/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package java.security.cert;
import java.io.ByteArrayInputStream;
import java.io.NotSerializableException;
import java.io.ObjectStreamException;
import java.io.ObjectStreamField;
import java.io.Serializable;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.PublicKey;
import java.security.SignatureException;
import java.util.Arrays;
/**
* Abstract class to represent identity certificates. It represents a way to
* verify the binding of a Principal and its public key. Examples are X.509,
* PGP, and SDSI.
*/
public abstract class Certificate implements Serializable {
private static final long serialVersionUID = -3585440601605666277L;
// The standard name of the certificate type
private final String type;
/**
* Creates a new {@code Certificate} with the specified type.
*
* @param type
* the certificate type.
*/
protected Certificate(String type) {
this.type = type;
}
/**
* Returns the certificate type.
*
* @return the certificate type.
*/
public final String getType() {
return type;
}
/**
* Compares the argument to the certificate, and returns {@code true} if they
* represent the <em>same</em> object using a class specific comparison. The
* implementation in Object returns {@code true} only if the argument is the
* exact same object as the callee (==).
*
* @param other
* the object to compare with this object.
* @return {@code true} if the object is the same as this object, {@code
* false} if it is different from this object.
* @see #hashCode
*/
public boolean equals(Object other) {
// obj equal to itself
if (this == other) {
return true;
}
if (other instanceof Certificate) {
try {
// check that encoded forms match
return Arrays.equals(this.getEncoded(),
((Certificate)other).getEncoded());
} catch (CertificateEncodingException e) {
throw new RuntimeException(e);
}
}
return false;
}
/**
* Returns an integer hash code for the certificate. Any two objects which
* return {@code true} when passed to {@code equals} must return the same
* value for this method.
*
* @return the certificate's hash
* @see #equals
*/
public int hashCode() {
try {
byte[] encoded = getEncoded();
int hash = 0;
for (int i=0; i<encoded.length; i++) {
hash += i*encoded[i];
}
return hash;
} catch (CertificateEncodingException e) {
throw new RuntimeException(e);
}
}
/**
* Returns the encoded representation for this certificate.
*
* @return the encoded representation for this certificate.
* @throws CertificateEncodingException
* if the encoding fails.
*/
public abstract byte[] getEncoded() throws CertificateEncodingException;
/**
* Verifies that this certificate was signed with the given public key.
*
* @param key
* PublicKey public key for which verification should be
* performed.
* @throws CertificateException
* if encoding errors are detected.
* @throws NoSuchAlgorithmException
* if an unsupported algorithm is detected.
* @throws InvalidKeyException
* if an invalid key is detected.
* @throws NoSuchProviderException
* if there is no default provider.
* @throws SignatureException
* if signature errors are detected.
*/
public abstract void verify(PublicKey key)
throws CertificateException,
NoSuchAlgorithmException,
InvalidKeyException,
NoSuchProviderException,
SignatureException;
/**
* Verifies that this certificate was signed with the given public key. It
* Uses the signature algorithm given by the provider.
*
* @param key
* PublicKey public key for which verification should be
* performed.
* @param sigProvider
* String the name of the signature provider.
* @exception CertificateException
* if encoding errors are detected.
* @exception NoSuchAlgorithmException
* if an unsupported algorithm is detected.
* @exception InvalidKeyException
* if an invalid key is detected.
* @exception NoSuchProviderException
* if the specified provider does not exists.
* @exception SignatureException
* if signature errors are detected.
*/
public abstract void verify(PublicKey key, String sigProvider)
throws CertificateException,
NoSuchAlgorithmException,
InvalidKeyException,
NoSuchProviderException,
SignatureException;
/**
* Returns a string containing a concise, human-readable description of the
* certificate.
*
* @return a printable representation for the certificate.
*/
public abstract String toString();
/**
* Returns the public key corresponding to this certificate.
*
* @return the public key corresponding to this certificate.
*/
public abstract PublicKey getPublicKey();
/**
* Returns an alternate object to be serialized.
*
* @return the object to serialize.
* @throws ObjectStreamException
* if the creation of the alternate object fails.
*/
protected Object writeReplace() throws ObjectStreamException {
try {
return new CertificateRep(getType(), getEncoded());
} catch (CertificateEncodingException e) {
throw new NotSerializableException("Could not create serialization object: " + e);
}
}
/**
* The alternate {@code Serializable} class to be used for serialization and
* deserialization of {@code Certificate} objects.
*/
protected static class CertificateRep implements Serializable {
private static final long serialVersionUID = -8563758940495660020L;
// The standard name of the certificate type
private final String type;
// The certificate data
private final byte[] data;
// Force default serialization to use writeUnshared/readUnshared
// for the certificate data
private static final ObjectStreamField[] serialPersistentFields = {
new ObjectStreamField("type", String.class),
new ObjectStreamField("data", byte[].class, true)
};
/**
* Creates a new {@code CertificateRep} instance with the specified
* certificate type and encoded data.
*
* @param type
* the certificate type.
* @param data
* the encoded data.
*/
protected CertificateRep(String type, byte[] data) {
this.type = type;
this.data = data;
}
/**
* Deserializes a {@code Certificate} from a serialized {@code
* CertificateRep} object.
*
* @return the deserialized {@code Certificate}.
* @throws ObjectStreamException
* if deserialization fails.
*/
protected Object readResolve() throws ObjectStreamException {
try {
CertificateFactory cf = CertificateFactory.getInstance(type);
return cf.generateCertificate(new ByteArrayInputStream(data));
} catch (Throwable t) {
throw new NotSerializableException("Could not resolve certificate: " + t);
}
}
}
}