With Authelia you can define a list of rules that are going to be evaluated in sequential order when authorization is delegated to Authelia.
The first matching rule of the list defines the policy applied to the resource, if no rule matches the resource a customizable default policy is applied.
A rule defines two things:
- the matching criteria of the request presented to the reverse proxy
- the policy applied when all criteria match.
The criteria are:
- domain: domain targeted by the request.
- resources: list of patterns that the path should match (one is sufficient).
- subject: the user or group of users to define the policy for.
- networks: the network range from where should comes the request.
A rule is matched when all criteria of the rule match.
A policy represents the level of authentication the user needs to pass before being authorized to request the resource.
There exist 4 policies:
- bypass: the resource is public as the user does not need any authentication to get access to it.
- one_factor: the user needs to pass at least the first factor to get access to the resource.
- two_factor: the user needs to pass two factors to get access to the resource.
- deny: the user does not have access to the resource.
The domains defined in rules must obviously be either a subdomain of the domain protected by Authelia or the protected domain itself. In order to match multiple subdomains, the wildcard matcher character
*. can be used as prefix of the domain. For instance, to define a rule for all subdomains of example.com, one would use
*.example.com in the rule. A single rule can define multiple domains for matching. These domains can be either listed in YAML-short form
["example1.com", "example2.com"] or in YAML long-form as dashed list.
A rule can define multiple regular expressions for matching the path of the resource similar to the list of domains. If any one of them matches, the resource criteria of the rule matches.
A subject is a representation of a user or a group of user for who the rule should apply.
For a user with unique identifier
john, the subject should be
user:john and for a group uniquely identified by
developers, the subject should be
group:developers. Similar to resources and domains you can define multiple subjects in a single rule.
If you want a combination of subjects to be matched at once using a logical
AND, you can specify a nested list of subjects like
- ["group:developers", "group:admins"]. In summary, the first list level of subjects are evaluated using a logical
OR, whereas the second level by a logical
AND. The last example below reads as: the group is
dev AND the username is
john OR the group is
A list of network ranges can be specified in a rule in order to apply different policies when requests come from different networks.
The main use case is when, lets say a resource should be exposed both on the Internet and from an authenticated VPN for instance. Passing a second factor a first time to get access to the VPN and a second time to get access to the application can sometimes be cumbersome if the endpoint is not considered overly sensitive.
Even if Authelia provides this flexibility, you might prefer a higher level of security and avoid this option entirely. You and only you can define your security policy and it’s up to you to configure Authelia accordingly.
Here is a complete example of complex access control list that can be defined in Authelia.
access_control: default_policy: deny rules: - domain: public.example.com policy: bypass - domain: secure.example.com policy: one_factor networks: - 192.168.1.0/24 - domain: - secure.example.com - private.example.com policy: two_factor - domain: singlefactor.example.com policy: one_factor - domain: "mx2.mail.example.com" subject: "group:admins" policy: deny - domain: "*.example.com" subject: - "group:admins" - "group:moderators" policy: two_factor - domain: dev.example.com resources: - "^/groups/dev/.*$" subject: "group:dev" policy: two_factor - domain: dev.example.com resources: - "^/users/john/.*$" subject: - ["group:dev", "user:john"] - "group:admins" policy: two_factor