fix: session refresh loop in all request interceptors (#71)

Author: anku255

CHANGELOG.md

@@ -6,6 +6,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.5.0] - 2024-06-06
+
+### Changes
+
+- Fixed the session refresh loop in all the request interceptors that occurred when an API returned a 401 response despite a valid session. Interceptors now attempt to refresh the session a maximum of ten times before throwing an error. The retry limit is configurable via the `maxRetryAttemptsForSessionRefresh` option.
+
+
 ## [0.4.2] - 2024-05-28
 
 - re-Adds FDI 2.0 and 3.0 support

app/build.gradle

@@ -1,6 +1,6 @@
 apply plugin: 'com.android.library'
 apply plugin: 'maven-publish'
-def publishVersionID = "0.4.2"
+def publishVersionID = "0.5.0"
 
 android {
     compileSdkVersion 32

app/src/main/java/com/supertokens/session/SuperTokens.java

@@ -50,6 +50,7 @@ private static void init(
             @NonNull String apiDomain,
             @Nullable String apiBasePath,
             @Nullable Integer sessionExpiredStatusCode,
+            @Nullable Integer maxRetryAttemptsForSessionRefresh,
             @Nullable String sessionTokenBackendDomain,
             @Nullable String tokenTransferMethod,
             @Nullable CustomHeaderProvider customHeaderProvider,
@@ -63,6 +64,7 @@ private static void init(
                 apiDomain,
                 apiBasePath,
                 sessionExpiredStatusCode,
+                maxRetryAttemptsForSessionRefresh,
                 sessionTokenBackendDomain,
                 tokenTransferMethod,
                 customHeaderProvider,
@@ -260,6 +262,7 @@ public static class Builder {
         Context applicationContext;
         String apiBasePath;
         Integer sessionExpiredStatusCode;
+        Integer maxRetryAttemptsForSessionRefresh;
         String sessionTokenBackendDomain;
         CustomHeaderProvider customHeaderProvider;
         EventHandler eventHandler;
@@ -280,6 +283,11 @@ public Builder sessionExpiredStatusCode(Integer sessionExpiredStatusCode) {
             return this;
         }
 
+        public Builder maxRetryAttemptsForSessionRefresh(Integer maxRetryAttemptsForSessionRefresh) {
+            this.maxRetryAttemptsForSessionRefresh = maxRetryAttemptsForSessionRefresh;
+            return this;
+        }
+
         public Builder sessionTokenBackendDomain(String cookieDomain) {
             this.sessionTokenBackendDomain = cookieDomain;
             return this;
@@ -301,7 +309,7 @@ public Builder tokenTransferMethod(String tokenTransferMethod) {
         }
 
         public void build() throws MalformedURLException {
-            SuperTokens.init(applicationContext, apiDomain, apiBasePath, sessionExpiredStatusCode, sessionTokenBackendDomain, tokenTransferMethod, customHeaderProvider, eventHandler);
+            SuperTokens.init(applicationContext, apiDomain, apiBasePath, sessionExpiredStatusCode, maxRetryAttemptsForSessionRefresh, sessionTokenBackendDomain, tokenTransferMethod, customHeaderProvider, eventHandler);
         }
     }
 }

app/src/main/java/com/supertokens/session/SuperTokensHttpURLConnection.java

@@ -129,6 +129,7 @@ public static HttpURLConnection newRequest(URL url, PreConnectCallback preConnec
         }
 
         try {
+            int sessionRefreshAttempts = 0;
             while (true) {
                 HttpURLConnection connection;
                 SuperTokensCustomHttpURLConnection customConnection;
@@ -184,8 +185,22 @@ public static HttpURLConnection newRequest(URL url, PreConnectCallback preConnec
                 }
 
