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User Guide

Table of Contents

Certbot Commands

Certbot uses a number of different commands (also referred to as "subcommands") to request specific actions such as obtaining, renewing, or revoking certificates. The most important and commonly-used commands will be discussed throughout this document; an exhaustive list also appears near the end of the document.

The certbot script on your web server might be named letsencrypt if your system uses an older package. Throughout the docs, whenever you see certbot, swap in the correct name as needed.

Getting certificates (and choosing plugins)

Certbot helps you achieve two tasks:

  1. Obtaining a certificate: automatically performing the required authentication steps to prove that you control the domain(s), saving the certificate to /etc/letsencrypt/live/ and renewing it on a regular schedule.
  2. Optionally, installing that certificate to supported web servers (like Apache or nginx) and other kinds of servers. This is done by automatically modifying the configuration of your server in order to use the certificate.

To obtain a certificate and also install it, use the certbot run command (or certbot, which is the same).

To just obtain the certificate without installing it anywhere, the certbot certonly ("certificate only") command can be used.

Some example ways to use Certbot:

# Obtain and install a certificate:
certbot

# Obtain a certificate but don't install it:
certbot certonly

# You may specify multiple domains with -d and obtain and
# install different certificates by running Certbot multiple times:
certbot certonly -d example.com -d www.example.com
certbot certonly -d app.example.com -d api.example.com

To perform these tasks, Certbot will ask you to choose from a selection of authenticator and installer plugins. The appropriate choice of plugins will depend on what kind of server software you are running and plan to use your certificates with.

Authenticators are plugins which automatically perform the required steps to prove that you control the domain names you're trying to request a certificate for. An authenticator is always required to obtain a certificate.

Installers are plugins which can automatically modify your web server's configuration to serve your website over HTTPS, using the certificates obtained by Certbot. An installer is only required if you want Certbot to install the certificate to your web server.

Some plugins are both authenticators and installers and it is possible to specify a distinct combination of authenticator and plugin.

Plugin Auth Inst Notes Challenge types (and port)
apache Y Y
Automates obtaining and installing a certificate with Apache.
 http-01 (80)
nginx Y Y
Automates obtaining and installing a certificate with Nginx.
 http-01 (80)
webroot Y N
Obtains a certificate by writing to the webroot directory of
an already running webserver.
 http-01 (80)
standalone Y N
Uses a "standalone" webserver to obtain a certificate.
Requires port 80 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.
 http-01 (80)
|dns_plugs| Y N
This category of plugins automates obtaining a certificate by
modifying DNS records to prove you have control over a
domain. Doing domain validation in this way is
the only way to obtain wildcard certificates from Let's
Encrypt.
 dns-01 (53)
manual Y N
Obtain a certificate by manually following instructions to
perform domain validation yourself. Certificates created this
way do not support autorenewal.
Autorenewal may be enabled by providing an authentication
hook script to automate the domain validation steps.
 http-01 (80) or dns-01 (53)

Under the hood, plugins use one of several ACME protocol challenges to prove you control a domain. The options are http-01 (which uses port 80) and dns-01 (requiring configuration of a DNS server on port 53, though that's often not the same machine as your webserver). A few plugins support more than one challenge type, in which case you can choose one with --preferred-challenges.

There are also many third-party-plugins available. Below we describe in more detail the circumstances in which each plugin can be used, and how to use it.

Apache

The Apache plugin currently supports modern OSes based on Debian, Fedora, SUSE, Gentoo, CentOS and Darwin. This automates both obtaining and installing certificates 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 certificate 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.

Under Windows, Certbot will generate a web.config file, if one does not already exist, in /.well-known/acme-challenge in order to let IIS serve the challenge files even if they do not have an extension.

Nginx

The Nginx plugin should work for most configurations. We recommend backing up Nginx configurations before using it (though you can also revert changes to configurations with certbot --nginx rollback). You can use it by providing the --nginx flag on the commandline.

certbot --nginx

Standalone

Use standalone mode to obtain a certificate if you don't want to use (or don't currently have) existing server software. The standalone plugin does not rely on any other server software running on the machine where you obtain the certificate.

To obtain a certificate 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 in order to perform domain validation, so you may need to stop your existing webserver.

It must still be possible for your machine to accept inbound connections from the Internet on the specified port using each requested domain name.

By default, Certbot first attempts to bind to the port for all interfaces using IPv6 and then bind to that port using IPv4; Certbot continues so long as at least one bind succeeds. On most Linux systems, IPv4 traffic will be routed to the bound IPv6 port and the failure during the second bind is expected.

Use --<challenge-type>-address to explicitly tell Certbot which interface (and protocol) to bind.

