This module provides the functionality necessary to use Let's Encrypt API and generate free SSL certificates for your domains. It can also be used to generate private RSA keys or Certificate Signing Requests without resorting to openssl command line. Crypt::LE is shipped with a self-sufficient client for obtaining SSL certificates - le.pl.

The client + library package is codenamed ZeroSSL with the project homepage at https://ZeroSSL.com

Note: If you do not need the automation and the flexibility this package offers, and just want to get a free SSL certificate without installing anything, you can do it too - with the In-Browser client, also at https://ZeroSSL.com

The code has been successfully tested on more than 300 combinations of OS and Perl versions. It should install and run fine on Linux, FreeBSD, NetBSD, etc. It also works on Mac OS X and Windows (tested with ActiveState and Strawberry Perl). You can find appropriate PPMs at ActiveState. Please note that pure Windows environments are supported starting from version 0.17 of the module. If you are using Cygwin, then earlier versions would work too.

With Linux systems there are just 3 essential things which should be in place for the package to be successfully installed: "gcc", "make" and the SSL development package. The SSL development package name differs depending on Linux distribution and it can be either "libssl-dev" or "openssl-devel". See https://zerossl.com/installation.html for more details.

With Windows you don't have to install anything but Perl. In fact, in case of Strawberry Perl you don't have to install Perl either - it is enough to download the portable version of it, unzip and then use "cpanm" to install Crypt::LE. This way you can even carry it with you on a flash drive and run it anywhere.

With CPANminus

cpanm Crypt::LE

With CPAN

cpan -i Crypt::LE

Manual installation:

perl Makefile.PL
make
make test
make install

With le.pl you should be able to quickly get your SSL certificates issued. Run it without parameters to see how it is used. The client supports 'http' and 'dns' challenges out of the box.

Important: By default all your actions are run against the test server, which behaves exactly as the live one, but produces certificates not trusted by the browsers. Once you have tested the process and want to get an actual trusted certificate, always append --live parameter to the command line.

Usage example:

le.pl --key account.key --csr domain.csr --csr-key domain.key --crt domain.crt --domains  "www.domain.ext,domain.ext" --generate-missing

That will generate an account key and a CSR if they are missing. If any of those files exists, they will just be loaded, so it is safe to re-run the client.

To use HTTP verification and have challenge files created/removed automatically, you can use --path and --unlink parameters:

le.pl ... --path /some/path/to/.well-known/acme-challenge --unlink

To use DNS verification of domain ownership, you can use --handle-as and handle-with parameters:

 le.pl ... --handle-as dns --handle-with Crypt::LE::Challenge::Simple

For more examples, logging configuration and all available parameters overview use --help:

le.pl --help

Note: It is advised to also use --email parameter for the very first run of the client, to register your account key with the email. While it is optional, that will allow you to receive certificaties expiration notifications and it might be used later to recover access to your account if you lose the key.

To RENEW your existing certificate use the same command line as you used for issuing the certificate, with one additional parameter:

   --renew XX, where XX is the number of days left until certificate expiration.

If client detects that it is XX or fewer days left until certificate expiration, then (and only then) the renewal process will be run, so the script can be safely put into crontab to run on a daily basis if needed.

The amount of days left is checked by either of two methods:

• If the certificate (which name is used with --crt parameter) is available locally, then it will be loaded and checked.
• If the certificate is not available locally (for example if you moved it to another server), then an attempt to connect to the domains listed in --domains or CSR will be made until the first successful response is received. The peer certificate will be then checked for expiration.

Both the library and the client can be easily extended with custom plugins to handle Let's Encrypt challenges (both pre- and post-verification). See Crypt::LE::Challenge::Simple module as an example of such plugin.

The client application can also be easily extended with modules handling process completion. See Crypt::LE::Complete::Simple module as an example of such plugin.

Client options related to plugins are:

• --handle-with
• --handle-params
• --handle-as
• --complete-with
• --complete-params

Please note that parameters for --handle-params and --complete-params are expected to be valid JSON documents or to point to files containing valid JSON documents.

Client uses Log::Log4perl module for logging. You can easily configure it to log into file, database, syslog, etc. Logger object is available to plugins which are called from the client and to the library itself. Below is an example of a logging configuration file to log both to screen and into le.log file:

 log4perl.rootLogger=DEBUG, File, Screen
 log4perl.appender.File = Log::Log4perl::Appender::File
 log4perl.appender.File.filename = le.log
 log4perl.appender.File.mode = append
 log4perl.appender.File.layout = PatternLayout
 log4perl.appender.File.layout.ConversionPattern = %d [%p] %m%n
 log4perl.appender.Screen = Log::Log4perl::Appender::Screen
 log4perl.appender.Screen.layout = PatternLayout
 log4perl.appender.Screen.layout.ConversionPattern = %d [%p] %m%n

Save the configuration into some file and then run le.pl with --log-config parameter specifying that configuration file name, for those settings to take effect.

After installing, you can find documentation for this module with the perldoc command.

perldoc Crypt::LE

You can also look for information at:

• RT, CPAN's request tracker (report bugs here)
• AnnoCPAN, Annotated CPAN documentation

For feedback or custom development requests see:

• Company homepage - https://do-know.com
• Project homepage - https://ZeroSSL.com

Crypt::LE has been initially created over weekend, when I noticed that some of my previously bought certificates are about to expire soon enough. The initial goal was to make this work, make it easy to use and possibly remove the need to use openssl command line. It may contain some (hopefully minor) bugs, so feel free to submit a bug report.

If you'd like to contribute a custom plugin, for example to support automatic DNS records creation and removal via API of certain DNS providers (or your registrar), feel free to create a module under Crypt::LE::Challenge:: namespace and either upload it to CPAN or submit a pull request.

In the former case please specify a dependency from Crypt::LE of at least version 0.11 in your Makefile.

In the latter case please be aware that your module might be uploaded to CPAN later (unless you object) and might be uploaded separately rather than as a part of Crypt::LE (this might happen if you are using dependencies not necessarily required for the rest of Crypt::LE package).

You can also contribute the completion-handling modules under Crypt::LE::Complete:: namespace, for example to scp the domain key and certificate to another host or to send an email about successful certificate renewal.

Copyright (C) 2016 Alexander Yezhov

This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

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