Module java.base
Package java.net

Class NetPermission

java.lang.Object
java.security.Permission
java.security.BasicPermission
java.net.NetPermission
All Implemented Interfaces:
Serializable, Guard
public final class NetPermission extends BasicPermission
This class is for various network permissions. A NetPermission contains a name (also referred to as a "target name") but no actions list; you either have the named permission or you don't.

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.*" and "*" signify a wildcard match, while "*foo" and "a*b" do not.

The following table lists the standard 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, and associated risks
Permission Target Name What the Permission Allows Risks of Allowing this Permission
allowHttpTrace The ability to use the HTTP TRACE method in HttpURLConnection. Malicious code using HTTP TRACE could get access to security sensitive information in the HTTP headers (such as cookies) that it might not otherwise have access to.
accessUnixDomainSocket The ability to accept, bind, connect or get the local address of a Unix Domain socket. Malicious code could connect to local processes using Unix domain sockets or impersonate local processes, by binding to the same pathnames (assuming they have the required Operating System permissions.
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.
getNetworkInformation The ability to retrieve all information about local network interfaces. Malicious code can read information about network hardware such as MAC addresses, which could be used to construct local IPv6 addresses.
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.
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.
requestPasswordAuthentication The ability to ask the authenticator registered with the system for a password Malicious code may steal this password.
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.
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.
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.
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.
setSocketImpl The ability to create a sub-class of Socket or ServerSocket with a user specified SocketImpl. Malicious user-defined SocketImpls can change the behavior of Socket and ServerSocket in surprising ways, by virtue of their ability to access the protected fields of SocketImpl.
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.
Implementation Note:
Implementations may define additional target names, but should use naming conventions such as reverse domain name notation to avoid name clashes.
Since:
1.2
See Also:

  • Constructor Details

    • NetPermission

      public NetPermission(String name)
      Creates a new NetPermission with the specified name. The name is the symbolic name of the NetPermission, such as "setDefaultAuthenticator", etc. An asterisk may appear at the end of the name, following a ".", or by itself, to signify a wildcard match.
      Parameters:
      name - the name of the NetPermission.
      Throws:
      NullPointerException - if name is null.
      IllegalArgumentException - if name is empty.

    • NetPermission

      public NetPermission(String name, String actions)
      Creates a new NetPermission object with the specified name. The name is the symbolic name of the NetPermission, and the actions String is currently unused and should be null.
      Parameters:
      name - the name of the NetPermission.
      actions - should be null.
      Throws:
      NullPointerException - if name is null.
      IllegalArgumentException - if name is empty.