docs(samples): add password leak sample and test

README.md

@@ -123,6 +123,7 @@ Samples are in the [`samples/`](https://github.com/googleapis/java-recaptchaente
 | List Related Account Group Memberships | [source code](https://github.com/googleapis/java-recaptchaenterprise/blob/main/samples/snippets/cloud-client/src/main/java/recaptcha/account_defender/ListRelatedAccountGroupMemberships.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-recaptchaenterprise&page=editor&open_in_editor=samples/snippets/cloud-client/src/main/java/recaptcha/account_defender/ListRelatedAccountGroupMemberships.java) |
 | List Related Account Groups | [source code](https://github.com/googleapis/java-recaptchaenterprise/blob/main/samples/snippets/cloud-client/src/main/java/recaptcha/account_defender/ListRelatedAccountGroups.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-recaptchaenterprise&page=editor&open_in_editor=samples/snippets/cloud-client/src/main/java/recaptcha/account_defender/ListRelatedAccountGroups.java) |
 | Search Related Account Group Memberships | [source code](https://github.com/googleapis/java-recaptchaenterprise/blob/main/samples/snippets/cloud-client/src/main/java/recaptcha/account_defender/SearchRelatedAccountGroupMemberships.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-recaptchaenterprise&page=editor&open_in_editor=samples/snippets/cloud-client/src/main/java/recaptcha/account_defender/SearchRelatedAccountGroupMemberships.java) |
+| Create Password Leak Assessment | [source code](https://github.com/googleapis/java-recaptchaenterprise/blob/main/samples/snippets/cloud-client/src/main/java/recaptcha/passwordleak/CreatePasswordLeakAssessment.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-recaptchaenterprise&page=editor&open_in_editor=samples/snippets/cloud-client/src/main/java/recaptcha/passwordleak/CreatePasswordLeakAssessment.java) |
 
 
 

samples/snippets/cloud-client/src/main/java/recaptcha/passwordleak/CreatePasswordLeakAssessment.java