DNS Plugins

If you'd like to obtain a wildcard certificate from Let's Encrypt or run certbot on a machine other than your target webserver, you can use one of Certbot's DNS plugins.

These plugins are not included in a default Certbot installation and must be installed separately. They are available in many OS package managers, as Docker images, and as snaps. Visit https://certbot.eff.org to learn the best way to use the DNS plugins on your system.

Once installed, you can find documentation on how to use each plugin at:

Manual

If you'd like to obtain a certificate 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 certificate 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.

The manual plugin can use either the http or the dns challenge. You can use the --preferred-challenges option to choose the challenge of your preference.

The http challenge will ask you to place a file with a specific name and specific content in the /.well-known/acme-challenge/ directory directly in the top-level directory (“web root”) containing the files served by your webserver. In essence it's the same as the webroot plugin, but not automated.

When using the dns challenge, certbot will ask you to place a TXT DNS record with specific contents under the domain name consisting of the hostname for which you want a certificate issued, prepended by _acme-challenge.

For example, for the domain example.com, a zone file entry would look like:

_acme-challenge.example.com. 300 IN TXT "gfj9Xq...Rg85nM"

Renewal with the manual plugin

Certificates created using --manual do not support automatic renewal unless combined with an authentication hook script via --manual-auth-hook to automatically set up the required HTTP and/or TXT challenges.

If you can use one of the other plugins which support autorenewal to create your certificate, doing so is highly recommended.

To manually renew a certificate using --manual without hooks, repeat the same certbot --manual command you used to create the certificate originally. As this will require you to copy and paste new HTTP files or DNS TXT records, the command cannot be automated with a cron job.

Combining plugins

Sometimes you may want to specify a combination of distinct authenticator and installer plugins. To do so, specify the authenticator plugin with --authenticator or -a and the installer plugin with --installer or -i.

For instance, you could create a certificate using the webroot plugin for authentication and the apache plugin for installation.

certbot run -a webroot -i apache -w /var/www/html -d example.com

Or you could create a certificate using the manual plugin for authentication and the nginx plugin for installation. (Note that this certificate cannot be renewed automatically.)

certbot run -a manual -i nginx -d example.com

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
haproxy Y Y Integration with the HAProxy load balancer
s3front Y Y Integration with Amazon CloudFront distribution of S3 buckets
gandi Y N Obtain certificates via the Gandi LiveDNS API
varnish Y N Obtain certificates via a Varnish server
external-auth Y Y A plugin for convenient scripting
pritunl N Y Install certificates in pritunl distributed OpenVPN servers
proxmox N Y Install certificates in Proxmox Virtualization servers
dns-standalone Y N Obtain certificates via an integrated DNS server
dns-ispconfig Y N DNS Authentication using ISPConfig as DNS server
dns-clouddns Y N DNS Authentication using CloudDNS API
dns-lightsail Y N DNS Authentication using Amazon Lightsail DNS API
dns-inwx Y Y DNS Authentication for INWX through the XML API
dns-azure Y N DNS Authentication using Azure DNS
dns-godaddy Y N DNS Authentication using Godaddy DNS
dns-yandexcloud Y N DNS Authentication using Yandex Cloud DNS
dns-bunny Y N DNS Authentication using BunnyDNS
njalla Y N DNS Authentication for njalla
DuckDNS Y N DNS Authentication for DuckDNS
Porkbun Y N DNS Authentication for Porkbun
Infomaniak Y N DNS Authentication using Infomaniak Domains API
dns-multi Y N DNS authentication of 100+ providers using go-acme/lego
dns-dnsmanager Y N DNS Authentication for dnsmanager.io
standalone-nfq Y N HTTP Authentication that works with any webserver (Linux only)
dns-solidserver Y N DNS Authentication using SOLIDserver (EfficientIP)
dns-stackit Y N DNS Authentication using STACKIT DNS
dns-ionos Y N DNS Authentication using IONOS Cloud DNS
dns-mijn-host Y N DNS Authentication using mijn.host DNS

If you're interested, you can also :ref:`write your own plugin <dev-plugin>`.

Managing certificates

To view a list of the certificates Certbot knows about, run the certificates subcommand:

certbot certificates

This returns information in the following format:

Found the following certificates:
  Certificate Name: example.com
    Domains: example.com, www.example.com
    Expiry Date: 2017-02-19 19:53:00+00:00 (VALID: 30 days)
    Certificate Path: /etc/letsencrypt/live/example.com/fullchain.pem
    Key Type: RSA
    Private Key Path: /etc/letsencrypt/live/example.com/privkey.pem

Certificate Name shows the name of the certificate. Pass this name using the --cert-name flag to specify a particular certificate for the run, certonly, certificates, renew, and delete commands. The certificate name cannot contain filepath separators (i.e. '/' or '\', depending on the platform). Example:

certbot certonly --cert-name example.com

Re-creating and Updating Existing Certificates

You can use certonly or run subcommands to request the creation of a single new certificate even if you already have an existing certificate with some of the same domain names.

