Class Certificate

public abstract class Certificate
extends Object

Abstract class for managing a variety of identity certificates. An identity certificate is a guarantee by a principal that a public key is that of 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.

Note: The classes in the package javax.security.cert exist for compatibility with earlier versions of the Java Secure Sockets Extension (JSSE). New applications should instead use the standard Java SE certificate classes located in java.security.cert.

Constructors

Certificate

public Certificate()

Methods

equals

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.

Overrides:

equals in class Object

Parameters:

other - the object to test for equality with this certificate.

Returns:

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

See Also:

Object.hashCode(), HashMap

hashCode

public int hashCode()

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

Overrides:

hashCode in class Object

Returns:

the hashcode value.

See Also:

Object.equals(java.lang.Object), System.identityHashCode(java.lang.Object)

getEncoded

public abstract byte[] getEncoded()
                           throws CertificateEncodingException

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:

encoded form of this certificate

Throws:

CertificateEncodingException - on internal certificate encoding failure

verify

public abstract void verify(PublicKey key)
                     throws CertificateException,
                            NoSuchAlgorithmException,
                            InvalidKeyException,
                            NoSuchProviderException,
                            SignatureException

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.

verify

public abstract void verify(PublicKey key,
                            String sigProvider)
                     throws CertificateException,
                            NoSuchAlgorithmException,
                            InvalidKeyException,
                            NoSuchProviderException,
                            SignatureException

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.

toString

public abstract String toString()

Returns a string representation of this certificate.

Overrides:

toString in class Object

Returns:

a string representation of this certificate.

getPublicKey

public abstract PublicKey getPublicKey()

Gets the public key from this certificate.

Returns:

the public key.