Auth0 Authentication Server

An authentication server using Auth0 as a backend.

The server takes the scopes from the JSON Web Token (JWT) and compares them against a configuration. If one or more scopes are found that match the configuration, the request succeeds (status 200) and the scopes and id are reported back in custom headers. Otherwise, the request fails (status 403).

Usage

The authentication server is meant to be used for authentication sub-queries (e.g. from nginx).

Configuration file

It expects a configuration file as follows:

{
  "audience": "<string>",
  "issuer": "<string>",
  "headerNames": {
    "method": "<string> || 'x-original-method'",
    "uri": "<string> || 'x-original-uri'",
    "groups": "<string> || 'x-groups'",
    "id": "<string> || 'x-id'"
  },
  "auth": {
    "<path1>": {
      "<verb1 e.g. GET>": ["role/scope 1", "role/scope 2"],
      "<verb2 e.g. POST>": ["role/scope 3"]
    }
  }
}

The "issuer" string should end with a slash ("/"). Before requesting the JWKS, the string ".well-known/jwks.json" will be appended to the "issuer" string.

Environment variables

The program expects two environment variables:

Environment variable	Description	Default value
AUTH0_CONFIG	Path of the configuration file	config.json
AUTH0_BIND_ADDRESS	IP address and port for the server	127.0.0.1:8888
RUST_LOG	Log level 'debug'

Running the server

In development, server can be started using the following command:

cargo run

In production, the server can be run by executing the program (optionally the environment variables can be set to change the default values).

Path/Role Resolution

All configured paths are compared with the starting portion of the requested path. The longest matching path is selected and the roles associated with the requested verb are used to compare against the scopes from the token.

Example

Configuration:

{
  "audience": "https://my.audience.com",
  "issuer": "https://my.issuer.com/",
  "headerNames": {
    "method": "x-original-method",
    "uri": "x-original-uri",
    "groups": "x-groups",
    "id": "x-id"
  },
  "auth": {
    "/": {
      "GET": ["read:user"],
    },
    "/api/": {
      "GET": ["read:admin"],
      "POST": ["write:admin"]
    }
  }
}

Request 1

Request: GET /image/xyz (is matched to "/")
Response: 200 (if token contains "read:user"), 403 (otherwise)

Request 2

Request: POST /api/objects (is matched to "/api")
Response: 200 (if token contains "write:admin"), 403 (otherwise)

Examples

Example nginx configuration:

server {
  ...

  location /auth {
    internal;
    proxy_pass              http://server_auth:8888;
    proxy_pass_request_body off;
    proxy_set_header        Content-Length "";
    proxy_set_header        X-Original-URI $request_uri;
    proxy_set_header        X-Original-METHOD $request_method;
  }

  location /api {
    auth_request     /auth;
    auth_request_set        $auth_user $upstream_http_x_id;
    auth_request_set        $auth_groups $upstream_http_x_groups;
    proxy_set_header        X-Auth-UserName $auth_user;
    proxy_set_header        X-Auth-Roles $auth_groups;
    ...
  }
}

hannes-hochreiner/auth0-auth-server