path: root/man/man1/openpgp2ssh.1

.\"  -*- nroff -*-
.Dd $Mdocdate: June 11, 2008 $
.Dt OPENPGP2SSH 1
.Os
.Sh NAME
openpgp2ssh
.Nd translate OpenPGP keys to SSH keys
.Sh SYNOPSIS
.Nm openpgp2ssh < mykey.gpg 
.Pp
.Nm gpg --export $KEYID | openpgp2ssh $KEYID
.Pp
.Nm gpg --export-secret-key $KEYID | openpgp2ssh $KEYID
.Sh DESCRIPTION
.Nm
takes an OpenPGP-formatted primary key and associated
subkeys on standard input, and spits out the requested equivalent
SSH-style key on standard output.
.Pp
If the data on standard input contains no subkeys, you can invoke
.Nm
without arguments.  If the data on standard input contains multiple
keys (e.g. a primary key and associated subkeys), you must specify a
specific OpenPGP key identifier as the first argument to indicate
which key to export.  The key ID is normally the 40 hex digit OpenPGP
fingerprint of the key or subkey desired, but
.Nm
will accept as few as the last 8 digits of the fingerprint as a key
ID.
.Pp
If the input contains an OpenPGP RSA or DSA public key, it will be
converted to the OpenSSH-style single-line keystring, prefixed with
the key type.  This format is suitable (with minor alterations) for
insertion into known_hosts files and authorized_keys files.
.Pp
If the input contains an OpenPGP RSA or DSA secret key, it will be
converted to the equivalent PEM-encoded private key.
.Pp
.Nm
is part of the
.Xr monkeysphere 5
framework for providing a PKI for SSH.
.Sh CAVEATS
The keys produced by this process are stripped of all identifying
information, including certifications, self-signatures, etc.  This is
intentional, since ssh attaches no inherent significance to these
features.
.Pp
.Nm
only works with RSA or DSA keys, because those are the
only ones which work with ssh.
.Pp
Assuming a valid key type, though, 
.Nm
will produce output for
any requested key.  This means, among other things, that it will
happily export revoked keys, unverifiable keys, expired keys, etc.
Make sure you do your own key validation before using this tool!
.Sh EXAMPLES
.Nm gpg --export-secret-key $KEYID | openpgp2ssh $KEYID | ssh-add -c /dev/stdin
.Pp
This pushes the secret key into the active
.Xr ssh-agent 1 . 
Tools such as 
.Xr ssh 1
which know how to talk to the 
.Xr ssh-agent 1
can now rely on the key.
.Sh AUTHOR
.Nm
and this man page were written by Daniel Kahn Gillmor
<dkg@fifthhorseman.net>.
.Sh BUGS
.Nm
Currently only exports into formats used by the OpenSSH.
It should support other key output formats, such as those used by
lsh(1) and putty(1).
.Pp
Secret key output is currently not passphrase-protected.
.Pp
.Nm
currently cannot handle passphrase-protected secret keys on input.
.Pp
Key identifiers consisting of an odd number of hex digits are not
accepted.  Users who use a key ID with a standard length of 8, 16, or
40 hex digits should not be affected by this.
.Pp
.Nm
only acts on keys associated with the first primary key
passed in.  If you send it more than one primary key, it will silently
ignore later ones.
.Sh SEE ALSO
.Xr monkeysphere 1 ,
.Xr monkeysphere 5 ,
.Xr ssh 1 ,
.Xr monkeysphere-server 8