java.security.cert
Class PKIXCertPathChecker

java.lang.Object
  |
  +--java.security.cert.PKIXCertPathChecker

All Implemented Interfaces:

Cloneable

public abstract class PKIXCertPathChecker

extends Object

implements Cloneable

An abstract class that performs one or more checks on an X509Certificate.

A concrete implementation of the PKIXCertPathChecker class can be created to extend the PKIX certification path validation algorithm. For example, an implementation may check for and process a critical private extension of each certificate in a certification path.

Instances of PKIXCertPathChecker are passed as parameters using the setCertPathCheckers or addCertPathChecker methods of the PKIXParameters and PKIXBuilderParameters class. Each of the PKIXCertPathCheckers check methods will be called, in turn, for each certificate processed by a PKIX CertPathValidator or CertPathBuilder implementation.

A PKIXCertPathChecker may be called multiple times on successive certificates in a certification path. Concrete subclasses are expected to maintain any internal state that may be necessary to check successive certificates. The init method is used to initialize the internal state of the checker so that the certificates of a new certification path may be checked. A stateful implementation must override the clone method if necessary in order to allow a PKIX CertPathBuilder to efficiently backtrack and try other paths. In these situations, the CertPathBuilder is able to restore prior path validation states by restoring the cloned PKIXCertPathCheckers.

The order in which the certificates are presented to the PKIXCertPathChecker may be either in the forward direction (from target to most-trusted CA) or in the reverse direction (from most-trusted CA to target). A PKIXCertPathChecker implementation must support reverse checking (the ability to perform its checks when it is presented with certificates in the reverse direction) and may support forward checking (the ability to perform its checks when it is presented with certificates in the forward direction). The isForwardCheckingSupported method indicates whether forward checking is supported.

Additional input parameters required for executing the check may be specified through constructors of concrete implementations of this class.

Concurrent Access

Unless otherwise specified, the methods defined in this class are not thread-safe. Multiple threads that need to access a single object concurrently should synchronize amongst themselves and provide the necessary locking. Multiple threads each manipulating separate objects need not synchronize.

Since:

1.4

See Also:

PKIXParameters, PKIXBuilderParameters

Constructor Summary

protected

PKIXCertPathChecker() Default constructor.

Method Summary

abstract void	check(Certificate cert, Collection unresolvedCritExts) Performs the check(s) on the specified certificate using its internal state and removes any critical extensions that it processes from the specified collection of OID strings that represent the unresolved critical extensions.
Object	clone() Returns a clone of this object.
abstract Set	getSupportedExtensions() Returns an immutable Set of X.509 certificate extensions that this PKIXCertPathChecker supports (i.e.
abstract void	init(boolean forward) Initializes the internal state of this PKIXCertPathChecker.
abstract boolean	isForwardCheckingSupported() Indicates if forward checking is supported.

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PKIXCertPathChecker

protected PKIXCertPathChecker()

Default constructor.

Method Detail

init

public abstract void init(boolean forward)
                   throws CertPathValidatorException

Initializes the internal state of this PKIXCertPathChecker.

The forward flag specifies the order that certificates will be passed to the check method (forward or reverse). A PKIXCertPathChecker must support reverse checking and may support forward checking.

Parameters:

forward - the order that certificates are presented to the check method. If true, certificates are presented from target to most-trusted CA (forward); if false, from most-trusted CA to target (reverse).

Throws:

CertPathValidatorException - if this PKIXCertPathChecker is unable to check certificates in the specified order; it should never be thrown if the forward flag is false since reverse checking must be supported

isForwardCheckingSupported

public abstract boolean isForwardCheckingSupported()

Indicates if forward checking is supported. Forward checking refers to the ability of the PKIXCertPathChecker to perform its checks when certificates are presented to the check method in the forward direction (from target to most-trusted CA).

Returns:

true if forward checking is supported, false otherwise

getSupportedExtensions

public abstract Set getSupportedExtensions()

Returns an immutable Set of X.509 certificate extensions that this PKIXCertPathChecker supports (i.e. recognizes, is able to process), or null if no extensions are supported.

Each element of the set is a String representing the Object Identifier (OID) of the X.509 extension that is supported. The OID is represented by a set of nonnegative integers separated by periods.

All X.509 certificate extensions that a PKIXCertPathChecker might possibly be able to process should be included in the set.

Returns:

an immutable Set of X.509 extension OIDs (in String format) supported by this PKIXCertPathChecker, or null if no extensions are supported

check

public abstract void check(Certificate cert,
                           Collection unresolvedCritExts)
                    throws CertPathValidatorException

Performs the check(s) on the specified certificate using its internal state and removes any critical extensions that it processes from the specified collection of OID strings that represent the unresolved critical extensions. The certificates are presented in the order specified by the init method.

Parameters:

cert - the Certificate to be checked

unresolvedCritExts - a Collection of OID strings representing the current set of unresolved critical extensions

Throws:

CertPathValidatorException - if the specified certificate does not pass the check

clone

public Object clone()

Returns a clone of this object. Calls the Object.clone() method. All subclasses which maintain state must support and override this method, if necessary.

Overrides:

clone in class Object

Returns:

a copy of this PKIXCertPathChecker

See Also:

Cloneable