NAME

signify-openbsd — cryptographically sign and verify files

SYNOPSIS

DESCRIPTION

The signify-openbsd utility creates and verifies cryptographic signatures. A signature verifies the integrity of a message. The mode of operation is selected with the following options:

-C

Verify a signed checksum list, and then verify the checksum for each file. If no files are specified, all of them are checked. sigfile should be the signed output of sha256(1).

-G

Generate a new key pair. Keynames should follow the convention of keyname.pub and keyname.sec for the public and secret keys, respectively.

-S

Sign the specified message file and create a signature.

-V

Verify the message and signature match.

The other options are as follows:

-c comment

Specify the comment to be added during key generation.

-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 -e and creates a new message file as output.)

-m message

When signing, the file containing the message to sign. When verifying, the file containing the message to verify. When verifying with -e, the file to create.

-n

When generating a key pair, do not ask for a passphrase. Otherwise, signify-openbsd will prompt the user for a passphrase to protect the secret key. When signing with -z, store a zero time stamp in the gzip(1) header.

-p pubkey

Public key produced by -G, and used by -V to check a signature.

-q

Quiet mode. Suppress informational output.

-s seckey

Secret (private) key produced by -G, and used by -S to sign a message.

-t keytype

When deducing the correct key to check a signature, make sure the actual key matches /etc/signify/*-keytype.pub.

-x sigfile

The signature file to create or verify. The default is message.sig.

-z

Sign and verify gzip(1) archives, where the signing data is embedded in the gzip(1) header.

The key and signature files created by signify-openbsd 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.

EXIT STATUS

The signify-openbsd utility exits 0 on success, and >0 if an error occurs. It may fail because of one of the following reasons:

• Some necessary files do not exist.
• Entered passphrase is incorrect.
• The message file was corrupted and its signature does not match.
• The message file is too large.

EXAMPLES

Create a new key pair:

Sign a file, specifying a signature name:

Verify a signature, using the default signature name:

Verify a release directory containing SHA256.sig and a full set of release files:

$ signify-openbsd -C -p /etc/signify/openbsd-72-base.pub -x SHA256.sig

Verify a bsd.rd before an upgrade:

$ signify-openbsd -C -p /etc/signify/openbsd-72-base.pub -x SHA256.sig bsd.rd

Sign a gzip archive:

$ signify-openbsd -Sz -s key-arc.sec -m in.tgz -x out.tgz

Verify a gzip pipeline:

$ ftp url | signify-openbsd -Vz -t arc | tar ztf -

SEE ALSO

gzip(1), pkg_add(1), sha256(1), fw_update(8), sysupgrade(8)

HISTORY

The signify-openbsd command first appeared in OpenBSD 5.5.

AUTHORS

Ted Unangst <tedu@openbsd.org> and Marc Espie <espie@openbsd.org>.