From dc30e34b3146fac78d75b080f55fae34d73a72b9 Mon Sep 17 00:00:00 2001 From: Stefan Eissing Date: Tue, 25 Jun 2019 11:14:38 +0000 Subject: [PATCH] mod_md: updated documenation with new directives and chapters about wildcards and monitoring. git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1862052 13f79535-47bb-0310-9956-ffa450edef68 --- docs/manual/mod/mod_md.xml | 549 ++++++++++++++++++++++++++++++------- 1 file changed, 454 insertions(+), 95 deletions(-) diff --git a/docs/manual/mod/mod_md.xml b/docs/manual/mod/mod_md.xml index 6c29bf9044..fb1e5d8cf1 100644 --- a/docs/manual/mod/mod_md.xml +++ b/docs/manual/mod/mod_md.xml @@ -33,12 +33,19 @@

This module manages common properties of domains for one or more virtual hosts. - Specifically it can use the ACME protocol - (RFC Draft) - to automate certificate provisioning. These will be configured for managed domains and - their virtual hosts automatically. This includes renewal of certificates before they - expire. The most famous Certificate Authority currently implementing the ACME protocol - is Let's Encrypt.

+ Its main feature is the use of the ACME protocol + (RFC 8555) + to automate certificate provisioning. Certificates will be renewed + by the module ahead of their expiration to account for disruption in internet + services. There are ways to monitor the status of all Managed Domains + and configurations that will run your own notification commands on renewal, + expiration and errors. +

+

+ The default ACME Certificate Authority is + Let's Encrypt, but it is possible + to configure another CA that supports the protocol. +

Warning

This module is experimental. Its behaviors, directives, and @@ -79,17 +86,17 @@ MDomain example.org

This module requires mod_watchdog to be loaded as well.

- Certificate signup and renewal with Let's Encrypt requires your server to be + Certificate sign-up and renewal with Let's Encrypt requires your server to be reachable on port 80 (http:) from the outside. The alternative method over port 443 (https:) is currently disabled for security reasons (status from 2018-01-14).

The module will select from the methods offered by Let's Encrypt. If LE decides - at one point in the future, to re-enable it again, mod_md will + at one point in the future, to re-enable it again, mod_md will use it when suitable.

But for now, only the port 80 variant is available (termed "http-01"). Only - when LE can reach your server on port 80 will mod_md work for + when LE can reach your server on port 80 will mod_md work for you. For now, at least.

If you do not want to offer any sites on port 80 any more, you may leave it open @@ -99,6 +106,120 @@ MDomain example.org from Let's Encrypt.

+ + Wildcard Certificates +

+ Wildcard certificates are possible with version 2.x of `mod_md``. But they are + not straight-forward. Let's Encrypt requires the `dns-01` challenge verification + for those. No other is considered good enough. +

+ The difficulty here is that Apache cannot do that on its own. (which is also + a security benefit, since corrupting a web server or the communication path to + it is the scenario `dns-01` protects against). As the name implies, `dns-01` + requires you to show some specific DNS records for your domain that contain + some challenge data. So you need to _write_ your domain's DNS records. +

+ If you know how to do that, you can integrated this with `mod_md`. Let's + say you have a script for that in `/usr/bin/acme-setup-dns` you configure + Apache with: +

+ +MDChallengeDns01 /usr/bin/acme-setup-dns + +

+ and Apache will call this script when it needs to setup/teardown a DNS challenge + record for a domain. +

+ Assuming you want a certificate for `*.mydomain.com`, mod_md will call: +

+ +/usr/bin/acme-setup-dns setup mydomain.com challenge-data +# this needs to remove all existing DNS TXT records for +# _acme-challenge.mydomain.com and create a new one with +# content "challenge-data" + +

+ and afterwards it will call +

+ +/usr/bin/acme-setup-dns teardown mydomain.com +# this needs to remove all existing DNS TXT records for +# _acme-challenge.mydomain.com + + + + Monitoring +

+ Apache has a standard module for monitoring: mod_status. + mod_md contributes a section and makes monitoring your + domains easy. +

+ You see all your MDs listed alphabetically, the domain names they contain, + an overall status, expiration times and specific settings. The settings + show your selection of renewal times (or the default), the CA that is used, + etc. +

+ The 'Renewal' column will show activity and error descriptions for certificate + renewals. This should make life easier for people to find out if everything + is all right or what went wrong. +

+ If there is an error with an MD it will be shown here as well. This let's + you assess problems without digging through your server logs. +

+ There is also a new 'md-status' handler available to give you the MD information + from 'server-status' in JSON format. You configure it as +

