The target name is the name of the network permission (see below). The naming convention follows the hierarchical property naming convention. Also, an asterisk may appear at the end of the name, following a ".", or by itself, to signify a wildcard match. For example: "foo.*" or "*" is valid, "*foo" or "a*b" is not valid.
The following table lists all the possible NetPermission target names, and for each provides a description of what the permission allows and a discussion of the risks of granting code the permission.
| Permission Target Name | What the Permission Allows | Risks of Allowing this Permission |
|---|---|---|
| setDefaultAuthenticator | The ability to set the way authentication information is retrieved when a proxy or HTTP server asks for authentication | Malicious code can set an authenticator that monitors and steals user authentication input as it retrieves the input from the user. |
| requestPasswordAuthentication | The ability to ask the authenticator registered with the system for a password | Malicious code may steal this password. |
| specifyStreamHandler | The ability to specify a stream handler when constructing a URL | Malicious code may create a URL with resources that it would normally not have access to (like file:/foo/fum/), specifying a stream handler that gets the actual bytes from someplace it does have access to. Thus it might be able to trick the system into creating a ProtectionDomain/CodeSource for a class even though that class really didn't come from that location. |
| setProxySelector | The ability to set the proxy selector used to make decisions on which proxies to use when making network connections. | Malicious code can set a ProxySelector that directs network traffic to an arbitrary network host. |
| getProxySelector | The ability to get the proxy selector used to make decisions on which proxies to use when making network connections. | Malicious code can get a ProxySelector to discover proxy hosts and ports on internal networks, which could then become targets for attack. |
| setCookieHandler | The ability to set the cookie handler that processes highly security sensitive cookie information for an Http session. | Malicious code can set a cookie handler to obtain access to highly security sensitive cookie information. Some web servers use cookies to save user private information such as access control information, or to track user browsing habit. |
| getCookieHandler | The ability to get the cookie handler that processes highly security sensitive cookie information for an Http session. | Malicious code can get a cookie handler to obtain access to highly security sensitive cookie information. Some web servers use cookies to save user private information such as access control information, or to track user browsing habit. |
| setResponseCache | The ability to set the response cache that provides access to a local response cache. | Malicious code getting access to the local response cache could access security sensitive information, or create false entries in the response cache. |
| getResponseCache | The ability to get the response cache that provides access to a local response cache. | Malicious code getting access to the local response cache could access security sensitive information. |
SecurityManager.checkPermission method is called,
passing this permission object as the permission to check.
Returns silently if access is granted. Otherwise, throws
a SecurityException.java.io.FilePermission,
the name will be a pathname.getName().hashCode(), where getName is
from the Permission superclass.More specifically, this method returns true if:
A BasicPermissionCollection stores a collection of BasicPermission permissions.
BasicPermission objects must be stored in a manner that allows them
to be inserted in any order, but that also enables the
PermissionCollection implies method
to be implemented in an efficient (and consistent) manner.
wait methods.
The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:
synchronized statement
that synchronizes on the object.
Class, by executing a
synchronized static method of that class.
Only one thread at a time can own an object's monitor.
wait methods.
The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
The current thread must own this object's monitor. The thread
releases ownership of this monitor and waits until another thread
notifies threads waiting on this object's monitor to wake up
either through a call to the notify method or the
notifyAll method. The thread then waits until it can
re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait();
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.The current thread must own this object's monitor.
This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:
A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout);
... // Perform action appropriate to condition
}
(For more information on this topic, see Section 3.2.3 in Doug Lea's
"Concurrent Programming in Java (Second Edition)" (Addison-Wesley,
2000), or Item 50 in Joshua Bloch's "Effective Java Programming
Language Guide" (Addison-Wesley, 2001).
If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.
Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
This method is similar to the wait method of one
argument, but it allows finer control over the amount of time to
wait for a notification before giving up. The amount of real time,
measured in nanoseconds, is given by:
1000000*timeout+nanos
In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).
The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:
notify method
or the notifyAll method.
timeout
milliseconds plus nanos nanoseconds arguments, has
elapsed.
The thread then waits until it can re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout, nanos);
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.