Dissolve gerrit-httpd top-level directory

Change-Id: I287b29b893c6f561dbbf6fa04dc714b4b7f48d54

java/com/google/gerrit/httpd/RunAsFilter.java

@@ -0,0 +1,130 @@
+// Copyright (C) 2013 The Android Open Source Project
+//
+// 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.google.gerrit.httpd;
+
+import static com.google.gerrit.httpd.restapi.RestApiServlet.replyError;
+import static javax.servlet.http.HttpServletResponse.SC_FORBIDDEN;
+import static javax.servlet.http.HttpServletResponse.SC_INTERNAL_SERVER_ERROR;
+
+import com.google.gerrit.extensions.registration.DynamicItem;
+import com.google.gerrit.extensions.restapi.AuthException;
+import com.google.gerrit.reviewdb.client.Account;
+import com.google.gerrit.server.CurrentUser;
+import com.google.gerrit.server.account.AccountResolver;
+import com.google.gerrit.server.config.AuthConfig;
+import com.google.gerrit.server.permissions.GlobalPermission;
+import com.google.gerrit.server.permissions.PermissionBackend;
+import com.google.gerrit.server.permissions.PermissionBackendException;
+import com.google.gwtorm.server.OrmException;
+import com.google.inject.Inject;
+import com.google.inject.Singleton;
+import com.google.inject.servlet.ServletModule;
+import java.io.IOException;
+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.servlet.http.HttpServletResponse;
+import org.eclipse.jgit.errors.ConfigInvalidException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/** Allows running a request as another user account. */
+@Singleton
+class RunAsFilter implements Filter {
+  private static final Logger log = LoggerFactory.getLogger(RunAsFilter.class);
+  private static final String RUN_AS = "X-Gerrit-RunAs";
+
+  static class Module extends ServletModule {
+    @Override
+    protected void configureServlets() {
+      filter("/*").through(RunAsFilter.class);
+    }
+  }
+
+  private final boolean enabled;
+  private final DynamicItem<WebSession> session;
+  private final PermissionBackend permissionBackend;
+  private final AccountResolver accountResolver;
+
+  @Inject
+  RunAsFilter(
+      AuthConfig config,
+      DynamicItem<WebSession> session,
+      PermissionBackend permissionBackend,
+      AccountResolver accountResolver) {
+    this.enabled = config.isRunAsEnabled();
+    this.session = session;
+    this.permissionBackend = permissionBackend;
+    this.accountResolver = accountResolver;
+  }
+
+  @Override
+  public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
+      throws IOException, ServletException {
+    HttpServletRequest req = (HttpServletRequest) request;
+    HttpServletResponse res = (HttpServletResponse) response;
+
+    String runas = req.getHeader(RUN_AS);
+    if (runas != null) {
+      if (!enabled) {
+        replyError(req, res, SC_FORBIDDEN, RUN_AS + " disabled by auth.enableRunAs = false", null);
+        return;
+      }
+
+      CurrentUser self = session.get().getUser();
+      try {
+        if (!self.isIdentifiedUser()) {
+          // Always disallow for anonymous users, even if permitted by the ACL,
+          // because that would be crazy.
+          throw new AuthException("denied");
+        }
+        permissionBackend.user(self).check(GlobalPermission.RUN_AS);
+      } catch (AuthException e) {
+        replyError(req, res, SC_FORBIDDEN, "not permitted to use " + RUN_AS, null);
+        return;
+      } catch (PermissionBackendException e) {
+        log.warn("cannot check runAs", e);
+        replyError(req, res, SC_INTERNAL_SERVER_ERROR, RUN_AS + " unavailable", null);
+        return;
+      }
+
+      Account target;
+      try {
+        target = accountResolver.find(runas);
+      } catch (OrmException | IOException | ConfigInvalidException e) {
+        log.warn("cannot resolve account for " + RUN_AS, e);
+        replyError(req, res, SC_INTERNAL_SERVER_ERROR, "cannot resolve " + RUN_AS, e);
+        return;
+      }
+      if (target == null) {
+        replyError(req, res, SC_FORBIDDEN, "no account matches " + RUN_AS, null);
+        return;
+      }
+      session.get().setUserAccountId(target.getId());
+    }
+
+    chain.doFilter(req, res);
+  }
+
+  @Override
+  public void init(FilterConfig filterConfig) {}
+
+  @Override
+  public void destroy() {}
+}