nginxinc · shawnhankim · Nov 3, 2022
diff --git a/README.md b/README.md
diff --git a/configure.sh b/configure.sh
@@ -120,7 +120,7 @@ fi
 # Build an intermediate configuration file
 # File format is: <NGINX variable name><space><IdP value>
 #
-jq -r '. | "$oidc_authz_endpoint \(.authorization_endpoint)\n$oidc_token_endpoint \(.token_endpoint)\n$oidc_jwks_uri \(.jwks_uri)"' < /tmp/${COMMAND}_$$_json > /tmp/${COMMAND}_$$_conf
+jq -r '. | "$oidc_authz_endpoint \(.authorization_endpoint)\n$oidc_token_endpoint \(.token_endpoint)\n$oidc_jwks_uri \(.jwks_uri)\n$oidc_end_session_endpoint \(.end_session_endpoint)\n$oidc_userinfo_endpoint \(.userinfo_endpoint)"' < /tmp/${COMMAND}_$$_json > /tmp/${COMMAND}_$$_conf
 
 # Create a random value for HMAC key, adding to the intermediate configuration file
 echo "\$oidc_hmac_key `openssl rand -base64 18`" >> /tmp/${COMMAND}_$$_conf
@@ -178,7 +178,7 @@ fi
 
 # Loop through each configuration variable
 echo "$COMMAND: NOTICE: Configuring $CONFDIR/openid_connect_configuration.conf"
-for OIDC_VAR in \$oidc_authz_endpoint \$oidc_token_endpoint \$oidc_jwt_keyfile \$oidc_hmac_key $CLIENT_ID_VAR $CLIENT_SECRET_VAR $PKCE_ENABLE_VAR; do
+for OIDC_VAR in \$oidc_authz_endpoint \$oidc_token_endpoint \$oidc_jwt_keyfile \$oidc_end_session_endpoint \$oidc_userinfo_endpoint \$oidc_hmac_key $CLIENT_ID_VAR $CLIENT_SECRET_VAR $PKCE_ENABLE_VAR; do
 	# Pull the configuration value from the intermediate file
 	VALUE=`grep "^$OIDC_VAR " /tmp/${COMMAND}_$$_conf | cut -f2 -d' '`
 	echo -n "$COMMAND: NOTICE:  - $OIDC_VAR ..."

diff --git a/frontend.conf b/frontend.conf
@@ -1,4 +1,4 @@
-# This is the backend application we are protecting with OpenID Connect
+# This is the backend site/app we are protecting with OpenID Connect
 upstream my_backend {
     zone my_backend 64k;
     server 10.0.0.1:80;
@@ -15,20 +15,39 @@ server {
     error_log /var/log/nginx/error.log debug;  # Reduce severity level as required
 
     listen 8010; # Use SSL/TLS in production
-    
+
     location / {
-        # This site is protected with OpenID Connect
+        # This site can be either directly protected with OpenID Connect or
+        # shown with just a landing page without login.
+
+        # Disable when you need to show a default landing page before login.
         auth_jwt "" token=$session_jwt;
         error_page 401 = @do_oidc_flow;
+        auth_jwt_key_file $oidc_jwt_keyfile;  # Enable when using filename
+        #auth_jwt_key_request /_jwks_uri;     # Enable when using URL
 
-        auth_jwt_key_file $oidc_jwt_keyfile; # Enable when using filename
-        #auth_jwt_key_request /_jwks_uri; # Enable when using URL
+        # Successfully authenticated users are proxied to the backend site/app
+        # with 'sub' claim passed as HTTP header. It is empty before login.
+        proxy_set_header userid $jwt_claim_sub;
+
+        # The 'access_token' is set in the OIDC flow. Otherwise, it is empty.
+        proxy_set_header Authorization "Bearer $access_token";
 
-        # Successfully authenticated users are proxied to the backend,
-        # with 'sub' claim passed as HTTP header
-        proxy_set_header username $jwt_claim_sub;
         proxy_pass http://my_backend; # The backend site/app
-
+        access_log /var/log/nginx/access.log main_jwt;
+    }
+
+    location = /login {
+        # This location can be called by SPA to start OIDC flow via login button
+        # after starting a landing page without login.
+        auth_jwt "" token=$session_jwt;
+        error_page 401 = @do_oidc_flow;
+
+        auth_jwt_key_file $oidc_jwt_keyfile; # Enable when using filename
+        #auth_jwt_key_request /_jwks_uri;    # Enable when using URL
+
+        # Redirect to the the landing page after successful login to AS.
+        js_content oidc.redirectPostLogin;
         access_log /var/log/nginx/access.log main_jwt;
     }
 }

diff --git a/openid_connect.js b/openid_connect.js
@@ -5,7 +5,18 @@
  */
 var newSession = false; // Used by oidcAuth() and validateIdToken()
 
