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, or certbot-auto
if you used an alternate installation method. Throughout the docs, whenever you see certbot
, swap in the correct name as needed.
Getting certificates (and choosing plugins)¶
The Certbot client supports two types of plugins for obtaining and installing certificates: authenticators and installers.
Authenticators are plugins used with the certonly
command to obtain a certificate.
The authenticator validates that you
control the domain(s) you are requesting a certificate for, obtains a certificate for the specified
domain(s), and places the certificate in the /etc/letsencrypt
directory on your
machine. The authenticator does not install the certificate (it does not edit any of your server’s configuration files to serve the
obtained certificate). If you specify multiple domains to authenticate, they will
all be listed in a single certificate. To obtain multiple separate certificates
you will need to run Certbot multiple times.
Installers are Plugins used with the install
command to install a certificate.
These plugins can modify your webserver’s configuration to
serve your website over HTTPS using certificates obtained by certbot.
Plugins that do both can be used with the certbot run
command, which is the default
when no command is specified. The run
subcommand can also be used to specify
a combination of distinct authenticator and installer plugins.
Plugin |
Auth |
Inst |
Notes |
Challenge types (and port) |
---|---|---|---|---|
Y |
Y |
Automates obtaining and installing a certificate with Apache.
|
http-01 (80) |
|
Y |
Y |
Automates obtaining and installing a certificate with Nginx.
|
http-01 (80) |
|
Y |
N |
Obtains a certificate by writing to the webroot directory of
an already running webserver.
|
http-01 (80) |
|
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) |
|
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) |
|
Y |
N |
Helps you obtain a certificate by giving you instructions to
perform domain validation yourself. Additionally allows you
to specify scripts to automate the validation task in a
customized way.
|
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 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.
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"
Additionally you can specify scripts to prepare for validation and
perform the authentication procedure and/or clean up after it by using
the --manual-auth-hook
and --manual-cleanup-hook
flags. This is
described in more depth in the hooks section.
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 |
---|---|---|---|
Y |
Y |
Integration with the HAProxy load balancer |
|
Y |
Y |
Integration with Amazon CloudFront distribution of S3 buckets |
|
Y |
N |
Obtain certificates via the Gandi LiveDNS API |
|
Y |
N |
Obtain certificates via a Varnish server |
|
Y |
Y |
A plugin for convenient scripting |
|
N |
Y |
Install certificates in pritunl distributed OpenVPN servers |
|
N |
Y |
Install certificates in Proxmox Virtualization servers |
|
Y |
N |
Obtain certificates via an integrated DNS server |
|
Y |
N |
DNS Authentication using ISPConfig as DNS server |
|
Y |
N |
DNS Authentication using CloudDNS API |
|
Y |
N |
DNS Authentication using Amazon Lightsail DNS API |
|
Y |
Y |
DNS Authentication for INWX through the XML API |
If you’re interested, you can also write your own 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. 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
Using ECDSA keys¶
As of version 1.10, Certbot supports two types of private key algorithms:
rsa
and ecdsa
. The type of key used by Certbot can be controlled
through the --key-type
option. You can also use the --elliptic-curve
option to control the curve used in ECDSA certificates.
Warning
If you obtain certificates using ECDSA keys, you should be careful not to downgrade your Certbot installation since ECDSA keys are not supported by older versions of Certbot. Downgrades like this are possible if you switch from something like the snaps or certbot-auto to packages provided by your operating system which often lag behind.
Changing existing certificates from RSA to ECDSA¶
Unless you are aware that you need to support very old HTTPS clients that are not supported by most sites, you can safely just transition your site to use ECDSA keys instead of RSA keys. To accomplish this if you have existing certificates managed by Certbot, you may freely change the certificate to a new private key.
If you want to use ECDSA keys for all certificates in the future, you can simply add the following line to Certbot’s configuration file
key-type = ecdsa
After this option is set, newly obtained certificates will use ECDSA keys. This includes certificates managed by Certbot that previously used RSA keys.
If you want to change a single certificate to use ECDSA keys, you’ll need to
issue a new Certbot command setting --key-type ecdsa
on the command line
like
certbot renew --key-type ecdsa --cert-name example.com --force-renewal
Obtaining ECDSA certificates in addition to RSA certificates¶
When Certbot configures the certificates it obtains with Apache or Nginx, all HTTPS clients that we try to support can use certificates with ECDSA keys. If, however, you are aware of having a specific need to support very old TLS clients, you may want to obtain both ECDSA and RSA certificates for the same domains. Certbot can only configure Apache or Nginx to use a single certificate, however, you could manually configure your software to use the different certificates depending on your needs.
