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

title	description	lead	date	draft	images	menu	reference	parent	weight	toc	aliases
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

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	HeaderProxyAuthorization, CookieSession
ext-authz	/api/authz/ext-authz	ExtAuthz	HeaderProxyAuthorization, 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, and Skipper via the webhook auth filter.

ForwardAuth Metadata

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

ForwardAuth Metadata Alternatives

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

ExtAuthz

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

ExtAuthz Metadata

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

ExtAuthz Metadata Alternatives

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

AuthRequest

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

Metadata	Source	Key
Method	Header	X-Original-Method
Scheme	Header	X-Original-URL
Hostname	Header	X-Original-URL
Path	Header	X-Original-URL
IP	Header	X-Forwarded-For
Authelia URL	N/A	N/A

Note: 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.

AuthRequest Metadata Alternatives

Metadata	Alternative Type	Source	Key
IP	Fallback	TCP Packet	Source IP

Legacy

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

Note: 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.

Metadata	Source	Key
Method	Header	X-Original-Method
Scheme	Header	X-Original-URL
Hostname	Header	X-Original-URL
Path	Header	X-Original-URL
Method	Header	X-Forwarded-Method
Scheme	Header	X-Forwarded-Proto
Hostname	Header	X-Forwarded-Host
Path	Header	X-Forwarded-URI
IP	Header	X-Forwarded-For
Authelia URL	Query Argument	rd
Authelia URL	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
2. No Authentication
3. Unsuccessful Authentication

Result 2 is the only result in which the next strategy is attempted, this occurs when there is not enough information in the request to perform authentication. Both result 1 and 2 result in a short-circuit, i.e. no other strategy will be attempted.

Result 1 occurs when the strategy requirements (i.e. a particular header) are present and the details are sufficient to authenticate them and the details are correct. Result 2 occurs when the strategy requirements are present and either the details are incomplete (i.e. malformed header) or the details are incorrect (i.e. bad password).

CookieSession

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.

If this strategy if included in an endpoint will redirect the user the Authelia Authorization Portal on supported proxies when they are not authorized and can potentially be authorized provided no other strategies have critical errors.

HeaderAuthorization

This strategy uses the Authorization header to determine the users' identity. If the user credentials are wrong, or the header is malformed it will respond with the WWW-Authenticate header and a 401 Unauthorized status code.

HeaderProxyAuthorization

This strategy uses the Proxy-Authorization header to determine the users' identity. If the user credentials are wrong, or the header is malformed it will respond with the Proxy-Authenticate header and a 407 Proxy Authentication Required status code.

HeaderAuthRequestProxyAuthorization

This strategy uses the Proxy-Authorization header to determine the users' identity. If the user credentials are wrong, or the header is malformed it will respond with the WWW-Authenticate header and a 401 Unauthorized status code. It is specifically intended for use with the AuthRequest implementation.

HeaderLegacy

This strategy uses the Proxy-Authorization header to determine the users' identity. If the user credentials are wrong, or the header is malformed it will respond with the WWW-Authenticate header.