If a certificate is requested with run or certonly specifying a certificate name that already exists, Certbot updates the existing certificate. Otherwise a new certificate is created and assigned the specified name.

The --force-renewal, --duplicate, and --expand options control Certbot's behavior when re-creating a certificate with the same name as an existing certificate. If you don't specify a requested behavior, Certbot may ask you what you intended.

--force-renewal tells Certbot to request a new certificate with the same domains as an existing certificate. Each domain must be explicitly specified via -d. If successful, this certificate is saved alongside the earlier one and symbolic links (the "live" reference) will be updated to point to the new certificate. This is a valid method of renewing a specific individual certificate.

--duplicate tells Certbot to create a separate, unrelated certificate with the same domains as an existing certificate. This certificate is saved completely separately from the prior one. Most users will not need to issue this command in normal circumstances.

--expand tells Certbot to update an existing certificate with a new certificate that contains all of the old domains and one or more additional new domains. With the --expand option, use the -d option to specify all existing domains and one or more new domains.

Example:

certbot --expand -d existing.com,example.com,newdomain.com

If you prefer, you can specify the domains individually like this:

certbot --expand -d existing.com -d example.com -d newdomain.com

Consider using --cert-name instead of --expand, as it gives more control over which certificate is modified and it lets you remove domains as well as adding them.

--allow-subset-of-names tells Certbot to continue with certificate generation if only some of the specified domain authorizations can be obtained. This may be useful if some domains specified in a certificate no longer point at this system.

Whenever you obtain a new certificate in any of these ways, the new certificate exists alongside any previously obtained certificates, whether or not the previous certificates have expired. The generation of a new certificate counts against several rate limits that are intended to prevent abuse of the ACME protocol, as described here.

Changing a Certificate's Domains

The --cert-name flag can also be used to modify the domains a certificate contains, by specifying new domains using the -d or --domains flag. If certificate example.com previously contained example.com and www.example.com, it can be modified to only contain example.com by specifying only example.com with the -d or --domains flag. Example:

certbot certonly --cert-name example.com -d example.com

The same format can be used to expand the set of domains a certificate contains, or to replace that set entirely:

certbot certonly --cert-name example.com -d example.org,www.example.org

RSA and ECDSA keys

Certbot supports two certificate private key algorithms: rsa and ecdsa.

As of version 2.0.0, Certbot defaults to ECDSA secp256r1 (P-256) certificate private keys for all new certificates. Existing certificates will continue to renew using their existing key type, unless a key type change is requested.

The type of key used by Certbot can be controlled through the --key-type option. You can use the --elliptic-curve option to control the curve used in ECDSA certificates and the --rsa-key-size option to control the size of RSA keys.

Warning

If you obtain certificates using ECDSA keys, you should be careful not to downgrade to a Certbot version earlier than 1.10.0 where ECDSA keys were not supported. Downgrades like this are possible if you switch from something like the snaps or pip to packages provided by your operating system which often lag behind.

Changing a certificate's key type

Unless you are aware that you need to support very old HTTPS clients that are not supported by most sites, you can safely transition your site to use ECDSA keys instead of RSA keys.

If you want to change a single certificate to use ECDSA keys, you'll need to create or renew a certificate while setting --key-type ecdsa on the command line:

certbot renew --key-type ecdsa --cert-name example.com --force-renewal

If you want to use ECDSA keys for all certificates in the future (including renewals of existing certificates), you can add the following line to Certbot's :ref:`configuration file <config-file>`:

key-type = ecdsa

which will take effect upon the next renewal of each certificate.

Revoking certificates

If you need to revoke a certificate, use the revoke subcommand to do so.

A certificate may be revoked by providing its name (see certbot certificates) or by providing its path directly:

certbot revoke --cert-name example.com

certbot revoke --cert-path /etc/letsencrypt/live/example.com/cert.pem

If the certificate being revoked was obtained via the --staging, --test-cert or a non-default --server flag, that flag must be passed to the revoke subcommand.

Note

After revocation, Certbot will (by default) ask whether you want to delete the certificate. Unless deleted, Certbot will try to renew revoked certificates the next time certbot renew runs.

You can also specify the reason for revoking your certificate by using the reason flag. Reasons include unspecified which is the default, as well as keycompromise, affiliationchanged, superseded, and cessationofoperation:

certbot revoke --cert-name example.com --reason keycompromise

Revoking by account key or certificate private key

By default, Certbot will try revoke the certificate using your ACME account key. If the certificate was created from the same ACME account, the revocation will be successful.

