authelia/docs/content/reference/guides/proxy-authorization.md

title	description	summary	date	draft	images	menu	reference	parent	weight	toc	aliases	seo
Proxy Authorization	A reference guide on Proxy Authorization implementations	This section contains reference guide on Proxy Authorization implementations Authelia supports.	2023-01-25T20:36:40+11:00	false				guides	220	true	/r/proxy-authz	title description canonical noindex false

Proxies can integrate with Authelia via several authorization endpoints. These endpoints are by default configured appropriately for most use cases; however they can be individually configured, removed, added, etc.

They are currently divided into two sections:

• Implementations
• Authn Strategies

These endpoints are meant to collect important information from these requests via headers to determine both metadata about the request (such as the resource and IP address of the user) which is determined via the Implementations, and the identity of the user which is determined via the Authn Strategies.

Default Endpoints

Name	Path	Implementation	Authn Strategies
forward-auth	/api/authz/forward-auth	ForwardAuth	[HeaderAuthorization], CookieSession
ext-authz	/api/authz/ext-authz	ExtAuthz	[HeaderAuthorization], CookieSession
auth-request	/api/authz/auth-request	AuthRequest	HeaderAuthRequestProxyAuthorization, CookieSession
legacy	/api/verify	Legacy	HeaderLegacy, CookieSession

Metadata

Various metadata is collected from the request made to the Authelia authorization server. This table describes the metadata collected. All of this metadata is utilized for the purpose of determining if the user is authorized to a particular resource.

Name	Description
Method	The Method Verb of the Request
Scheme	The URI Scheme of the Request
Hostname	The URI Hostname of the Request
Path	The URI Path of the Request
IP	The IP address of the client making the Request
Authelia URL	The URL of the Authelia Portal

Some values may have either fallbacks or override values. If they exist they will be in the alternatives table which will be below the main metadata table.

The metadata table contains the recommended source of this information and this source is often times automatic depending on the proxy implementation. The difference between an override and a fallback is an override values will take precedence over the metadata values, and fallbacks only take effect if the override values or metadata values are completely unset.

Implementations

ForwardAuth

This is the implementation which supports Traefik via the ForwardAuth Middleware, Caddy via the forward_auth directive, HAProxy via the auth-request lua plugin, and Skipper via the webhook auth filter.

ForwardAuth Metadata

Metadata	Source	Key
Method 1	Header	X-Forwarded-Method 2
Scheme 1	Header	X-Forwarded-Proto 2
Hostname 1	Header	X-Forwarded-Host 2
Path 1	Header	X-Forwarded-URI 2
IP 1	Header	X-Forwarded-For 3
Authelia URL 1	Session Cookie Configuration	authelia_url

ForwardAuth Metadata Alternatives

Metadata	Alternative Type	Source	Key
Scheme 1	Fallback	Header	Server Scheme
IP 1	Fallback	TCP Packet	Source IP
Authelia URL 1	Override	Query Argument	authelia_url

ExtAuthz

This is the implementation which supports Envoy via the HTTP ExtAuthz Filter.

ExtAuthz Metadata

Metadata	Source	Key
Method 1	Start Line	HTTP Method 2
Scheme 1	Header	X-Forwarded-Proto 2
Hostname 1	Header	Host 2
Path 1	Header	Endpoint Sub-Path 2
IP 1	Header	X-Forwarded-For 2
Authelia URL 1	Session Cookie Configuration	authelia_url

ExtAuthz Metadata Alternatives

Metadata	Alternative Type	Source	Key
Scheme 1	Fallback	Header	Server Scheme
IP 1	Fallback	TCP Packet	Source IP
Authelia URL 1	Override	Header	X-Authelia-URL

AuthRequest

This is the implementation which supports NGINX via the auth_request HTTP module, and can technically support HAProxy via the auth-request lua plugin.

