use refresh tokens

src/lib.rs

@@ -1,5 +1,7 @@
 #![doc = include_str!("../README.md")]
 
+use std::str::FromStr;
+
 use crate::error::Error;
 use http::Uri;
 use openidconnect::{
@@ -11,14 +13,13 @@ use openidconnect::{
     },
     reqwest::async_http_client,
     ClientId, ClientSecret, CsrfToken, EmptyExtraTokenFields, IdTokenFields, IssuerUrl, Nonce,
-    PkceCodeVerifier, StandardErrorResponse, StandardTokenResponse,
+    PkceCodeVerifier, RefreshToken, StandardErrorResponse, StandardTokenResponse,
 };
 use serde::{Deserialize, Serialize};
 
 pub mod error;
 mod extractor;
 mod middleware;
-mod util;
 
 pub use extractor::{OidcAccessToken, OidcClaims};
 pub use middleware::{OidcAuthLayer, OidcAuthMiddleware, OidcLoginLayer, OidcLoginMiddleware};
@@ -89,7 +90,7 @@ impl<AC: AdditionalClaims> OidcClient<AC> {
         let client = Client::from_provider_metadata(
             provider_metadata,
             ClientId::new(client_id),
-            client_secret.map(|x| ClientSecret::new(x)),
+            client_secret.map(ClientSecret::new),
         );
         Ok(Self {
             scopes,
@@ -122,4 +123,18 @@ struct OidcSession {
     pkce_verifier: PkceCodeVerifier,
     id_token: Option<String>,
     access_token: Option<String>,
+    refresh_token: Option<String>,
+}
+
+impl OidcSession {
+    pub(crate) fn id_token<AC: AdditionalClaims>(&self) -> Option<IdToken<AC>> {
+        self.id_token
+            .as_ref()
+            .map(|x| IdToken::<AC>::from_str(x).unwrap())
+    }
+    pub(crate) fn refresh_token(&self) -> Option<RefreshToken> {
+        self.refresh_token
+            .as_ref()
+            .map(|x| RefreshToken::new(x.to_string()))
+    }
 }

src/middleware.rs

@@ -10,21 +10,25 @@ use axum::{
 };
 use axum_core::{extract::FromRequestParts, response::Response};
 use futures_util::future::BoxFuture;
-use http::{Request, Uri};
+use http::{uri::PathAndQuery, Request, Uri};
 use tower_layer::Layer;
 use tower_service::Service;
 use tower_sessions::Session;
 
 use openidconnect::{
-    core::CoreAuthenticationFlow, reqwest::async_http_client, AccessTokenHash, AuthorizationCode,
-    CsrfToken, Nonce, OAuth2TokenResponse, PkceCodeChallenge, PkceCodeVerifier, RedirectUrl, Scope,
-    TokenResponse,
+    core::{
+        CoreAuthenticationFlow, CoreGenderClaim, CoreIdTokenFields, CoreJsonWebKeyType,
+        CoreJweContentEncryptionAlgorithm, CoreJwsSigningAlgorithm,
+    },
+    reqwest::async_http_client,
+    AccessTokenHash, AuthorizationCode, CsrfToken, ExtraTokenFields, IdTokenFields, Nonce,
+    OAuth2TokenResponse, PkceCodeChallenge, PkceCodeVerifier, RedirectUrl, RefreshToken, Scope,
+    StandardTokenResponse, TokenResponse, TokenType,
 };
 
 use crate::{
     error::{Error, MiddlewareError},
     extractor::{OidcAccessToken, OidcClaims},
-    util::strip_oidc_from_path,
     AdditionalClaims, BoxError, IdToken, OidcClient, OidcQuery, OidcSession, SESSION_KEY,
 };
 
