CertPathValidator

AI-generated Key Takeaways

• CertPathValidator is a class used for validating certification paths (certificate chains) in a provider-based architecture.

• To create an instance, use the static getInstance methods, providing the algorithm name (like "PKIX") and optionally a provider.

• The validate method is used to validate a CertPath with specific parameters, returning a CertPathValidatorResult if successful.

• getRevocationChecker allows customization of certificate revocation checks, offering flexibility in validation processes.

• Android supports the "PKIX" algorithm for CertPathValidator, ensuring compatibility with standard certificate validation practices.

public class CertPathValidator extends Object

A class for validating certification paths (also known as certificate chains).

This class uses a provider-based architecture. To create a CertPathValidator, call one of the static getInstance methods, passing in the algorithm name of the CertPathValidator desired and optionally the name of the provider desired.

Once a CertPathValidator object has been created, it can be used to validate certification paths by calling the validate method and passing it the CertPath to be validated and an algorithm-specific set of parameters. If successful, the result is returned in an object that implements the CertPathValidatorResult interface.

The getRevocationChecker() method allows an application to specify additional algorithm-specific parameters and options used by the CertPathValidator when checking the revocation status of certificates. Here is an example demonstrating how it is used with the PKIX algorithm:

 CertPathValidator cpv = CertPathValidator.getInstance("PKIX");
 PKIXRevocationChecker rc = (PKIXRevocationChecker)cpv.getRevocationChecker();
 rc.setOptions(EnumSet.of(Option.SOFT_FAIL));
 params.addCertPathChecker(rc);
 CertPathValidatorResult cpvr = cpv.validate(path, params);
 

Android provides the following CertPathValidator algorithms:

Algorithm	Supported API Levels
PKIX	1+

This algorithm is described in the CertPathValidator section of the Java Cryptography Architecture Standard Algorithm Name Documentation.

Concurrent Access

The static methods of this class are guaranteed to be thread-safe. Multiple threads may concurrently invoke the static methods defined in this class with no ill effects.

However, this is not true for the non-static methods defined by this class. Unless otherwise documented by a specific provider, threads that need to access a single CertPathValidator instance concurrently should synchronize amongst themselves and provide the necessary locking. Multiple threads each manipulating a different CertPathValidator instance need not synchronize.

See Also

• CertPath

Protected Constructor Summary

CertPathValidator(CertPathValidatorSpi validatorSpi, Provider provider, String algorithm) Creates a CertPathValidator object of the given algorithm, and encapsulates the given provider implementation (SPI object) in it.

Public Method Summary

final String	getAlgorithm() Returns the algorithm name of this CertPathValidator.
final static String	getDefaultType() Returns the default CertPathValidator type as specified by the certpathvalidator.type security property, or the string "PKIX" if no such property exists.
static CertPathValidator	getInstance(String algorithm) Returns a CertPathValidator object that implements the specified algorithm.
static CertPathValidator	getInstance(String algorithm, String provider) Returns a CertPathValidator object that implements the specified algorithm.
static CertPathValidator	getInstance(String algorithm, Provider provider) Returns a CertPathValidator object that implements the specified algorithm.
final Provider	getProvider() Returns the Provider of this CertPathValidator.
final CertPathChecker	getRevocationChecker() Returns a CertPathChecker that the encapsulated CertPathValidatorSpi implementation uses to check the revocation status of certificates.
final CertPathValidatorResult	validate(CertPath certPath, CertPathParameters params) Validates the specified certification path using the specified algorithm parameter set.

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Protected Constructors

protected CertPathValidator (CertPathValidatorSpi validatorSpi, Provider provider, String algorithm)

Creates a CertPathValidator object of the given algorithm, and encapsulates the given provider implementation (SPI object) in it.

Parameters

validatorSpi	the provider implementation
provider	the provider
algorithm	the algorithm name

Public Methods

public final String getAlgorithm ()

Returns the algorithm name of this CertPathValidator.

Returns

• the algorithm name of this CertPathValidator

public static final String getDefaultType ()

Returns the default CertPathValidator type as specified by the certpathvalidator.type security property, or the string "PKIX" if no such property exists.