-export default {auth, codeExchange, validateIdToken, logout};
+const EXTRA_PARAMS = 1;
+const REPLACE_PARAMS = 2;
+
+export default {
+    auth,
+    codeExchange,
+    validateIdToken,
+    logout,
+    redirectPostLogin,
+    redirectPostLogout,
+    userInfo
+};
 
 function retryOriginalRequest(r) {
     delete r.headersOut["WWW-Authenticate"]; // Remove evidence of original failed auth_jwt
@@ -104,6 +115,11 @@ function auth(r, afterSyncCheck) {
                         // ID Token is valid, update keyval
                         r.log("OIDC refresh success, updating id_token for " + r.variables.cookie_auth_token);
                         r.variables.session_jwt = tokenset.id_token; // Update key-value store
+                        if (tokenset.access_token) {
+                            r.variables.access_token = tokenset.access_token;
+                        } else {
+                            r.variables.access_token = "-";
+                        }
 
                         // Update refresh token (if we got a new one)
                         if (r.variables.refresh_token != tokenset.refresh_token) {
@@ -187,6 +203,12 @@ function codeExchange(r) {
                         // Add opaque token to keyval session store
                         r.log("OIDC success, creating session " + r.variables.request_id);
                         r.variables.new_session = tokenset.id_token; // Create key-value store entry
+                        if (tokenset.access_token) {
+                            r.variables.new_access_token = tokenset.access_token;
+                        } else {
+                            r.variables.new_access_token = "-";
+                        }
+
                         r.headersOut["Set-Cookie"] = "auth_token=" + r.variables.request_id + "; " + r.variables.oidc_cookie_flags;
                         r.return(302, r.variables.redirect_base + r.variables.cookie_auth_redir);
                    }
@@ -253,11 +275,31 @@ function validateIdToken(r) {
     }
 }
 
+//
+// Default RP-Initiated or Custom Logout w/ OP.
+// 
+// - An RP requests that the OP log out the end-user by redirecting the
+//   end-user's User Agent to the OP's Logout endpoint.
+// - https://openid.net/specs/openid-connect-rpinitiated-1_0.html#RPLogout
+// - https://openid.net/specs/openid-connect-rpinitiated-1_0.html#RedirectionAfterLogout
+//
 function logout(r) {
     r.log("OIDC logout for " + r.variables.cookie_auth_token);
-    r.variables.session_jwt = "-";
-    r.variables.refresh_token = "-";
-    r.return(302, r.variables.oidc_logout_redirect);
+    var idToken = r.variables.session_jwt;
+    var queryParams = '?post_logout_redirect_uri=' + 
+                      r.variables.redirect_base + 
+                      r.variables.oidc_logout_redirect +
+                      '&id_token_hint=' + idToken;
+    if (r.variables.oidc_end_session_query_params_option == REPLACE_PARAMS) {
+        queryParams = '?' + r.variables.oidc_end_session_query_params;
+    } else if (r.variables.oidc_end_session_query_params_option == EXTRA_PARAMS) {
+        queryParams += '&' + r.variables.oidc_end_session_query_params;
+    } 
+    r.variables.request_id    = '-';
+    r.variables.session_jwt   = '-';
+    r.variables.access_token  = '-';
+    r.variables.refresh_token = '-';
+    r.return(302, r.variables.oidc_end_session_endpoint + queryParams);
 }
 
 function getAuthZArgs(r) {
@@ -298,4 +340,59 @@ function idpClientAuth(r) {
     } else {
         return "code=" + r.variables.arg_code + "&client_secret=" + r.variables.oidc_client_secret;
     }   
+}
+
+//
+// Redirect URI after successful login from the OP.
+//
+function redirectPostLogin(r) {
+    if (r.variables.oidc_landing_page) {
+        r.return(302, r.variables.oidc_landing_page);
+    } else {
+        r.return(302, r.variables.redirect_base + r.variables.cookie_auth_redir);
+    }
+}
+
+//
+// Redirect URI after logged-out from the OP.
+//
+function redirectPostLogout(r) {
+    r.return(302, r.variables.post_logout_return_uri);
+}
+
+//
+// Return necessary user info claims after receiving and extracting all claims
+// that are received from the OpenID Connect Provider(OP).
+//
+function userInfo(r) {
+    r.subrequest('/_userinfo',
+        function(res) {
+            if (res.status == 200) {
+                var error_log = "OIDC userinfo JSON failure";
+                var claimsOP = ''; // Claims that are received by the OP.
+                try {
+                    claimsOP = JSON.parse(res.responseBody);
+                } catch (e) {
+                    error_log += ": " + res.responseBody;
+                    r.error(error_log);
+                    r.return(500);
+                    return;
+                }
+                // The claimsRP is to extract claims that are configured in
+                // $oidc_userinfo_response_data in the RP and send them to
+                // the client using the response of the OP.
+                var claimsRP = r.variables.oidc_userinfo_response_data.split(",");
+                var ret = {};
+                for (var i in claimsRP) {
+                    if (claimsRP[i] in claimsOP) {
+                        ret[claimsRP[i]] = claimsOP[claimsRP[i]];
+                    }
+                }
+                r.variables.user_info = JSON.stringify(ret);
+                r.return(200, r.variables.user_info);
+            } else {
+                r.return(res.status)
+            }
+        }
+    );
 }
diff --git a/openid_connect.server_conf b/openid_connect.server_conf
@@ -1,7 +1,8 @@
     # Advanced configuration START
     set $internal_error_message "NGINX / OpenID Connect login failure\n";
     set $pkce_id "";
-    resolver 8.8.8.8; # For DNS lookup of IdP endpoints;
+    resolver 8.8.8.8; # For global DNS lookup of IDP endpoint
+
     subrequest_output_buffer_size 32k; # To fit a complete tokenset response
     gunzip on; # Decompress IdP responses if necessary
     # Advanced configuration END
@@ -42,7 +43,7 @@
         proxy_set_body        "grant_type=authorization_code&client_id=$oidc_client&$args&redirect_uri=$redirect_base$redir_location";
         proxy_method          POST;
         proxy_pass            $oidc_token_endpoint;
-   }
+    }
 
