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	/*
	* Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.security.cert;

	import java.math.BigInteger;
	import java.security.*;
	import java.security.spec.*;
	import java.util.Collection;
	import java.util.Date;
	import java.util.List;
	import javax.security.auth.x500.X500Principal;

	import sun.security.x509.X509CertImpl;
	import sun.security.util.SignatureUtil;

	/**
	* <p>
	* Abstract class for X.509 certificates. This provides a standard
	* way to access all the attributes of an X.509 certificate.
	* <p>
	* In June of 1996, the basic X.509 v3 format was completed by
	* ISO/IEC and ANSI X9, which is described below in ASN.1:
	* <pre>
	* Certificate ::= SEQUENCE {
	* tbsCertificate TBSCertificate,
	* signatureAlgorithm AlgorithmIdentifier,
	* signature BIT STRING }
	* </pre>
	* <p>
	* These certificates are widely used to support authentication and
	* other functionality in Internet security systems. Common applications
	* include Privacy Enhanced Mail (PEM), Transport Layer Security (SSL),
	* code signing for trusted software distribution, and Secure Electronic
	* Transactions (SET).
	* <p>
	* These certificates are managed and vouched for by <em>Certificate
	* Authorities</em> (CAs). CAs are services which create certificates by
	* placing data in the X.509 standard format and then digitally signing
	* that data. CAs act as trusted third parties, making introductions
	* between principals who have no direct knowledge of each other.
	* CA certificates are either signed by themselves, or by some other
	* CA such as a "root" CA.
	* <p>
	* More information can be found in
	* <a href="http://tools.ietf.org/html/rfc5280">RFC 5280: Internet X.509
	* Public Key Infrastructure Certificate and CRL Profile</a>.
	* <p>
	* The ASN.1 definition of {@code tbsCertificate} is:
	* <pre>
	* TBSCertificate ::= SEQUENCE {
	* version [0] EXPLICIT Version DEFAULT v1,
	* serialNumber CertificateSerialNumber,
	* signature AlgorithmIdentifier,
	* issuer Name,
	* validity Validity,
	* subject Name,
	* subjectPublicKeyInfo SubjectPublicKeyInfo,
	* issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL,
	* -- If present, version must be v2 or v3
	* subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL,
	* -- If present, version must be v2 or v3
	* extensions [3] EXPLICIT Extensions OPTIONAL
	* -- If present, version must be v3
	* }
	* </pre>
	* <p>
	* Certificates are instantiated using a certificate factory. The following is
	* an example of how to instantiate an X.509 certificate:
	* <pre>
	* try (InputStream inStream = new FileInputStream("fileName-of-cert")) {
	* CertificateFactory cf = CertificateFactory.getInstance("X.509");
	* X509Certificate cert = (X509Certificate)cf.generateCertificate(inStream);
	* }
	* </pre>
	*
	* @author Hemma Prafullchandra
	*
	*
	* @see Certificate
	* @see CertificateFactory
	* @see X509Extension
	*/

	public abstract class X509Certificate extends Certificate
	implements X509Extension {

	private static final long serialVersionUID = -2491127588187038216L;

	private transient X500Principal subjectX500Principal, issuerX500Principal;

	/**
	* Constructor for X.509 certificates.
	*/
	protected X509Certificate() {
	super("X.509");
	}

	/**
	* Checks that the certificate is currently valid. It is if
	* the current date and time are within the validity period given in the
	* certificate.
	* <p>
	* The validity period consists of two date/time values:
	* the first and last dates (and times) on which the certificate
	* is valid. It is defined in
	* ASN.1 as:
	* <pre>
	* validity Validity
	*
	* Validity ::= SEQUENCE {
	* notBefore CertificateValidityDate,
	* notAfter CertificateValidityDate }
	*
	* CertificateValidityDate ::= CHOICE {
	* utcTime UTCTime,
	* generalTime GeneralizedTime }
	* </pre>
	*
	* @exception CertificateExpiredException if the certificate has expired.
	* @exception CertificateNotYetValidException if the certificate is not
	* yet valid.
	*/
	public abstract void checkValidity()
	throws CertificateExpiredException, CertificateNotYetValidException;

