Fix HTTP OPTIONS request auth handling

docs/content/configuration/auth.md

@@ -10,6 +10,7 @@ layout: doc_page
 |`druid.escalator.type`|String|Type of the Escalator that should be used for internal Druid communications. This Escalator must use an authentication scheme that is supported by an Authenticator in `druid.auth.authenticationChain`.|"noop"|no|
 |`druid.auth.authorizers`|JSON List of Strings|List of Authorizer type names |["allowAll"]|no|
 |`druid.auth.unsecuredPaths`| List of Strings|List of paths for which security checks will not be performed. All requests to these paths will be allowed.|[]|no|
+|`druid.auth.disableHttpOptionsAuthentication`|Boolean|If true, skip authentication checks for HTTP OPTIONS requests. Note that disabling authentication checks for OPTIONS requests will allow unauthenticated users to determine what Druid endpoints are valid, and this may leak sensitive information (for example, the `/druid/indexer/v1//task/{taskid}` endpoint on the Overlord and `/druid/coordinator/v1/datasources` endpoints on the Coordinator contain resource names), so the authentication checks should not be disabled unless truly necessary. |false|no|
 
 ## Enabling Authentication/Authorization
 

integration-tests/src/test/java/io/druid/tests/security/ITBasicAuthConfigurationTest.java

@@ -224,6 +224,18 @@ public void testAuthConfiguration() throws Exception
 
     LOG.info("Testing Avatica query on router with incorrect credentials.");
     testAvaticaAuthFailure(routerUrl);
+
+    LOG.info("Checking OPTIONS requests on services...");
+    testOptionsRequests(adminClient);
+  }
+
+  private void testOptionsRequests(HttpClient httpClient)
+  {
+    makeRequest(httpClient, HttpMethod.OPTIONS, config.getCoordinatorUrl() + "/status", null);
+    makeRequest(httpClient, HttpMethod.OPTIONS, config.getIndexerUrl() + "/status", null);
+    makeRequest(httpClient, HttpMethod.OPTIONS, config.getBrokerUrl() + "/status", null);
+    makeRequest(httpClient, HttpMethod.OPTIONS, config.getHistoricalUrl() + "/status", null);
+    makeRequest(httpClient, HttpMethod.OPTIONS, config.getRouterUrl() + "/status", null);
   }
 
   private void checkUnsecuredCoordinatorLoadQueuePath(HttpClient client)

server/src/main/java/io/druid/server/security/AllowOptionsResourceFilter.java

@@ -0,0 +1,77 @@
+/*
+ * Licensed to Metamarkets Group Inc. (Metamarkets) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. Metamarkets licenses this file
+ * to you 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 io.druid.server.security;
+
+import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.HttpMethod;
+import java.io.IOException;
+
+public class AllowOptionsResourceFilter implements Filter
+{
+  private final boolean disableAuthentication;
+
+  public AllowOptionsResourceFilter(
+      boolean disableAuthentication
+  )
+  {
+    this.disableAuthentication = disableAuthentication;
+  }
+
+  @Override
+  public void init(FilterConfig filterConfig) throws ServletException
+  {
+
+  }
+
+  @Override
+  public void doFilter(
+      ServletRequest request, ServletResponse response, FilterChain chain
+  ) throws IOException, ServletException
+  {
+    HttpServletRequest httpReq = (HttpServletRequest) request;
+
+    // Druid itself doesn't explictly handle OPTIONS requests, no resource handler will authorize such requests.
+    // so this filter catches all OPTIONS requests and authorizes them.
+    if (HttpMethod.OPTIONS.equals(httpReq.getMethod())) {
+      if (disableAuthentication) {
+        httpReq.setAttribute(
+            AuthConfig.DRUID_AUTHENTICATION_RESULT,
+            new AuthenticationResult(AuthConfig.ALLOW_ALL_NAME, AuthConfig.ALLOW_ALL_NAME, null)
+        );
+      }
+
+      httpReq.setAttribute(AuthConfig.DRUID_AUTHORIZATION_CHECKED, true);
+    }
+
+    chain.doFilter(request, response);
+  }
+
+  @Override
+  public void destroy()
+  {
+
+  }
+}

server/src/main/java/io/druid/server/security/AuthConfig.java

@@ -44,19 +44,23 @@ public class AuthConfig
 
   public AuthConfig()
   {
-    this(null, null, null);
+    this(null, null, null, null);
   }
 