When obtaining both ECDSA and RSA certificates for the same domains with
Certbot, we recommend using the --cert-name
option to give your
certificates names so that you can easily identify them. For instance, you may
want to append “ecdsa” to the name of your ECDSA certificate by using a command
like
certbot certonly --key-type ecdsa --cert-name example.com-ecdsa
Revoking certificates¶
If your account key has been compromised or you otherwise need to revoke a certificate,
use the revoke
command to do so. Note that the revoke
command takes the certificate path
(ending in cert.pem
), not a certificate name or domain. Example:
certbot revoke --cert-path /etc/letsencrypt/live/CERTNAME/cert.pem
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-path /etc/letsencrypt/live/CERTNAME/cert.pem --reason keycompromise
Additionally, if a certificate
is a test certificate obtained via the --staging
or --test-cert
flag, that flag must be passed to the
revoke
subcommand.
Once a certificate is revoked (or for other certificate management tasks), all of a certificate’s
relevant files can be removed from the system with the delete
subcommand:
certbot delete --cert-name example.com
Note
If you don’t use delete
to remove the certificate completely, it will be renewed automatically at the next renewal event.
Note
Revoking a certificate will have no effect on the rate limit imposed by the Let’s Encrypt server.
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.
See also
Many of the certbot clients obtained through a
distribution come with automatic renewal out of the box,
such as Debian and Ubuntu versions installed through apt
,
CentOS/RHEL 7 through EPEL, etc. See Automated Renewals
for more details.
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, configuration file, or renewal configuration files 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.)
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 File¶
When a certificate is issued, by default Certbot creates a renewal configuration file that
tracks the options that were selected when Certbot was run. This allows Certbot
to use those same options again when it comes time for renewal. These renewal
configuration files are located at /etc/letsencrypt/renewal/CERTNAME
.
For advanced certificate management tasks, it is 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. If you choose to modify the renewal configuration file
we advise you to test its validity with the certbot renew --dry-run
command.
Warning
Modifying any files in /etc/letsencrypt
can damage them so Certbot can no longer properly manage its certificates, and we do not recommend doing so.
For most tasks, it is safest to limit yourself to pointing symlinks at the files there, or using
--deploy-hook
to copy / make new files based upon those files, if your operational situation requires it
(for instance, combining certificates and keys in different way, or having copies of things with different
specific permissions that are demanded by other programs).
If the contents of /etc/letsencrypt/archive/CERTNAME
are moved to a new folder, first specify
the new folder’s name in the renewal configuration file, then run certbot update_symlinks
to
point the symlinks in /etc/letsencrypt/live/CERTNAME
to the new folder.
If you would like the live certificate files whose symlink location Certbot updates on each run to
reside in a different location, first move them to that location, then specify the full path of
each of the four files in the renewal configuration file. Since the symlinks are relative links,
you must follow this with an invocation of certbot update_symlinks
.
For example, say that a certificate’s renewal configuration file previously contained the following directives:
archive_dir = /etc/letsencrypt/archive/example.com
cert = /etc/letsencrypt/live/example.com/cert.pem
privkey = /etc/letsencrypt/live/example.com/privkey.pem
chain = /etc/letsencrypt/live/example.com/chain.pem
fullchain = /etc/letsencrypt/live/example.com/fullchain.pem
The following commands could be used to specify where these files are located:
mv /etc/letsencrypt/archive/example.com /home/user/me/certbot/example_archive
sed -i 's,/etc/letsencrypt/archive/example.com,/home/user/me/certbot/example_archive,' /etc/letsencrypt/renewal/example.com.conf
mv /etc/letsencrypt/live/example.com/*.pem /home/user/me/certbot/
sed -i 's,/etc/letsencrypt/live/example.com,/home/user/me/certbot,g' /etc/letsencrypt/renewal/example.com.conf
certbot update_symlinks
Automated Renewals¶
Many Linux distributions provide automated renewal when you use the packages installed through their system package manager. The following table is an incomplete list of distributions which do so, as well as their methods for doing so.
If you are not sure whether or not your system has this already
automated, refer to your distribution’s documentation, or check your
system’s crontab (typically in /etc/crontab/
and /etc/cron.*/*
and
systemd timers (systemctl list-timers
).
Distribution Name |
Distribution Version |
Automation Method |
---|---|---|
CentOS |
EPEL 7 |
systemd |
Debian |
stretch |
cron, systemd |
Debian |
testing/sid |
cron, systemd |
Fedora |
26 |
systemd |
Fedora |
27 |
systemd |
RHEL |
EPEL 7 |
systemd |
Ubuntu |
17.10 |
cron, systemd |
Ubuntu |
certbot PPA |
cron, systemd |
Where are my certificates?¶
All generated keys and issued certificates can be found in
/etc/letsencrypt/live/$domain
. In the case of creating a SAN certificate
with multiple alternative names, $domain
is the first domain passed in
via -d parameter. Rather than copying, please point
your (web) server configuration directly to those files (or create
symlinks). During the renewal, /etc/letsencrypt/live
is updated
with the latest necessary files.