@@ -0,0 +1,214 @@
+/*
+ * Copyright 2022 Google LLC
+ *
+ * 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 passwordleak;
+
+// [START recaptcha_enterprise_password_leak_verification]
+
+import com.google.cloud.recaptcha.passwordcheck.PasswordCheckResult;
+import com.google.cloud.recaptcha.passwordcheck.PasswordCheckVerification;
+import com.google.cloud.recaptcha.passwordcheck.PasswordCheckVerifier;
+import com.google.cloud.recaptchaenterprise.v1.RecaptchaEnterpriseServiceClient;
+import com.google.protobuf.ByteString;
+import com.google.recaptchaenterprise.v1.Assessment;
+import com.google.recaptchaenterprise.v1.CreateAssessmentRequest;
+import com.google.recaptchaenterprise.v1.Event;
+import com.google.recaptchaenterprise.v1.PrivatePasswordLeakVerification;
+import com.google.recaptchaenterprise.v1.TokenProperties;
+import java.io.IOException;
+import java.util.List;
+import java.util.concurrent.ExecutionException;
+import java.util.stream.Collectors;
+
+public class CreatePasswordLeakAssessment {
+
+  public static void main(String[] args)
+      throws IOException, ExecutionException, InterruptedException {
+    // TODO(developer): Replace these variables before running the sample.
+    // GCloud Project ID.
+    String projectID = "project-id";
+
+    // Site key obtained by registering a domain/app to use recaptcha Enterprise.
+    String recaptchaSiteKey = "recaptcha-site-key";
+
+    // The token obtained from the client on passing the recaptchaSiteKey.
+    // To get the token, integrate the recaptchaSiteKey with frontend. See,
+    // https://cloud.google.com/recaptcha-enterprise/docs/instrument-web-pages#frontend_integration_score
+    String token = "recaptcha-token";
+
+    // Action name corresponding to the token.
+    String recaptchaAction = "recaptcha-action";
+
+    checkPasswordLeak(projectID, recaptchaSiteKey, token, recaptchaAction);
+  }
+
+  /*
+   * Detect password leaks and breached credentials to prevent account takeovers (ATOs)
+   * and credential stuffing attacks.
+   * For more information, see: https://cloud.google.com/recaptcha-enterprise/docs/getting-started
+   * and https://security.googleblog.com/2019/02/protect-your-accounts-from-data.html
+   * Steps:
+   * 1. Use the 'createVerification' method to hash and Encrypt the hashed username and password.
+   * 2. Send the hash prefix (2-byte) and the encrypted credentials to create the assessment.
+   * (Hash prefix is used to partition the database.)
+   * 3. Password leak assessment returns a database whose prefix matches the sent hash prefix.
+   * Create Assessment also sends back re-encrypted credentials.
+   * 4. The re-encrypted credential is then locally verified to see if there is a
+   * match in the database.
+   *
+   * To perform hashing, encryption and verification (steps 1, 2 and 4),
+   * reCAPTCHA Enterprise provides a helper library in Java.
+   * See, https://github.com/GoogleCloudPlatform/java-recaptcha-password-check-helpers
+   *
+   * If you want to extend this behavior to your own implementation/ languages,
+   * make sure to perform the following steps:
+   * 1. Hash the credentials (First 2 bytes of the result is the 'lookupHashPrefix')
+   * 2. Encrypt the hash (result = 'encryptedUserCredentialsHash')
+   * 3. Get back the PasswordLeak information from reCAPTCHA Enterprise Create Assessment.
+   * 4. Decrypt the obtained 'credentials.getReencryptedUserCredentialsHash()'
+   * with the same key you used for encryption.
+   * 5. Check if the decrypted credentials are present in 'credentials.getEncryptedLeakMatchPrefixesList()'.
+   * 6. If there is a match, that indicates a credential breach.
+   */
+  public static void checkPasswordLeak(
+      String projectID, String recaptchaSiteKey, String token, String recaptchaAction)
+      throws ExecutionException, InterruptedException, IOException {
+    // Set the username and password to be checked.
+    String username = "username";
+    String password = "password123";
+
+    // Instantiate the java-password-leak-helper library to perform the cryptographic functions.
+    PasswordCheckVerifier passwordLeak = new PasswordCheckVerifier();
+
+    // Create the request to obtain the hash prefix and encrypted credentials.
+    PasswordCheckVerification verification =
+        passwordLeak.createVerification(username, password).get();
+
+    byte[] lookupHashPrefix = verification.getLookupHashPrefix();
+    byte[] encryptedUserCredentialsHash = verification.getEncryptedLookupHash();
+
+    // Pass the credentials to the createPasswordLeakAssessment() to get back
+    // the matching database entry for the hash prefix.
+    PrivatePasswordLeakVerification credentials =
+        createPasswordLeakAssessment(
+            projectID,
+            recaptchaSiteKey,
+            token,
+            recaptchaAction,
+            lookupHashPrefix,
+            encryptedUserCredentialsHash);
+
+    // Convert to appropriate input format.
+    List<byte[]> leakMatchPrefixes =
+        credentials.getEncryptedLeakMatchPrefixesList().stream()
+            .map(ByteString::toByteArray)
+            .collect(Collectors.toList());
+
+    // Verify if the encrypted credentials are present in the obtained match list.
+    PasswordCheckResult result =
+        passwordLeak
+            .verify(
+                verification,
+                credentials.getReencryptedUserCredentialsHash().toByteArray(),
+                leakMatchPrefixes)
+            .get();
+
+    // Check if the credential is leaked.
+    boolean isLeaked = result.areCredentialsLeaked();
+    System.out.printf("Is Credential leaked: %s", isLeaked);
+  }
+
+  // Create a reCAPTCHA Enterprise assessment.
+  // Returns:  PrivatePasswordLeakVerification which contains
+  // reencryptedUserCredentialsHash and credential breach database
+  // whose prefix matches the lookupHashPrefix.
+  private static PrivatePasswordLeakVerification createPasswordLeakAssessment(
+      String projectID,
+      String recaptchaSiteKey,
+      String token,
+      String recaptchaAction,
+      byte[] lookupHashPrefix,
+      byte[] encryptedUserCredentialsHash)
+      throws IOException {
+    try (RecaptchaEnterpriseServiceClient client = RecaptchaEnterpriseServiceClient.create()) {
+
+      // Set the properties of the event to be tracked.
+      Event event = Event.newBuilder().setSiteKey(recaptchaSiteKey).setToken(token).build();
+
+      // Set the hashprefix and credentials hash.
+      // Setting this will trigger the Password leak protection.
+      PrivatePasswordLeakVerification passwordLeakVerification =
+          PrivatePasswordLeakVerification.newBuilder()
+              .setLookupHashPrefix(ByteString.copyFrom(lookupHashPrefix))
+              .setEncryptedUserCredentialsHash(ByteString.copyFrom(encryptedUserCredentialsHash))
+              .build();
+
+      // Build the assessment request.
+      CreateAssessmentRequest createAssessmentRequest =
+          CreateAssessmentRequest.newBuilder()
+              .setParent(String.format("projects/%s", projectID))
+              .setAssessment(
+                  Assessment.newBuilder()
+                      .setEvent(event)
+                      // Set request for Password leak verification.
+                      .setPrivatePasswordLeakVerification(passwordLeakVerification)
+                      .build())
+              .build();
+
+      // Send the create assessment request.
+      Assessment response = client.createAssessment(createAssessmentRequest);
+
+      // Check validity and integrity of the response.
+      if (!checkTokenIntegrity(response.getTokenProperties(), recaptchaAction)) {
+        return passwordLeakVerification;
+      }
+
+      // Get the reCAPTCHA Enterprise score.
+      float recaptchaScore = response.getRiskAnalysis().getScore();
+      System.out.println("The reCAPTCHA score is: " + recaptchaScore);
+
+      // Get the assessment name (id). Use this to annotate the assessment.
+      String assessmentName = response.getName();
+      System.out.println(
+          "Assessment name: " + assessmentName.substring(assessmentName.lastIndexOf("/") + 1));
+
+      return response.getPrivatePasswordLeakVerification();
+    }
+  }
+
+  // Check for token validity and action integrity.
+  private static boolean checkTokenIntegrity(
+      TokenProperties tokenProperties, String recaptchaAction) {
+    // Check if the token is valid.
+    if (!tokenProperties.getValid()) {
+      System.out.println(
+          "The Account Defender Assessment call failed because the token was: "
+              + tokenProperties.getInvalidReason().name());
+      return false;
+    }
+
+    // Check if the expected action was executed.
+    if (!tokenProperties.getAction().equals(recaptchaAction)) {
+      System.out.printf(
+          "The action attribute in the reCAPTCHA tag '%s' does not match "
+              + "the action '%s' you are expecting to score",
+          tokenProperties.getAction(), recaptchaAction);
+      return false;
+    }
+    return true;
+  }
+}
+// [END recaptcha_enterprise_password_leak_verification]

