tomcat安全管理

背景知識

Java 的 SecurityManager 能讓 Web 瀏覽器在它自身的沙盒中運行小型應用（applet），從而具有防止不可信代碼訪問本地文件系統的文件以及防止其連接到主機，而不是加載該應用的位置，等等。如同 SecurityManager 能防止不可信的小型應用在你的瀏覽器上運行，運行 Tomcat 時，使用 SecurityManager 也能保護服務器，使其免受木馬型的 applet、JSP、JSP Bean 以及標簽庫的侵害，甚至也可以防止由于無意中的疏忽所造成的問題。

假設網站有一位經授權可發布 JSP 的用戶，他在無意中將下面這些代碼加入了 JSP 中：

<% System.exit(1); %>

每當 Tomcat 執行這個 JSP 文件時，Tomcat 都會退出。Java 的 SecurityManager 構成了系統管理員保證服務器安全可靠的另一道防線。

警告：使用 Tomcat 代碼庫時會執行一個安全審核。大多數關鍵包已受到保護，新的安全包保護機制已經實施。然而，在允許不可信用戶發布 Web 應用、JSP、servlet、bean 或標簽庫之前，你仍要反復確定自己配置的 SecurityManager 是否滿足了要求。但不管怎么說，利用 SecurityManager 來運行 Tomcat 肯定比沒有它好得多

權限

權限類用于定義 Tomcat 加載的類所具有的權限。標準 JDK 中包含了很多標準權限類，你還可以針對自己的 Web 應用自定義權限類。Tomcat 支持這兩種技術。

標準權限

關于適用于 Tomcat 的標準系統 SecurityManager 權限類，以下僅是一個簡短的總結。詳情請查看http://docs.oracle.com/javase/7/docs/technotes/guides/security/。

• java.util.PropertyPermission——控制對 JVM 屬性的讀/寫，比如說 java.home。
• java.lang.RuntimePermission——控制一些系統/運行時函數的使用，比如 exit() 和 exec()。 另外也控制包的訪問/定義。
• java.io.FilePermission——控制對文件和目錄的讀/寫/執行。
• java.net.SocketPermission——控制網絡套接字的使用。
• java.net.NetPermission——控制組播網絡連接的使用。
• java.lang.reflect.ReflectPermission——控制類反射的使用。
• java.security.SecurityPermission——控制對 Security 方法的訪問。
• java.security.AllPermission——允許訪問任何權限，仿佛沒有 SecurityManager。

Tomcat 自定義權限

Tomcat 使用了一個自定義權限類 org.apache.naming.JndiPermission。該權限能夠控制對 JNDI 命名的基于文件的資源的可讀訪問。權限名就是 JNDI 名，無任何行為。后面的 * 可以用來在授權時進行模糊匹配。比如，可以在策略文件中加入以下內容：

permission org.apache.naming.JndiPermission "jndi://localhost/examples/*";

從而為每個部署的 Web 應用動態生成這樣的權限項，允許它們讀取自己的靜態資源，而不允許讀取其他的文件（除非顯式地賦予這些文件權限）。

另外，Tomcat 還能動態生成下面這樣的文件權限。

permission java.io.FilePermission "** your application context**", "read";
permission java.io.FilePermission
  "** application working directory**", "read,write";permission java.io.FilePermission
  "** application working directory**/-", "read,write,delete";

*application working directory 是部署應用所用的文件夾或 WAR 文件。 application working directory 是應 Servlet 規范需要而提供給應用的暫時性目錄。

利用 SecurityManager 配置 Tomcat

策略文件格式

Java SecurityManager 所實現的安全策略配置在 $CATALINA_BASE/conf/catalina.policy 文件中。該文件完全替代了 JDK 系統目錄中提供的 java.policy 文件。既可以手動編輯 catalina.policy 文件，也可以使用Java 1.2 或以后版本附帶的 policytool 應用。

catalina.policy 文件中的項使用標準的 java.policy 文件格式，如下所示：

// 策略文件項范例  

grant [signedBy ,] [codeBase ] {
  permission    [ [, ]];
};

signedBy 和 codeBase 兩項在授予權限時是可選項。注釋行以 // 開始，在當前行結束。codeBase 以 URL 的形式。對于文件 URL，可以使用 ${java.home} 與 ${catalina.home}屬性（這些屬性代表的是使用 JAVA_HOME、CATALINA_HOME 和 CATALINA_BASE 環境變量為這些屬性定義的目錄路徑）。