For historical reasons, the containing directories are created with
permissions of 0700
meaning that certificates are accessible only
to servers that run as the root user. If you will never downgrade
to an older version of Certbot, then you can safely fix this using
chmod 0755 /etc/letsencrypt/{live,archive}
.
For servers that drop root privileges before attempting to read the
private key file, you will also need to use chgrp
and chmod
0640
to allow the server to read
/etc/letsencrypt/live/$domain/privkey.pem
.
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.
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
andchain.pem
(less common)cert.pem
contains the server certificate by itself, andchain.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 authenticatedCERTBOT_VALIDATION
: The validation stringCERTBOT_TOKEN
: Resource name part of the HTTP-01 challenge (HTTP-01 only)CERTBOT_REMAINING_CHALLENGES
: Number of challenges remaining after the current challengeCERTBOT_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
configuration 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.
If you use --server
to specify an ACME CA that implements the standardized
version of the spec, you may be able to obtain a certificate for a
wildcard domain. Some CAs (such as Let’s Encrypt) require that domain
validation for wildcard domains must be done through modifications to
DNS records which means that the dns-01 challenge type must be used. To
see a list of Certbot plugins that support this challenge type and how
to use them, see plugins.
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:
# This is an example of the kind of things you can do in a configuration file.
# All flags used by the client can be configured here. Run Certbot with
# "--help" to learn more about the available options.
#
# Note that these options apply automatically to all use of Certbot for
# obtaining or renewing certificates, so options specific to a single
# certificate on a system with several certificates should not be placed
# here.
# Use ECC for the private key
key-type = ecdsa
elliptic-curve = secp384r1
# Use a 4096 bit RSA key instead of 2048
rsa-key-size = 4096
# Uncomment and update to register with the specified e-mail address
# email = foo@example.com
# Uncomment to use the standalone authenticator on port 443
# authenticator = standalone
# Uncomment to use the webroot authenticator. Replace webroot-path with the
# path to the public_html / webroot folder being served by your web server.
# authenticator = webroot
# webroot-path = /usr/share/nginx/html
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
.
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
:
usage:
certbot [SUBCOMMAND] [options] [-d DOMAIN] [-d DOMAIN] ...
Certbot can obtain and install HTTPS/TLS/SSL certificates. By default,
it will attempt to use a webserver both for obtaining and installing the
certificate. The most common SUBCOMMANDS and flags are:
obtain, install, and renew certificates:
(default) run Obtain & install a certificate in your current webserver
certonly Obtain or renew a certificate, but do not install it
renew Renew all previously obtained certificates that are near expiry
enhance Add security enhancements to your existing configuration
-d DOMAINS Comma-separated list of domains to obtain a certificate for
--apache Use the Apache plugin for authentication & installation
--standalone Run a standalone webserver for authentication
--nginx Use the Nginx plugin for authentication & installation
--webroot Place files in a server's webroot folder for authentication
--manual Obtain certificates interactively, or using shell script hooks
-n Run non-interactively
--test-cert Obtain a test certificate from a staging server
--dry-run Test "renew" or "certonly" without saving any certificates to disk
manage certificates:
certificates Display information about certificates you have from Certbot
revoke Revoke a certificate (supply --cert-name or --cert-path)
delete Delete a certificate (supply --cert-name)
manage your account:
register Create an ACME account
unregister Deactivate an ACME account
update_account Update an ACME account
--agree-tos Agree to the ACME server's Subscriber Agreement
-m EMAIL Email address for important account notifications
optional arguments:
-h, --help show this help message and exit
-c CONFIG_FILE, --config CONFIG_FILE
path to config file (default: /etc/letsencrypt/cli.ini
and ~/.config/letsencrypt/cli.ini)
-v, --verbose This flag can be used multiple times to incrementally
increase the verbosity of output, e.g. -vvv. (default:
-2)
--max-log-backups MAX_LOG_BACKUPS
Specifies the maximum number of backup logs that
should be kept by Certbot's built in log rotation.
Setting this flag to 0 disables log rotation entirely,
causing Certbot to always append to the same log file.
(default: 1000)
-n, --non-interactive, --noninteractive
Run without ever asking for user input. This may
require additional command line flags; the client will
try to explain which ones are required if it finds one
missing (default: False)
--force-interactive Force Certbot to be interactive even if it detects
it's not being run in a terminal. This flag cannot be
used with the renew subcommand. (default: False)
-d DOMAIN, --domains DOMAIN, --domain DOMAIN
Domain names to apply. For multiple domains you can
use multiple -d flags or enter a comma separated list
of domains as a parameter. The first domain provided
will be the subject CN of the certificate, and all
domains will be Subject Alternative Names on the
certificate. The first domain will also be used in
some software user interfaces and as the file paths
for the certificate and related material unless
otherwise specified or you already have a certificate
with the same name. In the case of a name collision it
will append a number like 0001 to the file path name.
