I have a server where I work with a database and files using a java app.
When I start my app I give a report regarding file access to the server using:
public static boolean folderExists(String folderPath) {
File folderToCheck = new File(folderPath);
return folderToCheck.exists();
}
Every time I start my app (after a fresh restart of my computer)
I get a false response, even though the server is on.
The reason is because I must give an authentication as another user.
What I do is access the server through Windows
where I am being asked for username/password,
and after that I get a true response regarding file access to the server.
Is there a way to give the authentication username/password through Java,
and not through Windows?
Thank you
On Windows 'native' Java IO (e.g. java.io.File) always inherits the security context of the user running the JVM process. For example, you could run the Java app as a Windows service with the correct credentials.
The JCIFS project implements CIFS (the Windows SMB file server protocol) and allows you to directly specify the username/password.
See the API for examples.
I am pretty sure, that there is no way to grant fileaccess by java, without a Windows-Call.
You can call cacls file.log /e /t /p Everyone:f but this will be language-dependent.
I had a similar problem: How to change the file ACL in windows, if I only know the SID?
With Java7 there may be a way to do this.
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 have a server where I work with a database and files using a java app.
When I start my app I give a report regarding file access to the server using:
public static boolean folderExists(String folderPath) {
File folderToCheck = new File(folderPath);
return folderToCheck.exists();
}
Every time I start my app (after a fresh restart of my computer)
I get a false response, even though the server is on.
The reason is because I must give an authentication as another user.
What I do is access the server through Windows
where I am being asked for username/password,
and after that I get a true response regarding file access to the server.
Is there a way to give the authentication username/password through Java,
and not through Windows?
Thank you
On Windows 'native' Java IO (e.g. java.io.File) always inherits the security context of the user running the JVM process. For example, you could run the Java app as a Windows service with the correct credentials.
The JCIFS project implements CIFS (the Windows SMB file server protocol) and allows you to directly specify the username/password.
See the API for examples.
I am pretty sure, that there is no way to grant fileaccess by java, without a Windows-Call.
You can call cacls file.log /e /t /p Everyone:f but this will be language-dependent.
I had a similar problem: How to change the file ACL in windows, if I only know the SID?
With Java7 there may be a way to do this.
I have a client-side security policy, with a statement that grants permissions. I want to be able to specify it to grant the set of permissions for an RMI server only. For example this works:
grant{
//my permissions
};
But I cant figure out how to link the set of permissions so that they apply to my codebase on the server. Actually anything, as long as its tied to the server would be fine. I have tried:
grant codeBase "file://hostname/-"{
//my permissions
};
With the hostname being the name or IP of the machine, both with and w/o the port number. But this does not work, neither does using http instead of file. If I understand what I read so far correctly the hyphen at the end should apply the permissions to anything located on the server. Anyone know what I need to do to get this to work?
Thanks.
Heres the codebase specified when running the server:
-Djava.rmi.server.codebase=file://home/me/PageServer/build/classes/ pageserver.LoginService pageserver.PlannerService
Where is the local JVM getting the code that should be granted permissions?
If it's downloading the code from an HTTP codebase on the server, you can use a URL starting with "http:".
If it's local code, you can use a URL starting with "file:" and ending with a local path.
Disclaimer: I've written security files for Jini, which is built atop RMI, and it's been a few years. Apologies for anything I've missed.
Use a JAR for the codebase, and specify exactly the HTTP URL in the .policy file that you specified in -Djava.rmi.server.codebase.
I'm having trouble getting RMI security policies working. I have a .policy file on both the server and client, each of which is running a SecurityManager.
When I try and run the client its failing. My policy file grants everything atm. Heres the content:
grant { permission java.security.AllPermission };
I have the file client.policy in the root directory of my JAR file (I tried running it with the policy file outside the jar too). Then I run the client with this:
java -jar PagePlanner.jar -Djava.security.policy=client.policy -Djava.rmi.codebase=http://192.168.0.88:2077/home/me/NetbeansProjects/PageServer/dist/PageServer.jar -Djava.security.debug=access
Specifying my policy file and the path to my code base. I'm not sure if either of these are correct. I also tried setting the debug switch as I read somewhere it should give me extra info about whats going wrong, but it does not seem to make a difference.Heres the output when I run the client:
Exception in thread "main" java.security.AccessControlException: access denied (java.awt.AWTPermission setWindowAlwaysOnTop)
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.awt.Window.setAlwaysOnTop(Window.java:2038)
at gui.LoginForm.<init>(LoginForm.java:59)
at main.Main.main(Main.java:21)
From which point the client just hangs. Any ideas what I'm doing wrong here? The policy setup on the server-side is pretty much the same. I can post the details if that helps.
Cheers.
Run the client with -Djava.security.debug=access,failure. Most probably your .policy file isn't being found.
BTW you don't need to set the codebase at the client unless the client has its own implementations of abstract classes/interfaces and the server doesn't know about them. The codebase is normally only set at the server, so as to annotate classes that are downloaded to the client and the Registry.