I think this is how it should be done: https://github.com/ceki/logback/tree/LBCLASSIC-304 The behavior is mostly unchanged if no SecurityManager is installed since System.getSecurityManager() is cheap. Additional checks are only performed if that call returns a non-null result. The fact that Permission can only be checked by catching an AccessControlException is giving me the creeps, though. Must be rather old code... Joern On 06.11.2011, at 07:42, ceki wrote:
Keep in mind that the SecurityManager is usually installed by the container very early in the container life cycle and one usually does not change security managers on the fly, but your point is a good one nonetheless.
On 11/6/2011 1:32 AM, Joern Huxhorn wrote:
There is one issue with the code in http://goo.gl/zASBm, though: It checks for getClassLoader permission in a static code block only, i.e. when the class is initially loaded by the classloader, and saves that information for later reference.
I don't think that this is a valid optimization for precisely the reason that this permission can change during runtime (according to http://download.oracle.com/javase/1.4.2/docs/api/java/security/AccessControl... even per thread), for example if a different SecurityManager is installed.
The method using the statically initialized boolean should probably look like this instead:
public static ClassLoader getClassLoaderAsPrivileged(final Class clazz) { try { AccessController.checkPermission(new RuntimePermission("getClassLoader")); return AccessController.doPrivileged( new PrivilegedAction<ClassLoader>() { public ClassLoader run() { return clazz.getClassLoader(); } }); } catch (AccessControlException e) { return null; } }
Not sure if this would solve the problem at hand...
Joern.
On 05.11.2011, at 16:25, ceki wrote:
Thanks for the sample project. I can confirm that I observe a AccessControlException when logback is present. The AccessControlException is not thrown if slf4j-nop, slf4j-simple or slf4j-log4j are used as the slf4j binding.
Although logback does not install its own SecurityManager or modify the security configuration, it does attempt to determine whether it has "getClassLoader" permission. See http://goo.gl/zASBm
Here is the code in question:
AccessController.doPrivileged(new PrivilegedAction<Boolean>() { public Boolean run() { try { AccessController.checkPermission( new RuntimePermission("getClassLoader")); return true; } catch (AccessControlException e) { return false; } } });
If the privileged block above code is removed, then the AccessControlException goes away. The privileged block looks quite legitimate to me so I don't think it's a bug in logback.
To convince yourself the the privileged block is key, you can remove all logging related calls and all logging related dependencies, add the privileged block at the beginning of the test. You should observe an AccessControlException being thrown.
-- Ceki http://twitter.com/#!/ceki
On 11/5/2011 1:42 PM, Andrew Bourgeois wrote:
Ceki,
I redid the test in a clean Maven project. I don't know if attachments will pass through, so:
1) pom.xml:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <name>test</name> <groupId>be.test.fun</groupId> <artifactId>test</artifactId> <version>0.1.0-RC1</version> <dependencies> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.6.0</version> </dependency>
<dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.16</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.6.0</version> </dependency>
<!--dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-core</artifactId> <version>1.0.0</version> </dependency> <dependency> <groupId>ch.qos.logback</groupId> <artifactId>logback-classic</artifactId> <version>1.0.0</version> </dependency-->
<dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.4</version> <scope>test</scope> </dependency> </dependencies> <build> <resources> </resources> <plugins> <plugin> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.6</source> <target>1.6</target> <verbose>true</verbose> </configuration> </plugin> </plugins> </build> </project>
2) The JUnit test:
package be.test.fun;
import org.junit.Test; import java.rmi.RMISecurityManager; import org.slf4j.Logger; import org.slf4j.LoggerFactory;
public class SecurityManagerTest {
@Test public void securityManagerWithLogs() { Logger logger = LoggerFactory.getLogger(SecurityManagerTest.class);
System.setProperty("java.security.policy", "./src/test/resources/java.policy"); logger.debug("Policy location: {}", System.getProperty("java.security.policy")); if (System.getSecurityManager() == null) { System.setSecurityManager(new RMISecurityManager()); } System.setProperty("java.security.policy", "./src/test/resources/java.policy"); }
// @Test // public void securityManagerWithoutLogs() { // System.setProperty("java.security.policy", "./src/test/resources/java.policy"); // if (System.getSecurityManager() == null) { // System.setSecurityManager(new RMISecurityManager()); // } // System.setProperty("java.security.policy", "./src/test/resources/java.policy"); // } }
3) java.policy that you put into src/test.resources:
grant { permission java.security.AllPermission; };
So.... if you run this: ------------------------------------------------------- T E S T S ------------------------------------------------------- Running be.test.fun.SecurityManagerTest 2011-11-05 13:36:33,828 [main] DEBUG - (be.test.fun.SecurityManagerTest) - Policy location: ./src/test/resources/java.policy Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.201 sec
Results :
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
Now, comment the 2 LOG4J-related dependencies inside the POM, and uncomment the logback ones: ------------------------------------------------------- T E S T S ------------------------------------------------------- Running be.test.fun.SecurityManagerTest 13:38:04.222 [main] DEBUG be.test.fun.SecurityManagerTest - Policy location: ./src/test/resources/java.policy java.security.AccessControlException: access denied (java.lang.RuntimePermission setContextClassLoader) at java.security.AccessControlContext.checkPermission(AccessControlContext.java:323)
at java.security.AccessController.checkPermission(AccessController.java:546) at java.lang.SecurityManager.checkPermission(SecurityManager.java:532) at java.lang.Thread.setContextClassLoader(Thread.java:1394) at org.apache.maven.surefire.booter.SurefireBooter.runSuitesInProcess(SurefireBooter.java:366)
at org.apache.maven.surefire.booter.SurefireBooter.main(SurefireBooter.java:1021)
[INFO] ------------------------------------------------------------------------ [INFO] BUILD FAILURE [INFO] ------------------------------------------------------------------------ [INFO] Total time: 2.202s
And now comment the "securityManagerWithLogs" test method, and uncomment the "securityManagerWithoutLogs" one: ------------------------------------------------------- T E S T S ------------------------------------------------------- Running be.test.fun.SecurityManagerTest Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.105 sec
Results :
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0
Do you have the same output?
FYI:
[xvepak@localhost test]$ mvn -version Apache Maven 3.0.1 (r1038046; 2010-11-23 11:58:32+0100) Java version: 1.6.0_23 Java home: /home/xvepak/software/jdk1.6.0_23/jre Default locale: en_US, platform encoding: UTF-8 OS name: "linux" version: "2.6.18-238.12.1.el5" arch: "i386" Family: "unix"
Thank you for trying to help out!!
Best regards
Andrew Bourgeois
-----Original Message----- From: ceki Sent: Saturday, November 05, 2011 1:03 AM To: logback users list Subject: Re: [logback-user] SecurityManager issue using logback
On 05/11/2011 12:47 PM, Andrew Bourgeois wrote:
So to reformulate: The exception IS thrown when we have SLF4J code The exception ISN'T thrown when we remove the SLF4J.
That's not what I observe. An exception is thrown in both cases.
-- Ceki http://twitter.com/#!/ceki _______________________________________________ Logback-user mailing list Logback-user@qos.ch http://mailman.qos.ch/mailman/listinfo/logback-user