   @JsonCreator
   public AuthConfig(
       @JsonProperty("authenticatorChain") List<String> authenticationChain,
       @JsonProperty("authorizers") List<String> authorizers,
-      @JsonProperty("unsecuredPaths") List<String> unsecuredPaths
+      @JsonProperty("unsecuredPaths") List<String> unsecuredPaths,
+      @JsonProperty("disableHttpOptionsAuthentication") Boolean disableHttpOptionsAuthentication
   )
   {
     this.authenticatorChain = authenticationChain;
     this.authorizers = authorizers;
     this.unsecuredPaths = unsecuredPaths == null ? Collections.emptyList() : unsecuredPaths;
+    this.disableHttpOptionsAuthentication = disableHttpOptionsAuthentication == null
+                                            ? false
+                                            : disableHttpOptionsAuthentication;
   }
 
   @JsonProperty
@@ -68,6 +72,9 @@ public AuthConfig(
   @JsonProperty
   private final List<String> unsecuredPaths;
 
+  @JsonProperty
+  private final boolean disableHttpOptionsAuthentication;
+
   public List<String> getAuthenticatorChain()
   {
     return authenticatorChain;
@@ -83,14 +90,9 @@ public List<String> getUnsecuredPaths()
     return unsecuredPaths;
   }
 
-  @Override
-  public String toString()
+  public boolean isDisableHttpOptionsAuthentication()
   {
-    return "AuthConfig{" +
-           "authenticatorChain='" + authenticatorChain + '\'' +
-           ", authorizers='" + authorizers + '\'' +
-           ", unsecuredPaths='" + unsecuredPaths + '\'' +
-           '}';
+    return disableHttpOptionsAuthentication;
   }
 
   @Override
@@ -103,14 +105,31 @@ public boolean equals(Object o)
       return false;
     }
     AuthConfig that = (AuthConfig) o;
-    return Objects.equals(authenticatorChain, that.authenticatorChain) &&
-           Objects.equals(authorizers, that.authorizers) &&
-           Objects.equals(unsecuredPaths, that.unsecuredPaths);
+    return isDisableHttpOptionsAuthentication() == that.isDisableHttpOptionsAuthentication() &&
+           Objects.equals(getAuthenticatorChain(), that.getAuthenticatorChain()) &&
+           Objects.equals(getAuthorizers(), that.getAuthorizers()) &&
+           Objects.equals(getUnsecuredPaths(), that.getUnsecuredPaths());
   }
 
   @Override
   public int hashCode()
   {
-    return Objects.hash(authenticatorChain, authorizers, unsecuredPaths);
+    return Objects.hash(
+        getAuthenticatorChain(),
+        getAuthorizers(),
+        getUnsecuredPaths(),
+        isDisableHttpOptionsAuthentication()
+    );
+  }
+
+  @Override
+  public String toString()
+  {
+    return "AuthConfig{" +
+           "authenticatorChain=" + authenticatorChain +
+           ", authorizers=" + authorizers +
+           ", unsecuredPaths=" + unsecuredPaths +
+           ", disableHttpOptionsAuthentication=" + disableHttpOptionsAuthentication +
+           '}';
   }
 }

