========== User Guide ========== .. contents:: Table of Contents :local: Getting Certbot =============== To get specific instructions for installing Certbot on your OS, we recommend visiting certbot.eff.org_. If you're offline, you can find some general instructions `in the README / Introduction `__ __ installation_ .. _certbot.eff.org: https://certbot.eff.org .. _certbot-auto: The name of the certbot command ------------------------------- Many platforms now have native packages that give you a ``certbot`` or (for older packages) ``letsencrypt`` command you can run. On others, the ``certbot-auto`` / ``letsencrypt-auto`` installer and wrapper script is a stand-in. Throughout the documentation, whenever you see references to ``certbot`` script/binary, you should substitute in the name of the command that certbot.eff.org_ told you to use on your system (``certbot``, ``letsencrypt``, or ``certbot-auto``). Plugins ======= The Certbot client supports a number of different "plugins" that can be used to obtain and/or install certificates. Plugins that can obtain a cert are called "authenticators" and can be used with the "certonly" command. Plugins that can install a cert are called "installers". Plugins that do both can be used with the "certbot run" command, which is the default. =========== ==== ==== =============================================================== Plugin Auth Inst Notes =========== ==== ==== =============================================================== apache_ Y Y Automates obtaining and installing a cert with Apache 2.4 on Debian-based distributions with ``libaugeas0`` 1.0+. webroot_ Y N Obtains a cert by writing to the webroot directory of an already running webserver. standalone_ Y N Uses a "standalone" webserver to obtain a cert. Requires port 80 or 443 to be available. This is useful on systems with no webserver, or when direct integration with the local webserver is not supported or not desired. manual_ Y N Helps you obtain a cert by giving you instructions to perform domain validation yourself. nginx_ Y Y Very experimental and not included in certbot-auto_. =========== ==== ==== =============================================================== There are many third-party-plugins_ available. Apache ------ If you're running Apache 2.4 on a Debian-based OS with version 1.0+ of the ``libaugeas0`` package available, you can use the Apache plugin. This automates both obtaining *and* installing certs on an Apache webserver. To specify this plugin on the command line, simply include ``--apache``. Webroot ------- If you're running a local webserver for which you have the ability to modify the content being served, and you'd prefer not to stop the webserver during the certificate issuance process, you can use the webroot plugin to obtain a cert by including ``certonly`` and ``--webroot`` on the command line. In addition, you'll need to specify ``--webroot-path`` or ``-w`` with the top-level directory ("web root") containing the files served by your webserver. For example, ``--webroot-path /var/www/html`` or ``--webroot-path /usr/share/nginx/html`` are two common webroot paths. If you're getting a certificate for many domains at once, the plugin needs to know where each domain's files are served from, which could potentially be a separate directory for each domain. When requesting a certificate for multiple domains, each domain will use the most recently specified ``--webroot-path``. So, for instance, :: certbot certonly --webroot -w /var/www/example/ -d www.example.com -d example.com -w /var/www/other -d other.example.net -d another.other.example.net would obtain a single certificate for all of those names, using the ``/var/www/example`` webroot directory for the first two, and ``/var/www/other`` for the second two. The webroot plugin works by creating a temporary file for each of your requested domains in ``${webroot-path}/.well-known/acme-challenge``. Then the Let's Encrypt validation server makes HTTP requests to validate that the DNS for each requested domain resolves to the server running certbot. An example request made to your web server would look like: :: 66.133.109.36 - - [05/Jan/2016:20:11:24 -0500] "GET /.well-known/acme-challenge/HGr8U1IeTW4kY_Z6UIyaakzOkyQgPr_7ArlLgtZE8SX HTTP/1.1" 200 87 "-" "Mozilla/5.0 (compatible; Let's Encrypt validation server; +https://www.letsencrypt.org)" Note that to use the webroot plugin, your server must be configured to serve files from hidden directories. If ``/.well-known`` is treated specially by your webserver configuration, you might need to modify the configuration to ensure that files inside ``/.well-known/acme-challenge`` are served by the webserver. Standalone ---------- To obtain a cert using a "standalone" webserver, you can use the standalone plugin by including ``certonly`` and ``--standalone`` on the command line. This plugin needs to bind to port 80 or 443 in order to perform domain validation, so you may need to stop your existing webserver. To control which port the plugin uses, include one of the options shown below on the command line. * ``--standalone-supported-challenges http-01`` to use port 80 * ``--standalone-supported-challenges tls-sni-01`` to use port 443 The standalone plugin does not rely on any other server software running on the machine where you obtain the certificate. It must still be possible for that machine to accept inbound connections from the Internet on the specified port using each requested domain name. Manual ------ If you'd like to obtain a cert running ``certbot`` on a machine other than your target