[icedtea-web] RFC: Patch for PR861: Code in a jar cannot connect to jar host server

Deepak Bhole dbhole at redhat.com
Tue Jun 5 06:53:41 PDT 2012


* Jiri Vanek <jvanek at redhat.com> [2012-06-04 06:39]:
> On 05/28/2012 07:16 PM, Deepak Bhole wrote:
> >Hi,
> >
> >Attached patch resolves PR861:
> >http://icedtea.classpath.org/bugzilla/show_bug.cgi?id=861
> >
> >ChangeLog:
> >2012-05-28  Deepak Bhole<dbhole at redhat.com>
> >
> >     PR861: Allow loading from non codebase hosts. Allow code to connect to
> >     hosting server.
> >     * netx/net/sourceforge/jnlp/SecurityDesc.java
> >     (getSandBoxPermissions): Only add host if it is not empty.
> >     * netx/net/sourceforge/jnlp/runtime/JNLPClassLoader.java
> >     (getPermissions): Add SocketPermission for code source host.
> >     (findLoadedClassAll): Call super methods privileged so that connection to
> >     non codebase hosts can be made.
> >     (findClass): Same.
> >     (findResourcesBySearching): Same. Also use privileged context for enum
> >     operations because the enum is defined on the fly by URLClassLoader and
> >     checks for hosting server connectivity via next().
> >     (getAccessControlContextForClassLoading): New method. Returns a control
> >     context for classloader operations like find/load/etc.
> >     (CodeBaseClassLoader::findClass): Call super methods privileged so that
> >     connection to non codebase hosts can be made.
> >     (CodeBaseClassLoader::findResource): Same.
> >
> >Applets may specify jars from different host servers. The current code only
> >allows socket connect permissions for codebase. This is insufficient as a class
> >from one jar may need a class from another jar that is hosted on a different
> >server.
> >
> >Furthermore, if a class comes from server foo, it should be allowed to connect
> >to foo throughout its lifetime.
> >
> >Attached patch resolves the above issues and makes the site mentioned in the
> >bug (http://broadband.mpi-sws.org/transparency/glasnost.php) work again.
> >
> >OK for HEAD?
> >
> >Cheers,
> >Deepak
> 
> Hi!
> I have walked across the code and looks ok.
> Two questions inline.
> 
> Btw - can you suggest me a bit How I can write an reproducer?
> 
> There is ability in current framework to run several wirtual servers on "different urls" by different ports.
> So you can run application from localhost:1234 and downlaod resource from localhsot:56789. Will this be enough for this testing ( I will elaborate on this reproducers)
> 

Hi Jiri,

Different URLs will not be enough unfortunately. We will need different
DNSs to reproduce this :(

Is the patch itself OK to push btw?