+ +<Location "/md-status"> + SetHandler md-status +</Location> + +

+ on your server. As with 'server-status' you will want to add + authorization for this. +

+ If you just want to check the JSON status of a specific domain, simply append + that to your status url: +

+ +> curl https://<yourhost>/md-status/another-domain.org +{ + "name": "another-domain.org", + "domains": [ + "another-domain.org", + "www.another-domain.org" + ], + ... + +

+ This JSON status also shows a log of activities when domains are renewed: +

+ +{ +"when": "Wed, 19 Jun 2019 14:45:58 GMT", +"type": "progress", "detail": "The certificate for the managed domain has been renewed successfully and can be used. A graceful server restart now is recommended." +},{ +"when": "Wed, 19 Jun 2019 14:45:58 GMT", +"type": "progress", "detail": "Retrieving certificate chain for test-901-003-1560955549.org" +},{ +"when": "Wed, 19 Jun 2019 14:45:58 GMT", +"type": "progress", "detail": "Waiting for finalized order to become valid" +},{ +"when": "Wed, 19 Jun 2019 14:45:50 GMT", +"type": "progress", "detail": "Submitting CSR to CA for test-901-003-1560955549.org" +}, +... + +

+ You will also find this information in the file `job.json` in your staging and, + when activated, domains directory. This allows you to inspect these at + any later point in time as well. +

+ In addition, there is MDCertificateStatus which + gives access to relevant certificate information in JSON format. +

+ + @@ -112,7 +233,7 @@ MDomain example.org

All the names in the list are managed as one Managed Domain (MD). - mod_md will request one single certificate that is valid for all these names. This + mod_md will request one single certificate that is valid for all these names. This directive uses the global settings (see other MD directives below). If you need specific settings for one MD, use the MDomainSet. @@ -126,14 +247,13 @@ MDomain example.org changes in its service or status of your certificates.

The second setting, MDCertificateAgreement, - is the URL of the Terms of Service of the CA. When you configure the URL, - you confirm that you have read and agree to the terms described in the linked - document. Before you do that, the CA will not hand out certificates to you. + should have the value "accepted". By specifying this, you confirm that your + accept the Terms of Service of the CA.

Example ServerAdmin mailto:admin@example.org -MDCertificateAgreement https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf +MDCertificateAgreement accepted MDomain example.org www.example.org <VirtualHost *:443> @@ -155,7 +275,7 @@ MDomain example.org www.example.org There are two special names that you may use in this directive: 'manual' and 'auto'. This determines if a Managed Domain shall have exactly the name list as is configured ('manual') or offer more convenience. With 'auto' - all names of a virtual host are added to a MD. Conventiently, 'auto' is also + all names of a virtual host are added to a MD. Conveniently, 'auto' is also the default.

Example @@ -201,46 +321,48 @@ MDomain example2.org auto

- This directive allows you to define a Managed Domain (MD) with specific - settings, different from the global MD* ones. For example, you can have - such an MD use another CA then Let's Encrypt, have its unique renewal duration - etc. + This is the directive MDomain + with the added possibility to add setting just for this MD. In fact, + you may also use "<MDomain ..>" as a shortcut. +

+

+ This allows you to configure an MD that uses another Certificate Authority, + have other renewal requirements, etc.

Example -<MDomainSet sandbox.example.org> +<MDomain sandbox.example.org> MDCertificateAuthority https://someotherca.com/ACME - MDCertificateAgreement https://someotherca.com/terms/v_1.02.pdf -</MDomainSet> +</MDomain> + + +

+ A common use case is to configure https: requirements separately for + your domains. +

+ Example + +<MDomain example.org> + MDRequireHttps temporary +</MDomain> -

This is a specialized version of MDomain, - it should be used only when a fine grained configuration is required. - MDomain is the suggested choice - for the general use case.

 MDCertificateAgreement - The URL of the Terms-of-Service document, that the CA server requires you to accept. - MDCertificateAgreement url-of-terms-of-service + You confirm that you accepted the Terms of Service of the Certificate + Authority. + MDCertificateAgreement accepted server config -

When you use mod_md to obtain a certificate, you become a customer of the CA (e.g. Let's Encrypt). That means you need to read and agree to their Terms of Service, +

When you use mod_md to obtain a certificate, you become a customer of the CA (e.g. Let's Encrypt). That means you need to read and agree to their Terms of Service, so that you understand what they offer and what they might exclude or require from you. - mod_md cannot, by itself, agree to such a thing. + mod_md cannot, by itself, agree to such a thing.