(default: Ask)
--eab-kid EAB_KID Key Identifier for External Account Binding (default:
None)
--eab-hmac-key EAB_HMAC_KEY
HMAC key for External Account Binding (default: None)
--cert-name CERTNAME Certificate name to apply. This name is used by
Certbot for housekeeping and in file paths; it doesn't
affect the content of the certificate itself. To see
certificate names, run 'certbot certificates'. When
creating a new certificate, specifies the new
certificate's name. (default: the first provided
domain or the name of an existing certificate on your
system for the same domains)
--dry-run Perform a test run of the client, obtaining test
(invalid) certificates but not saving them to disk.
This can currently only be used with the 'certonly'
and 'renew' subcommands. Note: Although --dry-run
tries to avoid making any persistent changes on a
system, it is not completely side-effect free: if used
with webserver authenticator plugins like apache and
nginx, it makes and then reverts temporary config
changes in order to obtain test certificates, and
reloads webservers to deploy and then roll back those
changes. It also calls --pre-hook and --post-hook
commands if they are defined because they may be
necessary to accurately simulate renewal. --deploy-
hook commands are not called. (default: False)
--debug-challenges After setting up challenges, wait for user input
before submitting to CA (default: False)
--preferred-chain PREFERRED_CHAIN
If the CA offers multiple certificate chains, prefer
the chain with an issuer matching this Subject Common
Name. If no match, the default offered chain will be
used. (default: None)
--preferred-challenges PREF_CHALLS
A sorted, comma delimited list of the preferred
challenge to use during authorization with the most
preferred challenge listed first (Eg, "dns" or
"http,dns"). Not all plugins support all challenges.
See https://certbot.eff.org/docs/using.html#plugins
for details. ACME Challenges are versioned, but if you
pick "http" rather than "http-01", Certbot will select
the latest version automatically. (default: [])
--user-agent USER_AGENT
Set a custom user agent string for the client. User
agent strings allow the CA to collect high level
statistics about success rates by OS, plugin and use
case, and to know when to deprecate support for past
Python versions and flags. If you wish to hide this
information from the Let's Encrypt server, set this to
"". (default: CertbotACMEClient/1.11.0
(certbot(-auto); OS_NAME OS_VERSION) Authenticator/XXX
Installer/YYY (SUBCOMMAND; flags: FLAGS)
Py/major.minor.patchlevel). The flags encoded in the
user agent are: --duplicate, --force-renew, --allow-
subset-of-names, -n, and whether any hooks are set.
--user-agent-comment USER_AGENT_COMMENT
Add a comment to the default user agent string. May be
used when repackaging Certbot or calling it from
another tool to allow additional statistical data to
be collected. Ignored if --user-agent is set.
(Example: Foo-Wrapper/1.0) (default: None)
automation:
Flags for automating execution & other tweaks
--keep-until-expiring, --keep, --reinstall
If the requested certificate matches an existing
certificate, always keep the existing one until it is
due for renewal (for the 'run' subcommand this means
reinstall the existing certificate). (default: Ask)
--expand If an existing certificate is a strict subset of the
requested names, always expand and replace it with the
additional names. (default: Ask)
--version show program's version number and exit
--force-renewal, --renew-by-default
If a certificate already exists for the requested
domains, renew it now, regardless of whether it is
near expiry. (Often --keep-until-expiring is more
appropriate). Also implies --expand. (default: False)
--renew-with-new-domains
If a certificate already exists for the requested
certificate name but does not match the requested
domains, renew it now, regardless of whether it is
near expiry. (default: False)
--reuse-key When renewing, use the same private key as the
existing certificate. (default: False)
--allow-subset-of-names
When performing domain validation, do not consider it
a failure if authorizations can not be obtained for a
strict subset of the requested domains. This may be
useful for allowing renewals for multiple domains to
succeed even if some domains no longer point at this
system. This option cannot be used with --csr.
(default: False)
--agree-tos Agree to the ACME Subscriber Agreement (default: Ask)
--duplicate Allow making a certificate lineage that duplicates an
existing one (both can be renewed in parallel)
(default: False)
--os-packages-only (certbot-auto only) install OS package dependencies
and then stop (default: False)
--no-self-upgrade (certbot-auto only) prevent the certbot-auto script
from upgrading itself to newer released versions
(default: Upgrade automatically)
--no-bootstrap (certbot-auto only) prevent the certbot-auto script
from installing OS-level dependencies (default: Prompt
to install OS-wide dependencies, but exit if the user
says 'No')
--no-permissions-check
(certbot-auto only) skip the check on the file system
permissions of the certbot-auto script (default:
False)
-q, --quiet Silence all output except errors. Useful for
automation via cron. Implies --non-interactive.
