I am trying to run the example of the RMI application given in the Oracle website http://docs.oracle.com/javase/tutorial/rmi/running.html.
However, trying both Eclipse and in the command line, I can't run the server nor the client.
In fact, when running in Eclipse I get this error:
ComputeEngine exception:
java.security.AccessControlException: access denied ("java.net.SocketPermission" "127.0.0.1:1099" "connect,resolve")
I also have changed the VM Argument like this:
For the ComputeEngine (server):
-Djava.security.manager -Djava.rmi.server.codebase=file:/Users/name/Documents/workspace/PiComputationRM/src/compute/compute.jar -Djava.security.policy=/Users/name/Documents/workspace/PiComputationRM/server.policy
For the ComputePi (client):
-Djava.security.policy=/Users/name/Documents/workspace/PiComputationRM/client.policy
The content of my client and server policy is:
grant {
permission java.security.AllPermission;
};
Also when I try to run the server in terminal with:
java -Djava.security.policy="server.policy" src/engine/ComputeEngine.java
I got this error:
Error: Could not find or load main class src.engine.ComputeEngine.java
Please any help, I have spent many hours on the Internet in vain ??
ComputeEngine exception:
java.security.AccessControlException: access denied ("java.net.SocketPermission" "127.0.0.1:1099" "connect,resolve")
You are using a security manager and you haven't granted that permission in your .policy file.
I also have changed the VM Argument like this:
For the ComputeEngine (server):
-Djava.security.manager -Djava.rmi.server.codebase=file:/Users/name/Documents/workspace/PiComputationRM/src/compute/compute.jar -Djava.security.policy=/Users/name/Documents/workspace/PiComputationRM/server.policy
Several problems there:
a file: codebase isn't going to work unless it specifies a shared location that is visible by that name to the client and the Registry. This doesn't look like one of those.
you need to check whether that is the correct name for the policy file
you don't even need a security manager or policy in the server, unless the client is setting its own codebase and is going to provide classes to you. That doesn't happen in this example.
For the ComputePi (client):
-Djava.security.policy=/Users/name/Documents/workspace/PiComputationRM/client.policy
Double-check this name.
Also when I try to run the server in terminal with:
java -Djava.security.policy="server.policy" src/engine/ComputeEngine.java
I got this error:
Error: Could not find or load main class src.engine.ComputeEngine.java
Of course you did. You gave a compiler command to the JVM. Use the command provided in the tutorial. You don't name .java files to the JVM.
I have spent many hours on the Internet in vain
You should have been double-checking your work against the tutorial instead. You've misread the tutorial in at least two places.
I would also question whether you really need the codebase feature at all. I would start by removing it, and the security managers, altogether, and just get it working without them. It's too much of a complication for a first RMI project.
I downloaded Netbeans 7.4 and Java 7 Update 51. I get the below error when I try to start Java DB or derby connection from Netbeans. This is on a windows 8 PC. I downloaded the version for windows xp 32 bit at work. It works fine. I am not sure what is missing.
Thu Jan 16 00:48:23 EST 2014 : Security manager installed using the Basic server security policy.
Thu Jan 16 00:48:24 EST 2014 : access denied ("java.net.SocketPermission" "localhost:1527" "listen,resolve")
java.security.AccessControlException: access denied ("java.net.SocketPermission" "localhost:1527" "listen,resolve")
at java.security.AccessControlContext.checkPermission(AccessControlContext.java:372)
at java.security.AccessController.checkPermission(AccessController.java:559)
at java.lang.SecurityManager.checkPermission(SecurityManager.java:549)
at java.lang.SecurityManager.checkListen(SecurityManager.java:1134)
at java.net.ServerSocket.bind(ServerSocket.java:375)
at java.net.ServerSocket.<init>(ServerSocket.java:237)
at javax.net.DefaultServerSocketFactory.createServerSocket(ServerSocketFactory.java:231)
at org.apache.derby.impl.drda.NetworkServerControlImpl.createServerSocket(Unknown Source)
at org.apache.derby.impl.drda.NetworkServerControlImpl.access$000(Unknown Source)
at org.apache.derby.impl.drda.NetworkServerControlImpl$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at org.apache.derby.impl.drda.NetworkServerControlImpl.blockingStart(Unknown Source)
at org.apache.derby.impl.drda.NetworkServerControlImpl.executeWork(Unknown Source)
at org.apache.derby.drda.NetworkServerControl.main(Unknown Source)
This is what I did:
Find out exactly where the java home is by executing this instruction from NetBeans 7.4 :
System.out.println(System.getProperty("java.home"));
This is the output for my case:
C:\Program Files\Java\jdk1.7.0_51\jre
which is quite important for me, I was modifying another java.policy and took no effect and wasted me a couple of hours.
For reason of java.policy is an unix style file and read-only, I opened and edited it with notepad++ and executed as administrator (under the same java home):
C:\Program Files\Java\jdk1.7.0_51\jre\lib\security\java.policy
Add only these lines into the file after the first grant:
<pre>grant {
permission java.net.SocketPermission "localhost:1527", "listen";
};</pre>
Save the file, which is a little tricky for reason of the permission. But if you run notepad++ or any other edit program as administrator, you can solve the problem. Then try to connect the database from NetBeans, it works for me.