If you instead have the corresponding private key file to the certificate you wish to revoke, use --key-path to perform the revocation from any ACME account:

certbot revoke --cert-path /etc/letsencrypt/live/example.com/cert.pem --key-path /etc/letsencrypt/live/example.com/privkey.pem

Deleting certificates

If you need to delete a certificate, use the delete subcommand.

Note

Read this and the Safely deleting certificates sections carefully. This is an irreversible operation and must be done with care.

Certbot does not automatically revoke a certificate before deleting it. If you're no longer using a certificate and don't plan to use it anywhere else, you may want to follow the instructions in Revoking certificates instead. Generally, there's no need to revoke a certificate if its private key has not been compromised, but you may still receive expiration emails from Let's Encrypt unless you revoke.

Note

Do not manually delete certificate files from inside /etc/letsencrypt/. Always use the delete subcommand.

A certificate may be deleted by providing its name with --cert-name. You may find its name using certbot certificates.

Otherwise, you will be prompted to choose one or more certificates to delete:

certbot delete --cert-name example.com
# or to choose from a list:
certbot delete

Safely deleting certificates

Deleting a certificate without following the proper steps can result in a non-functioning server. To safely delete a certificate, follow all the steps below to make sure that references to a certificate are removed from the configuration of any installed server software (Apache, nginx, Postfix, etc) before deleting the certificate.

To explain further, when installing a certificate, Certbot modifies Apache or nginx's configuration to load the certificate and its private key from the /etc/letsencrypt/live/ directory. Before deleting a certificate, it is necessary to undo that modification, by removing any references to the certificate from the webserver's configuration files.

Follow these steps to safely delete a certificate:

  1. Find all references to the certificate (substitute example.com in the command for the name of the certificate you wish to delete):

    sudo bash -c 'grep -R live/example.com /etc/{nginx,httpd,apache2}'

    If there are no references found, skip directly to Step 4.

    If some references are found, they will look something like:

    /etc/apache2/sites-available/000-default-le-ssl.conf:SSLCertificateFile /etc/letsencrypt/live/example.com/fullchain.pem
/etc/apache2/sites-available/000-default-le-ssl.conf:SSLCertificateKeyFile /etc/letsencrypt/live/example.com/privkey.pem

  2. You will need a self-signed certificate to replace the certificate you are deleting. The following command will generate one for you, saving the certificate at /etc/letsencrypt/self-signed-cert.pem and its private key at /etc/letsencrypt/self-signed-privkey.pem:

    sudo openssl req -nodes -batch -x509 -newkey rsa:2048 -keyout /etc/letsencrypt/self-signed-privkey.pem -out /etc/letsencrypt/self-signed-cert.pem -days 356

  3. For each reference found in Step 1, open the file in a text editor and replace the reference to the existing certificate with a reference to the self-signed certificate.

    Continuing from the previous example, you would open /etc/apache2/sites-available/000-default-le-ssl.conf in a text editor and modify the two matching lines of text to instead say:

    SSLCertificateFile /etc/letsencrypt/self-signed-cert.pem
SSLCertificateKeyFile /etc/letsencrypt/self-signed-privkey.pem

  4. It is now safe to delete the certificate. Do so by running:

    sudo certbot delete --cert-name example.com

Renewing certificates

Note

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

.. seealso:: Most Certbot installations come with automatic
   renewal out of the box. See `Automated Renewals`_ for more details.


.. seealso:: Users of the `Manual`_ plugin should note that ``--manual`` certificates
   will not renew automatically, unless combined with authentication hook scripts.
   See `Renewal with the manual plugin <#manual-renewal>`_.

As of version 0.10.0, Certbot 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 command attempts 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. Unlike certonly, renew acts on multiple certificates and always takes into account whether each one is near expiry. Because of this, renew is suitable (and designed) for automated use, to allow your system to automatically renew each certificate when appropriate. Since renew only renews certificates that are near expiry it can be run as frequently as you want - since it will usually take no action.

The renew command includes hooks for running commands or scripts before or after a certificate is renewed. For example, if you have a single certificate obtained using the standalone plugin, you might need to stop the webserver before renewing so standalone can bind to the necessary ports, and then restart it after the plugin is finished. Example:

certbot renew --pre-hook "service nginx stop" --post-hook "service nginx start"

If a hook exits with a non-zero exit code, the error will be printed to stderr but renewal will be attempted anyway. A failing hook doesn't directly cause Certbot to exit with a non-zero exit code, but since Certbot exits with a non-zero exit code when renewals fail, a failed hook causing renewal failures will indirectly result in a non-zero exit code. Hooks will only be run if a certificate is due for renewal, so you can run the above command frequently without unnecessarily stopping your webserver.

