Implement revoction

README.md

@@ -6,7 +6,7 @@
 `kelunik/acme-client` is a standalone ACME client written in PHP.
 It's an alternative for the [official client](https://github.com/letsencrypt/letsencrypt) which is written in python.
 
-> **Warning**: This software is under heavy development. Use at your own risk. Revocation is not yet supported by this client.
+> **Warning**: This software is under heavy development. Use at your own risk.
 
 ## Installation
 
@@ -18,6 +18,9 @@ composer install
 
 ## Usage
 
+> **Note**: This client stores all data in `./data`, be sure to backup this folder regularly.
+> It contains your account keys, domain keys and certificates.
+
 Before you can issue certificates, you have to register an account first and read and understand the terms of service of the ACME CA you're using.
 For Let's Encrypt there's a [subscriber agreement](https://letsencrypt.org/repository/) you have to accept.
 
@@ -41,4 +44,12 @@ sudo bin/acme issue \
     --path /var/www/example.com
 ```
 
-For renewal, just run this command again.
+For renewal, just run this command again.
+
+To revoke a certificate, you need a valid account key currently, just like for issuance.
+
+```
+sudo bin/acme revoke \
+    --server acme-v01.api.letsencrypt.org/directory \
+    --cert data/live/example.com/cert.pem
+```