According to Java™ SE Development Kit 7, Update 51 Release Notes
Change in Default Socket Permissions
The default socket permissions assigned to all code including untrusted code have been changed in this release. Previously, all code was able to bind any socket type to any port number greater than or equal to 1024. It is still possible to bind sockets to the ephemeral port range on each system. The exact range of ephemeral ports varies from one operating system to another, but it is typically in the high range (such as from 49152 to 65535). The new restriction is that binding sockets outside of the ephemeral range now requires an explicit permission in the system security policy.
Most applications using client tcp sockets and a security manager will not see any problem, as these typically bind to ephemeral ports anyway. Applications using datagram sockets or server tcp sockets (and a security manager) may encounter security exceptions where none were seen before. If this occurs, users should review whether the port number being requested is expected, and if this is the case, a socket permission grant can be added to the local security policy, to resolve the issue.
This means that you have to explicity set the permissions for your application to be able to access the ports range between 1025 and 49151. You can therefore grant this permission by appending this line in the list of permissions granted:
Visit your Java Home Directory and access your policy file at $JAVA_HOME/jre/lib/security/java.policy and make the following changes.
grant{
//List of granted permissions
permission java.net.SocketPermission "localhost:1527", "listen";
}
See http://www.oracle.com/technetwork/java/javase/7u51-relnotes-2085002.html for the description of the "problem". Search other-libs/javadb
Depending on your requirement, what I did was go and modify the default security policy
cd $JAVA_HOME/jre/lib/security
Edit java.policy (make a backup first!)
Add the following
grant codeBase "file:${java.home}}/../db/lib/*" {
permission java.security.AllPermission;
};
Note that this is my requirement.
I'm granting every app who uses the u51 JRE the permission to start Derby.
EDIT
The alternative would be to use a less permissive set of permissions like:
grant codeBase "file:${java.home}}/../db/lib/*" {
permission java.net.SocketPermission "localhost:1527", "listen,resolve";
};
NetBeans, by default, uses the derby version installed with GlassFish. So my permissions look like this on the Mac. It will be similar on Windows, but the path will need to change.
grant codeBase "file:/Applications/NetBeans/glassfish-4.0/javadb/lib/*" {
permission java.net.SocketPermission "localhost:1527", "listen,resolve";
};
Because the upper measures didn't work I added the following permission to the end of the main permission section:
permission java.net.SocketPermission "localhost:1527", "listen,resolve";
You can also solve the problem on a per-user basis by granting the needed permission in a file called .java.policy in your home directory.
Works on both Unix and Windows systems as documented here: http://docs.oracle.com/javase/7/docs/technotes/guides/security/PolicyFiles.html
This might be useful if the system-wide policy file gets overwritten, for example when updating your JDK, or if you don't have permission to edit the system file.
This is what I have in my $HOME/.java.policy:
grant {
permission java.net.SocketPermission "localhost:1527", "listen";
};
I got a bit fed up with Oracle's approach to security lately. They seem to be trying to protect us from ourselves in ways that would be more appropriate to naive users than programmers. My view is that the code I put on my own machine should be able to do whatever it needs to. It's my fault if I put code there that does bad things. Clearly not a universally reliable perspective, but it's worked for me for about 35 years. On that basis, I add this to my /lib/security/java.policy file:
grant codeBase "file:/-" {
permission java.security.AllPermission;
};
note that the file:/- matches any file on the system, and the grant block says, in essence, "if the class is loaded from this file system, then trust it".
This was doing my head in for a bit until I stumbled across the following in the NetBeans wiki
JavaDB grant permissions
JavaDB grant permissions
How to grant permissions for Java DB / How to start Java DB
Related to issue #239962
JDK 7u51 comes with some security improvements which are causing
problems with starting Java DB on this Java version.
When you try to start DB from NetBeans you will probably get the
Exception:
java.security.AccessControlException: access denied
("java.net.SocketPermission" "localhost:1527" "listen,resolve")
The same exception you will get while starting using script /db/bin/startNetworkServer
Because there is no suitable way to fix it on the NetBeans side and
this should be fixed on the side of the Java DB.
There are several ways how to deal with this problem. I will mention
only the easiest way. You have to start DB manually from command line.
• Start Java DB with -noSecurityManager argument.
(JDK 7u51 location)/db/bin/startNetworkServer -noSecurityManager
Although it’s not exactly a solution it is usable as a quick workaround.
My solution to this was to reinstall jdk 1.7.45, uninstall netbeans and reinstall it selecting the outdated jdk. Don't know if there is a way to change sdk in NB without reinstalling it but it worked this way.
Well, one alternative is to change the port JavaDB listens to, to be now in the high range (such as from 49152 to 65535).
Go to Window->Services, then right click Java DB and in "Java DB Properties Dialog" goto to "Database Location", which in my system is "C:\Users\ahernandeza.netbeans-derby"
In that directory edit or create the file derby.properties, and add/edit the line:
derby.drda.portNumber=XXXX
Where XXXX is the new port, in my case i put 51527 and worked just fine.