-

In case of Let's Encrypt, their current Terms of Service are here. - Those terms might (and probably will) change over time. So, the certificate renewal might require you to update this agreement URL.

- Example - -MDCertificateAgreement https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf -MDomain example.org www.example.org mail.example.org - - @@ -248,7 +370,7 @@ MDomain example.org www.example.org mail.example.org MDCertificateAuthority The URL of the ACME Certificate Authority service. MDCertificateAuthority url - MDCertificateAuthority https://acme-v01.api.letsencrypt.org/directory + MDCertificateAuthority https://acme-v02.api.letsencrypt.org/directory server config @@ -256,15 +378,19 @@ MDomain example.org www.example.org mail.example.org

The URL where the CA offers its service.

- Let's Encrypt offers, right now, two such URLs. One for the real certificates and - one for testing (their staging area, at https://acme-staging.api.letsencrypt.org/directory). - In order to have mod_md use this testing service, configure your - server like this: + Let's Encrypt offers, right now, four such URLs. Two for + the own legacy version of the ACME protocol, commonly named ACMEv1. + And two for the RFC 8555 version, named ACMEv2. +

+ Each version has 2 endpoints, as their is a production endpoint and a + "staging" endpoint for testing. The testing endpoint works the same, but will + not give you certificates recognized by browsers. However, it also has + very relaxed rate limits. This allows testing of the service repeatedly + without you blocking yourself.

LE Staging Setup -MDCertificateAuthority https://acme-staging.api.letsencrypt.org/directory -MDCertificateAgreement https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf +MDCertificateAuthority https://acme-staging-v02.api.letsencrypt.org/directory @@ -279,33 +405,55 @@ MDCertificateAgreement https://letsencrypt.org/documents/LE-SA-v1.2-November-15- server config -

Specifies the protocol to use. Currently, only ACME is supported.

+

+ Specifies the protocol to use. Currently, only ACME is supported. +

MDDriveMode - Control when it is allowed to obtain/renew certificates. + former name of MDRenewMode. MDDriveMode always|auto|manual MDDriveMode auto server config -

In 'auto' mode, mod_md will drive a Managed Domain's - properties (e.g. certificate management) whenever necessary. When a MD is not used - in any virtual host, the module will do nothing. When a certificate is missing, it - will try to get one. When a certificate expires soon (see - MDRenewWindow), it will - renew it. -

- In 'manual' mode, it is your duty to do all this. The module will provide the existing - certificate to mod_ssl, if available. But it will not contact the CA for signup/renewal. - This can be useful in clustered setups where you want just one node to perform - the driving. -

- The third mode 'always' is like 'auto', with the difference that - mod_md will not check if the MD is actually used. +

This directive exists for backward compatibility as the old name for + MDRenewMode. +

+ + + + + MDRenewMode + Controls if certificates shall be renewed. + MDRenewMode always|auto|manual + MDRenewMode auto + + server config + + +

+ In the default 'auto' mode, the module will do what makes most sense + of each Managed Domain. For a domain without any certificates, it will + obtain them from the Certificate Authority. +

+

+ However, if you have defined an MD that is not used by any of Apache's + VirtualHosts, it will not bother. And for MDs with static certificate + files (see MDCertificateFile), + it assumes that you have your own source, and will not renew them either. +

+

+ You can override this default in either way. If you specify 'always', + the module will renew certificates for an MD, irregardless if the + domains are in use or if there are static files. +

+

+ For the opposite effect, configure 'manual' and no renewal will + be attempted.

@@ -334,15 +482,15 @@ MDCertificateAgreement https://letsencrypt.org/documents/LE-SA-v1.2-November-15-

Instead of listing all dns names on the same line, you may use - MDMember to add such names + MDMember to add such names to a managed domain.

Example -<MDomainSet example.org> +<MDomain example.org> MDMember www.example.org MDMember mail.example.org -</MDomainSet> +</MDomain>

@@ -390,16 +538,17 @@ MDCertificateAgreement https://letsencrypt.org/documents/LE-SA-v1.2-November-15- MDNotifyCmd - Run a program when Managed Domain are ready. + Run a program when a Managed Domain is ready. MDNotifyCmd path [ args ] server config -

The configured executable is run when Managed Domains have signed up or - renewed their certificates. It is given the names of the processed MDs as - additional arguments (after the parameters specified here). It should - return status code 0 to indicate that it has run successfully. +

+ The configured executable is run when a Managed Domain has signed up or + renewed its certificate. It is given the name of the processed MD as + additional arguments (after the parameters specified here). It should + return status code 0 to indicate that it has run successfully.

