The --txt option causes the output to be in opportunistic-encryption DNS TXT record format, with the specified gateway value. If information about how the key was generated is available, that is provided as a DNS-file comment. For example, --txt 10.11.12.13 might give (with the key data trimmed for clarity):

  ; RSA 2048 bits   xy.example.com   Sat Apr 15 13:53:22 2000
      IN TXT  "X-IPsec-Server(10)=10.11.12.13 AQOF8tZ2...+buFuFn/"

No name is supplied in the TXT record because there are too many possibilities, depending on how it will be used. If the text string is longer than 255 bytes, it is split up into multiple strings (matching the restrictions of the DNS TXT binary format). If any split is needed, the first split will be at the start of the key: this increases the chances that later hand editing will work.

The --version option causes the version of the binary to be emitted, and nothing else.

The --verbose may be present one or more times. Each occurance increases the verbosity level.

The --left and --right options cause the output to be in ipsec.conf(5) format, as a leftrsasigkey or rightrsasigkey parameter respectively. Again, generation information is included if available. For example, --left might give (with the key data trimmed down for clarity):

  # RSA 2048 bits   xy.example.com   Sat Apr 15 13:53:22 2000
  leftrsasigkey=0sAQOF8tZ2...+buFuFn/

The --dhclient option cause the output to be suitable for inclusion in dhclient.conf(5) as part of configuring WAVEsec. See <m[blue]http://www.wavesec.orgm[]>.

If --ipseckey is specified, the output format is the text form of a DNS IPSECKEY record (see RFC4025); the host name is the one included in the key information (or, if that is not available, the output of hostname --fqdn), with a . appended. The gateway information, if provided, is is included, otherwise, the gateway is assumed to be self, and to be of type FQDN. Generation information is included if available. For example (with the key data trimmed down for clarity):

  ; RSA 2048 bits   xy.example.com   Sat Apr 15 13:53:22 2000
  xy.example.com.   IN   IPSECKEYKEY   floyd albert

  ; RSA 2048 bits   xy.example.com   Sat Apr 15 13:53:22 2000
  xy.example.com.   IN   KEY   0x4200 4 1 AQOF8tZ2...+buFuFn/

Normally, the default key for this host (the one with no host identities specified for it) is the one extracted. The --id option overrides this, causing extraction of the key labeled with the specified identity, if any. The specified identity must exactly match the identity in the file; in particular, the comparison is case-sensitive.

There may also be multiple keys with the same identity. All keys are numbered based upon their linear sequence in the file (including all include directives)

The --file option overrides the default for where the key information should be found, and takes it from the specified secretfile.