samples/snippets/cloud-client/src/pom.xml

@@ -51,6 +51,11 @@
       <groupId>com.google.cloud</groupId>
       <artifactId>google-cloud-recaptchaenterprise</artifactId>
     </dependency>
+    <dependency>
+      <groupId>com.google.cloud</groupId>
+      <artifactId>recaptcha-password-check-helpers</artifactId>
+      <version>1.0.1</version>
+    </dependency>
 
 
     <!-- [Start_Selenium_dependencies] -->

samples/snippets/cloud-client/src/test/java/app/SnippetsIT.java

@@ -75,6 +75,23 @@ public class SnippetsIT {
   @LocalServerPort private int randomServerPort;
   private ByteArrayOutputStream stdOut;
 
+  @Test
+  public void testCreateAnnotateAssessment()
+      throws JSONException, IOException, InterruptedException, NoSuchAlgorithmException,
+          ExecutionException {
+    // Create an assessment.
+    String testURL = "http://localhost:" + randomServerPort + "/";
+    JSONObject createAssessmentResult =
+        createAssessment(testURL, ByteString.EMPTY, AssessmentType.ASSESSMENT);
+    String assessmentName = createAssessmentResult.getString("assessmentName");
+    // Verify that the assessment name has been modified post the assessment creation.
+    assertThat(assessmentName).isNotEmpty();
+
+    // Annotate the assessment.
+    AnnotateAssessment.annotateAssessment(PROJECT_ID, assessmentName);
+    assertThat(stdOut.toString()).contains("Annotated response sent successfully ! ");
+  }
+
   // Check if the required environment variables are set.
   public static void requireEnvVar(String envVarName) {
     assertWithMessage(String.format("Missing environment variable '%s' ", envVarName))
@@ -157,24 +174,10 @@ public void testDeleteSiteKey()
     assertThat(stdOut.toString()).contains("reCAPTCHA Site key successfully deleted !");
   }
 