	/**
	* Checks that the given date is within the certificate's
	* validity period. In other words, this determines whether the
	* certificate would be valid at the given date/time.
	*
	* @param date the Date to check against to see if this certificate
	* is valid at that date/time.
	*
	* @exception CertificateExpiredException if the certificate has expired
	* with respect to the {@code date} supplied.
	* @exception CertificateNotYetValidException if the certificate is not
	* yet valid with respect to the {@code date} supplied.
	*
	* @see #checkValidity()
	*/
	public abstract void checkValidity(Date date)
	throws CertificateExpiredException, CertificateNotYetValidException;

	/**
	* Gets the {@code version} (version number) value from the
	* certificate.
	* The ASN.1 definition for this is:
	* <pre>
	* version [0] EXPLICIT Version DEFAULT v1
	*
	* Version ::= INTEGER { v1(0), v2(1), v3(2) }
	* </pre>
	* @return the version number, i.e. 1, 2 or 3.
	*/
	public abstract int getVersion();

	/**
	* Gets the {@code serialNumber} value from the certificate.
	* The serial number is an integer assigned by the certification
	* authority to each certificate. It must be unique for each
	* certificate issued by a given CA (i.e., the issuer name and
	* serial number identify a unique certificate).
	* The ASN.1 definition for this is:
	* <pre>
	* serialNumber CertificateSerialNumber
	*
	* CertificateSerialNumber ::= INTEGER
	* </pre>
	*
	* @return the serial number.
	*/
	public abstract BigInteger getSerialNumber();

	/**
	* <strong>Denigrated</strong>, replaced by {@linkplain
	* #getIssuerX500Principal()}. This method returns the {@code issuer}
	* as an implementation specific Principal object, which should not be
	* relied upon by portable code.
	*
	* <p>
	* Gets the {@code issuer} (issuer distinguished name) value from
	* the certificate. The issuer name identifies the entity that signed (and
	* issued) the certificate.
	*
	* <p>The issuer name field contains an
	* X.500 distinguished name (DN).
	* The ASN.1 definition for this is:
	* <pre>
	* issuer Name
	*
	* Name ::= CHOICE { RDNSequence }
	* RDNSequence ::= SEQUENCE OF RelativeDistinguishedName
	* RelativeDistinguishedName ::=
	* SET OF AttributeValueAssertion
	*
	* AttributeValueAssertion ::= SEQUENCE {
	* AttributeType,
	* AttributeValue }
	* AttributeType ::= OBJECT IDENTIFIER
	* AttributeValue ::= ANY
	* </pre>
	* The {@code Name} describes a hierarchical name composed of
	* attributes,
	* such as country name, and corresponding values, such as US.
	* The type of the {@code AttributeValue} component is determined by
	* the {@code AttributeType}; in general it will be a
	* {@code directoryString}. A {@code directoryString} is usually
	* one of {@code PrintableString},
	* {@code TeletexString} or {@code UniversalString}.
	*
	* @return a Principal whose name is the issuer distinguished name.
	*/
	public abstract Principal getIssuerDN();

	/**
	* Returns the issuer (issuer distinguished name) value from the
	* certificate as an {@code X500Principal}.
	* <p>
	* It is recommended that subclasses override this method.
	*
	* @return an {@code X500Principal} representing the issuer
	* distinguished name
	* @since 1.4
	*/
	public X500Principal getIssuerX500Principal() {
	if (issuerX500Principal == null) {
	issuerX500Principal = X509CertImpl.getIssuerX500Principal(this);
	}
	return issuerX500Principal;
	}