Cheers,
Deepak

> >
> >
> >PR861.patch
> >
> >
> >diff -r 6df151bb5320 NEWS
> >--- a/NEWS	Fri May 25 11:44:13 2012 -0400
> >+++ b/NEWS	Mon May 28 13:11:12 2012 -0400
> >@@ -15,6 +15,7 @@
> >  * Plugin
> >    - PR820: IcedTea-Web 1.1.3 crashing Firefox when loading Citrix XenApp
> >    - PR895: IcedTea-Web searches for missing classes on each loadClass or findClass
> >+  - PR861: Allow loading from non codebase hosts. Allow code to connect to hosting server.
> >  * Common
> >    - PR918: java applet windows uses a low resulution black/white icon
> >
> >diff -r 6df151bb5320 netx/net/sourceforge/jnlp/SecurityDesc.java
> >--- a/netx/net/sourceforge/jnlp/SecurityDesc.java	Fri May 25 11:44:13 2012 -0400
> >+++ b/netx/net/sourceforge/jnlp/SecurityDesc.java	Mon May 28 13:11:12 2012 -0400
> >@@ -238,7 +238,7 @@
> >              for (int i = 0; i<  jnlpRIAPermissions.length; i++)
> >                  permissions.add(jnlpRIAPermissions[i]);
> >
> >-        if (downloadHost != null)
> >+        if (downloadHost != null&&  downloadHost.length()>  0)
> >              permissions.add(new SocketPermission(downloadHost,
> >                                                   "connect, accept"));
> 
> You are adding privileges - shouldn't application request for SocketPermission itself?
> >
> >diff -r 6df151bb5320 netx/net/sourceforge/jnlp/runtime/JNLPClassLoader.java
> >--- a/netx/net/sourceforge/jnlp/runtime/JNLPClassLoader.java	Fri May 25 11:44:13 2012 -0400
> >+++ b/netx/net/sourceforge/jnlp/runtime/JNLPClassLoader.java	Mon May 28 13:11:12 2012 -0400
> >@@ -25,9 +25,11 @@
> >  import java.io.InputStream;
> >  import java.io.InputStreamReader;
> >  import java.net.MalformedURLException;
> >+import java.net.SocketPermission;
> >  import java.net.URL;
> >  import java.net.URLClassLoader;
> >  import java.security.AccessControlContext;
> >+import java.security.AccessControlException;
> >  import java.security.AccessController;
> >  import java.security.AllPermission;
> >  import java.security.CodeSource;
> >@@ -35,9 +37,12 @@
> >  import java.security.PermissionCollection;
> >  import java.security.Permissions;
> >  import java.security.PrivilegedAction;
> >+import java.security.PrivilegedActionException;
> >  import java.security.PrivilegedExceptionAction;
> >+import java.security.ProtectionDomain;
> >  import java.util.ArrayList;
> >  import java.util.Arrays;
> >+import java.util.Collection;
> >  import java.util.Collections;
> >  import java.util.Enumeration;
> >  import java.util.HashMap;
> >@@ -948,6 +953,11 @@
> >                  result.add(runtimePermissions.get(i));
> >              }
> >
> >+            // Class from host X should be allowed to connect to host X
> >+            if (cs.getLocation().getHost().length()>  0)
> >+                result.add(new SocketPermission(cs.getLocation().getHost(),
> >+                        "connect, accept"));
> >+
> >              return result;
> >          } catch (RuntimeException ex) {
> >              if (JNLPRuntime.isDebug()) {
> >@@ -1316,10 +1326,21 @@
> >          for (int i = 0; i<  loaders.length; i++) {
> >              Class result = null;
> >
> >-            if (loaders[i] == this)
> >-                result = super.findLoadedClass(name);
> >-            else
> >+            if (loaders[i] == this) {
> >+                final String fName = name;
> >+                try {
> >+                    result = AccessController.doPrivileged(
> >+                            new PrivilegedExceptionAction<Class<?>>() {
> >+                                public Class<?>  run() {
> >+                                    return JNLPClassLoader.super.findLoadedClass(fName);
> >+                                }
> >+                            }, getAccessControlContextForClassLoading());
> >+                } catch (PrivilegedActionException pae) {
> >+                    result = null;
> >+                }
> >+            } else {
> >                  result = loaders[i].findLoadedClassAll(name);
> >+            }
> >
> >              if (result != null)
> >                  return result;
> >@@ -1517,12 +1538,20 @@
> >      protected Class findClass(String name) throws ClassNotFoundException {
> >          for (int i = 0; i<  loaders.length; i++) {
> >              try {
> >-                if (loaders[i] == this)
> >-                    return super.findClass(name);
> >-                else
> >+                if (loaders[i] == this) {
> >+                    final String fName = name;
> >+                    return AccessController.doPrivileged(
> >+                            new PrivilegedExceptionAction<Class<?>>() {
> >+                                public Class<?>  run() throws ClassNotFoundException {
> >+                                    return JNLPClassLoader.super.findClass(fName);
> >+                                }
> >+                            }, getAccessControlContextForClassLoading());
> >+                } else {
> >                      return loaders[i].findClass(name);
> >+                }
> >              } catch (ClassNotFoundException ex) {
> >              } catch (ClassFormatError cfe) {
> >+            } catch (PrivilegedActionException pae) {
> >              }
> 
> Although unrelated this consumed exception scares me.
> >          }
> >
> >@@ -1631,20 +1660,42 @@
> >       */
> >      private Enumeration<URL>  findResourcesBySearching(String name) throws IOException {
> >          List<URL>  resources = new ArrayList<URL>();
> >-        Enumeration<URL>  e;
> >+        Enumeration<URL>  e = null;
> >
> >          for (int i = 0; i<  loaders.length; i++) {
> >              // TODO check if this will blow up or not
> >              // if loaders[1].getResource() is called, wont it call getResource() on
> >              // the original caller? infinite recursion?
> >
> >-            if (loaders[i] == this)
> >-                e = super.findResources(name);
> >-            else
> >+            if (loaders[i] == this) {
> >+                final String fName = name;
