Merge pull request #82 from DolphFlynn/brute

Brute

README.md

@@ -17,6 +17,10 @@ Additionally it facilitates several well-known attacks against JWT implementatio
 
 ## Changelog
 
+**Unreleased**
+- Add ability to test for HMAC signatures using [weak secrets](https://github.com/wallarm/jwt-secrets).
+- Remember last used key within Signing dialog.
+
 **2.4 2024-12-24**
 - Add support for non-JSON claims within JWS (Thanks to [@Hannah-PortSwigger](https://github.com/Hannah-PortSwigger) for suggesting this).
 
@@ -150,6 +154,7 @@ The `Attack` option implements several well-known attacks against JSON Web Signa
 * Signing with an empty HMAC key
 * Signing with a *Psychic signature*
 * Embedding a Collaborator payload
+* Weak HMAC secret
 
 These are described in more detail [below](#Attacks).
 
@@ -218,6 +223,9 @@ Burp Suite's [Collaborator](https://portswigger.net/burp/documentation/collabora
 is fetching content based on the `x5u` or `jku` headers. 
 Note that this functionality is only available in Burp Suite Professional.
 
+### Weak HMAC secret
+Attempt to brute-force the signing key for JWS with HMAC signatures using known [JWT secrets](https://github.com/wallarm/jwt-secrets).
+
 ## Issues / Enhancements
 If you have found a bug or think that a particular feature is missing, please raise an issue on the [GitHub repository](https://github.com/DolphFlynn/jwt-editor/issues).
 

src/main/java/com/blackberry/jwteditor/model/jose/Header.java

@@ -23,6 +23,7 @@
 
 import static com.blackberry.jwteditor.utils.JSONUtils.isJsonCompact;
 import static com.blackberry.jwteditor.utils.JSONUtils.prettyPrintJSON;
+import static com.nimbusds.jose.HeaderParameterNames.ALGORITHM;
 
 public class Header extends Base64Encoded {
 
@@ -44,4 +45,9 @@ public JSONObject json()
     {
         return new JSONObject(decoded());
     }
+
+    public String algorithm() {
+        JSONObject json = json();
+        return json.has(ALGORITHM) ? json.getString(ALGORITHM) : "";
+    }
 }

src/main/java/com/blackberry/jwteditor/operations/weak/ErrorLoggingRunnable.java

@@ -0,0 +1,44 @@
+/*
+Author : Dolph Flynn
+
+Copyright 2025 Dolph Flynn
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package com.blackberry.jwteditor.operations.weak;
+
+import burp.api.montoya.logging.Logging;
+
+class ErrorLoggingRunnable implements Runnable {
+    interface Task {
+        void action() throws Exception;
+    }
+
+    private final Logging logging;
+    private final Task task;
+
+    ErrorLoggingRunnable(Logging logging, Task task) {
+        this.logging = logging;
+        this.task = task;
+    }
+
+    @Override
+    public void run() {
+        try {
+            task.action();
+        } catch (Exception e) {
+            logging.logToError(e);
+        }
+    }
+}

src/main/java/com/blackberry/jwteditor/operations/weak/WeakSecretFinder.java

@@ -0,0 +1,79 @@
+/*
+Author : Dolph Flynn
+
+Copyright 2025 Dolph Flynn
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package com.blackberry.jwteditor.operations.weak;
+
+import burp.api.montoya.logging.Logging;
+import com.blackberry.jwteditor.model.jose.JWS;
+
+import java.io.Closeable;
+import java.util.concurrent.ExecutorService;
+
+import static com.blackberry.jwteditor.operations.weak.WeakSecretsFinderStatus.*;
+import static java.util.concurrent.Executors.newSingleThreadExecutor;
+
+public class WeakSecretFinder implements Closeable {
+    private final ExecutorService executorService;
+    private final WeakSecretsFinderModel model;
+    private final Logging logging;
+
+    public WeakSecretFinder(WeakSecretsFinderModel model, Logging logging) {
+        this.model = model;
+        this.logging = logging;
+        this.executorService = newSingleThreadExecutor();
+    }
+
+    public void bruteForce(JWS jws) {
+        executorService.submit(new ErrorLoggingRunnable(logging, new Worker(model, jws)));
+    }
+
+    @Override
+    public void close() {
+        executorService.shutdown();
+    }
+
+    private static class Worker implements ErrorLoggingRunnable.Task {
+        private final WeakSecrets weakSecrets;
+        private final WeakSecretsFinderModel model;
+        private final WeakSecretTester tester;
+
+        private Worker(WeakSecretsFinderModel model, JWS jws) {
+            this.model = model;
+            this.weakSecrets = new WeakSecrets();
+            this.tester = new WeakSecretTester(jws);
+        }
+
+        @Override
+        public void action() throws Exception {
+            String secret;
+
+            while (model.status() == RUNNING && (secret = weakSecrets.next()) != null) {
+                model.setProgress(weakSecrets.progress());
+
+                if (tester.isSecretCorrect(secret)) {
+                    model.setStatus(SUCCESS);
+                    model.setSecret(secret);
+                }
+            }
+
+            if (model.status() == RUNNING) {
+                model.setStatus(FAILED);
+            }
+        }
+    }
+}