	/**
	* <strong>Denigrated</strong>, replaced by {@linkplain
	* #getSubjectX500Principal()}. This method returns the {@code subject}
	* as an implementation specific Principal object, which should not be
	* relied upon by portable code.
	*
	* <p>
	* Gets the {@code subject} (subject distinguished name) value
	* from the certificate. If the {@code subject} value is empty,
	* then the {@code getName()} method of the returned
	* {@code Principal} object returns an empty string ("").
	*
	* <p> The ASN.1 definition for this is:
	* <pre>
	* subject Name
	* </pre>
	*
	* <p>See {@link #getIssuerDN() getIssuerDN} for {@code Name}
	* and other relevant definitions.
	*
	* @return a Principal whose name is the subject name.
	*/
	public abstract Principal getSubjectDN();

	/**
	* Returns the subject (subject distinguished name) value from the
	* certificate as an {@code X500Principal}. If the subject value
	* is empty, then the {@code getName()} method of the returned
	* {@code X500Principal} object returns an empty string ("").
	* <p>
	* It is recommended that subclasses override this method.
	*
	* @return an {@code X500Principal} representing the subject
	* distinguished name
	* @since 1.4
	*/
	public X500Principal getSubjectX500Principal() {
	if (subjectX500Principal == null) {
	subjectX500Principal = X509CertImpl.getSubjectX500Principal(this);
	}
	return subjectX500Principal;
	}

	/**
	* Gets the {@code notBefore} date from the validity period of
	* the certificate.
	* The relevant ASN.1 definitions are:
	* <pre>
	* validity Validity
	*
	* Validity ::= SEQUENCE {
	* notBefore CertificateValidityDate,
	* notAfter CertificateValidityDate }
	*
	* CertificateValidityDate ::= CHOICE {
	* utcTime UTCTime,
	* generalTime GeneralizedTime }
	* </pre>
	*
	* @return the start date of the validity period.
	* @see #checkValidity
	*/
	public abstract Date getNotBefore();

	/**
	* Gets the {@code notAfter} date from the validity period of
	* the certificate. See {@link #getNotBefore() getNotBefore}
	* for relevant ASN.1 definitions.
	*
	* @return the end date of the validity period.
	* @see #checkValidity
	*/
	public abstract Date getNotAfter();

	/**
	* Gets the DER-encoded certificate information, the
	* {@code tbsCertificate} from this certificate.
	* This can be used to verify the signature independently.
	*
	* @return the DER-encoded certificate information.
	* @exception CertificateEncodingException if an encoding error occurs.
	*/
	public abstract byte[] getTBSCertificate()
	throws CertificateEncodingException;

	/**
	* Gets the {@code signature} value (the raw signature bits) from
	* the certificate.
	* The ASN.1 definition for this is:
	* <pre>
	* signature BIT STRING
	* </pre>
	*
	* @return the signature.
	*/
	public abstract byte[] getSignature();

	/**
	* Gets the signature algorithm name for the certificate
	* signature algorithm. An example is the string "SHA256withRSA".
	* The ASN.1 definition for this is:
	* <pre>
	* signatureAlgorithm AlgorithmIdentifier
	*
	* AlgorithmIdentifier ::= SEQUENCE {
	* algorithm OBJECT IDENTIFIER,
	* parameters ANY DEFINED BY algorithm OPTIONAL }
	* -- contains a value of the type
	* -- registered for use with the
	* -- algorithm object identifier value
	* </pre>
	*
	* <p>The algorithm name is determined from the {@code algorithm}
	* OID string.
	*
	* @return the signature algorithm name.
	*/
	public abstract String getSigAlgName();

	/**
	* Gets the signature algorithm OID string from the certificate.
	* An OID is represented by a set of nonnegative whole numbers separated
	* by periods.
	* For example, the string "1.2.840.10040.4.3" identifies the SHA-1
	* with DSA signature algorithm defined in
	* <a href="http://www.ietf.org/rfc/rfc3279.txt">RFC 3279: Algorithms and
	* Identifiers for the Internet X.509 Public Key Infrastructure Certificate
	* and CRL Profile</a>.
	*
	* <p>See {@link #getSigAlgName() getSigAlgName} for
	* relevant ASN.1 definitions.
	*
	* @return the signature algorithm OID string.
	*/
	public abstract String getSigAlgOID();

