SYNOPSIS
dkim-genkey [options]DESCRIPTION
dkim-genkey generates (1) a private key for signing messages using dkim-filter(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 verifiers.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".
OPTIONS
- -b bits
- 
Specifies the size of the key, in
bits,
to be generated.  The default is 1024 which is the value recommended by
the DKIM specification.
- -d domain
- 
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".
- -D directory
- 
Instructs the tool to change to the named
directory
prior to creating files.  By default the current directory is used.
- -g granularity
- 
Defines the key
granularity,
i.e. the user(s) who may use the key.  The default is "*" meaning any
user can use the key.
- -h algorithms
- 
Specifies a list of hash
algorithms
which can be used with this key.  By default all hash algorithms are allowed.
- -n note
- 
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.
- -s selector
- 
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.