When Certbot detects that a certificate is due for renewal, --pre-hook and --post-hook hooks run before and after each attempt to renew it. If you want your hook to run only after a successful renewal, use --deploy-hook in a command like this.

certbot renew --deploy-hook /path/to/deploy-hook-script

You can also specify hooks by placing files in subdirectories of Certbot's configuration directory. Assuming your configuration directory is /etc/letsencrypt, any executable files found in /etc/letsencrypt/renewal-hooks/pre, /etc/letsencrypt/renewal-hooks/deploy, and /etc/letsencrypt/renewal-hooks/post will be run as pre, deploy, and post hooks respectively when any certificate is renewed with the renew subcommand. These hooks are run in alphabetical order and are not run for other subcommands. (The order the hooks are run is determined by the byte value of the characters in their filenames and is not dependent on your locale.)

Hooks specified in the command line, :ref:`configuration file <config-file>`, or :ref:`renewal configuration files <renewal-config-file>` are run as usual after running all hooks in these directories. One minor exception to this is if a hook specified elsewhere is simply the path to an executable file in the hook directory of the same type (e.g. your pre-hook is the path to an executable in /etc/letsencrypt/renewal-hooks/pre), the file is not run a second time. You can stop Certbot from automatically running executables found in these directories by including --no-directory-hooks on the command line.

More information about 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.

If you are manually renewing all of your certificates, the --force-renewal flag may be helpful; 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.)

Starting with Certbot 2.7.0, certbot provides the environment variables RENEWED_DOMAINS and FAILED_DOMAINS to all post renewal hooks. These variables contain a space separated list of domains. These variables can be used to determine if a renewal has succeeded or failed as part of your post renewal hook.

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. When run with a set of domains corresponding to an existing certificate, the certonly command attempts to renew that specific 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 to improve the renewal process, and we apologize for any inconvenience you encounter in integrating these commands into your individual environment.

Note

certbot renew exit status will only be 1 if a renewal attempt failed. This means certbot renew exit status will be 0 if no certificate needs to be updated. If you write a custom script and expect to run a command only after a certificate was actually renewed you will need to use the --deploy-hook since the exit status will be 0 both on successful renewal and when renewal is not necessary.

Modifying the Renewal Configuration of Existing Certificates

When creating a certificate, Certbot will keep track of all of the relevant options chosen by the user. At renewal time, Certbot will remember these options and apply them once again.

Sometimes, you may encounter the need to change some of these options for future certificate renewals. To achieve this, you will need to perform the following steps:

Certbot v2.3.0 and newer

The certbot reconfigure command can be used to change a certificate's renewal options. This command will use the new renewal options to perform a test renewal against the Let's Encrypt staging server. If this is successful, the new renewal options will be saved and will apply to future renewals.

You will need to specify the --cert-name, which can be found by running certbot certificates.

A list of common options that may be updated with the reconfigure command can be found by running certbot help reconfigure.

As a practical example, if you were using the webroot authenticator and had relocated your website to another directory, you can change the --webroot-path to the new directory using the following command:

certbot reconfigure --cert-name example.com --webroot-path /path/to/new/location

Certbot v2.2.0 and older

  1. Perform a dry run renewal with the amended options on the command line. This allows you to confirm that the change is valid and will result in successful future renewals.
  2. If the dry run is successful, perform a live renewal of the certificate. This will persist the change for future renewals. If the certificate is not yet due to expire, you will need to force a renewal using --force-renewal.

Note

Rate limits from the certificate authority may prevent you from performing multiple renewals in a short period of time. It is strongly recommended to perform the second step only once, when you have decided on what options should change.

As a practical example, if you were using the webroot authenticator and had relocated your website to another directory, you would need to change the --webroot-path to the new directory. Following the above advice:

  1. Perform a dry-run renewal of the individual certificate with the amended options:

    certbot renew --cert-name example.com --webroot-path /path/to/new/location --dry-run

  2. If the dry-run was successful, make the change permanent by performing a live renewal of the certificate with the amended options, including --force-renewal:

    certbot renew --cert-name example.com --webroot-path /path/to/new/location --force-renewal

    --cert-name selects the particular certificate to be modified. Without this option, all certificates will be selected.

    --webroot-path is the option intended to be changed. All other previously selected options will be kept the same and do not need to be included in the command.