	/**
	* Gets the DER-encoded signature algorithm parameters from this
	* certificate's signature algorithm. In most cases, the signature
	* algorithm parameters are null; the parameters are usually
	* supplied with the certificate's public key.
	* If access to individual parameter values is needed then use
	* {@link java.security.AlgorithmParameters AlgorithmParameters}
	* and instantiate with the name returned by
	* {@link #getSigAlgName() getSigAlgName}.
	*
	* <p>See {@link #getSigAlgName() getSigAlgName} for
	* relevant ASN.1 definitions.
	*
	* @return the DER-encoded signature algorithm parameters, or
	* null if no parameters are present.
	*/
	public abstract byte[] getSigAlgParams();

	/**
	* Gets the {@code issuerUniqueID} value from the certificate.
	* The issuer unique identifier is present in the certificate
	* to handle the possibility of reuse of issuer names over time.
	* RFC 5280 recommends that names not be reused and that
	* conforming certificates not make use of unique identifiers.
	* Applications conforming to that profile should be capable of
	* parsing unique identifiers and making comparisons.
	*
	* <p>The ASN.1 definition for this is:
	* <pre>
	* issuerUniqueID [1] IMPLICIT UniqueIdentifier OPTIONAL
	*
	* UniqueIdentifier ::= BIT STRING
	* </pre>
	*
	* @return the issuer unique identifier or null if it is not
	* present in the certificate.
	*/
	public abstract boolean[] getIssuerUniqueID();

	/**
	* Gets the {@code subjectUniqueID} value from the certificate.
	*
	* <p>The ASN.1 definition for this is:
	* <pre>
	* subjectUniqueID [2] IMPLICIT UniqueIdentifier OPTIONAL
	*
	* UniqueIdentifier ::= BIT STRING
	* </pre>
	*
	* @return the subject unique identifier or null if it is not
	* present in the certificate.
	*/
	public abstract boolean[] getSubjectUniqueID();

	/**
	* Gets a boolean array representing bits of
	* the {@code KeyUsage} extension, (OID = 2.5.29.15).
	* The key usage extension defines the purpose (e.g., encipherment,
	* signature, certificate signing) of the key contained in the
	* certificate.
	* The ASN.1 definition for this is:
	* <pre>
	* KeyUsage ::= BIT STRING {
	* digitalSignature (0),
	* nonRepudiation (1),
	* keyEncipherment (2),
	* dataEncipherment (3),
	* keyAgreement (4),
	* keyCertSign (5),
	* cRLSign (6),
	* encipherOnly (7),
	* decipherOnly (8) }
	* </pre>
	* RFC 5280 recommends that when used, this be marked
	* as a critical extension.
	*
	* @return the KeyUsage extension of this certificate, represented as
	* an array of booleans. The order of KeyUsage values in the array is
	* the same as in the above ASN.1 definition. The array will contain a
	* value for each KeyUsage defined above. If the KeyUsage list encoded
	* in the certificate is longer than the above list, it will not be
	* truncated. Returns null if this certificate does not
	* contain a KeyUsage extension.
	*/
	public abstract boolean[] getKeyUsage();

	/**
	* Gets an unmodifiable list of Strings representing the OBJECT
	* IDENTIFIERs of the {@code ExtKeyUsageSyntax} field of the
	* extended key usage extension, (OID = 2.5.29.37). It indicates
	* one or more purposes for which the certified public key may be
	* used, in addition to or in place of the basic purposes
	* indicated in the key usage extension field. The ASN.1
	* definition for this is:
	* <pre>
	* ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId
	*
	* KeyPurposeId ::= OBJECT IDENTIFIER
	* </pre>
	*
	* Key purposes may be defined by any organization with a
	* need. Object identifiers used to identify key purposes shall be
	* assigned in accordance with IANA or ITU-T Rec. X.660 \|
	* ISO/IEC/ITU 9834-1.
	* <p>
	* This method was added to version 1.4 of the Java 2 Platform Standard
	* Edition. In order to maintain backwards compatibility with existing
	* service providers, this method is not {@code abstract}
	* and it provides a default implementation. Subclasses
	* should override this method with a correct implementation.
	*
	* @return the ExtendedKeyUsage extension of this certificate,
	* as an unmodifiable list of object identifiers represented
	* as Strings. Returns null if this certificate does not
	* contain an ExtendedKeyUsage extension.
	* @throws CertificateParsingException if the extension cannot be decoded
	* @since 1.4
	*/
	public List<String> getExtendedKeyUsage() throws CertificateParsingException {
	return X509CertImpl.getExtendedKeyUsage(this);
	}

