The permission java.security.AllPermission
implies all permissions and grants all possible permissions to code. This facility was included for routine testing purposes to make it less cumbersome to deal with a multitude of permissions and for use when the code is completely trusted. Code is typically granted AllPermission
using the security policy file but it is also possible to associate AllPermission
with a ProtectionDomain
, programatically. This permission is dangerous in production environments and must never be granted to untrusted code.
Noncompliant Code Example (security policy file)
This noncompliant example grants AllPermission
to the klib
library.
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// Grant the klib library AllPermission
grant codebase "file:${klib.home}/j2se/home/klib.jar" {
permission java.security.AllPermission;
};
|
The permission itself is specified in the security policy file used by the security manager. Alternatively, a permission object can be obtained in the code by subclassing the java.security.Permission
class (or any subclass such as BasicPermission
). AllPermission
can be granted to a ProtectionDomain
using such an object. This is again a bad practice.
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// grant the klib library AllPermission
grant codebase "file:${klib.home}/j2se/home/klib.jar" {
permission java.security.AllPermission;
};
|
Compliant Solution
This compliant solution shows a policy file that can be used to enforce fine-grained permissions.
...
To check whether the caller has the requisite permissions, standard Java APIs use code such as:
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//security Security manager code perm = new java.io.FilePermission("/tmp/JavaFile","read"); AccessController.checkPermission(perm); //other code... |
Always assign appropriate permissions to code. When more control over the granularity of permissions is required, define custom permissions. (SEC10-J. Define custom security permissions for fine grained security)
Noncompliant Code Example (PermissionCollection
)
This noncompliant example shows an overridden getPermissions()
method, defined in a custom class loader. It grants java.security.AllPermission
to any class that it loads. This example also violates SEC11-J. Call the superclass's getPermissions method when writing a custom class loader.
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protected PermissionCollection getPermissions(CodeSource cs) { PermissionCollection pc = new Permissions(); pc.add(new java.security.AllPermission()); // other permissions return pc; } |
This example also violates SEC11-J. Call the superclass's getPermissions method when writing a custom class loader.
Compliant Solution
This compliant solution does not grant the java.security.AllPermission
to any class that it loads.
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protected PermissionCollection getPermissions(CodeSource cs) { PermissionCollection pc = super.getPermissions(cs); // add fine-grained permissions return pc; } |
...
EX1: It may be necessary to grant AllPermission
to trusted library code so that callbacks work as expected. For example, it is a common practice to grant AllPermission
to the optional Java packages (extension libraries):
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// Standard extensions extend the core platform and are getgranted all permissions by default grant codeBase "file:${{java.ext.dirs}}/*" { permission java.security.AllPermission; }; |
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