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NAME

App::sslmaker - Be your own SSL certificate authority

VERSION

0.04

DESCRIPTION

App::sslmaker is a module that provide methods for acting as your own CA (certificate authority). It can creating SSL keys, certificates and signing requests. The methods should have good defaults and "just work", so you don't have to worry about the details. "Just work" depends on safe defaults, which will change when new and more secure standards come along.

The openssl commands are based on the instructions from https://jamielinux.com/blog/category/CA/.

This module is used by the sslmaker command line application, but can also act as a standalone toolkit.

From https://jamielinux.com/articles/2013/08/act-as-your-own-certificate-authority/:

  Most websites, such as shopping, banking or email websites, need to let their
  customers know that the connection is secure. Thus, they need to pay a
  well-known and internationally trusted CA (eg, VeriSign) to issue an SSL
  certificate. However, this isn't always necessary. For example, if you're
  setting up a virtual private network (VPN) or an intranet website, it might
  make more sense to issue your own certificates.

  Being a CA means dealing with cryptographic pairs of private keys and public
  certificates. Ideally the cryptographic pairs should be generated in a secure
  environment, which means a personal laptop or computer that is disconnected
  from the Internet. It is not recommended to generate any certificates
  directly on your server.

DISCLAIMER

This module is based on tips and tricks from online resources, and has been reviewed by security experts. Even so, the "AUTHOR" of this application or any parts involved cannot be held responsible for the security of your server, application or other parts that use the files generated by this library.

COMMAND LINE USAGE

  $ sslmaker [options] {action} {arg1,...}

  # Generate root CA key and certificate
  $ sslmaker --home /path/to/pki/CA root

  # Generate intermediate CA key and certificate
  $ sslmaker --root-home /path/to/pki/CA --home /path/to/pki/intermediate intermediate

  # Generate client or server key and certificate signing request
  $ sslmaker --home /path/to/pki/intermediate generate <commonName>
  $ sslmaker --home /path/to/pki/intermediate generate www.example.com
  $ sslmaker --home /path/to/pki/intermediate nginx www.example.com

  # Sign a certificate signing request
  $ sslmaker --home /path/to/pki/intermediate sign www.example.com.csr.pem [outfile]

SYNOPSIS

  my $sslmaker = App::sslmaker->new(subject => '/C=US/ST=Gotham/L=Gotham/O=Wayne Enterprises/OU=Batcave/CN=batman');
  my $key = $sslmaker->make_key;
  my $csr = $sslmaker->make_csr({ key => $key->path });

  # the content of the csr
  print $csr->slurp;

  # move to a non-temp location
  $csr->move("/path/to/certs/output.csr.pem");
  $key->move("/path/to/certs/output.csr.pem");

All methods will throw an exception on error, unless otherwise noted.

ATTRIBUTES

subject

  $self = $self->subject('/C=NO/ST=Oslo/L=Oslo/O=Example/OU=Prime/emailAddress=admin@example.com');
  $str = $self->subject;

Holds the default subject field for the certificate.

METHODS

make_cert

  $asset = $self->make_cert({
              key => "/path/to/private/input.key.pem",
              passphrase => "/path/to/passphrase.txt",
              days => $number_of_days, # default: 365
              subject => '/C=NO/ST=Oslo', # optional
            });

This method will generate a SSL certificate using a key generated by "make_key". passphrase should match the argument given to "make_key". An optional subject can be provided. The subject string will be merged with the "subject" attribute. days can be used to set how many days the certificate should be valid.

The returned $asset is a Path::Tiny object which holds the generated certificate file. It is possible to specify the location of this object by passing on cert to this method.

make_crl

  $asset = $self->make_crl({
              key => "/path/to/private/input.key.pem",
              cert => "/path/to/cefrt/input.cert.pem",
              passphrase => "/path/to/passphrase.txt", # optional
            });

This method will generate a certificate revocation list (CRL) using a key generated by "make_key". passphrase should match the argument given to "make_key".

The returned $asset is a Path::Tiny object which holds the generated certificate file. It is possible to specify the location of this object by passing on crl to this method.

You can inspect the generated asset using the command openssl crl -in $crl_asset -text.

See also "revoke_cert".

make_csr

  $asset = $self->make_csr({
              key => "/path/to/private/input.key.pem",
              passphrase => "/path/to/passphrase.txt",
              subject => '/C=NO/ST=Oslo',
              days => $number_of_days, # default: 365
            });

This method will generate a SSL certificate signing request using a key generated by "make_key". passphrase is only required if the key was generated with a passphrase. An optional subject can be provided. The subject string will be merged with the "subject" attribute.