For advanced certificate management tasks, it is also possible to manually modify the certificate's renewal configuration file, but this is discouraged since it can easily break Certbot's ability to renew your certificates. These renewal configuration files are located at /etc/letsencrypt/renewal/CERTNAME.conf. If you choose to modify the renewal configuration file we advise you to make a backup of the file beforehand and test its validity with the certbot renew --dry-run command.

Warning

Manually modifying files under /etc/letsencrypt/renewal/ can damage them if done improperly and we do not recommend doing so.

Automated Renewals

Most Certbot installations come with automatic renewals preconfigured. This is done by means of a scheduled task which runs certbot renew periodically.

If you are unsure whether you need to configure automated renewal:

  1. Review the instructions for your system and installation method at https://certbot.eff.org/instructions. They will describe how to set up a scheduled task, if necessary. If no step is listed, your system comes with automated renewal pre-installed, and you should not need to take any additional actions.
  2. On Linux and BSD, you can check to see if your installation method has pre-installed a timer for you. To do so, look for the certbot renew command in either your system's crontab (typically /etc/crontab or /etc/cron.*/*) or systemd timers (systemctl list-timers).
  3. If you're still not sure, you can configure automated renewal manually by following the steps in the next section. Certbot has been carefully engineered to handle the case where both manual automated renewal and pre-installed automated renewal are set up.

Setting up automated renewal

If you think you may need to set up automated renewal, follow these instructions to set up a scheduled task to automatically renew your certificates in the background. If you are unsure whether your system has a pre-installed scheduled task for Certbot, it is safe to follow these instructions to create one.

Note

If you're using Windows, these instructions are not neccessary as Certbot on Windows comes with a scheduled task for automated renewal pre-installed.

If you are using macOS and installed Certbot using Homebrew, follow the instructions at https://certbot.eff.org/instructions to set up automated renewal. The instructions below are not applicable on macOS.

Run the following line, which will add a cron job to /etc/crontab:

SLEEPTIME=$(awk 'BEGIN{srand(); print int(rand()*(3600+1))}'); echo "0 0,12 * * * root sleep $SLEEPTIME && certbot renew -q" | sudo tee -a /etc/crontab > /dev/null

If you needed to stop your webserver to run Certbot, you'll want to add pre and post hooks to stop and start your webserver automatically. For example, if your webserver is HAProxy, run the following commands to create the hook files in the appropriate directory:

sudo sh -c 'printf "#!/bin/sh\nservice haproxy stop\n" > /etc/letsencrypt/renewal-hooks/pre/haproxy.sh'
sudo sh -c 'printf "#!/bin/sh\nservice haproxy start\n" > /etc/letsencrypt/renewal-hooks/post/haproxy.sh'
sudo chmod 755 /etc/letsencrypt/renewal-hooks/pre/haproxy.sh
sudo chmod 755 /etc/letsencrypt/renewal-hooks/post/haproxy.sh

Congratulations, Certbot will now automatically renew your certificates in the background.

If you are interested in learning more about how Certbot renews your certificates, see the Renewing certificates section above.

Where are my certificates?

All generated keys and issued certificates can be found in /etc/letsencrypt/live/$domain, where $domain is the certificate name (see the note below). 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

The certificate name $domain used in the path /etc/letsencrypt/live/$domain follows this convention:

  • it is the name given to --cert-name,
  • if --cert-name is not set by the user it is the first domain given to --domains,
  • if the first domain is a wildcard domain (eg. *.example.com) the certificate name will be example.com,
  • if a name collision would occur with a certificate already named example.com, the new certificate name will be constructed using a numerical sequence as example.com-001.

For historical reasons, the containing directories are created with permissions of 0700 meaning that certificates are accessible only to servers that run as the root user. If you will never downgrade to an older version of Certbot, then you can safely fix this using chmod 0755 /etc/letsencrypt/{live,archive}.

For servers that drop root privileges before attempting to read the private key file, you will also need to use chgrp and chmod 0640 to allow the server to read /etc/letsencrypt/live/$domain/privkey.pem.

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.

Note

As of Certbot version 0.29.0, private keys for new certificate default to 0600. Any changes to the group mode or group owner (gid) of this file will be preserved on renewals.

This is what Apache needs for SSLCertificateKeyFile, and Nginx for ssl_certificate_key.

fullchain.pem

All certificates, including server certificate (aka leaf certificate or end-entity certificate). The server certificate is the first one in this file, followed by any intermediates.

This is what Apache >= 2.4.8 needs for SSLCertificateFile, and what Nginx needs for ssl_certificate.

cert.pem and chain.pem (less common)

cert.pem contains the server certificate by itself, and chain.pem contains the additional intermediate certificate or certificates that web browsers will need in order to validate the server certificate. If you provide one of these files to your web server, you must provide both of them, or some browsers will show "This Connection is Untrusted" errors for your site, some of the time.