(default: False)
security:
Security parameters & server settings
--rsa-key-size N Size of the RSA key. (default: 2048)
--key-type {rsa,ecdsa}
Type of generated private key(Only *ONE* per
invocation can be provided at this time) (default:
rsa)
--elliptic-curve N The SECG elliptic curve name to use. Please see RFC
8446 for supported values. (default: secp256r1)
--must-staple Adds the OCSP Must Staple extension to the
certificate. Autoconfigures OCSP Stapling for
supported setups (Apache version >= 2.3.3 ). (default:
False)
--redirect Automatically redirect all HTTP traffic to HTTPS for
the newly authenticated vhost. (default: redirect
enabled for install and run, disabled for enhance)
--no-redirect Do not automatically redirect all HTTP traffic to
HTTPS for the newly authenticated vhost. (default:
redirect enabled for install and run, disabled for
enhance)
--hsts Add the Strict-Transport-Security header to every HTTP
response. Forcing browser to always use SSL for the
domain. Defends against SSL Stripping. (default: None)
--uir Add the "Content-Security-Policy: upgrade-insecure-
requests" header to every HTTP response. Forcing the
browser to use https:// for every http:// resource.
(default: None)
--staple-ocsp Enables OCSP Stapling. A valid OCSP response is
stapled to the certificate that the server offers
during TLS. (default: None)
--strict-permissions Require that all configuration files are owned by the
current user; only needed if your config is somewhere
unsafe like /tmp/ (default: False)
--auto-hsts Gradually increasing max-age value for HTTP Strict
Transport Security security header (default: False)
testing:
The following flags are meant for testing and integration purposes only.
--test-cert, --staging
Use the staging server to obtain or revoke test
(invalid) certificates; equivalent to --server
https://acme-staging-v02.api.letsencrypt.org/directory
(default: False)
--debug Show tracebacks in case of errors, and allow certbot-
auto execution on experimental platforms (default:
False)
--no-verify-ssl Disable verification of the ACME server's certificate.
(default: False)
--http-01-port HTTP01_PORT
Port used in the http-01 challenge. This only affects
the port Certbot listens on. A conforming ACME server
will still attempt to connect on port 80. (default:
80)
--http-01-address HTTP01_ADDRESS
The address the server listens to during http-01
challenge. (default: )
--https-port HTTPS_PORT
Port used to serve HTTPS. This affects which port
Nginx will listen on after a LE certificate is
installed. (default: 443)
--break-my-certs Be willing to replace or renew valid certificates with
invalid (testing/staging) certificates (default:
False)
paths:
Flags for changing execution paths & servers
--cert-path CERT_PATH
Path to where certificate is saved (with auth --csr),
installed from, or revoked. (default: None)
--key-path KEY_PATH Path to private key for certificate installation or
revocation (if account key is missing) (default: None)
--fullchain-path FULLCHAIN_PATH
Accompanying path to a full certificate chain
(certificate plus chain). (default: None)
--chain-path CHAIN_PATH
Accompanying path to a certificate chain. (default:
None)
--config-dir CONFIG_DIR
Configuration directory. (default: /etc/letsencrypt)
--work-dir WORK_DIR Working directory. (default: /var/lib/letsencrypt)
--logs-dir LOGS_DIR Logs directory. (default: /var/log/letsencrypt)
--server SERVER ACME Directory Resource URI. (default:
https://acme-v02.api.letsencrypt.org/directory)
manage:
Various subcommands and flags are available for managing your
certificates:
certificates List certificates managed by Certbot
delete Clean up all files related to a certificate
renew Renew all certificates (or one specified with --cert-
name)
revoke Revoke a certificate specified with --cert-path or
--cert-name
update_symlinks Recreate symlinks in your /etc/letsencrypt/live/
directory
run:
Options for obtaining & installing certificates
certonly:
Options for modifying how a certificate is obtained
--csr CSR Path to a Certificate Signing Request (CSR) in DER or
PEM format. Currently --csr only works with the
'certonly' subcommand. (default: None)
renew:
The 'renew' subcommand will attempt to renew all certificates (or more
precisely, certificate lineages) you have previously obtained if they are
close to expiry, and print a summary of the results. By default, 'renew'
will reuse the options used to create obtain or most recently successfully
renew each certificate lineage. You can try it with `--dry-run` first. For
more fine-grained control, you can renew individual lineages with the
`certonly` subcommand. Hooks are available to run commands before and
after renewal; see https://certbot.eff.org/docs/using.html#renewal for
more information on these.
