opendkim-genkey - DKIM filter key generation tool
opendkim-genkey generates (1) a private key for signing messages using
opendkim(8) and (2) a DNS TXT record suitable for inclusion in a zone
file which publishes the matching public key for use by remote DKIM
The filenames of these are based on the selector (see below); the
private key will have a suffix of ".private" and the TXT record will
have a suffix of ".txt".
Both long and short names are supported for most options.
-a (--append-domain) Appends the domain name (see -d below) to the
label in the generated TXT record, followed by a trailing
period. By default it is assumed the domain name is implicit
from the context of the zone file, and is therefore not included
in the output.
(--bits=n) Specifies the size of the key, in bits, to be
generated. The default is 1024 which is the value recommended
by the DKIM specification.
(--domain=string) Names the domain which will use this key for
signing. Currently only used in a comment in the TXT record
file. The default is "example.com".
(--directory=path) Instructs the tool to change to the named
directory prior to creating files. By default the current
directory is used.
(--hash-algorithms=name[:name[...]]) Specifies a list of hash
algorithms which can be used with this key. By default all hash
algorithms are allowed.
--help Print a help message and exit.
(--note=string) Includes arbitrary note text in the key record.
By default, no such text is included.
-r (--restricted) Restricts the key for use in e-mail signing only.
The default is to allow the key to be used for any service.
(--selector=name) Specifies the selector, or name, of the key
pair generated. The default is "default".
-S (--[no]subdomains) Disallows subdomain signing by this key. By
default the key record will be generated such that verifiers are
told subdomain signing is permitted. Note that for backward
compatibility reasons, -S means the same as --nosubdomains.
-t (--[no]testmode) Indicates the generated key record should be
tagged such that verifiers are aware DKIM is in test at the
-v (--verbose) Increase verbose output.
-V (--version) Print version number and exit.
Requires that the openssl(8) binary be installed and in the executing
shell's search path.
This man page covers the version of opendkim-genkey that shipped with
version 2.9.2 of OpenDKIM.
Copyright (c) 2007, 2008 Sendmail, Inc. and its suppliers. All rights
Copyright (c) 2009, 2011-2013, The Trusted Domain Project. All rights
RFC6376 - DomainKeys Identified Mail
The Trusted Domain Project opendkim-genkey(8)