	/**
	* Gets the certificate constraints path length from the
	* critical {@code BasicConstraints} extension, (OID = 2.5.29.19).
	* <p>
	* The basic constraints extension identifies whether the subject
	* of the certificate is a Certificate Authority (CA) and
	* how deep a certification path may exist through that CA. The
	* {@code pathLenConstraint} field (see below) is meaningful
	* only if {@code cA} is set to TRUE. In this case, it gives the
	* maximum number of CA certificates that may follow this certificate in a
	* certification path. A value of zero indicates that only an end-entity
	* certificate may follow in the path.
	* <p>
	* The ASN.1 definition for this is:
	* <pre>
	* BasicConstraints ::= SEQUENCE {
	* cA BOOLEAN DEFAULT FALSE,
	* pathLenConstraint INTEGER (0..MAX) OPTIONAL }
	* </pre>
	*
	* @return the value of {@code pathLenConstraint} if the
	* BasicConstraints extension is present in the certificate and the
	* subject of the certificate is a CA, otherwise -1.
	* If the subject of the certificate is a CA and
	* {@code pathLenConstraint} does not appear,
	* {@code Integer.MAX_VALUE} is returned to indicate that there is no
	* limit to the allowed length of the certification path.
	*/
	public abstract int getBasicConstraints();

	/**
	* Gets an immutable collection of subject alternative names from the
	* {@code SubjectAltName} extension, (OID = 2.5.29.17).
	* <p>
	* The ASN.1 definition of the {@code SubjectAltName} extension is:
	* <pre>
	* SubjectAltName ::= GeneralNames
	*
	* GeneralNames :: = SEQUENCE SIZE (1..MAX) OF GeneralName
	*
	* GeneralName ::= CHOICE {
	* otherName [0] OtherName,
	* rfc822Name [1] IA5String,
	* dNSName [2] IA5String,
	* x400Address [3] ORAddress,
	* directoryName [4] Name,
	* ediPartyName [5] EDIPartyName,
	* uniformResourceIdentifier [6] IA5String,
	* iPAddress [7] OCTET STRING,
	* registeredID [8] OBJECT IDENTIFIER}
	* </pre>
	* <p>
	* If this certificate does not contain a {@code SubjectAltName}
	* extension, {@code null} is returned. Otherwise, a
	* {@code Collection} is returned with an entry representing each
	* {@code GeneralName} included in the extension. Each entry is a
	* {@code List} whose first entry is an {@code Integer}
	* (the name type, 0-8) and whose second entry is a {@code String}
	* or a byte array (the name, in string or ASN.1 DER encoded form,
	* respectively).
	* <p>
	* <a href="http://www.ietf.org/rfc/rfc822.txt">RFC 822</a>, DNS, and URI
	* names are returned as {@code String}s,
	* using the well-established string formats for those types (subject to
	* the restrictions included in RFC 5280). IPv4 address names are
	* returned using dotted quad notation. IPv6 address names are returned
	* in the form "a1:a2:...:a8", where a1-a8 are hexadecimal values
	* representing the eight 16-bit pieces of the address. OID names are
	* returned as {@code String}s represented as a series of nonnegative
	* integers separated by periods. And directory names (distinguished names)
	* are returned in <a href="http://www.ietf.org/rfc/rfc2253.txt">
	* RFC 2253</a> string format. No standard string format is
	* defined for otherNames, X.400 names, EDI party names, or any
	* other type of names. They are returned as byte arrays
	* containing the ASN.1 DER encoded form of the name.
	* <p>
	* Note that the {@code Collection} returned may contain more
	* than one name of the same type. Also, note that the returned
	* {@code Collection} is immutable and any entries containing byte
	* arrays are cloned to protect against subsequent modifications.
	* <p>
	* This method was added to version 1.4 of the Java 2 Platform Standard
	* Edition. In order to maintain backwards compatibility with existing
	* service providers, this method is not {@code abstract}
	* and it provides a default implementation. Subclasses
	* should override this method with a correct implementation.
	*
	* @return an immutable {@code Collection} of subject alternative
	* names (or {@code null})
	* @throws CertificateParsingException if the extension cannot be decoded
	* @since 1.4
	*/
	public Collection<List<?>> getSubjectAlternativeNames()
	throws CertificateParsingException {
	return X509CertImpl.getSubjectAlternativeNames(this);
	}

