opendkim-genkey.sh - DKIM filter key generation tool
opendkim-genkey.sh 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
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".
Specifies the size of the key, in bits, to be generated. The
default is 1024 which is the value recommended by the DKIM
Names the domain which will use this key for signing. Currently
only used in a comment in the TXT record file. The default is
Instructs the tool to change to the named directory prior to
creating files. By default the current directory is used.
Defines the key granularity, i.e. the user(s) who may use the
key. The default is "*" meaning any user can use the key.
Specifies a list of hash algorithms which can be used with this
key. By default all hash algorithms are allowed.
Includes arbitrary note text in the key record. By default, no
such text is included.
-r Restricts the key for use in e-mail signing only. The default
is to allow the key to be used for any service.
Specifies the selector, or name, of the key pair generated. The
default is "default".
-S Disallows subdomain signing by this key. By default the key
record will be generated such that verifiers are told subdomain
signing is permitted.
-t Indicates the generated key record should be tagged such that
verifiers are aware DKIM is in test at the signing domain.
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.sh that shipped
with version 2.1.3 of OpenDKIM.
Copyright (c) 2007, 2008 Sendmail, Inc. and its suppliers. All rights
Copyright (c) 2009, The OpenDKIM Project. All rights reserved.
RFC4871 - DomainKeys Identified Mail
The OpenDKIM Project opendkim-genkey(8)