.\" $OpenBSD: signify.1,v 1.31 2015/07/14 23:30:02 florian Exp $
.\"
.\"Copyright (c) 2013 Marc Espie <espie@openbsd.org>
.\"Copyright (c) 2013 Ted Unangst <tedu@openbsd.org>
.\"
.\"Permission to use, copy, modify, and distribute this software for any
.\"purpose with or without fee is hereby granted, provided that the above
.\"copyright notice and this permission notice appear in all copies.
.\"
.\"THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\"WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\"MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\"ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\"WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\"ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\"OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.Dd $Mdocdate: July 14 2015 $
.Dt SIGNIFY 1
.Os
.Sh NAME
.Nm signify
.Nd cryptographically sign and verify files
.Sh SYNOPSIS
.Nm signify
.Fl C
.Op Fl q
.Fl p Ar pubkey
.Fl x Ar sigfile
.Op Ar
.Nm signify
.Fl G
.Op Fl n
.Op Fl c Ar comment
.Fl p Ar pubkey
.Fl s Ar seckey
.Nm signify
.Fl S
.Op Fl e
.Op Fl x Ar sigfile
.Fl s Ar seckey
.Fl m Ar message
.Nm signify
.Fl V
.Op Fl eq
.Op Fl x Ar sigfile
.Fl p Ar pubkey
.Fl m Ar message
.Sh DESCRIPTION
The
.Nm
utility creates and verifies cryptographic signatures.
A signature verifies the integrity of a
.Ar message .
The mode of operation is selected with the following options:
.Bl -tag -width Dsssigfile
.It Fl C
Verify a signed checksum list, and then verify the checksum for
each file.
If no files are specified, all of them are checked.
.Ar sigfile
should be the signed output of
.Xr sha256 1 .
.It Fl G
Generate a new key pair.
.It Fl S
Sign the specified message file and create a signature.
.It Fl V
Verify the message and signature match.
.El
.Pp
The other options are as follows:
.Bl -tag -width Dsssignature
.It Fl c Ar comment
Specify the comment to be added during key generation.
.It Fl e
When signing, embed the message after the signature.
When verifying, extract the message from the signature.
(This requires that the signature was created using
.Fl e
and creates a new message file as output.)
.It Fl m Ar message
When signing, the file containing the message to sign.
When verifying, the file containing the message to verify.
When verifying with
.Fl e ,
the file to create.
.It Fl n
Do not ask for a passphrase during key generation.
Otherwise,
.Nm
will prompt the user for a passphrase to protect the secret key.
.It Fl p Ar pubkey
Public key produced by
.Fl G ,
and used by
.Fl V
to check a signature.
.It Fl q
Quiet mode.
Suppress informational output.
.It Fl s Ar seckey
Secret (private) key produced by
.Fl G ,
and used by
.Fl S
to sign a message.
.It Fl x Ar sigfile
The signature file to create or verify.
The default is
.Ar message Ns .sig .
.El
.Pp
The key and signature files created by
.Nm
have the same format.
The first line of the file is a free form text comment that may be edited,
so long as it does not exceed a single line.
.\" Signature comments will be generated based on the name of the secret
.\" key used for signing.
.\" This comment can then be used as a hint for the name of the public key
.\" when verifying.
The second line of the file is the actual key or signature base64 encoded.
.Sh EXIT STATUS
.Ex -std signify
It may fail because of one of the following reasons:
.Pp
.Bl -bullet -compact
.It
Some necessary files do not exist.
.It
Entered passphrase is incorrect.
.It
The message file was corrupted and its signature does not match.
.It
The message file is too large.
.El
.Sh EXAMPLES
Create a new key pair:
.Dl $ signify -G -p newkey.pub -s newkey.sec
.Pp
Sign a file, specifying a signature name:
.Dl $ signify -S -s key.sec -m message.txt -x msg.sig
.Pp
Verify a signature, using the default signature name:
.Dl $ signify -V -p key.pub -m generalsorders.txt
.Pp
Verify a release directory containing
.Pa SHA256.sig
and a full set of release files:
.Bd -literal -offset indent -compact
$ signify -C -p /etc/signify/openbsd-58-base.pub -x SHA256.sig
.Ed
.Pp
Verify a bsd.rd before an upgrade:
.Bd -literal -offset indent -compact
$ signify -C -p /etc/signify/openbsd-58-base.pub -x SHA256.sig bsd.rd
.Ed
.Sh SEE ALSO
.Xr fw_update 1 ,
.Xr pkg_add 1 ,
.Xr sha256 1
.Sh HISTORY
The
.Nm
command first appeared in
.Ox 5.5 .
.Sh AUTHORS
.An Ted Unangst Aq Mt tedu@openbsd.org