protected X509Certificate() 
{
        super("X.509");
}

Constructor for X.509 certificates.

 abstract public  void checkValidity() throws CertificateExpiredException, CertificateNotYetValidException
Checks that the certificate is currently valid. It is if
the current date and time are within the validity period given in the
certificate.

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:
validity             Validity

Validity ::= SEQUENCE {
    notBefore      CertificateValidityDate,
    notAfter       CertificateValidityDate }

CertificateValidityDate ::= CHOICE {
    utcTime        UTCTime,
    generalTime    GeneralizedTime }

 abstract public  void checkValidity(Date date) 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.

 abstract public int getBasicConstraints()
Gets the certificate constraints path length from the
critical BasicConstraints extension, (OID = 2.5.29.19).

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
pathLenConstraint field (see below) is meaningful
only if 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.

The ASN.1 definition for this is:
BasicConstraints ::= SEQUENCE {
    cA                  BOOLEAN DEFAULT FALSE,
    pathLenConstraint   INTEGER (0..MAX) OPTIONAL }

 public List<String> getExtendedKeyUsage() throws CertificateParsingException 
{
        return X509CertImpl.getExtendedKeyUsage(this);
}

Gets an unmodifiable list of Strings representing the OBJECT IDENTIFIERs of the 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:

ExtKeyUsageSyntax ::= SEQUENCE SIZE (1..MAX) OF KeyPurposeId


KeyPurposeId ::= OBJECT IDENTIFIER

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.

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 abstract and it provides a default implementation. Subclasses should override this method with a correct implementation.

 public Collection<?> getIssuerAlternativeNames() throws CertificateParsingException 
{
        return X509CertImpl.getIssuerAlternativeNames(this);
}

Gets an immutable collection of issuer alternative names from the IssuerAltName extension, (OID = 2.5.29.18).

The ASN.1 definition of the IssuerAltName extension is:

IssuerAltName ::= GeneralNames

The ASN.1 definition of GeneralNames is defined in getSubjectAlternativeNames .

If this certificate does not contain an IssuerAltName extension, null is returned. Otherwise, a Collection is returned with an entry representing each GeneralName included in the extension. Each entry is a List whose first entry is an Integer (the name type, 0-8) and whose second entry is a 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 getSubjectAlternativeNames method.

Note that the Collection returned may contain more than one name of the same type. Also, note that the returned Collection is immutable and any entries containing byte arrays are cloned to protect against subsequent modifications.

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 abstract and it provides a default implementation. Subclasses should override this method with a correct implementation.

 abstract public Principal getIssuerDN()
Denigrated, replaced by {@linkplain
#getIssuerX500Principal()}. This method returns the issuer
as an implementation specific Principal object, which should not be
relied upon by portable code.


Gets the issuer (issuer distinguished name) value from
the certificate. The issuer name identifies the entity that signed (and
issued) the certificate.

The issuer name field contains an
X.500 distinguished name (DN).
The ASN.1 definition for this is:
issuer    Name


Name ::= CHOICE { RDNSequence }
RDNSequence ::= SEQUENCE OF RelativeDistinguishedName
RelativeDistinguishedName ::=
    SET OF AttributeValueAssertion

AttributeValueAssertion ::= SEQUENCE {
                              AttributeType,
                              AttributeValue }
AttributeType ::= OBJECT IDENTIFIER
AttributeValue ::= ANY

The Name describes a hierarchical name composed of
attributes,
such as country name, and corresponding values, such as US.
The type of the AttributeValue component is determined by
the AttributeType; in general it will be a
directoryString. A directoryString is usually
one of PrintableString,
TeletexString or UniversalString.

 abstract public boolean[] getIssuerUniqueID()
Gets the 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 3280 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.

The ASN.1 definition for this is:
issuerUniqueID  [1]  IMPLICIT UniqueIdentifier OPTIONAL

UniqueIdentifier  ::=  BIT STRING

 public X500Principal getIssuerX500Principal() 
{
        if (issuerX500Principal == null) {
            issuerX500Principal = X509CertImpl.getIssuerX500Principal(this);
        }
        return issuerX500Principal;
}

Returns the issuer (issuer distinguished name) value from the certificate as an X500Principal.