-  @Test
-  public void testCreateAnnotateAssessment()
-      throws JSONException, IOException, InterruptedException, NoSuchAlgorithmException {
-    // Create an assessment.
-    String testURL = "http://localhost:" + randomServerPort + "/";
-    JSONObject createAssessmentResult = createAssessment(testURL, ByteString.EMPTY);
-    String assessmentName = createAssessmentResult.getString("assessmentName");
-    // Verify that the assessment name has been modified post the assessment creation.
-    assertThat(assessmentName).isNotEmpty();
-
-    // Annotate the assessment.
-    AnnotateAssessment.annotateAssessment(PROJECT_ID, assessmentName);
-    assertThat(stdOut.toString()).contains("Annotated response sent successfully ! ");
-  }
-
   @Test
   public void testCreateAnnotateAccountDefender()
-      throws JSONException, IOException, InterruptedException, NoSuchAlgorithmException {
+      throws JSONException, IOException, InterruptedException, NoSuchAlgorithmException,
+          ExecutionException {
 
     String testURL = "http://localhost:" + randomServerPort + "/";
     // Create a random SHA-256 Hashed account id.
@@ -186,7 +189,8 @@ public void testCreateAnnotateAccountDefender()
     ByteString hashedAccountId = ByteString.copyFrom(hashBytes);
 
     // Create the assessment.
-    JSONObject createAssessmentResult = createAssessment(testURL, hashedAccountId);
+    JSONObject createAssessmentResult =
+        createAssessment(testURL, hashedAccountId, AssessmentType.ACCOUNT_DEFENDER);
     String assessmentName = createAssessmentResult.getString("assessmentName");
     // Verify that the assessment name has been modified post the assessment creation.
     assertThat(assessmentName).isNotEmpty();
@@ -219,33 +223,48 @@ public void testCreateAnnotateAccountDefender()
                 "Finished searching related account group memberships for %s", hashedAccountId));
   }
 
+  @Test
   public void testGetMetrics() throws IOException {
     GetMetrics.getMetrics(PROJECT_ID, RECAPTCHA_SITE_KEY_1);
     assertThat(stdOut.toString())
         .contains("Retrieved the bucket count for score based key: " + RECAPTCHA_SITE_KEY_1);
   }
 
-  public JSONObject createAssessment(String testURL)
-      throws IOException, JSONException, InterruptedException {
+  @Test
+  public void testPasswordLeakAssessment()
+      throws JSONException, IOException, ExecutionException, InterruptedException {
+    String testURL = "http://localhost:" + randomServerPort + "/";
+    createAssessment(testURL, ByteString.EMPTY, AssessmentType.PASSWORD_LEAK);
+    assertThat(stdOut.toString()).contains("Is Credential leaked: ");
+  }
+
+  public JSONObject createAssessment(
+      String testURL, ByteString hashedAccountId, AssessmentType assessmentType)
+      throws IOException, JSONException, InterruptedException, ExecutionException {
 
     // Setup the automated browser test and retrieve the token and action.
     JSONObject tokenActionPair = initiateBrowserTest(testURL);
 
     // Send the token for analysis. The analysis score ranges from 0.0 to 1.0
-    if (!hashedAccountId.isEmpty()) {
+    if (assessmentType == AssessmentType.ACCOUNT_DEFENDER) {
       AccountDefenderAssessment.accountDefenderAssessment(
           PROJECT_ID,
           RECAPTCHA_SITE_KEY_1,
           tokenActionPair.getString("token"),
           tokenActionPair.getString("action"),
           hashedAccountId);
-
-    } else {
+    } else if (assessmentType == AssessmentType.ASSESSMENT) {
       recaptcha.CreateAssessment.createAssessment(
           PROJECT_ID,
           RECAPTCHA_SITE_KEY_1,
           tokenActionPair.getString("token"),
           tokenActionPair.getString("action"));
+    } else if (assessmentType == AssessmentType.PASSWORD_LEAK) {
+      passwordleak.CreatePasswordLeakAssessment.checkPasswordLeak(
+          PROJECT_ID,
+          RECAPTCHA_SITE_KEY_1,
+          tokenActionPair.getString("token"),
+          tokenActionPair.getString("action"));
     }
 
     // Assert the response.
@@ -274,6 +293,14 @@ public JSONObject createAssessment(String testURL)
         .put("assessmentName", assessmentName);
   }
 
+  enum AssessmentType {
+    ASSESSMENT,
+    ACCOUNT_DEFENDER,
+    PASSWORD_LEAK;
+
+    AssessmentType() {}
+  }
+
   public JSONObject initiateBrowserTest(String testURL)
       throws IOException, JSONException, InterruptedException {
     // Construct the URL to call for validating the assessment.