                 if (responseCode == SuperTokens.config.sessionExpiredStatusCode) {
+                    /**
+                     * An API may return a 401 error response even with a valid session, causing a session refresh loop in the interceptor.
+                     * To prevent this infinite loop, we break out of the loop after retrying the original request a specified number of times.
+                     * The maximum number of retry attempts is defined by maxRetryAttemptsForSessionRefresh config variable.
+                     */
+                    if (sessionRefreshAttempts >= SuperTokens.config.maxRetryAttemptsForSessionRefresh) {
+                        String errorMsg = "Received a 401 response from " + url + ". Attempted to refresh the session and retry the request with the updated session tokens " + SuperTokens.config.maxRetryAttemptsForSessionRefresh + " times, but each attempt resulted in a 401 error. The maximum session refresh limit has been reached. Please investigate your API. To increase the session refresh attempts, update maxRetryAttemptsForSessionRefresh in the config.";
+                        System.err.println(errorMsg);
+                        throw new IllegalAccessException(errorMsg);
+                    }
+
                     // Network call threw UnauthorisedAccess, try to call the refresh token endpoint and retry original call
                     Utils.Unauthorised unauthorisedResponse = SuperTokensHttpURLConnection.onUnauthorisedResponse(preRequestLocalSessionState, applicationContext);
+
+                    sessionRefreshAttempts++;
+
                     if (unauthorisedResponse.status != Utils.Unauthorised.UnauthorisedStatus.RETRY) {
 
                         if (unauthorisedResponse.error != null) {

app/src/main/java/com/supertokens/session/SuperTokensInterceptor.java

@@ -98,6 +98,7 @@ public Response intercept(@NotNull Chain chain) throws IOException {
         }
 
         try {
+            int sessionRefreshAttempts = 0;
             while (true) {
                 Request.Builder requestBuilder = chain.request().newBuilder();
                 Utils.LocalSessionState preRequestLocalSessionState;
@@ -134,6 +135,17 @@ public Response intercept(@NotNull Chain chain) throws IOException {
                 }
 
                 if (response.code() == SuperTokens.config.sessionExpiredStatusCode) {
+                    /**
+                     * An API may return a 401 error response even with a valid session, causing a session refresh loop in the interceptor.
+                     * To prevent this infinite loop, we break out of the loop after retrying the original request a specified number of times.
+                     * The maximum number of retry attempts is defined by maxRetryAttemptsForSessionRefresh config variable.
+                     */
+                    if (sessionRefreshAttempts >= SuperTokens.config.maxRetryAttemptsForSessionRefresh) {
+                        String errorMsg = "Received a 401 response from " + requestUrl + ". Attempted to refresh the session and retry the request with the updated session tokens " + SuperTokens.config.maxRetryAttemptsForSessionRefresh + " times, but each attempt resulted in a 401 error. The maximum session refresh limit has been reached. Please investigate your API. To increase the session refresh attempts, update maxRetryAttemptsForSessionRefresh in the config.";
+                        System.err.println(errorMsg);
+                        throw new IOException(errorMsg);
+                    }
+
                     // Cloning the response object, if retry is false then we return this
                     Response clonedResponse = new Response.Builder()
                             .body(response.peekBody(Long.MAX_VALUE))
@@ -152,6 +164,9 @@ public Response intercept(@NotNull Chain chain) throws IOException {
                     response.close();
 
                     Utils.Unauthorised unauthorisedResponse = onUnauthorisedResponse(preRequestLocalSessionState, applicationContext, chain);
+
+                    sessionRefreshAttempts++;
+
                     if (unauthorisedResponse.status != Utils.Unauthorised.UnauthorisedStatus.RETRY) {
                         if (unauthorisedResponse.error != null) {
                             throw unauthorisedResponse.error;

