Adds a basic authentication module that adds a real identity to the l…

…ogs.

Works only when a .aur file is used, since it requires code executed by a
base file to hook the authentication process. In the medium term, we need
to create our own client so that we can hook auth + updates for all methods
without going through .aur files that may or may not be imported.

src/main/java/org/apache/aurora/auth/IdentityAuthModule.java

@@ -0,0 +1,120 @@
+/**
+ * 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 org.apache.aurora.auth;
+
+import java.nio.charset.StandardCharsets;
+
+import java.util.Set;
+import java.util.logging.Logger;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonSyntaxException;
+import com.google.inject.AbstractModule;
+
+import org.apache.aurora.gen.SessionKey;
+
+/**
+ * An authentication module that uses an {@link IdentitySessionValidator}.
+ */
+public class IdentityAuthModule extends AbstractModule {
+  private static final Logger LOG = Logger.getLogger(IdentityAuthModule.class.getName());
+  private static final Gson GSON = new Gson();
+
+  private static class Identity {
+    String identifier;
+  }
+
+  @Override
+  protected void configure() {
+    LOG.info("Using Identity authentication module.");
+    bind(SessionValidator.class).to(IdentitySessionValidator.class);
+    bind(CapabilityValidator.class).to(IdentityCapabilityValidator.class);
+  }
+
+  /**
+   * Extracts the identity of the current user from a SessionKey.
+   *
+   * @param key A SessionKey,
+   * @return A string representing the identity of the user.
+   */
+  private static String extractIdentity(SessionKey key) {
+    // This try/catch is needed now because any operation not using a .aur file
+    // will not inject the correct information into the session. Once we have a custom
+    // client, this will no longer be an issue and we can change this to raise
+    // an AuthFailedException.
+    try {
+      String rawData = new String(key.getData(), StandardCharsets.UTF_8);
+      Identity identity = GSON.fromJson(rawData, Identity.class);
+      return identity.identifier;
+    } catch (JsonSyntaxException ex) {
+      return "UNKNOWN";
+    }
+  }
+
+  /**
+   * A SessionValidator that simply returns the UTF-8 value of SessionKey.data as Identity.
+   *
+   * This is NOT useful for real authentication; it only serves to put the current username
+   * into job create/update logs.
+   */
+  static class IdentitySessionValidator implements SessionValidator {
+    @Override
+    public SessionContext checkAuthenticated(final SessionKey key, Set<String> targetRoles)
+        throws AuthFailedException {
+
+      return new SessionContext() {
+        @Override
+        public String getIdentity() {
+          return extractIdentity(key);
+        }
+      };
+    }
+
+    @Override
+    public String toString(SessionKey sessionKey) {
+      return sessionKey.toString();
+    }
+  }
+
+  static class IdentityCapabilityValidator implements CapabilityValidator {
+    @Override
+    public SessionContext checkAuthorized(final SessionKey key, Capability capability, AuditCheck check)
+        throws AuthFailedException {
+
+      return new SessionContext() {
+        @Override
+        public String getIdentity() {
+          return extractIdentity(key);
+        }
+      };
+    }
+
+    @Override
+    public SessionContext checkAuthenticated(final SessionKey key, Set<String> targetRoles)
+        throws AuthFailedException {
+
+      return new SessionContext() {
+        @Override
+        public String getIdentity() {
+          return extractIdentity(key);
+        }
+      };
+    }
+
+    @Override
+    public String toString(SessionKey sessionKey) {
+      return sessionKey.toString();
+    }
+  }
+}