src/main/java/com/blackberry/jwteditor/operations/weak/WeakSecretTester.java

@@ -0,0 +1,49 @@
+/*
+Author : Dolph Flynn
+
+Copyright 2025 Dolph Flynn
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package com.blackberry.jwteditor.operations.weak;
+
+import com.blackberry.jwteditor.model.jose.JWS;
+import com.blackberry.jwteditor.model.keys.JWKKey;
+import com.blackberry.jwteditor.model.keys.JWKKeyFactory;
+import com.nimbusds.jose.JWSAlgorithm;
+import com.nimbusds.jose.JWSHeader;
+import com.nimbusds.jose.jwk.JWK;
+import com.nimbusds.jose.jwk.OctetSequenceKey;
+import com.nimbusds.jose.util.Base64URL;
+
+class WeakSecretTester {
+    private final JWS jws;
+    private final JWSHeader verificationInfo;
+
+    public WeakSecretTester(JWS jws) {
+        this.jws = jws;
+
+        JWSAlgorithm algorithm = JWSAlgorithm.parse(jws.header().algorithm());
+        this.verificationInfo = new JWSHeader.Builder(algorithm).build();
+    }
+
+    boolean isSecretCorrect(String secret) throws Exception {
+        Base64URL encodedSecret = Base64URL.encode(secret);
+
+        JWK key = new OctetSequenceKey.Builder(encodedSecret).build();
+        JWKKey jwkKey = JWKKeyFactory.from(key);
+
+        return jws.verify(jwkKey, verificationInfo);
+    }
+}

src/main/java/com/blackberry/jwteditor/operations/weak/WeakSecrets.java

@@ -0,0 +1,58 @@
+/*
+Author : Dolph Flynn
+
+Copyright 2024 Dolph Flynn
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package com.blackberry.jwteditor.operations.weak;
+
+import java.io.*;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import static java.nio.charset.StandardCharsets.UTF_8;
+
+// Secret Source: https://github.com/wallarm/jwt-secrets
+class WeakSecrets {
+    private static final int TOTAL_NUMBER_OF_SECRETS = 103975;
+
+    private final BufferedReader bufferedReader;
+    private final Object lock;
+    private final AtomicInteger counter;
+
+    WeakSecrets() {
+        InputStream inputStream = this.getClass().getResourceAsStream("/jwt.secrets.list.txt");
+
+        this.bufferedReader = new BufferedReader(new InputStreamReader(inputStream, UTF_8));
+        this.lock = new Object();
+        this.counter = new AtomicInteger();
+    }
+
+    String next() {
+        synchronized (lock) {
+            counter.incrementAndGet();
+
+            try {
+                return bufferedReader.readLine();
+            } catch (IOException e) {
+                throw new UncheckedIOException(e);
+            }
+        }
+    }
+
+    int progress() {
+        double progress = (100.0 * counter.get()) / TOTAL_NUMBER_OF_SECRETS;
+        return (int) progress;
+    }
+}

src/main/java/com/blackberry/jwteditor/operations/weak/WeakSecretsFinderModel.java

@@ -0,0 +1,60 @@
+/*
+Author : Dolph Flynn
+
+Copyright 2024 Dolph Flynn
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package com.blackberry.jwteditor.operations.weak;
+
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
+
+import static com.blackberry.jwteditor.operations.weak.WeakSecretsFinderStatus.RUNNING;
+
+public class WeakSecretsFinderModel {
+    private final AtomicInteger percentageComplete;
+    private final AtomicReference<WeakSecretsFinderStatus> status;
+    private final AtomicReference<String> secret;
+
+    public WeakSecretsFinderModel() {
+        this.percentageComplete = new AtomicInteger();
+        this.status = new AtomicReference<>(RUNNING);
+        this.secret = new AtomicReference<>();
+    }
+
+    void setProgress(int percentageComplete) {
+        this.percentageComplete.set(percentageComplete);
+    }
+
+    public int progress() {
+        return percentageComplete.get();
+    }
+
+    void setSecret(String secret) {
+        this.secret.set(secret);
+    }
+
+    public String secret() {
+        return secret.get();
+    }
+
+    public void setStatus(WeakSecretsFinderStatus status) {
+        this.status.set(status);
+    }
+
+    public WeakSecretsFinderStatus status() {
+        return status.get();
+    }
+}

src/main/java/com/blackberry/jwteditor/operations/weak/WeakSecretsFinderStatus.java

@@ -0,0 +1,23 @@
+/*
+Author : Dolph Flynn
+
+Copyright 2025 Dolph Flynn
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package com.blackberry.jwteditor.operations.weak;
+
+public enum WeakSecretsFinderStatus {
+    RUNNING, SUCCESS, CANCELLED, FAILED
+}

src/main/java/com/blackberry/jwteditor/presenter/EditorPresenter.java

@@ -29,6 +29,7 @@
 import com.blackberry.jwteditor.view.dialog.operations.*;
 import com.blackberry.jwteditor.view.editor.EditorMode;
 import com.blackberry.jwteditor.view.editor.EditorView;
+import com.blackberry.jwteditor.view.weak.WeakKeyAttackDialog;
 import com.nimbusds.jose.util.Base64URL;
 import org.json.JSONException;
 
@@ -252,6 +253,18 @@ public void onAttackEmbedCollaboratorPayloadClicked() {
         showDialogAndUpdateJWS(dialog);
     }
 
+    public void onAttackWeakHMACSecret() {
+        JWS jws = getJWS();
+
+        if (!jws.header().algorithm().startsWith("HS")) {
+            messageDialogFactory.showWarningDialog("error_title_unable_to_attack_weak_symmetric", "error_unable_to_attack_weak_symmetric");
+            return;
+        }
+
+        WeakKeyAttackDialog dialog = new WeakKeyAttackDialog(view.window(), logging, getJWS());
+        dialog.display();
+    }
+
     public void onSignClicked() {
         signingDialog(SigningDialog.Mode.NORMAL);
     }