certbot/docs/using.rst

==========
User Guide
==========

.. contents:: Table of Contents
   :local:

.. _installation:

Installation
============

.. _letsencrypt-auto:

letsencrypt-auto
----------------

``letsencrypt-auto`` is a wrapper which installs some dependencies
from your OS standard package repositories (e.g using `apt-get` or
`yum`), and for other dependencies it sets up a virtualized Python
environment with packages downloaded from PyPI [#venv]_. It also
provides automated updates.

Firstly, please `install Git`_ and run the following commands:

.. code-block:: shell

   git clone https://github.com/letsencrypt/letsencrypt
   cd letsencrypt

.. warning:: Alternatively you could `download the ZIP archive`_ and
   extract the snapshot of our repository, but it's strongly
   recommended to use the above method instead.

.. _`install Git`: https://git-scm.com/book/en/v2/Getting-Started-Installing-Git
.. _`download the ZIP archive`:
   https://github.com/letsencrypt/letsencrypt/archive/master.zip

To install and run the client you just need to type:

.. code-block:: shell

   ./letsencrypt-auto

Throughout the documentation, whenever you see references to
``letsencrypt`` script/binary, you can substitute in
``letsencrypt-auto``. For example, to get the help you would type:

.. code-block:: shell

  ./letsencrypt-auto --help


Running with Docker
-------------------

Docker_ is an amazingly simple and quick way to obtain a
certificate. However, this mode of operation is unable to install
certificates or configure your webserver, because our installer
plugins cannot reach it from inside the Docker container.

You should definitely read the :ref:`where-certs` section, in order to
know how to manage the certs
manually. https://github.com/letsencrypt/letsencrypt/wiki/Ciphersuite-guidance
provides some information about recommended ciphersuites. If none of
these make much sense to you, you should definitely use the
letsencrypt-auto_ method, which enables you to use installer plugins
that cover both of those hard topics.

If you're still not convinced and have decided to use this method,
from the server that the domain you're requesting a cert for resolves
to, `install Docker`_, then issue the following command:

.. code-block:: shell

   sudo docker run -it --rm -p 443:443 -p 80:80 --name letsencrypt \
               -v "/etc/letsencrypt:/etc/letsencrypt" \
               -v "/var/lib/letsencrypt:/var/lib/letsencrypt" \
               quay.io/letsencrypt/letsencrypt:latest auth

and follow the instructions (note that ``auth`` command is explicitly
used - no installer plugins involved). Your new cert will be available
in ``/etc/letsencrypt/live`` on the host.

.. _Docker: https://docker.com
.. _`install Docker`: https://docs.docker.com/userguide/


Distro packages
---------------

Unfortunately, this is an ongoing effort. If you'd like to package
Let's Encrypt client for your distribution of choice please have a
look at the :doc:`packaging`.


From source
-----------

Installation from source is only supported for developers and the
whole process is described in the :doc:`contributing`.

.. warning:: Please do **not** use ``python setup.py install`` or
   ``python pip install .``. Please do **not** attempt the
   installation commands as superuser/root and/or without virtual
   environment, e.g. ``sudo python setup.py install``, ``sudo pip
   install``, ``sudo ./venv/bin/...``. These modes of operation might
   corrupt your operating system and are **not supported** by the
   Let's Encrypt team!


Comparison of different methods
-------------------------------

Unless you have a very specific requirements, we kindly ask you to use
the letsencrypt-auto_ method. It's the fastest, the most thoroughly
tested and the most reliable way of getting our software and the free
SSL certificates!


Plugins
=======

Officially supported plugins:

========== = = ================================================================
Plugin     A I Notes and status
========== = = ================================================================
standalone Y N Very stable. Uses port 80 (force by
               ``--standalone-supported-challenges http-01``) or 443
               (force by ``--standalone-supported-challenges dvsni``).
apache     Y Y Alpha. Automates Apache installation, works fairly well but on
               Debian-based distributions only for now.
webroot    Y N Works with already running webserver, by writing necessary files
               to the disk (``--webroot-path`` should be pointed to your
               ``public_html``). Currently, when multiple domains are specified
               (`-d`), they must all use the same web root path.
manual     Y N Hidden from standard UI, use with ``-a manual``. Requires to
               copy and paste commands into a new terminal session. Allows to
               run client on machine different than target webserver, e.g. your
               laptop.
nginx      Y Y Very experimental. Not included in letsencrypt-auto_.
========== = = ================================================================

Third party plugins are listed at
https://github.com/letsencrypt/letsencrypt/wiki/Plugins. If
that's not enough, you can always :ref:`write your own plugin
<dev-plugin>`.