EDIT
At fisrt glance it worked, the service started just fine, but when creating or starting a database in NB, i got the error Unable to connect. CAnnot establish a connection to jdbc:derby://localhost:1527/sample
Although i changed the pprt to 51527, it tries to connect to 1527
If linux, then
file=`find $(dirname $(readlink -f $(which java)))/.. -iname 'java.policy'`; grep 1527 $file || sudo sed -i '0,/"listen"/{s/"listen".*/\0\n\tpermission java.net.SocketPermission "localhost:1527", "listen";/}' $file
cat $file
it automatically finds your java and changes permissions
I found a quick solution to this problem -
Start your JavaDB from the command line\terminal like so:
<base folder>/db/bin/startNetworkServer -noSecurityManager
Then it runs fine without adding new permissions.
The problem is the Java 7u51, it have a bug that affect Derby and other programs and libraries, I suggest to install the Java 7u45
I am trying to execute this jnlp application.
However, I keep receiving this security exception:
java.lang.ExceptionInInitializerError
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:399)
at java.lang.Class.newInstance0(Class.java:370)
at java.lang.Class.newInstance(Class.java:322)
at com.sun.javafx.applet.FXApplet2.init(FXApplet2.java:63)
at com.sun.deploy.uitoolkit.impl.fx.FXApplet2Adapter.init(FXApplet2Adapter.java:207)
at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.security.AccessControlException: access denied ("java.util.PropertyPermission" "java.net.useSystemProxies" "write")
at java.security.AccessControlContext.checkPermission(AccessControlContext.java:364)
at java.security.AccessController.checkPermission(AccessController.java:560)
at java.lang.SecurityManager.checkPermission(SecurityManager.java:549)
at java.lang.System.setProperty(System.java:783)
at ensemble.Ensemble2.<clinit>(Ensemble2.java:77)
... 10 more
I tried changing the security settings in the Java control panel (OSX 10.8.3), but they seem to be disabled and I cannot modify them (I do can check the "Enable Java content in the browser" option, but it is resetted when I click apply). This is shown in the following figure:
Is there another mechanism for bypassing the Java security manager and being able to execute a jnlp application ?
UPDATE:
After reinstalling Java I was finally able to change the security options in the Java Control panel (I did not do anything special, just reinstall it from scratch). Unfortunately, when I execute the jnlp application it dies silently without showing any errors. This problem could be related to the fact that I am using the jdk 1.8 (since the jnlp application requires javafx) and it is just a preview version (and OSX does not seem to like a lot Java these days...), it is my best guess but I cannot be completely sure.
Possible reasons for this:
I have heard that Java 7 on Mac is still not stable.
By default JNLP files run in a "sandbox" to prevent malicious code from wreaking havoc on your system. This sandbox restricts access to the local filesystem and local network. I imagine that system properties are restricted too, and it looks like the app is trying to write to them. To allow unrestricted access, you need to sign the JAR file and configure the JNLP file with <security><all-permissions/></security>
I want to experiment with Activatable objects in RMI. Is there a simple example somewhere that works? I'm trying to use Oracle's tutorial but I get java.security.AccessControlException: access denied (java.net.SocketPermission 127.0.0.1:1098 connect,resolve)
Try to add this as first argument to your java-vm
-Djava.security.policy=rmi.security
example of rmi.security (could be more specific, created with policytool)
grant {
permission java.security.AllPermission;
};
Is there a way to run Java VM (java.exe) on Windows Server 2008 and disable all network connections using a command line argument or a system variable?
You can do this by enabling default Java security manager. By default no security is enforced so you are allowed to do anything, but if security manager is enabled it will restrict network access, file access and lots of other things unless you specify otherwise in the security policy file.
To enable the default security manager pass this argument to JVM on start.
java -Djava.security.manager=default my.main.Class
By doing this any network access attempt from inside JVM will throw java.net.NetPermission.
This will also break things like file access, so if you need to allow it you will need to specify those in a special security policy file (-Djava.security.policy=path/to/policy.file). There should be plenty of examples of how to set it up, just search for "java permissions" to get you started.
I had the same task to test offline installer for our product. All said above is almost right, but creating .policy file is not easy for the first time. Here is what I did:
Crated generic policy file that has no permission to resolve host names (see code snippet below);
Added -Djava.security.manager -Djava.security.policy=pathto/policy.file in jvm parameters;
generic .policy file content:
grant {
permission java.io.FilePermission "<<ALL FILES>>", "read,write,execute,delete";
permission java.util.PropertyPermission "*", "read,write";
permission java.lang.RuntimePermission "*";
permission java.net.NetPermission "*";
permission java.lang.reflect.ReflectPermission "*";
};
If something tries to get content outside during the test, it fails with security exception.
Well, I haven't tried that but theoretically you could set the system properties for SOCKS proxy to a non-existent one and according to the documentation all TCP sockets will be tried through the SOCKS proxy - and fail.
Something like this:
java -DsocksProxyHost=127.0.0.1 SomeClass