默認策略文件

默認的 $CATALINA_BASE/conf/catalina.policy 文件如下所示：

// Licensed to the Apache Software Foundation (ASF) under one or more// contributor license agreements.  See the NOTICE file distributed with// this work for additional information regarding copyright ownership.// The ASF 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.
// ============================================================================// catalina.policy - Security Policy Permissions for Tomcat//// This file contains a default set of security policies to be enforced (by the// JVM) when Catalina is executed with the "-security" option.  In addition// to the permissions granted here, the following additional permissions are// granted to each web application://// * Read access to the web application's document root directory// * Read, write and delete access to the web application's working directory// ============================================================================
// ========== SYSTEM CODE PERMISSIONS =========================================
// These permissions apply to javac
grant codeBase "file:${java.home}/lib/-" {
        permission java.security.AllPermission;
};
// These permissions apply to all shared system extensions
grant codeBase "file:${java.home}/jre/lib/ext/-" {
        permission java.security.AllPermission;
};
// These permissions apply to javac when ${java.home] points at $JAVA_HOME/jre
grant codeBase "file:${java.home}/../lib/-" {
        permission java.security.AllPermission;
};
// These permissions apply to all shared system extensions when// ${java.home} points at $JAVA_HOME/jre
grant codeBase "file:${java.home}/lib/ext/-" {
        permission java.security.AllPermission;
};
// ========== CATALINA CODE PERMISSIONS =======================================
// These permissions apply to the daemon code
grant codeBase "file:${catalina.home}/bin/commons-daemon.jar" {
        permission java.security.AllPermission;
};
// These permissions apply to the logging API// Note: If tomcat-juli.jar is in ${catalina.base} and not in ${catalina.home},// update this section accordingly.//  grant codeBase "file:${catalina.base}/bin/tomcat-juli.jar" {..}
grant codeBase "file:${catalina.home}/bin/tomcat-juli.jar" {
        permission java.io.FilePermission
         "${java.home}${file.separator}lib${file.separator}logging.properties", "read";

        permission java.io.FilePermission
         "${catalina.base}${file.separator}conf${file.separator}logging.properties", "read";
        permission java.io.FilePermission
         "${catalina.base}${file.separator}logs", "read, write";
        permission java.io.FilePermission
         "${catalina.base}${file.separator}logs${file.separator}*", "read, write";

        permission java.lang.RuntimePermission "shutdownHooks";
        permission java.lang.RuntimePermission "getClassLoader";
        permission java.lang.RuntimePermission "setContextClassLoader";

        permission java.lang.management.ManagementPermission "monitor";

        permission java.util.logging.LoggingPermission "control";

        permission java.util.PropertyPermission "java.util.logging.config.class", "read";
        permission java.util.PropertyPermission "java.util.logging.config.file", "read";
        permission java.util.PropertyPermission "org.apache.juli.AsyncLoggerPollInterval", "read";
        permission java.util.PropertyPermission "org.apache.juli.AsyncMaxRecordCount", "read";
        permission java.util.PropertyPermission "org.apache.juli.AsyncOverflowDropType", "read";
        permission java.util.PropertyPermission "org.apache.juli.ClassLoaderLogManager.debug", "read";
        permission java.util.PropertyPermission "catalina.base", "read";