It is recommended that subclasses override this method.

 abstract public boolean[] getKeyUsage()
Gets a boolean array representing bits of
the 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:
KeyUsage ::= BIT STRING {
    digitalSignature        (0),
    nonRepudiation          (1),
    keyEncipherment         (2),
    dataEncipherment        (3),
    keyAgreement            (4),
    keyCertSign             (5),
    cRLSign                 (6),
    encipherOnly            (7),
    decipherOnly            (8) }

RFC 3280 recommends that when used, this be marked
as a critical extension.

 abstract public Date getNotAfter()
Gets the notAfter date from the validity period of
the certificate. See getNotBefore 
for relevant ASN.1 definitions.

 abstract public Date getNotBefore()
Gets the notBefore date from the validity period of
the certificate.
The relevant ASN.1 definitions are:
validity             Validity


Validity ::= SEQUENCE {
    notBefore      CertificateValidityDate,
    notAfter       CertificateValidityDate }

CertificateValidityDate ::= CHOICE {
    utcTime        UTCTime,
    generalTime    GeneralizedTime }

 abstract public BigInteger getSerialNumber()
Gets the 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:
serialNumber     CertificateSerialNumber


CertificateSerialNumber  ::=  INTEGER

 abstract public String getSigAlgName()
Gets the signature algorithm name for the certificate
signature algorithm. An example is the string "SHA256withRSA".
The ASN.1 definition for this is:
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


The algorithm name is determined from the algorithm
OID string.

 abstract public String getSigAlgOID()
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
RFC 3279: Algorithms and
Identifiers for the Internet X.509 Public Key Infrastructure Certificate
and CRL Profile.

See getSigAlgName  for
relevant ASN.1 definitions.

 abstract public byte[] getSigAlgParams()
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
AlgorithmParameters 
and instantiate with the name returned by
getSigAlgName .

See getSigAlgName  for
relevant ASN.1 definitions.

 abstract public byte[] getSignature()
Gets the signature value (the raw signature bits) from
the certificate.
The ASN.1 definition for this is:
signature     BIT STRING

 public Collection<?> getSubjectAlternativeNames() throws CertificateParsingException 
{
        return X509CertImpl.getSubjectAlternativeNames(this);
}

Gets an immutable collection of subject alternative names from the SubjectAltName extension, (OID = 2.5.29.17).

The ASN.1 definition of the SubjectAltName extension is:

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}

If this certificate does not contain a SubjectAltName extension, null is returned. Otherwise, a Collection is returned with an entry representing each GeneralName included in the extension. Each entry is a List whose first entry is an Integer (the name type, 0-8) and whose second entry is a String or a byte array (the name, in string or ASN.1 DER encoded form, respectively).

RFC 822, DNS, and URI names are returned as Strings, using the well-established string formats for those types (subject to the restrictions included in RFC 3280). 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 Strings represented as a series of nonnegative integers separated by periods. And directory names (distinguished names) are returned in RFC 2253 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.

Note that the Collection returned may contain more than one name of the same type. Also, note that the returned Collection is immutable and any entries containing byte arrays are cloned to protect against subsequent modifications.

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 abstract and it provides a default implementation. Subclasses should override this method with a correct implementation.

 abstract public Principal getSubjectDN()
Denigrated, replaced by {@linkplain
#getSubjectX500Principal()}. This method returns the subject
as an implementation specific Principal object, which should not be
relied upon by portable code.


Gets the subject (subject distinguished name) value
from the certificate.  If the subject value is empty,
then the getName() method of the returned
Principal object returns an empty string ("").

 The ASN.1 definition for this is:
subject    Name


See getIssuerDN  for Name
and other relevant definitions.

 abstract public boolean[] getSubjectUniqueID()
Gets the subjectUniqueID value from the certificate.

The ASN.1 definition for this is:
subjectUniqueID  [2]  IMPLICIT UniqueIdentifier OPTIONAL

UniqueIdentifier  ::=  BIT STRING

 public X500Principal getSubjectX500Principal() 
{
        if (subjectX500Principal == null) {
            subjectX500Principal = X509CertImpl.getSubjectX500Principal(this);
        }
        return subjectX500Principal;
}

Returns the subject (subject distinguished name) value from the certificate as an X500Principal. If the subject value is empty, then the getName() method of the returned X500Principal object returns an empty string ("").

It is recommended that subclasses override this method.

 abstract public byte[] getTBSCertificate() throws CertificateEncodingException
Gets the DER-encoded certificate information, the
tbsCertificate from this certificate.
This can be used to verify the signature independently.

 abstract public int getVersion()
Gets the version (version number) value from the
certificate.
The ASN.1 definition for this is:
version  [0] EXPLICIT Version DEFAULT v1

Version ::=  INTEGER  {  v1(0), v2(1), v3(2)  }