@@ -408,36 +557,44 @@ MDCertificateAgreement https://letsencrypt.org/documents/LE-SA-v1.2-November-15- MDPortMap Map external to internal ports for domain ownership verification. MDPortMap map1 [ map2 ] - MDPortMap 80:80 443:443 + MDPortMap http:80 https:443 server config

- The ACME protocol provides two methods to verify domain ownership: one that uses - port 80 and one for port 443. If your server is not reachable by at least one - of the two, ACME will not work for you. + The ACME protocol provides two methods to verify domain ownership via + HTTP: one that uses 'http:' urls (port 80) and one for 'https:' urls + (port 443). If your server is not reachable by at least one + of the two, ACME may only work by configuring your DNS server, + see MDChallengeDns01.

- mod_md will look at your server configuration and try to figure - out which of those are available. Then it can select the proper ACME challenge - to create a certificate for your site. + On most public facing servers, 'http:' arrives on port 80 and + 'https:' on port 443. The module checks the ports your Apache server + is listening on and assumes those are available. This means that + when your server does not listen on port 80, it assumes that + 'http:' requests from the internet will not work.

- However if you have some fancy port forwarding in place, your server may be - reachable from the Internet on port 443, but the local port that httpd uses is - another one. Your server might only listen on ports 5001 and 5002, but be reached - on ports 443 and 80. How should mod_md figure that one out? -

- With MDPortMap you can tell it which 'Internet port' - corresponds to which local port. + This is a good guess, but it may be wrong. For example, your Apache + might listen to port 80, but your firewall might block it. 'http:' + is only available in your intranet. So, the module will falsely assume + that Let's Encrypt can use 'http:' challenges with your server. This + will then fail, because your firewall will drop those.

Example -MDPortMap 80:- 443:5002 +MDPortMap http:- https:8433

- This example says that the server is not reachable on port 80 from the outside, but - local port 5002 is the one responding to https: requests. + The above example shows how you can specify that 'http:' requests from + the internet will never arrive. In addition it says that 'https:' requests + will arrive on local port 8433. +

+ This is necessary if you have port forwarding in place, your server may be + reachable from the Internet on port 443, but the local port that httpd uses is + another one. Your server might only listen on ports 8443 and 8000, but be reached + on ports 443 and 80 (from the internet).

@@ -486,10 +643,10 @@ MDPrivateKeys RSA 3072

- If the validity of the certificate falls below duration, mod_md + If the validity of the certificate falls below duration, mod_md will get a new signed certificate.

- Normally, certificates are valid for around 90 days and mod_md will renew + Normally, certificates are valid for around 90 days and mod_md will renew them the earliest 33% of their complete lifetime before they expire (so for 90 days validity, 30 days before it expires). If you think this is not what you need, you can specify either the exact time, as in: @@ -562,7 +719,7 @@ MDRequireHttps permanent

You can achieve the same with mod_alias and some Redirect configuration, basically. If you do it yourself, please make sure to exclude the paths - /.well-known/* from your redirection, otherwise mod_md + /.well-known/* from your redirection, otherwise mod_md might have trouble signing on new certificates.

If you set this globally, it applies to all managed domains. If you want @@ -570,9 +727,9 @@ MDRequireHttps permanent

Example -<MDomainSet xxx.yyy> +<MDomain xxx.yyy> MDRequireHttps temporary -</MDomainSet> +</MDomain> @@ -604,7 +761,7 @@ MDRequireHttps permanent MDCAChallenges Type of ACME challenge used to prove domain ownership. MDCAChallenges name [ name ... ] - MDCAChallenges tls-sni-01 http-01 + MDCAChallenges tls-alpn-01 http-01 dns-01 server config @@ -612,8 +769,8 @@ MDRequireHttps permanent

Sets challenge types and their execution order when proving domain ownership. The names are protocol specific. - The current ACME protocol version implemented by Let's Encrypt defines two challenge - types that are supported by mod_md. By default, it will try + The current ACME protocol version implemented by Let's Encrypt defines three challenge + types that are supported by mod_md. By default, it will try the one on port 443 when available.

@@ -630,12 +787,214 @@ MDRequireHttps permanent

Controls if the base server, the one outside all VirtualHosts should be managed by - mod_md or not. Default is to not do this, for the very reason that + mod_md or not. By default, it will not. For the very reason that it may have confusing side-effects. It is recommended that you have virtual hosts for all managed domains and do not rely on the global, fallback server configuration.

