Certificate

public abstract class Certificate extends Object
implements Serializable
Known Direct Subclasses

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.

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.
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

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 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