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Message-ID: <5.2.1.1.2.20031027092232.00b08ec8@pop.bol.com.br>
From: th.campos at bol.com.br (Thiago Campos)
Subject: Java 1.4.2_02 InsecurityManager JVM crash
Let's hope that noone uses -deprecation while compiling :)
This function was replaced a time ago
To who doesn't know, from the Java Docs
"protected int classDepth(String name)
Deprecated. This type of security checking is not recommended. It is
recommended that the checkPermission call be used instead. "
At 01:20 26/10/2003 +0200, Marc Schoenefeld wrote:
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>Hash: SHA1
>
>Hello,
>
> Java 2 Security Managers are objects that should enforce
> system integrity and safety. Everyone would expect that
> the provided base classes from the JDK are therefore a
> role model for code quality and stability. But that's
> all theory. Let's do some practice:
>
> Imagine a lazy implementor (like me) of a SecurityManager,
> he codes the following:
>
> /* InsecurityManager-Demonstration */
> /* coded by Marc Schoenefeld */
> public class InSecurityManager extends SecurityManager {
>
> public void doit() {
> System.out.println("doit");
> int o = classDepth(null);
> }
>
> public static void main(String[] a) {
> InSecurityManager m = new InSecurityManager();
> m.doit();
> }
>}
> When you run the class with the command
>
> java InSecurityManager
>
> you get a jvm crash, instead of a null pointer exception.
> I tested this with the latest 1.3.1,1.4.1,1.4.2 implementations.
> All Sun implementations crash, the IBM 1.4.1 (comes with
> Websphere or Cloudscape) is stable.
>
> This sample of code will do no harm to productive environments,
> because you cannot instantiate a second security manager, but
> it may be a snapshot of the inner condition of jvm security.
>
> Lesson learned: Do not believe white papers or specifications,
> test the implementation and report bugs to the vendor. Choose
> a stable implementation.
>
> Sincerely
> Marc Schoenefeld
>
>
>- --
>
>Never be afraid to try something new. Remember, amateurs built the
>ark; professionals built the Titanic. -- Anonymous
>
>Marc Sch?nefeld Dipl. Wirtsch.-Inf. / Software Developer
>
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