Certificate

public abstract class Certificate extends Object
implements Serializable

Known Direct Subclasses X509Certificate X509Certificate Abstract class for X.509 certificates.

Abstract class for managing a variety of identity certificates. An identity certificate is a binding of a principal to a public key which is vouched for by another principal. (A principal represents an entity such as an individual user, a group, or a corporation.)

This class is an abstraction for certificates that have different formats but important common uses. For example, different types of certificates, such as X.509 and PGP, share general certificate functionality (like encoding and verifying) and some types of information (like a public key).

X.509, PGP, and SDSI certificates can all be implemented by subclassing the Certificate class, even though they contain different sets of information, and they store and retrieve the information in different ways.

See Also

• X509Certificate
• CertificateFactory

Nested Class Summary

class

Certificate.CertificateRep

Alternate Certificate class for serialization.

Protected Constructor Summary

Certificate(String type) Creates a certificate of the specified type.

Public Method Summary

boolean	equals(Object other) Compares this certificate for equality with the specified object.
abstract byte[]	getEncoded() Returns the encoded form of this certificate.
abstract PublicKey	getPublicKey() Gets the public key from this certificate.
final String	getType() Returns the type of this certificate.
int	hashCode() Returns a hashcode value for this certificate from its encoded form.
abstract String	toString() Returns a string representation of this certificate.
abstract void	verify(PublicKey key, String sigProvider) Verifies that this certificate was signed using the private key that corresponds to the specified public key.
void	verify(PublicKey key, Provider sigProvider) Verifies that this certificate was signed using the private key that corresponds to the specified public key.
abstract void	verify(PublicKey key) Verifies that this certificate was signed using the private key that corresponds to the specified public key.

Protected Method Summary

Object

writeReplace() Replace the Certificate to be serialized.

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 Certificate (String type)

Creates a certificate of the specified type.

Parameters

type	the standard name of the certificate type. See the CertificateFactory section in the Java Cryptography Architecture Standard Algorithm Name Documentation for information about standard certificate types.

Public Methods

public boolean equals (Object other)

Compares this certificate for equality with the specified object. If the other object is an instanceof Certificate, then its encoded form is retrieved and compared with the encoded form of this certificate.

Parameters

other	the object to test for equality with this certificate.

Returns

• true iff the encoded forms of the two certificates match, false otherwise.

public abstract byte[] getEncoded ()

Returns the encoded form of this certificate. It is assumed that each certificate type would have only a single form of encoding; for example, X.509 certificates would be encoded as ASN.1 DER.

Returns

• the encoded form of this certificate

Throws

CertificateEncodingException	if an encoding error occurs.

public abstract PublicKey getPublicKey ()

Gets the public key from this certificate.

Returns

• the public key.

public final String getType ()

Returns the type of this certificate.

Returns

• the type of this certificate.

public int hashCode ()

Returns a hashcode value for this certificate from its encoded form.

Returns

• the hashcode value.

public abstract String toString ()

Returns a string representation of this certificate.

Returns

• a string representation of this certificate.

public abstract void verify (PublicKey key, String sigProvider)

Verifies that this certificate was signed using the private key that corresponds to the specified public key. This method uses the signature verification engine supplied by the specified provider.

Parameters

key	the PublicKey used to carry out the verification.
sigProvider	the name of the signature provider.

Throws

NoSuchAlgorithmException	on unsupported signature algorithms.
InvalidKeyException	on incorrect key.
NoSuchProviderException	on incorrect provider.
SignatureException	on signature errors.
CertificateException	on encoding errors.

public void verify (PublicKey key, Provider sigProvider)

Verifies that this certificate was signed using the private key that corresponds to the specified public key. This method uses the signature verification engine supplied by the specified provider. Note that the specified Provider object does not have to be registered in the provider list.

This method was added to version 1.8 of the Java Platform Standard Edition. In order to maintain backwards compatibility with existing service providers, this method cannot be abstract and by default throws an UnsupportedOperationException.

Parameters

key	the PublicKey used to carry out the verification.
sigProvider	the signature provider.

Throws

NoSuchAlgorithmException	on unsupported signature algorithms.
InvalidKeyException	on incorrect key.
SignatureException	on signature errors.
CertificateException	on encoding errors.
UnsupportedOperationException	if the method is not supported

public abstract void verify (PublicKey key)

Verifies that this certificate was signed using the private key that corresponds to the specified public key.

Parameters

key	the PublicKey used to carry out the verification.

Throws

NoSuchAlgorithmException	on unsupported signature algorithms.
InvalidKeyException	on incorrect key.
NoSuchProviderException	if there's no default provider.
SignatureException	on signature errors.
CertificateException	on encoding errors.

Protected Methods

protected Object writeReplace ()

Replace the Certificate to be serialized.

Returns

• the alternate Certificate object to be serialized

Throws

ObjectStreamException	if a new object representing this Certificate could not be created