	/**
	* Gets an immutable collection of issuer alternative names from the
	* {@code IssuerAltName} extension, (OID = 2.5.29.18).
	* <p>
	* The ASN.1 definition of the {@code IssuerAltName} extension is:
	* <pre>
	* IssuerAltName ::= GeneralNames
	* </pre>
	* The ASN.1 definition of {@code GeneralNames} is defined
	* in {@link #getSubjectAlternativeNames getSubjectAlternativeNames}.
	* <p>
	* If this certificate does not contain an {@code IssuerAltName}
	* extension, {@code null} is returned. Otherwise, a
	* {@code Collection} is returned with an entry representing each
	* {@code GeneralName} included in the extension. Each entry is a
	* {@code List} whose first entry is an {@code Integer}
	* (the name type, 0-8) and whose second entry is a {@code String}
	* or a byte array (the name, in string or ASN.1 DER encoded form,
	* respectively). For more details about the formats used for each
	* name type, see the {@code getSubjectAlternativeNames} method.
	* <p>
	* Note that the {@code Collection} returned may contain more
	* than one name of the same type. Also, note that the returned
	* {@code Collection} is immutable and any entries containing byte
	* arrays are cloned to protect against subsequent modifications.
	* <p>
	* This method was added to version 1.4 of the Java 2 Platform Standard
	* Edition. In order to maintain backwards compatibility with existing
	* service providers, this method is not {@code abstract}
	* and it provides a default implementation. Subclasses
	* should override this method with a correct implementation.
	*
	* @return an immutable {@code Collection} of issuer alternative
	* names (or {@code null})
	* @throws CertificateParsingException if the extension cannot be decoded
	* @since 1.4
	*/
	public Collection<List<?>> getIssuerAlternativeNames()
	throws CertificateParsingException {
	return X509CertImpl.getIssuerAlternativeNames(this);
	}

	/**
	* 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 is not {@code abstract}
	* and it provides a default implementation.
	*
	* @param key the PublicKey used to carry out the verification.
	* @param sigProvider the signature provider.
	*
	* @exception NoSuchAlgorithmException on unsupported signature
	* algorithms.
	* @exception InvalidKeyException on incorrect key.
	* @exception SignatureException on signature errors.
	* @exception CertificateException on encoding errors.
	* @exception UnsupportedOperationException if the method is not supported
	* @since 1.8
	*/
	public void verify(PublicKey key, Provider sigProvider)
	throws CertificateException, NoSuchAlgorithmException,
	InvalidKeyException, SignatureException {
	String sigName = getSigAlgName();
	Signature sig = (sigProvider == null)
	? Signature.getInstance(sigName)
	: Signature.getInstance(sigName, sigProvider);

	try {
	SignatureUtil.initVerifyWithParam(sig, key,
	SignatureUtil.getParamSpec(sigName, getSigAlgParams()));
	} catch (ProviderException e) {
	throw new CertificateException(e.getMessage(), e.getCause());
	} catch (InvalidAlgorithmParameterException e) {
	throw new CertificateException(e);
	}

	byte[] tbsCert = getTBSCertificate();
	sig.update(tbsCert, 0, tbsCert.length);

	if (sig.verify(getSignature()) == false) {
	throw new SignatureException("Signature does not match.");
	}
	}
	}

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