     location = /_refresh {
         # This location is called by oidcAuth() when performing a token refresh. We
@@ -66,17 +67,51 @@
         error_page 500 502 504 @oidc_error;
     }
 
+    location = /userinfo {
+        # This location is to provide signed-in user information claims that are
+        # defined in $oidc_userinfo_response_data.
+        default_type application/json;
+        if ($oidc_userinfo_response_data = '') {
+            return 200 '{"name": "", "message":"details not provided per your policy"}';
+        }
+        js_content oidc.userInfo;
+    }
+
+    location = /_userinfo {
+        # This location is called by oidc.userInfo() when calling /userinfo
+        # to get signed-in user information from the OP:
+        # - https://openid.net/specs/openid-connect-core-1_0.html#UserInfo
+        internal;
+        proxy_ssl_server_name on;             # For SNI to the IdP
+        proxy_set_header Authorization "Bearer $access_token";
+        proxy_pass       $oidc_userinfo_endpoint;
+    }
+
     location = /logout {
+        # RP-Initiated Logout to interact with $oidc_end_session_endpoint as per:
+        #  https://openid.net/specs/openid-connect-rpinitiated-1_0.html#RPLogout
         status_zone "OIDC logout";
-        add_header Set-Cookie "auth_token=; $oidc_cookie_flags"; # Send empty cookie
-        add_header Set-Cookie "auth_redir=; $oidc_cookie_flags"; # Erase original cookie
         js_content oidc.logout;
     }
 
     location = /_logout {
-        # This location is the default value of $oidc_logout_redirect (in case it wasn't configured)
+        # This location is a RP's callback URI that is the default value of 
+        # $oidc_logout_redirect which is called by OP after successful logout.
+
+        # Clean cookies
+        add_header Set-Cookie "auth_token=; $oidc_cookie_flags"; # Send empty cookie
+        add_header Set-Cookie "auth_redir=; $oidc_cookie_flags"; # Erase original cookie
+        add_header Set-Cookie "auth_nonce=; $oidc_cookie_flags"; 
+
+        # Enable one of the following examples.
+
+        # Example 1. Built-in, simple logout page
         default_type text/plain;
         return 200 "Logged out\n";
+
+        # Example 2. Redirect to either the landing page or custom logout page
+        #            using the map of $post_logout_return_uri.
+        #js_content oidc.redirectPostLogout;
     }
 
     location @oidc_error {

diff --git a/openid_connect_configuration.conf b/openid_connect_configuration.conf
@@ -28,6 +28,40 @@ map $host $oidc_jwt_keyfile {
     default "http://127.0.0.1:8080/auth/realms/master/protocol/openid-connect/certs";
 }
 