+ + MDCertificateFile + Specify a static certificate file for the MD. + MDCertificateFile path-to-pem-file + + server config + + +

+ This is used inside a MDomainSet and specifies + the file holding the certificate chain for the Managed Domain. The matching + key is specified via MDCertificateKeyFile. +

+ Example + +<MDomain mydomain.com> + MDCertificateFile /etc/ssl/my.cert + MDCertificateKeyFile /etc/ssl/my.key +</MDomain> + + + +

+ This is that equivalent of the mod_ssl + SSLCertificateFile directive. It + has several uses. +

+ If you want to migrate an existing domain, using static files, to + automated Let's Encrypt certificates, for one. You define the + MDomainSet, add the files here and remove + the SSLCertificateFile from + your VirtualHosts. +

+ This will give you the same as before, with maybe less repeating lines + in your configuration. Then you can add MDRenewMode + 'always' to it and the module will get a new certificate before + the one from the file expires. When it has done so, you remove the + MDCertificateFile and reload the server. +

+ Another use case is that you renew your Let's Encrypt certificates with + another ACME clients, for example the excellent + certbot. Then let your MDs point + to the files from certbot and have both working together. +

+ + + + + MDCertificateKeyFile + Specify a static private key for for the static cerrtificate. + MDCertificateKeyFile path-to-file + + server config + + +

+ This is used inside a MDomainSet and specifies + the file holding the private key for the Managed Domain. The matching + certificate is specified via MDCertificateFile. +

+ This is that equivalent of the mod_ssl + SSLCertificateKeyFile directive. +

+ + + + + MDCertificateStatus + Exposes public certificate information in JSON. + MDCertificateStatus on|off + MDCertificateStatus on + + server config + + +

+ When enabled, a resources is available in Managed Domains at + 'https://domain/.httpd/certificate-status' that returns a JSON + document list key properties of the current and of a renewed + certificate - when available. +

+ Example + +{ + "valid-until": "Thu, 29 Aug 2019 16:06:35 GMT", + "valid-from": "Fri, 31 May 2019 16:06:35 GMT", + "serial": "03039C464D454EDE79FCD2CAE859F668F269", + "sha256-fingerprint": "1ff3bfd2c7c199489ed04df6e29a9b4ea6c015fe8a1b0ce3deb88afc751e352d" + "renewal" : { ...renewed cert information... } +} + + + + + + + + MDChallengeDns01 + + MDChallengeDns01 path-to-command + + server config + + +

+ Define a program to be called when the `dns-01` challenge needs to be setup/torn down. + The program is given the argument `setup` or `teardown` followed by the domain name. + For `setup` the challenge content is additionally given. +

+ You do not need to specify this, as long as a 'http:' or 'https:' challenge + method is possible. However, Let's Encrypt makes 'dns-01' the only + challenge available for wildcard certificates. If you require + one of those, you need to configure this. +

+ See the section about wildcard certificates above for more details. +

+ + + + + MDMessageCmd + Handle events for Manage Domains + MDMessageCmd path-to-cmd optional-args + + server config + + +

+ This command gets called when one of the following events happen for + a Managed Domain: "renewed", "expiring", "errored". The command may + be invoked for more than these in the future and ignore events + it is not prepared to handle. +

+ This is the more flexible companion to MDNotifyCmd. +

+ Example +MDMessageCmd /etc/apache/md-message + +# will be invoked when a new certificate for mydomain.org is available as: +/etc/apache/md-message renewed mydomain.com + + + +

+ The program should not block, as the module will wait for it to finish. A + return code other than 0 is regarded as an error. +

+ 'errored' is no immediate cause for concern since renewal is attempted + early enough to allow the internet to come back. +

+ 'expiring' should be taken serious. It is issued when the + MDWarnWindow is reached. By default this is + 10% of the certificate lifetime, so for Let's Encrypt this currently + means 9 days before it expires. The warning is repeated at most once + a day. +

+ + + + + MDWarnWindow + Define the time window when you want to be warned about an expiring certificate. + MDWarnWindow duration + MDWarnWindow 10% + + server config + + +

+ See MDRenewWindow for a description on + how you can specify the time. +

+ The modules checks the remaining lifetime of certificates and invokes + MDMessageCmd when there is less than the warn + window left. With the default, this mean 9 days for certificates from + Let's Encrypt. +

+ It also applies to Managed Domains with static certificate files ( + see MDCertificateFile). +

+ + + + + MDServerStatus + Control if Managed Domain information is added to server-status. + MDServerStatus on|off + MDServerStatus on + + server config + + +

+ Apaches 'server-status' handler allows you configure a resource to monitor + what is going on. This includes now a section listing all Managed Domains + with the DNS names, renewal status, lifetimes and main properties. +

+ You can switch that off using this directive. +

+ + +