AuthRequest Metadata

Metadata	Source	Key
Method 1	Header	X-Original-Method 2
Scheme 1	Header	X-Original-URL 2
Hostname 1	Header	X-Original-URL 2
Path 1	Header	X-Original-URL 2
IP 1	Header	X-Forwarded-For 3
Authelia URL 1	Session Cookie Configuration	authelia_url

{{< callout context="note" title="Note" icon="outline/info-circle" >}} This endpoint does not support automatic redirection. This is because there is no support on NGINX's side to achieve this with ngx_http_auth_request_module and the redirection must be performed within the NGINX configuration. However, we return the appropriate URL to redirect users to with the Location header which simplifies this process especially for multi-cookie domain deployments. {{< /callout >}}

AuthRequest Metadata Alternatives

Metadata	Alternative Type	Source	Key
IP 1	Fallback	TCP Packet	Source IP
Authelia URL 1	Override	Query Argument	authelia_url

Legacy

This is the legacy implementation which used to operate similar to both the ForwardAuth and AuthRequest implementations.

{{< callout context="note" title="Note" icon="outline/info-circle" >}} This implementation has duplicate entries for metadata. This is due to the fact this implementation used to cater for the AuthRequest and ForwardAuth implementations. The table is in order of precedence where if a header higher in the list exists it is used over those lower in the list. {{< /callout >}}

Metadata	Source	Key
Method 1	Header	X-Original-Method
Scheme 1	Header	X-Original-URL
Hostname 1	Header	X-Original-URL
Path 1	Header	X-Original-URL
Method 1	Header	X-Forwarded-Method
Scheme 1	Header	X-Forwarded-Proto
Hostname 1	Header	X-Forwarded-Host
Path 1	Header	X-Forwarded-URI
IP 1	Header	X-Forwarded-For
Authelia URL 1	Query Argument	rd
Authelia URL 1	Header	X-Authelia-URL

Authn Strategies

Authentication strategies are used to determine the users identity which is essential to determining if they are authorized to visit a particular resource. Authentication strategies are executed in order, and have three potential results.

1. Successful Authentication
   • This result occurs when the required metadata i.e. headers are in the request for the strategy and they can be validated.
   • This result causes a short-circuit which generally results in a 200 OK.
2. Unsuccessful Authentication
   • This result occurs when the required metadata i.e. headers are in the request for the strategy and they can not be validated as they are either explicitly invalid or the means of validation could not be attempted due to an error.
   • This result causes a short-circuit applying the failure action and no other strategies will be attempted.
3. No Authentication
   • This result occurs when the required metadata i.e. headers are absent from the request for the strategy.
   • This result does not cause a short-circuit and:
     1. The next strategy will be attempted.
     2. If there is no next strategy the failure action will be applied.

CookieSession

Failure Action: Redirect the user for authentication.

Metadata: Cookie header value, considered absent when the configured cookie key is absent from this header or the header is absent.

This strategy uses a cookie which links the user to a session to determine the users identity. This is the default strategy for end-users.

HeaderAuthorization

Failure Action: Responds with the WWW-Authenticate header and a 401 Unauthorized status code.

Metadata: Authorization header, considered absent when the header is absent.

This strategy uses the Authorization header to determine the users' identity.

HeaderProxyAuthorization

Failure Action: Responds with the Proxy-Authenticate header and a 407 Proxy Authentication Required status code.

Metadata: Proxy-Authorization header, considered absent when the header is absent.

This strategy uses the Proxy-Authorization header to determine the users' identity.

HeaderAuthRequestProxyAuthorization

Failure Action: Responds with the WWW-Authenticate header and a 401 Unauthorized status code.

Metadata: Proxy-Authorization header, considered absent when the header is absent.

This strategy uses the Proxy-Authorization header to determine the users' identity. It is specifically intended for use with the AuthRequest implementation.

HeaderLegacy

Failure Action: Responds with the WWW-Authenticate header and a 401 Unauthorized status code.

Metadata: Proxy-Authorization header, considered absent when the header is absent.

This strategy uses the Proxy-Authorization header to determine the users' identity.

Footnotes

---

1. This is considered required metadata, and must either be provided via the primary metadata source or the alternative source for the request to be considered valid. ↩︎

2. This is considered a required header. If an alternative or fallback source is described this is very likely to be incorrect and cannot be supported. ↩︎

3. This header is not required but the fallback is likely desirable in most scenarios. ↩︎