--pre-hook PRE_HOOK Command to be run in a shell before obtaining any
certificates. Intended primarily for renewal, where it
can be used to temporarily shut down a webserver that
might conflict with the standalone plugin. This will
only be called if a certificate is actually to be
obtained/renewed. When renewing several certificates
that have identical pre-hooks, only the first will be
executed. (default: None)
--post-hook POST_HOOK
Command to be run in a shell after attempting to
obtain/renew certificates. Can be used to deploy
renewed certificates, or to restart any servers that
were stopped by --pre-hook. This is only run if an
attempt was made to obtain/renew a certificate. If
multiple renewed certificates have identical post-
hooks, only one will be run. (default: None)
--deploy-hook DEPLOY_HOOK
Command to be run in a shell once for each
successfully issued certificate. For this command, the
shell variable $RENEWED_LINEAGE will point to the
config live subdirectory (for example,
"/etc/letsencrypt/live/example.com") containing the
new certificates and keys; the shell variable
$RENEWED_DOMAINS will contain a space-delimited list
of renewed certificate domains (for example,
"example.com www.example.com" (default: None)
--disable-hook-validation
Ordinarily the commands specified for --pre-
hook/--post-hook/--deploy-hook will be checked for
validity, to see if the programs being run are in the
$PATH, so that mistakes can be caught early, even when
the hooks aren't being run just yet. The validation is
rather simplistic and fails if you use more advanced
shell constructs, so you can use this switch to
disable it. (default: False)
--no-directory-hooks Disable running executables found in Certbot's hook
directories during renewal. (default: False)
--disable-renew-updates
Disable automatic updates to your server configuration
that would otherwise be done by the selected installer
plugin, and triggered when the user executes "certbot
renew", regardless of if the certificate is renewed.
This setting does not apply to important TLS
configuration updates. (default: False)
--no-autorenew Disable auto renewal of certificates. (default: True)
certificates:
List certificates managed by Certbot
delete:
Options for deleting a certificate
revoke:
Options for revocation of certificates
--reason {unspecified,keycompromise,affiliationchanged,superseded,cessationofoperation}
Specify reason for revoking certificate. (default:
unspecified)
--delete-after-revoke
Delete certificates after revoking them, along with
all previous and later versions of those certificates.
(default: None)
--no-delete-after-revoke
Do not delete certificates after revoking them. This
option should be used with caution because the 'renew'
subcommand will attempt to renew undeleted revoked
certificates. (default: None)
register:
Options for account registration
--register-unsafely-without-email
Specifying this flag enables registering an account
with no email address. This is strongly discouraged,
because you will be unable to receive notice about
impending expiration or revocation of your
certificates or problems with your Certbot
installation that will lead to failure to renew.
(default: False)
-m EMAIL, --email EMAIL
Email used for registration and recovery contact. Use
comma to register multiple emails, ex:
u1@example.com,u2@example.com. (default: Ask).
--eff-email Share your e-mail address with EFF (default: None)
--no-eff-email Don't share your e-mail address with EFF (default:
None)
update_account:
Options for account modification
unregister:
Options for account deactivation.
--account ACCOUNT_ID Account ID to use (default: None)
install:
Options for modifying how a certificate is deployed
rollback:
Options for rolling back server configuration changes
--checkpoints N Revert configuration N number of checkpoints.
(default: 1)
plugins:
Options for the "plugins" subcommand
--init Initialize plugins. (default: False)
--prepare Initialize and prepare plugins. (default: False)
--authenticators Limit to authenticator plugins only. (default: None)
--installers Limit to installer plugins only. (default: None)
update_symlinks:
Recreates certificate and key symlinks in /etc/letsencrypt/live, if you
changed them by hand or edited a renewal configuration file
enhance:
Helps to harden the TLS configuration by adding security enhancements to
already existing configuration.
plugins:
Plugin Selection: Certbot client supports an extensible plugins
architecture. See 'certbot plugins' for a list of all installed plugins
and their names. You can force a particular plugin by setting options
provided below. Running --help <plugin_name> will list flags specific to
that plugin.
--configurator CONFIGURATOR
Name of the plugin that is both an authenticator and
an installer. Should not be used together with
--authenticator or --installer. (default: Ask)
-a AUTHENTICATOR, --authenticator AUTHENTICATOR
Authenticator plugin name. (default: None)
-i INSTALLER, --installer INSTALLER
Installer plugin name (also used to find domains).
(default: None)
--apache Obtain and install certificates using Apache (default:
False)
--nginx Obtain and install certificates using Nginx (default:
False)
--standalone Obtain certificates using a "standalone" webserver.
(default: False)
--manual Provide laborious manual instructions for obtaining a
certificate (default: False)
--webroot Obtain certificates by placing files in a webroot
directory. (default: False)
--dns-cloudflare Obtain certificates using a DNS TXT record (if you are
using Cloudflare for DNS). (default: False)
--dns-cloudxns Obtain certificates using a DNS TXT record (if you are
using CloudXNS for DNS). (default: False)
--dns-digitalocean Obtain certificates using a DNS TXT record (if you are
using DigitalOcean for DNS). (default: False)
--dns-dnsimple Obtain certificates using a DNS TXT record (if you are
using DNSimple for DNS). (default: False)
--dns-dnsmadeeasy Obtain certificates using a DNS TXT record (if you are
using DNS Made Easy for DNS). (default: False)
--dns-gehirn Obtain certificates using a DNS TXT record (if you are
using Gehirn Infrastructure Service for DNS).