        // Note: To enable per context logging configuration, permit read access to
        // the appropriate file. Be sure that the logging configuration is
        // secure before enabling such access.
        // E.g. for the examples web application (uncomment and unwrap
        // the following to be on a single line):
        // permission java.io.FilePermission "${catalina.base}${file.separator}
        //  webapps${file.separator}examples${file.separator}WEB-INF
        //  ${file.separator}classes${file.separator}logging.properties", "read";
};
// These permissions apply to the server startup code
grant codeBase "file:${catalina.home}/bin/bootstrap.jar" {
        permission java.security.AllPermission;
};
// These permissions apply to the servlet API classes// and those that are shared across all class loaders// located in the "lib" directory
grant codeBase "file:${catalina.home}/lib/-" {
        permission java.security.AllPermission;
};
// If using a per instance lib directory, i.e. ${catalina.base}/lib,// then the following permission will need to be uncommented// grant codeBase "file:${catalina.base}/lib/-" {//         permission java.security.AllPermission;// };
// ========== WEB APPLICATION PERMISSIONS =====================================
// These permissions are granted by default to all web applications// In addition, a web application will be given a read FilePermission// for all files and directories in its document root.
grant {
    // Required for JNDI lookup of named JDBC DataSource's and
    // javamail named MimePart DataSource used to send mail
    permission java.util.PropertyPermission "java.home", "read";
    permission java.util.PropertyPermission "java.naming.*", "read";
    permission java.util.PropertyPermission "javax.sql.*", "read";

    // OS Specific properties to allow read access
    permission java.util.PropertyPermission "os.name", "read";
    permission java.util.PropertyPermission "os.version", "read";
    permission java.util.PropertyPermission "os.arch", "read";
    permission java.util.PropertyPermission "file.separator", "read";
    permission java.util.PropertyPermission "path.separator", "read";
    permission java.util.PropertyPermission "line.separator", "read";

    // JVM properties to allow read access
    permission java.util.PropertyPermission "java.version", "read";
    permission java.util.PropertyPermission "java.vendor", "read";
    permission java.util.PropertyPermission "java.vendor.url", "read";
    permission java.util.PropertyPermission "java.class.version", "read";
    permission java.util.PropertyPermission "java.specification.version", "read";
    permission java.util.PropertyPermission "java.specification.vendor", "read";
    permission java.util.PropertyPermission "java.specification.name", "read";

    permission java.util.PropertyPermission "java.vm.specification.version", "read";
    permission java.util.PropertyPermission "java.vm.specification.vendor", "read";
    permission java.util.PropertyPermission "java.vm.specification.name", "read";
    permission java.util.PropertyPermission "java.vm.version", "read";
    permission java.util.PropertyPermission "java.vm.vendor", "read";
    permission java.util.PropertyPermission "java.vm.name", "read";

    // Required for OpenJMX
    permission java.lang.RuntimePermission "getAttribute";

    // Allow read of JAXP compliant XML parser debug
    permission java.util.PropertyPermission "jaxp.debug", "read";

    // All JSPs need to be able to read this package
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.tomcat";

    // Precompiled JSPs need access to these packages.
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.jasper.el";
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.jasper.runtime";
    permission java.lang.RuntimePermission
     "accessClassInPackage.org.apache.jasper.runtime.*";

    // Precompiled JSPs need access to these system properties.
    permission java.util.PropertyPermission
     "org.apache.jasper.runtime.BodyContentImpl.LIMIT_BUFFER", "read";
    permission java.util.PropertyPermission
     "org.apache.el.parser.COERCE_TO_ZERO", "read";

    // The cookie code needs these.
    permission java.util.PropertyPermission
     "org.apache.catalina.STRICT_SERVLET_COMPLIANCE", "read";
    permission java.util.PropertyPermission
     "org.apache.tomcat.util.http.ServerCookie.STRICT_NAMING", "read";
    permission java.util.PropertyPermission
     "org.apache.tomcat.util.http.ServerCookie.FWD_SLASH_IS_SEPARATOR", "read";

    // Applications using Comet need to be able to access this package
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.comet";