The returned $asset is a Path::Tiny object which holds the generated signing request file. It is possible to specify the location of this object by passing on csr to this method.

make_directories

  $self->make_directories({
    home => "/path/to/pki",
    templates => 1, # default: false
  });

Used to generate a suitable file structure, which reflect what openssl.cnf expects. Set $emplates to a true value to generate files.

  $home/          # need to be writable by current user
  $home/certs/
  $home/crl/
  $home/newcerts/
  $home/private/  # will have mode 700
  # optional templates
  $home/index.txt
  $home/serial

make_key

  $asset = $self->make_key({
              passphrase => "/path/to/passphrase.txt", # optional
              bits => 8192, # default: 4096
            });

This method will generate a SSL key.

The key will be protected with passphrase if given as input. In addition if passphrase does not exist, it will be created with a random passphrase.

The returned $asset is a Path::Tiny object which holds the generated key. It is possible to specify the location of this object by passing on key to this method.

From https://jamielinux.com/articles/2013/08/act-as-your-own-certificate-authority/:

  The very first cryptographic pair we generate includes what is known as a
  root certificate. The root key (ca.key.pem) generated in this step should be
  kept extremely secure, otherwise an attacker can issue valid certificates for
  themselves. We'll therefore protect it with AES 256-bit encryption and a
  strong password just in case it falls into the wrong hands.

new

  $self = App::sslmaker->new(%args);
  $self = App::sslmaker->new(\%args);

Object constructor.

render_to_file

  $asset = $self->render_to_file($template, \%stash);
  $asset = $self->render_to_file($template, $out_file, \%args);

This method can render a $template to either a temp file or $out_file. The $template will have access to %stash and $self.

See "TEMPLATES" for list of valid templates.

revoke_cert

  $self->with_config(
    revoke_cert => {
      key => "/path/to/private/ca.key.pem",
      cert => "/path/to/certs/ca.cert.pem",
      crl => "/path/to/crl.pem",
      revoke => "/path/to/newcerts/1000.pem",
    },
  );

This method can revoke a certificate. It need to be run either with OPENSSL_CONF or inside "with_config".

sign_csr

  $asset = $self->sign_csr({
              csr => "/path/to/certs/input.csr.pem",
              ca_key => "/path/to/private/ca.key.pem",
              ca_cert => "/path/to/certs/ca.cert.pem",
              passphrase => "/path/to/passphrase.txt",
              extensions => "v3_ca", # default: usr_cert
            });

This method will sign a csr file generated by "make_csr". ca_key and passphrase is the same values as you would provide "make_key" and ca_cert is the output from "make_cert".

The returned $asset is a Path::Tiny object which holds the generated certificate. It is possible to specify the location of this object by passing on cert to this method.

with_config

  $any = $self->with_config($method => \%args);

Used to call a method with a temp "openssl.cnf" file. The %stash in the template will be constructed from the %args, which is also passed on to the next $method. Example:

  $asset = $self->with_config(make_key => {
              home => "/path/to/pki",
              passphrase => "/path/to/pki/private/passphrase.txt",
              bits => 8192,
           });

The config file will be removed when $self go out of scope.

An alternative to this method is to set the OPENSSL_CONF environment variable before calling $method:

  local $ENV{OPENSSL_CONF} = "/path/to/openssl.cnf";
  $asset = $self->make_key({...});

TEMPLATES

"render_to_file" can render these templates, which is bundled with this module:

  • crlnumber

    Creates a file which stores the SSL CRL number. If n is present in %stash, it will be used as the start number, which defaults to 1000.

  • index.txt

    This is currently just an empty file.

  • nginx.config

    Used to render an example nginx config. %stash should contain cert, client_certificate, crl, key, server_name and verify_client.

  • openssl.cnf

    Creates a config file for openssl. TODO: Descrive stash values.

  • serial

    Creates a file which stores the SSL serial number. If n is present in %stash, it will be used as the start number, which defaults to 1000.

COPYRIGHT AND LICENCE

Code

Copyright (C) 2014, Jan Henning Thorsen

The code is free software, you can redistribute it and/or modify it under the terms of the Artistic License version 2.0.

Documentation

Documentation is licensed under the terms of Creative Commons Attribution-ShareAlike 3.0 Unported license.

The documentation is put together by Jan Henning Thorsen, with citations from Jamie Nguyen's website https://jamielinux.com/.

AUTHOR

Jan Henning Thorsen - jhthorsen@cpan.org