(default: False)
--dns-google Obtain certificates using a DNS TXT record (if you are
using Google Cloud DNS). (default: False)
--dns-linode Obtain certificates using a DNS TXT record (if you are
using Linode for DNS). (default: False)
--dns-luadns Obtain certificates using a DNS TXT record (if you are
using LuaDNS for DNS). (default: False)
--dns-nsone Obtain certificates using a DNS TXT record (if you are
using NS1 for DNS). (default: False)
--dns-ovh Obtain certificates using a DNS TXT record (if you are
using OVH for DNS). (default: False)
--dns-rfc2136 Obtain certificates using a DNS TXT record (if you are
using BIND for DNS). (default: False)
--dns-route53 Obtain certificates using a DNS TXT record (if you are
using Route53 for DNS). (default: False)
--dns-sakuracloud Obtain certificates using a DNS TXT record (if you are
using Sakura Cloud for DNS). (default: False)
apache:
Apache Web Server plugin (Please note that the default values of the
Apache plugin options change depending on the operating system Certbot is
run on.)
--apache-enmod APACHE_ENMOD
Path to the Apache 'a2enmod' binary (default: None)
--apache-dismod APACHE_DISMOD
Path to the Apache 'a2dismod' binary (default: None)
--apache-le-vhost-ext APACHE_LE_VHOST_EXT
SSL vhost configuration extension (default: -le-
ssl.conf)
--apache-server-root APACHE_SERVER_ROOT
Apache server root directory (default: /etc/apache2)
--apache-vhost-root APACHE_VHOST_ROOT
Apache server VirtualHost configuration root (default:
None)
--apache-logs-root APACHE_LOGS_ROOT
Apache server logs directory (default:
/var/log/apache2)
--apache-challenge-location APACHE_CHALLENGE_LOCATION
Directory path for challenge configuration (default:
/etc/apache2)
--apache-handle-modules APACHE_HANDLE_MODULES
Let installer handle enabling required modules for you
(Only Ubuntu/Debian currently) (default: False)
--apache-handle-sites APACHE_HANDLE_SITES
Let installer handle enabling sites for you (Only
Ubuntu/Debian currently) (default: False)
--apache-ctl APACHE_CTL
Full path to Apache control script (default:
apache2ctl)
--apache-bin APACHE_BIN
Full path to apache2/httpd binary (default: None)
dns-cloudflare:
Obtain certificates using a DNS TXT record (if you are using Cloudflare
for DNS).
--dns-cloudflare-propagation-seconds DNS_CLOUDFLARE_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 10)
--dns-cloudflare-credentials DNS_CLOUDFLARE_CREDENTIALS
Cloudflare credentials INI file. (default: None)
dns-cloudxns:
Obtain certificates using a DNS TXT record (if you are using CloudXNS for
DNS).
--dns-cloudxns-propagation-seconds DNS_CLOUDXNS_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 30)
--dns-cloudxns-credentials DNS_CLOUDXNS_CREDENTIALS
CloudXNS credentials INI file. (default: None)
dns-digitalocean:
Obtain certificates using a DNS TXT record (if you are using DigitalOcean
for DNS).
--dns-digitalocean-propagation-seconds DNS_DIGITALOCEAN_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 10)
--dns-digitalocean-credentials DNS_DIGITALOCEAN_CREDENTIALS
DigitalOcean credentials INI file. (default: None)
dns-dnsimple:
Obtain certificates using a DNS TXT record (if you are using DNSimple for
DNS).
--dns-dnsimple-propagation-seconds DNS_DNSIMPLE_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 30)
--dns-dnsimple-credentials DNS_DNSIMPLE_CREDENTIALS
DNSimple credentials INI file. (default: None)
dns-dnsmadeeasy:
Obtain certificates using a DNS TXT record (if you are using DNS Made Easy
for DNS).
--dns-dnsmadeeasy-propagation-seconds DNS_DNSMADEEASY_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 60)
--dns-dnsmadeeasy-credentials DNS_DNSMADEEASY_CREDENTIALS
DNS Made Easy credentials INI file. (default: None)
dns-gehirn:
Obtain certificates using a DNS TXT record (if you are using Gehirn
Infrastructure Service for DNS).
--dns-gehirn-propagation-seconds DNS_GEHIRN_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 30)
--dns-gehirn-credentials DNS_GEHIRN_CREDENTIALS
Gehirn Infrastructure Service credentials file.
(default: None)
dns-google:
Obtain certificates using a DNS TXT record (if you are using Google Cloud
DNS for DNS).
--dns-google-propagation-seconds DNS_GOOGLE_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 60)
--dns-google-credentials DNS_GOOGLE_CREDENTIALS
Path to Google Cloud DNS service account JSON file.