@@ -93,14 +97,16 @@ where
         let mut inner = std::mem::replace(&mut self.inner, inner);
 
         if request.extensions().get::<OidcAccessToken>().is_some() {
+            // the OidcAuthMiddleware had a valid id token
             Box::pin(async move {
                 let response: Response = inner
                     .call(request)
                     .await
                     .map_err(|e| MiddlewareError::NextMiddleware(e.into()))?;
-                return Ok(response);
+                Ok(response)
             })
         } else {
+            // no valid id token or refresh token was found and the user has to login
             Box::pin(async move {
                 let (mut parts, _) = request.into_parts();
 
@@ -129,6 +135,9 @@ where
                     .set_redirect_uri(RedirectUrl::new(handler_uri.to_string())?);
 
                 if let (Some(mut login_session), Some(query)) = (login_session, query) {
+                    // the request has the request headers of the oidc redirect
+                    // parse the headers and exchange the code for a valid token
+
                     if login_session.csrf_token.secret() != &query.state {
                         return Err(MiddlewareError::CsrfTokenInvalid);
                     }
@@ -165,11 +174,16 @@ where
                     login_session.id_token = Some(id_token.to_string());
                     login_session.access_token =
                         Some(token_response.access_token().secret().to_string());
+                    login_session.refresh_token = token_response
+                        .refresh_token()
+                        .map(|x| x.secret().to_string());
 
                     session.insert(SESSION_KEY, login_session).unwrap();
 
                     Ok(Redirect::temporary(&handler_uri.to_string()).into_response())
                 } else {
+                    // generate a login url and redirect the user to it
+
                     let (pkce_challenge, pkce_verifier) = PkceCodeChallenge::new_random_sha256();
                     let (auth_url, csrf_token, nonce) = {
                         let mut auth = oidcclient.client.authorize_url(
@@ -191,6 +205,7 @@ where
                         pkce_verifier,
                         id_token: None,
                         access_token: None,
+                        refresh_token: None,
                     };
 
                     session.insert(SESSION_KEY, oidc_session).unwrap();
@@ -293,7 +308,7 @@ where
                 .extensions
                 .get::<Session>()
                 .ok_or(MiddlewareError::SessionNotFound)?;
-            let login_session: Option<OidcSession> =
+            let mut login_session: Option<OidcSession> =
                 session.get(SESSION_KEY).map_err(MiddlewareError::from)?;
 
             let handler_uri =
@@ -303,20 +318,75 @@ where
                 .client
                 .set_redirect_uri(RedirectUrl::new(handler_uri.to_string())?);
 
-            if let Some(OidcSession {
-                nonce,
-                csrf_token: _,
-                pkce_verifier: _,
-                id_token: Some(id_token),
-                access_token,
-            }) = &login_session
-            {
-                let id_token = IdToken::<AC>::from_str(&id_token).unwrap();
-                if let Ok(claims) = id_token.claims(&oidcclient.client.id_token_verifier(), nonce) {
+            if let Some(login_session) = &mut login_session {
+                let id_token_claims = login_session.id_token::<AC>().and_then(|id_token| {
+                    id_token
+                        .claims(&oidcclient.client.id_token_verifier(), &login_session.nonce)
+                        .ok()
+                        .cloned()
+                });
+
+                match (id_token_claims, login_session.refresh_token()) {
+                    // stored id token is valid and can be used
+                    (Some(claims), _) => {
+                        parts.extensions.insert(OidcClaims(claims));
+                        parts.extensions.insert(OidcAccessToken(
+                            login_session.access_token.clone().unwrap_or_default(),
+                        ));
+                    }
+                    // stored id token is invalid and can't be uses, but we have a refresh token
+                    // and can use it and try to get another id token.
+                    (_, Some(refresh_token)) => {
+                        let mut refresh_request =
+                            oidcclient.client.exchange_refresh_token(&refresh_token);
+
+                        for scope in oidcclient.scopes.iter() {
+                            refresh_request =
+                                refresh_request.add_scope(Scope::new(scope.to_string()));
+                        }
+
+                        let token_response =
+                            refresh_request.request_async(async_http_client).await?;
+
+                        // Extract the ID token claims after verifying its authenticity and nonce.
+                        let id_token = token_response
+                            .id_token()
+                            .ok_or(MiddlewareError::IdTokenMissing)?;
+                        let claims = id_token
+                            .claims(&oidcclient.client.id_token_verifier(), &login_session.nonce)?;
+
+                        // Verify the access token hash to ensure that the access token hasn't been substituted for
+                        // another user's.
+                        if let Some(expected_access_token_hash) = claims.access_token_hash() {
+                            let actual_access_token_hash = AccessTokenHash::from_token(
+                                token_response.access_token(),
+                                &id_token.signing_alg()?,
+                            )?;
+                            if actual_access_token_hash != *expected_access_token_hash {
+                                return Err(MiddlewareError::AccessTokenHashInvalid);
+                            }
+                        }
+
+                        login_session.id_token = Some(id_token.to_string());
+                        login_session.access_token =
+                            Some(token_response.access_token().secret().to_string());
+                        login_session.refresh_token = token_response
+                            .refresh_token()
+                            .map(|x| x.secret().to_string());
+
                         parts.extensions.insert(OidcClaims(claims.clone()));
-                    parts
+                        parts.extensions.insert(OidcAccessToken(
+                            login_session.access_token.clone().unwrap_or_default(),
+                        ));
+
+                        let session = parts
                             .extensions
-                        .insert(OidcAccessToken(access_token.clone().unwrap_or_default()));
+                            .get::<Session>()
+                            .ok_or(MiddlewareError::SessionNotFound)?;
+
+                        session.insert(SESSION_KEY, login_session).unwrap();
+                    }
+                    (None, None) => {}
                 }
             }
 
