Hi guys,
I am reading the SocketPermission source code recently and find some
thing strange. Below is a simple test case to describe the strange thing:
SocketPermission star_All = new SocketPermission("*.java.net",
"listen,accept,connect");
SocketPermission www_All = new SocketPermission("java.net",
"listen,accept,connect");
System.out.println(star_All.implies(www_All));
star_All = new SocketPermission("java.net", "listen,accept,connect");
www_All = new SocketPermission("java.net", "listen,accept,connect");
System.out.println(star_All.implies(www_All));
Return is false and true.
The reason is:
SocketPermission treat wildcard special. If the initial string has a
wildcard, the cname comes from the substring. For example, the cname of
"*.java.net" is ".java.net". (Why the first dot remains?)
In my initial idea, "*.java.net" should imply "java.net". Any idea about it?
More interestingly, I add "localhost.localdomain" and "mytest" pointing
to the "127.0.0.1" in the /etc/hosts (Ubuntu) and rewrite the test case to:
SocketPermission star_All = new
SocketPermission("localhost.localdomain", "listen,accept,connect");
SocketPermission www_All = new SocketPermission("mytest",
"listen,accept,connect");
System.out.println(star_All.implies(www_All));
Return is true.
If on a multi-host machine, is it reasonable?
By the way, I am curious about the reason why SocketPermission does not
use the initial string as its cname, for example:
SocketPermission star_All = new SocketPermission("*.blabla.bla",
"listen,accept,connect");
SocketPermission www_All = new SocketPermission("bla.blabla.bla",
"listen,accept,connect");
System.out.println(star_All.implies(www_All));
In the above test case, the two permission looks similiar. If using the
initial string, I expect the return should be true. But it return false,
because of the UnknowHostException. Any idea about this?