webserver or perform the steps for domain validation yourself, you can use the manual plugin. While hidden from the UI, you can use the plugin to obtain a cert by specifying ``certonly`` and ``--manual`` on the command line. This requires you to copy and paste commands into another terminal session, which may be on a different computer. Nginx ----- In the future, if you're running Nginx you will hopefully be able to use this plugin to automatically obtain and install your certificate. The Nginx plugin is still experimental, however, and is not installed with certbot-auto_. If installed, you can select this plugin on the command line by including ``--nginx``. .. _third-party-plugins: Third-party plugins ------------------- There are also a number of third-party plugins for the client, provided by other developers. Many are beta/experimental, but some are already in widespread use: =========== ==== ==== =============================================================== Plugin Auth Inst Notes =========== ==== ==== =============================================================== plesk_ Y Y Integration with the Plesk web hosting tool haproxy_ Y Y Integration with the HAProxy load balancer s3front_ Y Y Integration with Amazon CloudFront distribution of S3 buckets gandi_ Y Y Integration with Gandi's hosting products and API varnish_ Y N Obtain certs via a Varnish server external_ Y N A plugin for convenient scripting (See also ticket 2782_) icecast_ N Y Deploy certs to Icecast 2 streaming media servers pritunl_ N Y Install certs in pritunl distributed OpenVPN servers proxmox_ N Y Install certs in Proxmox Virtualization servers postfix_ N Y STARTTLS Everywhere is becoming a Certbot Postfix/Exim plugin =========== ==== ==== =============================================================== .. _plesk: https://github.com/plesk/letsencrypt-plesk .. _haproxy: https://code.greenhost.net/open/letsencrypt-haproxy .. _s3front: https://github.com/dlapiduz/letsencrypt-s3front .. _gandi: https://github.com/Gandi/letsencrypt-gandi .. _icecast: https://github.com/e00E/lets-encrypt-icecast .. _varnish: http://git.sesse.net/?p=letsencrypt-varnish-plugin .. _2782: https://github.com/certbot/certbot/issues/2782 .. _pritunl: https://github.com/kharkevich/letsencrypt-pritunl .. _proxmox: https://github.com/kharkevich/letsencrypt-proxmox .. _external: https://github.com/marcan/letsencrypt-external .. _postfix: https://github.com/EFForg/starttls-everywhere If you're interested, you can also :ref:`write your own 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. The ``certbot`` client now supports a ``renew`` action to check all installed certificates for impending expiry and attempt to renew them. The simplest form is simply ``certbot renew`` This will attempt to renew any previously-obtained certificates that expire in less than 30 days. The same plugin and options that were used at the time the certificate was originally issued will be used for the renewal attempt, unless you specify other plugins or options. You can also specify hooks to be run before or after a certificate is renewed. For example, if you want to use the standalone_ plugin to renew your certificates, you may want to use a command like ``certbot renew --standalone --pre-hook "service nginx stop" --post-hook "service nginx start"`` This will stop Nginx so standalone can bind to the necessary ports and then restart Nginx after the plugin is finished. The hooks will only be run if a certificate is due for renewal, so you can run this command frequently without unnecessarily stopping your webserver. More information about renewal hooks can be found by running ``certbot --help renew``. If you're sure that this command executes successfully without human intervention, you can add the command to ``crontab`` (since certificates are only renewed when they're determined to be near expiry, the command can run on a regular basis, like every week or every day). In that case, you are likely to want to use the ``-q`` or ``--quiet`` quiet flag to silence all output except errors. The ``--force-renew`` flag may be helpful for automating renewal; it causes the expiration time of the certificate(s) to be ignored when considering renewal, and attempts to renew each and every installed certificate regardless of its age. (This form is not appropriate to run daily because each certificate will be renewed every day, which will quickly run into the certificate authority rate limit.) Note that options provided to ``certbot renew`` will apply to *every* certificate for which renewal is attempted; for example, ``certbot renew --rsa-key-size 4096`` would try to replace every near-expiry certificate with an equivalent certificate using a 4096-bit RSA public key. If a certificate is successfully renewed using specified options, those options will be saved and used for future renewals of that certificate. An alternative form that provides for more fine-grained control over the renewal process (while renewing specified certificates one at a time), is ``certbot certonly`` with the complete set of subject domains of a specific certificate specified via `-d` flags. You may also want to include the ``-n`` or ``--noninteractive`` flag to prevent blocking on user input (which is useful when running the command from cron). ``certbot certonly -n -d example.com -d www.example.com`` (All of the domains covered by the certificate must be specified in this case in order to renew and replace the old certificate rather than obtaining a new one; don't forget any `www.