@@ -328,7 +398,37 @@ where
                 .await
                 .map_err(|e| MiddlewareError::NextMiddleware(e.into()))?
                 .into_response();
-            return Ok(response);
+            Ok(response)
         })
     }
 }
+
+/// Helper function to remove the OpenID Connect authentication response query attributes from a
+/// [`Uri`].
+pub fn strip_oidc_from_path(base_url: Uri, uri: &Uri) -> Result<Uri, MiddlewareError> {
+    let mut base_url = base_url.into_parts();
+
+    base_url.path_and_query = uri
+        .path_and_query()
+        .map(|path_and_query| {
+            let query = path_and_query
+                .query()
+                .and_then(|uri| {
+                    uri.split('&')
+                        .filter(|x| {
+                            !x.starts_with("code")
+                                && !x.starts_with("state")
+                                && !x.starts_with("session_state")
+                        })
+                        .map(|x| x.to_string())
+                        .reduce(|acc, x| acc + "&" + &x)
+                })
+                .map(|x| format!("?{x}"))
+                .unwrap_or_default();
+
+            PathAndQuery::from_maybe_shared(format!("{}{}", path_and_query.path(), query))
+        })
+        .transpose()?;
+
+    Ok(Uri::from_parts(base_url)?)
+}

src/util.rs

@@ -1,33 +0,0 @@
-use http::{uri::PathAndQuery, Uri};
-
-use crate::error::MiddlewareError;
-
-/// Helper function to remove the OpenID Connect authentication response query attributes from a
-/// [`Uri`].
-pub fn strip_oidc_from_path(base_url: Uri, uri: &Uri) -> Result<Uri, MiddlewareError> {
-    let mut base_url = base_url.into_parts();
-
-    base_url.path_and_query = uri
-        .path_and_query()
-        .map(|path_and_query| {
-            let query = path_and_query
-                .query()
-                .and_then(|uri| {
-                    uri.split('&')
-                        .filter(|x| {
-                            !x.starts_with("code")
-                                && !x.starts_with("state")
-                                && !x.starts_with("session_state")
-                        })
-                        .map(|x| x.to_string())
-                        .reduce(|acc, x| acc + "&" + &x)
-                })
-                .map(|x| "?" + x)
-                .unwrap_or_default();
-
-            PathAndQuery::from_maybe_shared(format!("{}{}", path_and_query.path(), query))
-        })
-        .transpose()?;
-
-    Ok(Uri::from_parts(base_url)?)
-}