The default CertPathValidator type can be used by applications that do not want to use a hard-coded type when calling one of the getInstance methods, and want to provide a default type in case a user does not specify its own.

The default CertPathValidator type can be changed by setting the value of the certpathvalidator.type security property to the desired type.

Returns

• the default CertPathValidator type as specified by the certpathvalidator.type security property, or the string "PKIX" if no such property exists.

See Also

• security properties

public static CertPathValidator getInstance (String algorithm)

Returns a CertPathValidator object that implements the specified algorithm.

This method traverses the list of registered security Providers, starting with the most preferred Provider. A new CertPathValidator object encapsulating the CertPathValidatorSpi implementation from the first Provider that supports the specified algorithm is returned.

Note that the list of registered providers may be retrieved via the Security.getProviders() method.

Parameters

algorithm	the name of the requested CertPathValidator algorithm. See the CertPathValidator section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard algorithm names.

Returns

• a CertPathValidator object that implements the specified algorithm.

Throws

NoSuchAlgorithmException	if no Provider supports a CertPathValidatorSpi implementation for the specified algorithm.

See Also

• Provider

public static CertPathValidator getInstance (String algorithm, String provider)

Returns a CertPathValidator object that implements the specified algorithm.

A new CertPathValidator object encapsulating the CertPathValidatorSpi implementation from the specified provider is returned. The specified provider must be registered in the security provider list.

Note that the list of registered providers may be retrieved via the Security.getProviders() method.

Parameters

algorithm	the name of the requested CertPathValidator algorithm. See the CertPathValidator section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard algorithm names.
provider	the name of the provider.

Returns

• a CertPathValidator object that implements the specified algorithm.

Throws

NoSuchAlgorithmException	if a CertPathValidatorSpi implementation for the specified algorithm is not available from the specified provider.
NoSuchProviderException	if the specified provider is not registered in the security provider list.
IllegalArgumentException	if the provider is null or empty.

See Also

• Provider

public static CertPathValidator getInstance (String algorithm, Provider provider)

Returns a CertPathValidator object that implements the specified algorithm.

A new CertPathValidator object encapsulating the CertPathValidatorSpi implementation from the specified Provider object is returned. Note that the specified Provider object does not have to be registered in the provider list.

Parameters

algorithm	the name of the requested CertPathValidator algorithm. See the CertPathValidator section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard algorithm names.
provider	the provider.

Returns

• a CertPathValidator object that implements the specified algorithm.

Throws

NoSuchAlgorithmException	if a CertPathValidatorSpi implementation for the specified algorithm is not available from the specified Provider object.
IllegalArgumentException	if the provider is null.

See Also

• Provider

public final Provider getProvider ()

Returns the Provider of this CertPathValidator.

Returns

• the Provider of this CertPathValidator

public final CertPathChecker getRevocationChecker ()

Returns a CertPathChecker that the encapsulated CertPathValidatorSpi implementation uses to check the revocation status of certificates. A PKIX implementation returns objects of type PKIXRevocationChecker. Each invocation of this method returns a new instance of CertPathChecker.

The primary purpose of this method is to allow callers to specify additional input parameters and options specific to revocation checking. See the class description for an example.

Returns

• a CertPathChecker

Throws

UnsupportedOperationException	if the service provider does not support this method

public final CertPathValidatorResult validate (CertPath certPath, CertPathParameters params)

Validates the specified certification path using the specified algorithm parameter set.

The CertPath specified must be of a type that is supported by the validation algorithm, otherwise an InvalidAlgorithmParameterException will be thrown. For example, a CertPathValidator that implements the PKIX algorithm validates CertPath objects of type X.509.

Parameters

certPath	the CertPath to be validated
params	the algorithm parameters

Returns

• the result of the validation algorithm

Throws

CertPathValidatorException	if the CertPath does not validate
InvalidAlgorithmParameterException	if the specified parameters or the type of the specified CertPath are inappropriate for this CertPathValidator