Apache < 2.4.8 needs these for SSLCertificateFile. and SSLCertificateChainFile, respectively.

If you're using OCSP stapling with Nginx >= 1.3.7, chain.pem should be provided as the ssl_trusted_certificate to validate OCSP responses.

Note

All files are PEM-encoded. If you need other format, such as DER or PFX, then you could convert using openssl. You can automate that with --deploy-hook if you're using automatic renewal.

Pre and Post Validation Hooks

Certbot allows for the specification of pre and post validation hooks when run in manual mode. The flags to specify these scripts are --manual-auth-hook and --manual-cleanup-hook respectively and can be used as follows:

certbot certonly --manual --manual-auth-hook /path/to/http/authenticator.sh --manual-cleanup-hook /path/to/http/cleanup.sh -d secure.example.com

This will run the authenticator.sh script, attempt the validation, and then run the cleanup.sh script. Additionally certbot will pass relevant environment variables to these scripts:

  • CERTBOT_DOMAIN: The domain being authenticated
  • CERTBOT_VALIDATION: The validation string
  • CERTBOT_TOKEN: Resource name part of the HTTP-01 challenge (HTTP-01 only)
  • CERTBOT_REMAINING_CHALLENGES: Number of challenges remaining after the current challenge
  • CERTBOT_ALL_DOMAINS: A comma-separated list of all domains challenged for the current certificate

Additionally for cleanup:

  • CERTBOT_AUTH_OUTPUT: Whatever the auth script wrote to stdout

Example usage for HTTP-01:

certbot certonly --manual --preferred-challenges=http --manual-auth-hook /path/to/http/authenticator.sh --manual-cleanup-hook /path/to/http/cleanup.sh -d secure.example.com

/path/to/http/authenticator.sh

#!/bin/bash
echo $CERTBOT_VALIDATION > /var/www/htdocs/.well-known/acme-challenge/$CERTBOT_TOKEN

/path/to/http/cleanup.sh

#!/bin/bash
rm -f /var/www/htdocs/.well-known/acme-challenge/$CERTBOT_TOKEN

Example usage for DNS-01 (Cloudflare API v4) (for example purposes only, do not use as-is)

certbot certonly --manual --preferred-challenges=dns --manual-auth-hook /path/to/dns/authenticator.sh --manual-cleanup-hook /path/to/dns/cleanup.sh -d secure.example.com

/path/to/dns/authenticator.sh

#!/bin/bash

# Get your API key from https://www.cloudflare.com/a/account/my-account
API_KEY="your-api-key"
EMAIL="your.email@example.com"

# Strip only the top domain to get the zone id
DOMAIN=$(expr match "$CERTBOT_DOMAIN" '.*\.\(.*\..*\)')

# Get the Cloudflare zone id
ZONE_EXTRA_PARAMS="status=active&page=1&per_page=20&order=status&direction=desc&match=all"
ZONE_ID=$(curl -s -X GET "https://api.cloudflare.com/client/v4/zones?name=$DOMAIN&$ZONE_EXTRA_PARAMS" \
     -H     "X-Auth-Email: $EMAIL" \
     -H     "X-Auth-Key: $API_KEY" \
     -H     "Content-Type: application/json" | python -c "import sys,json;print(json.load(sys.stdin)['result'][0]['id'])")

# Create TXT record
CREATE_DOMAIN="_acme-challenge.$CERTBOT_DOMAIN"
RECORD_ID=$(curl -s -X POST "https://api.cloudflare.com/client/v4/zones/$ZONE_ID/dns_records" \
     -H     "X-Auth-Email: $EMAIL" \
     -H     "X-Auth-Key: $API_KEY" \
     -H     "Content-Type: application/json" \
     --data '{"type":"TXT","name":"'"$CREATE_DOMAIN"'","content":"'"$CERTBOT_VALIDATION"'","ttl":120}' \
             | python -c "import sys,json;print(json.load(sys.stdin)['result']['id'])")
# Save info for cleanup
if [ ! -d /tmp/CERTBOT_$CERTBOT_DOMAIN ];then
        mkdir -m 0700 /tmp/CERTBOT_$CERTBOT_DOMAIN
fi
echo $ZONE_ID > /tmp/CERTBOT_$CERTBOT_DOMAIN/ZONE_ID
echo $RECORD_ID > /tmp/CERTBOT_$CERTBOT_DOMAIN/RECORD_ID