server/src/main/java/io/druid/server/security/AuthenticationUtils.java

@@ -27,6 +27,16 @@
 
 public class AuthenticationUtils
 {
+  public static void addAllowOptionsFilter(ServletContextHandler root, boolean disableHttpOptionsAuthentication)
+  {
+    FilterHolder holder = new FilterHolder(new AllowOptionsResourceFilter(disableHttpOptionsAuthentication));
+    root.addFilter(
+        holder,
+        "/*",
+        null
+    );
+  }
+
   public static void addAuthenticationFilterChain(
       ServletContextHandler root,
       List<Authenticator> authenticators

services/src/main/java/io/druid/cli/CliOverlord.java

@@ -344,6 +344,8 @@ public void initialize(Server server, Injector injector)
       AuthenticationUtils.addNoopAuthorizationFilters(root, UNSECURED_PATHS);
       AuthenticationUtils.addNoopAuthorizationFilters(root, authConfig.getUnsecuredPaths());
 
+      AuthenticationUtils.addAllowOptionsFilter(root, authConfig.isDisableHttpOptionsAuthentication());
+
       authenticators = authenticatorMapper.getAuthenticatorChain();
       AuthenticationUtils.addAuthenticationFilterChain(root, authenticators);
 

services/src/main/java/io/druid/cli/CoordinatorJettyServerInitializer.java

@@ -125,12 +125,13 @@ public void initialize(Server server, Injector injector)
       AuthenticationUtils.addNoopAuthorizationFilters(root, CliOverlord.UNSECURED_PATHS);
     }
 
+    AuthenticationUtils.addAllowOptionsFilter(root, authConfig.isDisableHttpOptionsAuthentication());
+
     authenticators = authenticatorMapper.getAuthenticatorChain();
     AuthenticationUtils.addAuthenticationFilterChain(root, authenticators);
 
     JettyServerInitUtils.addExtensionFilters(root, injector);
 
-
     // Check that requests were authorized before sending responses
     AuthenticationUtils.addPreResponseAuthorizationCheckFilter(
         root,

services/src/main/java/io/druid/cli/MiddleManagerJettyServerInitializer.java

@@ -78,10 +78,11 @@ public void initialize(Server server, Injector injector)
     AuthenticationUtils.addNoopAuthorizationFilters(root, UNSECURED_PATHS);
     AuthenticationUtils.addNoopAuthorizationFilters(root, authConfig.getUnsecuredPaths());
 
+    AuthenticationUtils.addAllowOptionsFilter(root, authConfig.isDisableHttpOptionsAuthentication());
+
     authenticators = authenticatorMapper.getAuthenticatorChain();
     AuthenticationUtils.addAuthenticationFilterChain(root, authenticators);
 
-
     JettyServerInitUtils.addExtensionFilters(root, injector);
 
     // Check that requests were authorized before sending responses

services/src/main/java/io/druid/cli/QueryJettyServerInitializer.java

@@ -102,6 +102,8 @@ public void initialize(Server server, Injector injector)
     AuthenticationUtils.addNoopAuthorizationFilters(root, UNSECURED_PATHS);
     AuthenticationUtils.addNoopAuthorizationFilters(root, authConfig.getUnsecuredPaths());
 
+    AuthenticationUtils.addAllowOptionsFilter(root, authConfig.isDisableHttpOptionsAuthentication());
+
     authenticators = authenticatorMapper.getAuthenticatorChain();
     AuthenticationUtils.addAuthenticationFilterChain(root, authenticators);
 

services/src/main/java/io/druid/cli/RouterJettyServerInitializer.java

@@ -111,6 +111,8 @@ public void initialize(Server server, Injector injector)
     AuthenticationUtils.addNoopAuthorizationFilters(root, UNSECURED_PATHS);
     AuthenticationUtils.addNoopAuthorizationFilters(root, authConfig.getUnsecuredPaths());
 
+    AuthenticationUtils.addAllowOptionsFilter(root, authConfig.isDisableHttpOptionsAuthentication());
+
     final List<Authenticator> authenticators = authenticatorMapper.getAuthenticatorChain();
     AuthenticationUtils.addAuthenticationFilterChain(root, authenticators);