app/src/main/java/com/supertokens/session/Utils.java

@@ -83,6 +83,14 @@ public static class NormalisedInputType {
         String apiDomain;
         String apiBasePath;
         int sessionExpiredStatusCode;
+
+        /**
+         * This specifies the maximum number of times the interceptor will attempt to refresh
+         * the session  when a 401 Unauthorized response is received. If the number of retries
+         * exceeds this limit, no further attempts will be made to refresh the session, and
+         * and an error will be thrown.
+         */
+        int maxRetryAttemptsForSessionRefresh;
         String sessionTokenBackendDomain;
         CustomHeaderProvider customHeaderMapper;
         EventHandler eventHandler;
@@ -93,13 +101,15 @@ public NormalisedInputType(
                 String apiDomain,
                 String apiBasePath,
                 int sessionExpiredStatusCode,
+                int maxRetryAttemptsForSessionRefresh,
                 String sessionTokenBackendDomain,
                 String tokenTransferMethod,
                 CustomHeaderProvider customHeaderMapper,
                 EventHandler eventHandler) {
             this.apiDomain = apiDomain;
             this.apiBasePath = apiBasePath;
             this.sessionExpiredStatusCode = sessionExpiredStatusCode;
+            this.maxRetryAttemptsForSessionRefresh = maxRetryAttemptsForSessionRefresh;
             this.sessionTokenBackendDomain = sessionTokenBackendDomain;
             this.customHeaderMapper = customHeaderMapper;
             this.eventHandler = eventHandler;
@@ -153,6 +163,7 @@ public static NormalisedInputType normaliseInputOrThrowError(
                 String apiDomain,
                 @Nullable String apiBasePath,
                 @Nullable Integer sessionExpiredStatusCode,
+                @Nullable Integer maxRetryAttemptsForSessionRefresh,
                 @Nullable String sessionTokenBackendDomain,
                 @Nullable String tokenTransferMethod,
                 @Nullable CustomHeaderProvider customHeaderProvider,
@@ -169,6 +180,11 @@ public static NormalisedInputType normaliseInputOrThrowError(
                 _sessionExpiredStatusCode = sessionExpiredStatusCode;
             }
 
+            int _maxRetryAttemptsForSessionRefresh = 10;
+            if (maxRetryAttemptsForSessionRefresh != null) {
+                _maxRetryAttemptsForSessionRefresh = maxRetryAttemptsForSessionRefresh;
+            }
+
             String _sessionTokenBackendDomain = null;
             if (sessionTokenBackendDomain != null) {
                 _sessionTokenBackendDomain = normaliseSessionScopeOrThrowError(sessionTokenBackendDomain);
@@ -190,7 +206,7 @@ public static NormalisedInputType normaliseInputOrThrowError(
                 _tokenTransferMethod = tokenTransferMethod;
             }
 
-            return new NormalisedInputType(_apiDomain, _apiBasePath, _sessionExpiredStatusCode,
+            return new NormalisedInputType(_apiDomain, _apiBasePath, _sessionExpiredStatusCode, _maxRetryAttemptsForSessionRefresh,
                     _sessionTokenBackendDomain, _tokenTransferMethod, _customHeaderProvider, _eventHandler);
         }
     }

examples/with-thirdparty/README.md

@@ -20,10 +20,10 @@ dependencyResolutionManagement {
 }
 ```
 
-Add the folliwing to your app level `build.gradle`
+Add the following to your app level `build.gradle`
 
 ```gradle
-implementation("com.github.supertokens:supertokens-android:0.4.2")
+implementation("com.github.supertokens:supertokens-android:0.5.0")
 implementation ("com.google.android.gms:play-services-auth:20.7.0")
 implementation("com.squareup.retrofit2:retrofit:2.9.0")
 implementation("net.openid:appauth:0.11.1")

examples/with-thirdparty/app/build.gradle.kts

@@ -41,7 +41,7 @@ dependencies {
     implementation("androidx.appcompat:appcompat:1.6.1")
     implementation("com.google.android.material:material:1.8.0")
     implementation("androidx.constraintlayout:constraintlayout:2.1.4")
-    implementation("com.github.supertokens:supertokens-android:0.4.0")
+    implementation("com.github.supertokens:supertokens-android:0.5.0")
     implementation ("com.google.android.gms:play-services-auth:20.7.0")
     implementation("com.squareup.retrofit2:retrofit:2.9.0")
     implementation("net.openid:appauth:0.11.1")

testHelpers/server/index.js

@@ -507,6 +507,10 @@ app.get("/testError", (req, res) => {
     res.status(500).send("test error message");
 });
 
+app.get("/throw-401", (req, res) => {
+    res.status(401).send("Unauthorised");
+})
+
 app.get("/stop", async (req, res) => {
     process.exit();
 });