Renewal
=======

.. note:: Let's Encrypt CA issues short lived certificates (90
   days). Make sure you renew the certificates at least once in 3
   months.

In order to renew certificates simply call the ``letsencrypt`` (or
letsencrypt-auto_) again, and use the same values when prompted. You
can automate it slightly by passing necessary flags on the CLI (see
`--help all`), or even further using the :ref:`config-file`. If you're
sure that UI doesn't prompt for any details you can add the command to
``crontab`` (make it less than every 90 days to avoid problems, say
every month).

Please note that the CA will send notification emails to the address
you provide if you do not renew certificates that are about to expire.

Let's Encrypt is working hard on automating the renewal process. Until
the tool is ready, we are sorry for the inconvenience!


.. _where-certs:

Where are my certificates?
==========================

First of all, we encourage you to use Apache or nginx installers, both
which perform the certificate managemant automatically. If, however,
you prefer to manage everything by hand, this section provides
information on where to find necessary files.

All generated keys and issued certificates can be found in
``/etc/letsencrypt/live/$domain``. Rather than copying, please point
your (web) server configuration directly to those files (or create
symlinks). During the renewal_, ``/etc/letsencrypt/live`` is updated
with the latest necessary files.

.. note:: ``/etc/letsencrypt/archive`` and ``/etc/letsencrypt/keys``
   contain all previous keys and certificates, while
   ``/etc/letsencrypt/live`` symlinks to the latest versions.

The following files are available:

``privkey.pem``
  Private key for the certificate.

  .. warning:: This **must be kept secret at all times**! Never share
     it with anyone, including Let's Encrypt developers. You cannot
     put it into safe, however - your server still needs to access
     this file in order for SSL/TLS to work.

  This is what Apache needs for `SSLCertificateKeyFile
  <https://httpd.apache.org/docs/2.4/mod/mod_ssl.html#sslcertificatekeyfile>`_,
  and nginx for `ssl_certificate_key
  <http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_certificate_key>`_.

``cert.pem``
  Server certificate only.

  This is what Apache needs for `SSLCertificateFile
  <https://httpd.apache.org/docs/2.4/mod/mod_ssl.html#sslcertificatefile>`_.

``chain.pem``
  All certificates that need to be served by the browser **excluding**
  server certificate, i.e. root and intermediate certificates only.

  This is what Apache needs for `SSLCertificateChainFile
  <https://httpd.apache.org/docs/2.4/mod/mod_ssl.html#sslcertificatechainfile>`_.

``fullchain.pem``
  All certificates, **including** server certificate. This is
  concatenation of ``chain.pem`` and ``cert.pem``.

  This is what nginx needs for `ssl_certificate
  <http://nginx.org/en/docs/http/ngx_http_ssl_module.html#ssl_certificate>`_.


For both chain files, all certificates are ordered from root (primary
certificate) towards leaf.

Please note, that **you must use** either ``chain.pem`` or
``fullchain.pem``. In case of webservers, using only ``cert.pem``,
will cause nasty errors served through the browsers!

.. note:: All files are PEM-encoded (as the filename suffix
   suggests). If you need other format, such as DER or PFX, then you
   could convert using ``openssl``, but this means you will not
   benefit from automatic renewal_!


.. _config-file:

Configuration file
==================

It is possible to specify configuration file with
``letsencrypt-auto --config cli.ini`` (or shorter ``-c cli.ini``). An
example configuration file is shown below:

.. include:: ../examples/cli.ini
   :code: ini

By default, the following locations are searched:

- ``/etc/letsencrypt/cli.ini``
- ``$XDG_CONFIG_HOME/letsencrypt/cli.ini`` (or
  ``~/.config/letsencrypt/cli.ini`` if ``$XDG_CONFIG_HOME`` is not
  set).

.. keep it up to date with constants.py


Getting help
============

If you're having problems you can chat with us on `IRC (#letsencrypt @
Freenode) <https://webchat.freenode.net?channels=%23letsencrypt>`_ or
get support on our `forums <https://community.letsencrypt.org>`_.

If you find a bug in the software, please do report it in our `issue
tracker
<https://github.com/letsencrypt/letsencrypt/issues>`_. Remember to
give us us as much information as possible:

- copy and paste exact command line used and the output (though mind
  that the latter might include some personally identifiable
  information, including your email and domains)
- copy and paste logs from ``/var/log/letsencrypt`` (though mind they
  also might contain personally identifiable information)
- copy and paste ``letsencrypt --version`` output
- your operating system, including specific version
- specify which installation_ method you've chosen


.. rubric:: Footnotes

.. [#venv] By using this virtualized Python environment (`virtualenv
           <https://virtualenv.pypa.io>`_) we don't pollute the main
           OS space with packages from PyPI!