(See https://developers.google.com/identity/protocols/
OAuth2ServiceAccount#creatinganaccount forinformation
about creating a service account and
https://cloud.google.com/dns/access-
control#permissions_and_roles for information about
therequired permissions.) (default: None)
dns-linode:
Obtain certificates using a DNS TXT record (if you are using Linode for
DNS).
--dns-linode-propagation-seconds DNS_LINODE_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 120)
--dns-linode-credentials DNS_LINODE_CREDENTIALS
Linode credentials INI file. (default: None)
dns-luadns:
Obtain certificates using a DNS TXT record (if you are using LuaDNS for
DNS).
--dns-luadns-propagation-seconds DNS_LUADNS_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 30)
--dns-luadns-credentials DNS_LUADNS_CREDENTIALS
LuaDNS credentials INI file. (default: None)
dns-nsone:
Obtain certificates using a DNS TXT record (if you are using NS1 for DNS).
--dns-nsone-propagation-seconds DNS_NSONE_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 30)
--dns-nsone-credentials DNS_NSONE_CREDENTIALS
NS1 credentials file. (default: None)
dns-ovh:
Obtain certificates using a DNS TXT record (if you are using OVH for DNS).
--dns-ovh-propagation-seconds DNS_OVH_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 30)
--dns-ovh-credentials DNS_OVH_CREDENTIALS
OVH credentials INI file. (default: None)
dns-rfc2136:
Obtain certificates using a DNS TXT record (if you are using BIND for
DNS).
--dns-rfc2136-propagation-seconds DNS_RFC2136_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 60)
--dns-rfc2136-credentials DNS_RFC2136_CREDENTIALS
RFC 2136 credentials INI file. (default: None)
dns-route53:
Obtain certificates using a DNS TXT record (if you are using AWS Route53
for DNS).
--dns-route53-propagation-seconds DNS_ROUTE53_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 10)
dns-sakuracloud:
Obtain certificates using a DNS TXT record (if you are using Sakura Cloud
for DNS).
--dns-sakuracloud-propagation-seconds DNS_SAKURACLOUD_PROPAGATION_SECONDS
The number of seconds to wait for DNS to propagate
before asking the ACME server to verify the DNS
record. (default: 90)
--dns-sakuracloud-credentials DNS_SAKURACLOUD_CREDENTIALS
Sakura Cloud credentials file. (default: None)
manual:
Authenticate through manual configuration or custom shell scripts. When
using shell scripts, an authenticator script must be provided. The
environment variables available to this script depend on the type of
challenge. $CERTBOT_DOMAIN will always contain the domain being
authenticated. For HTTP-01 and DNS-01, $CERTBOT_VALIDATION is the
validation string, and $CERTBOT_TOKEN is the filename of the resource
requested when performing an HTTP-01 challenge. An additional cleanup
script can also be provided and can use the additional variable
$CERTBOT_AUTH_OUTPUT which contains the stdout output from the auth
script. For both authenticator and cleanup script, on HTTP-01 and DNS-01
challenges, $CERTBOT_REMAINING_CHALLENGES will be equal to the number of
challenges that remain after the current one, and $CERTBOT_ALL_DOMAINS
contains a comma-separated list of all domains that are challenged for the
current certificate.
--manual-auth-hook MANUAL_AUTH_HOOK
Path or command to execute for the authentication
script (default: None)
--manual-cleanup-hook MANUAL_CLEANUP_HOOK
Path or command to execute for the cleanup script
(default: None)
nginx:
Nginx Web Server plugin
--nginx-server-root NGINX_SERVER_ROOT
Nginx server root directory. (default: /etc/nginx or
/usr/local/etc/nginx)
--nginx-ctl NGINX_CTL
Path to the 'nginx' binary, used for 'configtest' and
retrieving nginx version number. (default: nginx)
--nginx-sleep-seconds NGINX_SLEEP_SECONDS
Number of seconds to wait for nginx configuration
changes to apply when reloading. (default: 1)
null:
Null Installer
standalone:
Spin up a temporary webserver
webroot:
Place files in webroot directory
--webroot-path WEBROOT_PATH, -w WEBROOT_PATH
public_html / webroot path. This can be specified
multiple times to handle different domains; each
domain will have the webroot path that preceded it.
For instance: `-w /var/www/example -d example.com -d
www.example.com -w /var/www/thing -d thing.net -d
m.thing.net` (default: Ask)
--webroot-map WEBROOT_MAP
JSON dictionary mapping domains to webroot paths; this
implies -d for each entry. You may need to escape this
from your shell. E.g.: --webroot-map
'{"eg1.is,m.eg1.is":"/www/eg1/", "eg2.is":"/www/eg2"}'
This option is merged with, but takes precedence over,
-w / -d entries. At present, if you put webroot-map in
a config file, it needs to be on a single line, like:
webroot-map = {"example.com":"/var/www"}. (default:
{})
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
outputyour operating system, including specific version
specify which installation method you’ve chosen