Lua implementation to make NGINX operate as an OpenID Connect RP or OAuth 2.0 RS using the Lua extension scripting features (http://wiki.nginx.org/HttpLuaModule) which are for instance part of OpenResty (http://openresty.org/)
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Latest commit fe0263a Nov 18, 2016 @zandbelt zandbelt oops

README.md

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lua-resty-openidc

lua-resty-openidc is a library for NGINX implementing the OpenID Connect Relying Party (RP) and the OAuth 2.0 Resource Server (RS) functionality.

When used as an OpenID Connect Relying Party it authenticates users against an OpenID Connect Provider using OpenID Connect Discovery and the Basic Client Profile (i.e. the Authorization Code flow). When used as an OAuth 2.0 Resource Server it can validate OAuth 2.0 Bearer Access Tokens against an Authorization Server or, in case a JSON Web Token is used for an Access Token, verification can happen against a pre-configured secret/key .

It maintains sessions for authenticated users by leveraging lua-resty-session thus offering a configurable choice between storing the session state in a client-side browser cookie or use in of the server-side storage mechanisms shared-memory|memcache|redis.

It supports server-wide caching of resolved Discovery documents and validated Access Tokens.

It can be used as a reverse proxy terminating OAuth/OpenID Connect in front of an origin server so that the origin server/services can be protected with the relevant standards without implementing those on the server itself.

Dependencies

lua-resty-openidc depends on the following packages:

The dependencies above come automatically with OpenResty. You will need to install two extra pure-Lua dependencies that implement session management and HTTP client functions:

If you run as an OAuth 2.0 Resource Server and your access tokens are JWT bearer tokens and you want to verify those tokens locally (no external callouts required, see 2nd configuration example below), you need to install two more pure-Lua dependencies:

Installation

If you're using luarocks execute the following:

 luarocks install lua-resty-openidc

Otherwise copy openidc.lua somewhere in your lua_package_path under a directory named resty. If you are using OpenResty, the default location would be /usr/local/openresty/lualib/resty.

Sample Configuration for Google+ Signin

Sample nginx.conf configuration for authenticating users against Google+ Signin, protecting a reverse-proxied path.

events {
  worker_connections 128;
}

http {

  lua_package_path '~/lua/?.lua;;';

  resolver 8.8.8.8;

  lua_ssl_trusted_certificate /opt/local/etc/openssl/cert.pem;
  lua_ssl_verify_depth 5;

  # cache for discovery metadata documents
  lua_shared_dict discovery 1m;

  server {
    listen 8080;

    location / {

      access_by_lua '

          local opts = {
             -- the full redirect URI must be protected by this script and becomes:
             -- ngx.var.scheme.."://"..ngx.var.http_host..opts.redirect_uri_path
             -- unless the scheme is overridden using opts.redirect_uri_scheme or an X-Forwarded-Proto header in the incoming request
             redirect_uri_path = "/redirect_uri",
             discovery = "https://accounts.google.com/.well-known/openid-configuration",
             client_id = "<client_id>",
             client_secret = "<client_secret>"
             --authorization_params = { hd="pingidentity.com" },
             --scope = "openid email profile",
             --iat_slack = 600,
             --redirect_uri_scheme = "https",
             --logout_path = "/logout",
             --token_endpoint_auth_method = ["client_secret_basic"|"client_secret_post"],
             --ssl_verify = "no"
          }

          -- call authenticate for OpenID Connect user authentication
          local res, err = require("resty.openidc").authenticate(opts)

          if err then
            ngx.status = 500
            ngx.say(err)
            ngx.exit(ngx.HTTP_INTERNAL_SERVER_ERROR)
          end

          -- at this point res is a Lua table with 3 keys:
          --   id_token    : a Lua table with the claims from the id_token (required)
          --   access_token: the access token (optional)
          --   user        : a Lua table with the claims returned from the user info endpoint (optional)

          --if res.id_token.hd ~= "pingidentity.com" then
          --  ngx.exit(ngx.HTTP_FORBIDDEN)
          --end

          --if res.user.email ~= "hzandbelt@pingidentity.com" then
          --  ngx.exit(ngx.HTTP_FORBIDDEN)
          --end

          -- set headers with user info (overwriting any existing!)
          ngx.req.set_header("X-USER", res.id_token.sub)                    
      ';

      proxy_pass http://localhost:80;
    }
  }
}

Sample Configuration for OAuth 2.0 JWT Token Validation

Sample nginx.conf configuration for verifying Bearer JWT Access Tokens against a pre-configured secret/key. Once successfully verified, the NGINX server may function as a reverse proxy to an internal origin server.

events {
  worker_connections 128;
}

http {

  lua_package_path '~/lua/?.lua;;';

  resolver 8.8.8.8;

  # cache for JWT verification results
  lua_shared_dict introspection 10m;

  server {
    listen 8080;

    location /api {

      access_by_lua '

          local opts = {
            -- example of a shared secret for HS??? signature verification
            --secret = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa", 
            -- example of a public cert for RS??? signature verification
            secret = [[-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----]]
          }

          -- call bearer_jwt_verify for OAuth 2.0 JWT validation
          local res, err = require("resty.openidc").bearer_jwt_verify(opts)

           if err or not res then
            ngx.status = 403
            ngx.say(err and err or "no access_token provided")
            ngx.exit(ngx.HTTP_FORBIDDEN)
          end

          -- at this point res is a Lua table that represents the JSON
          -- payload in the JWT token 

          --if res.scope ~= "edit" then
          --  ngx.exit(ngx.HTTP_FORBIDDEN)
          --end

          --if res.client_id ~= "ro_client" then
          --  ngx.exit(ngx.HTTP_FORBIDDEN)
          --end          
      ';

       proxy_pass http://localhost:80;     
    }
  }
}

Sample Configuration for PingFederate OAuth 2.0

Sample nginx.conf configuration for validating Bearer Access Tokens against a PingFederate OAuth 2.0 Authorization Server.

events {
  worker_connections 128;
}

http {

  lua_package_path '~/lua/?.lua;;';

  resolver 8.8.8.8;

  lua_ssl_trusted_certificate /opt/local/etc/openssl/cert.pem;
  lua_ssl_verify_depth 5;

  # cache for validation results
  lua_shared_dict introspection 10m;

  server {
    listen 8080;

    location /api {

      access_by_lua '

          local opts = {
             introspection_endpoint="https://localhost:9031/as/token.oauth2",
             introspection_token_param_name="token",
             introspection_params = {
                grant_type="urn:pingidentity.com:oauth2:grant_type:validate_bearer",
             },
             client_id="rs_client",
             client_secret="2Federate",
             ssl_verify = "no"
          }

          -- call introspect for OAuth 2.0 Bearer Access Token validation
          local res, err = require("resty.openidc").introspect(opts)

          if err then
            ngx.status = 403
            ngx.say(err)
            ngx.exit(ngx.HTTP_FORBIDDEN)
          end

          -- at this point res is a Lua table that represents the JSON
          -- object returned from the introspection/validation endpoint

          --if res.scope ~= "edit" then
          --  ngx.exit(ngx.HTTP_FORBIDDEN)
          --end

          --if res.client_id ~= "ro_client" then
          --  ngx.exit(ngx.HTTP_FORBIDDEN)
          --end          
      ';
    }
  }
}

Disclaimer

This software is open sourced by Ping Identity but not supported commercially as such. Any questions/issues should go to the Github issues tracker or the author hzandbelt@pingidentity.com directly See also the DISCLAIMER file in this directory.