Add auth with encrypted password sample

Author: nsteinmetz

src/docs/content/docs/usage/authentication.md

@@ -12,16 +12,18 @@ Authentication can be activated in Reaper for the web UI only. It relies on [Apa
 
 To activate authentication, add the following block to your Reaper yaml file : 
 
-```
+```ini
 accessControl:
   sessionTimeout: PT10M
   shiro:
     iniConfigs: ["file:/path/to/shiro.ini"]
 ```
 
+## With clear passwords
+
 Create a `shiro.ini` file and adapt it from the following sample : 
 
-```
+```ini
 [main]
 authc = org.apache.shiro.web.filter.authc.PassThruAuthenticationFilter
 authc.loginUrl = /webui/login.html
@@ -42,10 +44,33 @@ user2 = password2
 /** = anon
 ```
 
-Then start Reaper.
+## With encrypted passwords
+
+Based on [Shiro's document on Encrypting passwords](https://shiro.apache.org/configuration.html#Configuration-EncryptingPasswords) :
+
+```ini
+[main]
+authc = org.apache.shiro.web.filter.authc.PassThruAuthenticationFilter
+authc.loginUrl = /webui/login.html
+sha256Matcher = org.apache.shiro.authc.credential.Sha256CredentialsMatcher
+iniRealm.credentialsMatcher = $sha256Matcher
 
-Both the REST API and the `/webui/login.html` pages will be accessible anonymously, but all other pages will require to be authenticated.
+[users]
+john = 807A09440428C0A8AEF58BD3ECE32938B0D76E638119E47619756F5C2C20FF3A
 
- 
 
+[urls]
+# Allow anonynous access to login page (and dependencies), but no other pages
+/webui/ = authc
+/webui = authc
+/webui/login.html = anon
+/webui/*.html* = authc
+/webui/*.js* = anon
+/ping = anon
+/login = anon
+/** = anon
+```
+
+Then start Reaper.
 
+Both the REST API and the `/webui/login.html` pages will be accessible anonymously, but all other pages will require to be authenticated.