Add method to revoke a refresh_token

auth0/src/main/java/com/auth0/android/authentication/AuthenticationAPIClient.java

@@ -78,6 +78,9 @@ public class AuthenticationAPIClient {
     private static final String PASSWORD_KEY = "password";
     private static final String EMAIL_KEY = "email";
     private static final String PHONE_NUMBER_KEY = "phone_number";
+    private static final String OAUTH_CODE_KEY = "code";
+    private static final String REDIRECT_URI_KEY = "redirect_uri";
+    private static final String TOKEN_KEY = "token";
     private static final String DELEGATION_PATH = "delegation";
     private static final String ACCESS_TOKEN_PATH = "access_token";
     private static final String SIGN_UP_PATH = "signup";
@@ -90,8 +93,7 @@ public class AuthenticationAPIClient {
     private static final String RESOURCE_OWNER_PATH = "ro";
     private static final String TOKEN_INFO_PATH = "tokeninfo";
     private static final String USER_INFO_PATH = "userinfo";
-    private static final String OAUTH_CODE_KEY = "code";
-    private static final String REDIRECT_URI_KEY = "redirect_uri";
+    private static final String REVOKE_PATH = "revoke";
     private static final String HEADER_AUTHORIZATION = "Authorization";
 
     private final Auth0 auth0;
@@ -617,6 +619,43 @@ public DatabaseConnectionRequest<Void, AuthenticationException> resetPassword(@N
         return new DatabaseConnectionRequest<>(request);
     }
 
+    /**
+     * Request the revoke of a given refresh_token. Once revoked, the refresh_token cannot be used to obtain new tokens.
+     * The client must be of type 'Native' or have the 'Token Endpoint Authentication Method' set to 'none' for this endpoint to work.
+     * 
+     * Example usage:
+     * <pre>
+     * {@code
+     * client.revokeToken("{refresh_token}")
+     *      .start(new BaseCallback<Void>() {
+     *          {@literal}Override
+     *          public void onSuccess(Void payload) {}
+     *
+     *          {@literal}Override
+     *          public void onFailure(AuthenticationException error) {}
+     *      });
+     * }
+     * </pre>
+     *
+     * @param refreshToken the token to revoke
+     * @return a request to start
+     */
+    @SuppressWarnings("WeakerAccess")
+    public Request<Void, AuthenticationException> revokeToken(@NonNull String refreshToken) {
+        final Map<String, Object> parameters = ParameterBuilder.newBuilder()
+                .setClientId(getClientId())
+                .set(TOKEN_KEY, refreshToken)
+                .asDictionary();
+
+        HttpUrl url = HttpUrl.parse(auth0.getDomainUrl()).newBuilder()
+                .addPathSegment(OAUTH_PATH)
+                .addPathSegment(REVOKE_PATH)
+                .build();
+
+        return factory.POST(url, client, gson, authErrorBuilder)
+                .addParameters(parameters);
+    }
+
     /**
      * Requests new Credentials using a valid Refresh Token. The received token will have the same audience and scope as first requested. How the new Credentials are requested depends on the {@link Auth0#isOIDCConformant()} flag.
      * - If the instance is OIDC Conformant the endpoint will be /oauth/token with 'refresh_token' grant, and the response will include an id_token and an access_token if 'openid' scope was requested when the refresh_token was obtained.

auth0/src/test/java/com/auth0/android/authentication/AuthenticationAPIClientTest.java

@@ -1573,6 +1573,46 @@ public void shouldFetchProfileAfterLoginRequest() throws Exception {
         assertThat(callback, hasPayloadOfType(Authentication.class));
     }
 
+
+    @Test
+    public void shouldRevokeToken() throws Exception {
+        Auth0 auth0 = new Auth0(CLIENT_ID, mockAPI.getDomain(), mockAPI.getDomain());
+        AuthenticationAPIClient client = new AuthenticationAPIClient(auth0);
+
+        mockAPI.willReturnSuccessfulEmptyBody();
+        final MockAuthenticationCallback<Void> callback = new MockAuthenticationCallback<>();
+        client.revokeToken("refreshToken")
+                .start(callback);
+
+        final RecordedRequest request = mockAPI.takeRequest();
+        assertThat(request.getHeader("Accept-Language"), is(getDefaultLocale()));
+        assertThat(request.getPath(), equalTo("/oauth/revoke"));
+
+        Map<String, String> body = bodyFromRequest(request);
+        assertThat(body, hasEntry("client_id", CLIENT_ID));
+        assertThat(body, hasEntry("token", "refreshToken"));
+
+        assertThat(callback, hasNoError());
+    }
+
+    @Test
+    public void shouldRevokeTokenSync() throws Exception {
+        Auth0 auth0 = new Auth0(CLIENT_ID, mockAPI.getDomain(), mockAPI.getDomain());
+        AuthenticationAPIClient client = new AuthenticationAPIClient(auth0);
+
+        mockAPI.willReturnSuccessfulEmptyBody();
+        client.revokeToken("refreshToken")
+                .execute();
+
+        final RecordedRequest request = mockAPI.takeRequest();
+        assertThat(request.getHeader("Accept-Language"), is(getDefaultLocale()));
+        assertThat(request.getPath(), equalTo("/oauth/revoke"));
+
+        Map<String, String> body = bodyFromRequest(request);
+        assertThat(body, hasEntry("client_id", CLIENT_ID));
+        assertThat(body, hasEntry("token", "refreshToken"));
+    }
+
     @Test
     public void shouldRenewAuthWithOAuthTokenIfOIDCConformant() throws Exception {
         Auth0 auth0 = new Auth0(CLIENT_ID, mockAPI.getDomain(), mockAPI.getDomain());

auth0/src/test/java/com/auth0/android/util/AuthenticationAPI.java

@@ -106,6 +106,11 @@ public AuthenticationAPI willReturnSuccessfulSignUp() {
         return this;
     }
 
+    public AuthenticationAPI willReturnSuccessfulEmptyBody() {
+        server.enqueue(responseEmpty(200));
+        return this;
+    }
+
     public AuthenticationAPI willReturnSuccessfulLogin() {
         String json = "{\n" +
                 "  \"refresh_token\": \"" + REFRESH_TOKEN + "\",\n" +
@@ -175,7 +180,12 @@ public AuthenticationAPI willReturnApplicationResponseWithBody(String body, int
         return this;
     }
 
-    private MockResponse responseWithPlainText(String statusMessage, int statusCode){
+    private MockResponse responseEmpty(int statusCode) {
+        return new MockResponse()
+                .setResponseCode(statusCode);
+    }
+
+    private MockResponse responseWithPlainText(String statusMessage, int statusCode) {
         return new MockResponse()
                 .setResponseCode(statusCode)
                 .addHeader("Content-Type", "text/plain")