> >+                try {
> >+                    e = AccessController.doPrivileged(
> >+                            new PrivilegedExceptionAction<Enumeration<URL>>() {
> >+                                public Enumeration<URL>  run() throws IOException {
> >+                                    return JNLPClassLoader.super.findResources(fName);
> >+                                }
> >+                            }, getAccessControlContextForClassLoading());
> >+                } catch (PrivilegedActionException pae) {
> >+                }
> >+            } else {
> >                  e = loaders[i].findResources(name);
> >+            }
> >
> >-            while (e.hasMoreElements())
> >-                resources.add(e.nextElement());
> >+            final Enumeration<URL>  fURLEnum = e;
> >+            try {
> >+                resources.addAll(AccessController.doPrivileged(
> >+                    new PrivilegedExceptionAction<Collection<URL>>() {
> >+                        public Collection<URL>  run() {
> >+                            List<URL>  resources = new ArrayList<URL>();
> >+                            while (fURLEnum != null&&  fURLEnum.hasMoreElements()) {
> >+                                resources.add(fURLEnum.nextElement());
> >+                            }
> >+                            return resources;
> >+                        }
> >+                    }, getAccessControlContextForClassLoading()));
> >+            } catch (PrivilegedActionException pae) {
> >+            }
> >          }
> >
> >          // Add resources from codebase (only if nothing was found above,
> >@@ -1896,6 +1947,56 @@
> >          }
> >      }
> >
> >+    /**
> >+     * Returns an appropriate AccessControlContext for loading classes in
> >+     * the running instance.
> >+     *
> >+     * The default context during class-loading only allows connection to
> >+     * codebase. However applets are allowed to load jars from arbitrary
> >+     * locations and the codebase only access falls short if a class from
> >+     * one location needs a class from another.
> >+     *
> >+     * Given protected access since CodeBaseClassloader uses this function too.
> >+     *
> >+     * @return The appropriate AccessControlContext for loading classes for this instance
> >+     */
> >+    public AccessControlContext getAccessControlContextForClassLoading() {
> >+        AccessControlContext context = AccessController.getContext();
> >+
> >+        try {
> >+            context.checkPermission(new AllPermission());
> >+            return context; // If context already has all permissions, don't bother
> >+        } catch (AccessControlException ace) {
> >+            // continue below
> >+        }
> >+
> >+        // Since this is for class-loading, technically any class from one jar
> >+        // should be able to access a class from another, therefore making the
> >+        // original context code source irrelevant
> >+        PermissionCollection permissions = this.security.getSandBoxPermissions();
> >+
> >+        // Local cache access permissions
> >+        for (Permission resourcePermission : resourcePermissions) {
> >+            permissions.add(resourcePermission);
> >+        }
> >+
> >+        // Permissions for all remote hosting urls
> >+        for (URL u: jarLocationSecurityMap.keySet()) {
> >+            permissions.add(new SocketPermission(u.getHost(),
> >+                                                 "connect, accept"));
> >+        }
> >+
> >+        // Permissions for codebase urls
> >+        for (URL u : codeBaseLoader.getURLs()) {
> >+            permissions.add(new SocketPermission(u.getHost(),
> >+                    "connect, accept"));
> >+        }
> >+
> >+        ProtectionDomain pd = new ProtectionDomain(null, permissions);
> >+
> >+        return new AccessControlContext(new ProtectionDomain[] { pd });
> >+    }
> >+
> >      /*
> >       * Helper class to expose protected URLClassLoader methods.
> >       */
> >@@ -1927,10 +2028,16 @@
> >                  throw new ClassNotFoundException(name);
> >
> >              try {
> >-                return super.findClass(name);
> >-            } catch (ClassNotFoundException cnfe) {
> >+                final String fName = name;
> >+                return AccessController.doPrivileged(
> >+                        new PrivilegedExceptionAction<Class<?>>() {
> >+                            public Class<?>  run() throws ClassNotFoundException {
> >+                                return CodeBaseClassLoader.super.findClass(fName);
> >+                            }
> >+                        }, parentJNLPClassLoader.getAccessControlContextForClassLoading());
> >+            } catch (PrivilegedActionException pae) {
> >                  notFoundResources.put(name, super.getURLs());
> >-                throw cnfe;
> >+                throw new ClassNotFoundException("Could not find class " + name);
> >              }
> >          }
> >
> >@@ -1983,8 +2090,18 @@
> >              if (Arrays.equals(super.getURLs(), notFoundResources.get(name)))
> >                  return null;
> >
> >+            URL url = null;
> >              if (!name.startsWith("META-INF")) {
> >-                URL url = super.findResource(name);
> >+                try {
> >+                    final String fName = name;
> >+                    url = AccessController.doPrivileged(
> >+                            new PrivilegedExceptionAction<URL>() {
> >+                                public URL run() {
> >+                                    return CodeBaseClassLoader.super.findResource(fName);
> >+                                }
> >+                            }, parentJNLPClassLoader.getAccessControlContextForClassLoading());
> >+                } catch (PrivilegedActionException pae) {
> >+                }
> >
> >                  if (url == null) {
> >                      notFoundResources.put(name, super.getURLs());
> 
> Thanx for patch!
>    J.



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