    // Applications using WebSocket need to be able to access these packages
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.tomcat.websocket";
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.tomcat.websocket.server";
};
// The Manager application needs access to the following packages to support the// session display functionality. These settings support the following// configurations:// - default CATALINA_HOME == CATALINA_BASE// - CATALINA_HOME != CATALINA_BASE, per instance Manager in CATALINA_BASE// - CATALINA_HOME != CATALINA_BASE, shared Manager in CATALINA_HOME
grant codeBase "file:${catalina.base}/webapps/manager/-" {
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina";
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.ha.session";
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.manager";
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.manager.util";
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.util";
};
grant codeBase "file:${catalina.home}/webapps/manager/-" {
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina";
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.ha.session";
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.manager";
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.manager.util";
    permission java.lang.RuntimePermission "accessClassInPackage.org.apache.catalina.util";
};
// You can assign additional permissions to particular web applications by// adding additional "grant" entries here, based on the code base for that// application, /WEB-INF/classes/, or /WEB-INF/lib/ jar files.//// Different permissions can be granted to JSP pages, classes loaded from// the /WEB-INF/classes/ directory, all jar files in the /WEB-INF/lib/// directory, or even to individual jar files in the /WEB-INF/lib/ directory.//// For instance, assume that the standard "examples" application// included a JDBC driver that needed to establish a network connection to the// corresponding database and used the scrape taglib to get the weather from// the NOAA web server.  You might create a "grant" entries like this://// The permissions granted to the context root directory apply to JSP pages.// grant codeBase "file:${catalina.base}/webapps/examples/-" {//      permission java.net.SocketPermission "dbhost.mycompany.com:5432", "connect";//      permission java.net.SocketPermission "*.noaa.gov:80", "connect";// };//// The permissions granted to the context WEB-INF/classes directory// grant codeBase "file:${catalina.base}/webapps/examples/WEB-INF/classes/-" {// };//// The permission granted to your JDBC driver// grant codeBase "jar:file:${catalina.base}/webapps/examples/WEB-INF/lib/driver.jar!/-" {//      permission java.net.SocketPermission "dbhost.mycompany.com:5432", "connect";// };// The permission granted to the scrape taglib// grant codeBase "jar:file:${catalina.base}/webapps/examples/WEB-INF/lib/scrape.jar!/-" {//      permission java.net.SocketPermission "*.noaa.gov:80", "connect";// };

使用 SecurityManager 啟動 Tomcat

一旦配置好了用于 SecurityManager 的 catalina.policy 文件，就可以使用 -security 選項啟動帶有 SecurityManager 的 Tomcat。 $CATALINA_HOME/bin/catalina.sh start -security (Unix) %CATALINA_HOME%\bin\catalina start -security (Windows)

配置 Tomcat 中的包保護

從 Tomcat 5 開始，可以通過配置保護 Tomcat 內部包，使其免于被定義與訪問。詳情查看 http://www.oracle.com/technetwork/java/seccodeguide-139067.html。

警告：假如去除默認的包保護，可能會造成安全漏洞。

默認屬性文件

默認的 $CATALINA_BASE/conf/catalina.properties 文件如下所示：

## List of comma-separated packages that start with or equal this string
# will cause a security exception to be thrown when# passed to checkPackageAccess unless the
# corresponding RuntimePermission ("accessClassInPackage."+package) has
# been granted.package.access=sun.,org.apache.catalina.,org.apache.coyote.,
org.apache.tomcat.,org.apache.jasper.#
# List of comma-separated packages that start with or equal this string
# will cause a security exception to be thrown when
# passed to checkPackageDefinition unless the
# corresponding RuntimePermission ("defineClassInPackage."+package) has
# been granted.## by default, no packages are restricted for definition, and none of
# the class loaders supplied with the JDK call checkPackageDefinition.
#package.definition=sun.,java.,org.apache.catalina.,org.apache.coyote.,
org.apache.tomcat.,org.apache.jasper.

一旦為 SecurityManager 配置了 catalina.properties 文件 ，記得重啟 Tomcat。

疑難解答

假如應用執行一個由于缺乏所需權限而被禁止的操作，當 SecurityManager 偵測到這種違規時，就會拋出 AccessControLException 或 SecurityException 異常。雖然調試缺失的權限是很有難度的，但還是有一個辦法，那就是將在執行中制定的所有安全決策的調試輸出打開，這需要在啟動 Tomcat 之前設置一個系統屬性。最簡單的方法就是通過 CATALINA_OPTS 環境變量來實現，命令如下所示：

export CATALINA_OPTS=-Djava.security.debug=all (Unix) set CATALINA_OPTS=-Djava.security.debug=all (Windows)

記住，一定要在啟動 Tomcat 之前去做。

警告：這將生成很多兆的輸出內容！但是，它能通過搜索關鍵字 FAILED 來鎖定問題所在位置，確定需要檢查的權限。此外，查閱 Java 安全文檔可了解更多的可設置選項。