+map $host $oidc_end_session_endpoint {
+    default "http://127.0.0.1:8080/auth/realms/master/protocol/openid-connect/logout";
+}
+
+map $host $oidc_end_session_query_params_option {
+    # 0: default query params for the RP-initiated logout
+    # 1: extra query params is added after the default query params
+    # 2: replace default query params with custom query params
+    default 0;
+}
+
+map $host $oidc_end_session_query_params {
+    # Each IdP use different query params of the $oidc_end_session_endpoint. For
+    # example, The Amazon Cognito requires `client_id` and `logout_uri`. The
+    # Auth0 requires `client_id` and `returnTo`. If this option is empty, then
+    # `post_logout_redirect_uri` and `id_token_hint` are used as default query
+    # params, and the AzureAD/Okta/Keycloak/OneLogin/PingIdentity use them.
+    default "";
+    #www.example.com "client_id=$oidc_client&logout_uri=$redirect_base/_logout";
+}
+
+map $host $oidc_userinfo_endpoint {
+    default "http://127.0.0.1:8080/auth/realms/master/protocol/openid-connect/userinfo";
+}
+
+map $host $oidc_userinfo_response_data {
+    # The $oidc_userinfo_endpoint returns OP's response that contains default or
+    # customized claims. This is used for scenarios where the SPA needs to show
+    # user name or specific profiles instead of forwarding the response from the
+    # OP to the SPA to minimize exposure of user information.
+    default "";
+    #www.example.com "sub,name,preferred_username,given_name,family_name,email,photo";
+}
+
 map $host $oidc_client {
     default "my-client-id";
 }
@@ -44,12 +78,35 @@ map $host $oidc_scopes {
     default "openid+profile+email+offline_access";
 }
 
+map $host $oidc_landing_page {
+    # Where to send browser after successful login. This option is only 
+    # recommended for scenarios where a landing page shows default information
+    # without login, and the RP redirects to the landing page after successful
+    # login from the OP. If this is empty, then the RP redirects to $request_uri.
+    default "";
+    #www.example.com $redirect_base;
+}
+
 map $host $oidc_logout_redirect {
-    # Where to send browser after requesting /logout location. This can be
-    # replaced with a custom logout page, or complete URL.
+    # This is a RP's callback URI which is called by OP after successful logout.
     default "/_logout"; # Built-in, simple logout page
 }
 
+map $host $post_logout_return_uri {
+    # Where to send browser after the RP requests /logout to the OP, and after
+    # the RP (/_logout) is called by the OP and cleans cookies. The following
+    # examples can be replaced with a custom logout page, or a complete URL.
+
+    # Example 1: Redirect to the langding page.
+    default $oidc_landing_page;
+
+    # Example 2: Redirect to a custom logout page
+    #www.example.com $redirect_base/signout;
+
+    # Example 3: Redirect to an another complete URL
+    #www.example.com https://www.nginx.com;
+}
+
 map $host $oidc_hmac_key {
     # This should be unique for every NGINX instance/cluster
     default "ChangeMe";
@@ -87,15 +144,20 @@ map $http_x_forwarded_proto $proto {
 proxy_cache_path /var/cache/nginx/jwk levels=1 keys_zone=jwk:64k max_size=1m;
 
 # Change timeout values to at least the validity period of each token type
-keyval_zone zone=oidc_id_tokens:1M state=conf.d/oidc_id_tokens.json timeout=1h;
-keyval_zone zone=refresh_tokens:1M state=conf.d/refresh_tokens.json timeout=8h;
-keyval_zone zone=oidc_pkce:128K timeout=90s; # Temporary storage for PKCE code verifier.
-
-keyval $cookie_auth_token $session_jwt zone=oidc_id_tokens;   # Exchange cookie for JWT
-keyval $cookie_auth_token $refresh_token zone=refresh_tokens; # Exchange cookie for refresh token
-keyval $request_id $new_session zone=oidc_id_tokens; # For initial session creation
-keyval $request_id $new_refresh zone=refresh_tokens; # ''
-keyval $pkce_id $pkce_code_verifier zone=oidc_pkce;
+keyval_zone zone=oidc_id_tokens:1M     state=/var/lib/nginx/state/oidc_id_tokens.json     timeout=1h;
+keyval_zone zone=oidc_access_tokens:1M state=/var/lib/nginx/state/oidc_access_tokens.json timeout=1h;
+keyval_zone zone=refresh_tokens:1M     state=/var/lib/nginx/state/refresh_tokens.json     timeout=8h;
+keyval_zone zone=oidc_pkce:128K        timeout=90s; # Temporary storage for PKCE code verifier.
+keyval_zone zone=oidc_userinfo:128K    timeout=90s; # Temporary storage for user information.
+
+keyval $cookie_auth_token $session_jwt   zone=oidc_id_tokens;     # Exchange cookie for JWT
+keyval $cookie_auth_token $access_token  zone=oidc_access_tokens; # Exchange cookie for access token
+keyval $cookie_auth_token $refresh_token zone=refresh_tokens;     # Exchange cookie for refresh token
+keyval $request_id $new_session          zone=oidc_id_tokens;     # For initial session creation
+keyval $request_id $new_access_token     zone=oidc_access_tokens;
+keyval $request_id $new_refresh          zone=refresh_tokens;
+keyval $request_id $user_info            zone=oidc_userinfo;
+keyval $pkce_id    $pkce_code_verifier   zone=oidc_pkce;
 
 auth_jwt_claim_set $jwt_audience aud; # In case aud is an array
 js_import oidc from conf.d/openid_connect.js;