/ 
App-sshca-0.0.2
River stage zero No dependents
/ App::sshca

NAME

sshca - A minimal SSH Certificate Authority

VERSION

version 0.0.2

SYNOPSIS

$ sshca init
Successfully created SH CA directory ~/sshca
$ sshca issue certName ~/.ssh/id_ed25519.pub
User certificate with identity 'certName' and serial number 1:
... certificate data ...
$ sshca renew 1
... certificate data ...

DESCRIPTION

This is a simple SSH Certificate Authority. SSH certificates greatly enhance the functionality of SSH public keys. The sshca script hands out certificates for public keys and tracks these certs. It can be used to create both user and host certificates.

Read more about SSH certificates in the following articles:

COMMANDS

init

sshca [global-options] init [options] <ca-directory>

Creates a certificate authority administrative directory ca-directory.

Available options:

  • --serial=<number>

    Used to override the initial serial number (defaults to 1)

issue

sshca [global-options] issue [options] <identity> <pubkey filename>

Issues a new user certificate for the public key read from <pubkey filename>. If the filename is equal to - (hyphen), the public key data is read from standard input.

Available options:

  • --host

    When provided, issues a host certificate instead of a user certificate

  • --option=<option>

    Add the given option to the certificate; this option may be passed multiple times

  • --principal=<principal>

    Adds the given principal to the certificate; this option may be passed multiple times. Principles on "host" certificates must be host names or IP addresses; principles on "user" certificates the values are documented to be user names, but can also be used as the more general concept of tags.

renew

sshca [global-options] renew <identifier>

Issues a new certificate using the input data that was provided to generate the certificate with serial number identifier, except for the validity period.

Available options:

  • --serial|--fingerprint|--identity

    Used to change the interpretation of the identifier argument.

    • --serial indicates the identifier argument is to be interpreted as a certificate serial number.

    • (planned) --fingerprint indicates the identifier argument is to be interpreted as a public key finger print; in case multiple certificates have been issued for this public key the last issued certificate is renewed.

    • (planned) --identity indicates the identifier argument is to be interpreted as a certificate identity; in case multiple certificates have been issued for this identity the last issued certificate is renewed.

  • --validity

    Indicates the validity period of the new certificate.

revoke

Planned.

history

Planned.

GLOBAL OPTIONS

These options can be specified before commands and are accepted with all commands:

  • --debug

  • --config (ignored on init command)

  • --basedir (ignored on init command)

ENVIRONMENT VARIABLES

Environment variables override hard-coded defaults as well as configuration values. Command line options take precedence over environment variables.

SSHCA_CONF

Used to specify the location of the configuration file, disabling the built-in list of locations to be tried.

SSHCA_HOME

Used to override the location of the administrative files.

CONFIGURATION

The configuration file (sshca.conf) is a YAML file with the following keys:

  • basedir

  • ca_keytype

    Default: ed25519

  • hostcert_validity

    Default: +53w

  • usercert_validity

    Default: +13w1d

FUTURE DEVELOPMENT

The current version stores the certificate data in the filesystem. Next iterations should be more flexible and contain configurable storage backends, e.g. using DBI which would allow storing the data in SQLite or PostgreSQL.

SEE ALSO

LICENSE AND COPYRIGHT

Copyright 2025 Erik Huelsmann <ehuels@gmail.com>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.