# Sleep to make sure the change has time to propagate over to DNS
sleep 25

/path/to/dns/cleanup.sh

#!/bin/bash

# Get your API key from https://www.cloudflare.com/a/account/my-account
API_KEY="your-api-key"
EMAIL="your.email@example.com"

if [ -f /tmp/CERTBOT_$CERTBOT_DOMAIN/ZONE_ID ]; then
        ZONE_ID=$(cat /tmp/CERTBOT_$CERTBOT_DOMAIN/ZONE_ID)
        rm -f /tmp/CERTBOT_$CERTBOT_DOMAIN/ZONE_ID
fi

if [ -f /tmp/CERTBOT_$CERTBOT_DOMAIN/RECORD_ID ]; then
        RECORD_ID=$(cat /tmp/CERTBOT_$CERTBOT_DOMAIN/RECORD_ID)
        rm -f /tmp/CERTBOT_$CERTBOT_DOMAIN/RECORD_ID
fi

# Remove the challenge TXT record from the zone
if [ -n "${ZONE_ID}" ]; then
    if [ -n "${RECORD_ID}" ]; then
        curl -s -X DELETE "https://api.cloudflare.com/client/v4/zones/$ZONE_ID/dns_records/$RECORD_ID" \
                -H "X-Auth-Email: $EMAIL" \
                -H "X-Auth-Key: $API_KEY" \
                -H "Content-Type: application/json"
    fi
fi

Changing the ACME Server

By default, Certbot uses Let's Encrypt's production server at https://acme-v02.api.letsencrypt.org/directory. You can tell Certbot to use a different CA by providing --server on the command line or in a :ref:`configuration file <config-file>` with the URL of the server's ACME directory. For example, if you would like to use Let's Encrypt's staging server, you would add --server https://acme-staging-v02.api.letsencrypt.org/directory to the command line.

Note

--dry-run uses the Let's Encrypt staging server, unless --server is specified on the CLI or in the :ref:`cli.ini configuration file <config-file>`. Take caution when using --dry-run with a custom server, as it may cause real certificates to be issued and discarded.

If Certbot does not trust the SSL certificate used by the ACME server, you can use the REQUESTS_CA_BUNDLE environment variable to override the root certificates trusted by Certbot. Certbot uses the requests library, which does not use the operating system trusted root store. Make sure that REQUESTS_CA_BUNDLE is set globally in the environment and not only on the CLI, or scheduled renewal will not succeed.

Lock Files

When processing a validation Certbot writes a number of lock files on your system to prevent multiple instances from overwriting each other's changes. This means that by default two instances of Certbot will not be able to run in parallel.

Since the directories used by Certbot are configurable, Certbot will write a lock file for all of the directories it uses. This include Certbot's --work-dir, --logs-dir, and --config-dir. By default these are /var/lib/letsencrypt, /var/log/letsencrypt, and /etc/letsencrypt respectively. Additionally if you are using Certbot with Apache or nginx it will lock the configuration folder for that program, which are typically also in the /etc directory.

Note that these lock files will only prevent other instances of Certbot from using those directories, not other processes. If you'd like to run multiple instances of Certbot simultaneously you should specify different directories as the --work-dir, --logs-dir, and --config-dir for each instance of Certbot that you would like to run.

Configuration file

Certbot accepts a global configuration file that applies its options to all invocations of Certbot. Certificate specific configuration choices should be set in the .conf files that can be found in /etc/letsencrypt/renewal.

By default no cli.ini file is created (though it may exist already if you installed Certbot via a package manager, for instance). After creating one it is possible to specify the location of this configuration file with certbot --config cli.ini (or shorter -c cli.ini). An example configuration file is shown below:

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).

Since this configuration file applies to all invocations of certbot it is incorrect to list domains in it. Listing domains in cli.ini may prevent renewal from working. Additionally due to how arguments in cli.ini are parsed, options which wish to not be set should not be listed. Options set to false will instead be read as being set to true by older versions of Certbot, since they have been listed in the config file.

Log Rotation

By default certbot stores status logs in /var/log/letsencrypt. By default certbot will begin rotating logs once there are 1000 logs in the log directory. Meaning that once 1000 files are in /var/log/letsencrypt Certbot will delete the oldest one to make room for new logs. The number of subsequent logs can be changed by passing the desired number to the command line flag --max-log-backups. Setting this flag to 0 disables log rotation entirely, causing certbot to always append to the same log file.

Note

Some distributions, including Debian and Ubuntu, disable certbot's internal log rotation in favor of a more traditional logrotate script. If you are using a distribution's packages and want to alter the log rotation, check /etc/logrotate.d/ for a certbot rotation script.

Certbot command-line options

Certbot supports a lot of command line options. Here's the full list, from certbot --help all:

.. literalinclude:: cli-help.txt

Getting help

If you're having problems, we recommend posting on the Let's Encrypt Community Forum.

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