:51 -04:00

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Groff

.\" $OpenBSD: ssh-keysign.8,v 1.16 2019/11/30 07:07:59 jmc Exp $
.\"
.\" Copyright (c) 2002 Markus Friedl. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd $Mdocdate: November 30 2019 $
.Dt SSH-KEYSIGN 8
.Os
.Sh NAME
.Nm ssh-keysign
.Nd OpenSSH helper for host-based authentication
.Sh SYNOPSIS
.Nm
.Sh DESCRIPTION
.Nm
is used by
.Xr ssh 1
to access the local host keys and generate the digital signature
required during host-based authentication.
.Pp
.Nm
is disabled by default and can only be enabled in the
global client configuration file
.Pa /etc/ssh/ssh_config
by setting
.Cm EnableSSHKeysign
to
.Dq yes .
.Pp
.Nm
is not intended to be invoked by the user, but from
.Xr ssh 1 .
See
.Xr ssh 1
and
.Xr sshd 8
for more information about host-based authentication.
.Sh FILES
.Bl -tag -width Ds -compact
.It Pa /etc/ssh/ssh_config
Controls whether
.Nm
is enabled.
.Pp
.It Pa /etc/ssh/ssh_host_dsa_key
.It Pa /etc/ssh/ssh_host_ecdsa_key
.It Pa /etc/ssh/ssh_host_ed25519_key
.It Pa /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,
.Nm
must be set-uid root if host-based authentication is used.
.Pp
.It Pa /etc/ssh/ssh_host_dsa_key-cert.pub
.It Pa /etc/ssh/ssh_host_ecdsa_key-cert.pub
.It Pa /etc/ssh/ssh_host_ed25519_key-cert.pub
.It Pa /etc/ssh/ssh_host_rsa_key-cert.pub
If these files exist they are assumed to contain public certificate
information corresponding with the private keys above.
.El
.Sh SEE ALSO
.Xr ssh 1 ,
.Xr ssh-keygen 1 ,
.Xr ssh_config 5 ,
.Xr sshd 8
.Sh HISTORY
.Nm
first appeared in
.Ox 3.2 .
.Sh AUTHORS
.An Markus Friedl Aq Mt markus@openbsd.org