` domains! Specifying a subset of the domains creates a new, separate certificate containing only those domains, rather than replacing the original certificate.) The ``certonly`` form attempts to renew one individual certificate. 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. Certbot is working hard on improving the renewal process, and we apologize for any inconveniences you encounter in integrating these commands into your individual environment. .. _command-line: Command line options ==================== Certbot supports a lot of command line options. Here's the full list, from ``certbot --help all``: .. literalinclude:: cli-help.txt .. _where-certs: Where are my certificates? ========================== 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 Certbot developers. You cannot put it into a safe, however - your server still needs to access this file in order for SSL/TLS to work. This is what Apache needs for `SSLCertificateKeyFile `_, and nginx for `ssl_certificate_key `_. ``cert.pem`` Server certificate only. This is what Apache < 2.4.8 needs for `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 < 2.4.8 needs for `SSLCertificateChainFile `_, and what nginx >= 1.3.7 needs for `ssl_trusted_certificate `_. ``fullchain.pem`` All certificates, **including** server certificate. This is concatenation of ``cert.pem`` and ``chain.pem``. This is what Apache >= 2.4.8 needs for `SSLCertificateFile `_, and what nginx needs for `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``. You can automate that with ``--renew-hook`` if you're using automatic renewal_. .. _config-file: Configuration file ================== It is possible to specify configuration file with ``certbot-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 (#certbot @ OFTC) `_ or at `IRC (#letsencrypt @ freenode) `_ or get support on the Let's Encrypt `forums `_. If you find a bug in the software, please do report it in our `issue tracker `_. Remember to give 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 ``certbot --version`` output - your operating system, including specific version - specify which installation method you've chosen Other methods of installation ============================= 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/certbot/certbot/wiki/Ciphersuite-guidance provides some information about recommended ciphersuites. If none of these make much sense to you, you should definitely use the certbot-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 certbot \ -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/ Operating System Packages -------------------------- **FreeBSD** * Port: ``cd /usr/ports/security/py-letsencrypt && make install clean`` * Package: ``pkg install py27-letsencrypt`` **OpenBSD** * Port: ``cd /usr/ports/security/letsencrypt/client && make install clean`` * Package: ``pkg_add letsencrypt`` **Arch Linux** .. code-block:: shell sudo pacman -S certbot **Debian** If you run Debian Stretch or Debian Sid, you can install certbot packages. .. code-block:: shell sudo apt-get update sudo apt-get install certbot python-certbot-apache If you don't want to use the Apache plugin, you can omit the ``python-certbot-apache`` package. Packages exist for Debian Jessie via backports. First you'll have to follow the instructions at http://backports.debian.org/Instructions/ to enable the Jessie backports repo, if you have not already done so. Then run: .. code-block:: shell sudo apt-get install letsencrypt python-letsencrypt-apache -t jessie-backports **Fedora** .. code-block:: shell sudo dnf install letsencrypt **Gentoo** The official Certbot client is available in Gentoo Portage. If you want to use the Apache plugin, it has to be installed separately: .. code-block:: shell emerge -av app-crypt/letsencrypt emerge -av app-crypt/letsencrypt-apache Currently, only the Apache plugin is included in Portage. However, if you Warning! You can use Layman to add the mrueg overlay which does include a package for the Certbot Nginx plugin, however, this plugin is known to be buggy and should only be used with caution after creating a backup up your Nginx configuration. We strongly recommend you use the app-crypt/letsencrypt package instead until the Nginx plugin is ready. .. code-block:: shell emerge -av app-portage/layman layman -S layman -a mrueg emerge -av app-crypt/letsencrypt-nginx When using the Apache plugin, you will run into a "cannot find a cert or key directive" error if you're sporting the default Gentoo ``httpd.conf``. You can fix this by commenting out two lines in ``/etc/apache2/httpd.conf`` as follows: Change .. code-block:: shell LoadModule ssl_module modules/mod_ssl.so to .. code-block:: shell # LoadModule ssl_module modules/mod_ssl.so # For the time being, this is the only way for the Apache plugin to recognise the appropriate directives when installing the certificate. Note: this change is not required for the other plugins. **Other Operating Systems** OS packaging is an ongoing effort. If you'd like to package Certbot 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 Certbot team! Comparison of different methods ------------------------------- Unless you have a very specific requirements, we kindly suggest that you use the certbot-auto_ method. It's the fastest, the most thoroughly tested and the most reliable way of getting our software and the free TLS/SSL certificates! Beyond the methods discussed here, other methods may be possible, such as installing Certbot directly with pip from PyPI or downloading a ZIP archive from GitHub may be technically possible but are not presently recommended or supported.