Module java.base
Package java.security.cert

## Class X509CRL

- java.lang.Object
- - java.security.cert.CRL
  - - java.security.cert.X509CRL

All Implemented Interfaces:
  `X509Extension`

    public abstract class X509CRL
    extends CRL
    implements X509Extension

Abstract class for an X.509 Certificate Revocation List (CRL). A CRL is a time-stamped list identifying revoked certificates. It is signed by a Certificate Authority (CA) and made freely available in a public repository.

Each revoked certificate is identified in a CRL by its certificate serial number. When a certificate-using system uses a certificate (e.g., for verifying a remote user's digital signature), that system not only checks the certificate signature and validity but also acquires a suitably- recent CRL and checks that the certificate serial number is not on that CRL. The meaning of "suitably-recent" may vary with local policy, but it usually means the most recently-issued CRL. A CA issues a new CRL on a regular periodic basis (e.g., hourly, daily, or weekly). Entries are added to CRLs as revocations occur, and an entry may be removed when the certificate expiration date is reached.

The X.509 v2 CRL format is described below in ASN.1:

     CertificateList  ::=  SEQUENCE  {
         tbsCertList          TBSCertList,
         signatureAlgorithm   AlgorithmIdentifier,
         signature            BIT STRING  }

More information can be found in RFC 5280: Internet X.509 Public Key Infrastructure Certificate and CRL Profile.

The ASN.1 definition of `tbsCertList` is:

     TBSCertList  ::=  SEQUENCE  {
         version                 Version OPTIONAL,
                                 -- if present, must be v2
         signature               AlgorithmIdentifier,
         issuer                  Name,
         thisUpdate              ChoiceOfTime,
         nextUpdate              ChoiceOfTime OPTIONAL,
         revokedCertificates     SEQUENCE OF SEQUENCE  {
             userCertificate         CertificateSerialNumber,
             revocationDate          ChoiceOfTime,
             crlEntryExtensions      Extensions OPTIONAL
                                     -- if present, must be v2
             }  OPTIONAL,
         crlExtensions           [0]  EXPLICIT Extensions OPTIONAL
                                      -- if present, must be v2
         }

CRLs are instantiated using a certificate factory. The following is an example of how to instantiate an X.509 CRL:

     try (InputStream inStream = new FileInputStream("fileName-of-crl")) {
         CertificateFactory cf = CertificateFactory.getInstance("X.509");
         X509CRL crl = (X509CRL)cf.generateCRL(inStream);
     }

Since:
  1.2
See Also:
  `CRL`, `CertificateFactory`, `X509Extension`

### Constructor Summary

Constructors
`protected` `X509CRL()` Constructor for X.509 CRLs.

### Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
`boolean` `equals​(Object other)` Compares this CRL for equality with the given object.
`abstract byte[]` `getEncoded()` Returns the ASN.1 DER-encoded form of this CRL.
`abstract Principal` `getIssuerDN()` Denigrated, replaced by getIssuerX500Principal().
`X500Principal` `getIssuerX500Principal()` Returns the issuer (issuer distinguished name) value from the CRL as an `X500Principal`.
`abstract Date` `getNextUpdate()` Gets the `nextUpdate` date from the CRL.
`abstract X509CRLEntry` `getRevokedCertificate​(BigInteger serialNumber)` Gets the CRL entry, if any, with the given certificate serialNumber.
`X509CRLEntry` `getRevokedCertificate​(X509Certificate certificate)` Get the CRL entry, if any, for the given certificate.
`abstract Set<? extends X509CRLEntry>` `getRevokedCertificates()` Gets all the entries from this CRL.
`abstract String` `getSigAlgName()` Gets the signature algorithm name for the CRL signature algorithm.
`abstract String` `getSigAlgOID()` Gets the signature algorithm OID string from the CRL.
`abstract byte[]` `getSigAlgParams()` Gets the DER-encoded signature algorithm parameters from this CRL's signature algorithm.
`abstract byte[]` `getSignature()` Gets the `signature` value (the raw signature bits) from the CRL.
`abstract byte[]` `getTBSCertList()` Gets the DER-encoded CRL information, the `tbsCertList` from this CRL.
`abstract Date` `getThisUpdate()` Gets the `thisUpdate` date from the CRL.
`abstract int` `getVersion()` Gets the `version` (version number) value from the CRL.
`int` `hashCode()` Returns a hashcode value for this CRL from its encoded form.
`abstract void` `verify​(PublicKey key)` Verifies that this CRL was signed using the private key that corresponds to the given public key.
`abstract void` `verify​(PublicKey key, String sigProvider)` Verifies that this CRL was signed using the private key that corresponds to the given public key.
`void` `verify​(PublicKey key, Provider sigProvider)` Verifies that this CRL was signed using the private key that corresponds to the given public key.

### Methods declared in class java.security.cert.CRL

`getType, isRevoked, toString`

### Methods declared in class java.lang.Object

`clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

### Methods declared in interface java.security.cert.X509Extension

`getCriticalExtensionOIDs, getExtensionValue, getNonCriticalExtensionOIDs, hasUnsupportedCriticalExtension`

### Constructor Detail

#### X509CRL

    protected X509CRL()

Constructor for X.509 CRLs.

### Method Detail

#### equals

    public boolean equals​(Object other)

Compares this CRL for equality with the given object. If the `other` object is an `instanceof` `X509CRL`, then its encoded form is retrieved and compared with the encoded form of this CRL.

Overrides:
  `equals` in class `Object`
Parameters:
  `other` - the object to test for equality with this CRL.
Returns:
  true iff the encoded forms of the two CRLs match, false otherwise.
See Also:
  `Object.hashCode()`, `HashMap`

#### hashCode

    public int hashCode()

Returns a hashcode value for this CRL 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 CRLException

Returns the ASN.1 DER-encoded form of this CRL.

Returns:
  the encoded form of this certificate
Throws:
  `CRLException` - if an encoding error occurs.

#### verify

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

Verifies that this CRL was signed using the private key that corresponds to the given 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.
  `CRLException` - on encoding errors.

#### verify

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

Verifies that this CRL was signed using the private key that corresponds to the given public key. This method uses the signature verification engine supplied by the given 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.
  `CRLException` - on encoding errors.

#### verify

    public void verify​(PublicKey key,
                       Provider sigProvider)
                throws CRLException,
                       NoSuchAlgorithmException,
                       InvalidKeyException,
                       SignatureException

Verifies that this CRL was signed using the private key that corresponds to the given public key. This method uses the signature verification engine supplied by the given 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 `abstract` and it provides a default implementation.

Parameters:
  `key` - the PublicKey used to carry out the verification.
  `sigProvider` - the signature provider.
Throws:
  `NoSuchAlgorithmException` - on unsupported signature algorithms.
  `InvalidKeyException` - on incorrect key.
  `SignatureException` - on signature errors.
  `CRLException` - on encoding errors.
Since:
  1.8

#### getVersion

    public abstract int getVersion()

Gets the `version` (version number) value from the CRL. The ASN.1 definition for this is:

     version    Version OPTIONAL,
                 -- if present, must be v2

     Version  ::=  INTEGER  {  v1(0), v2(1), v3(2)  }
                 -- v3 does not apply to CRLs but appears for consistency
                 -- with definition of Version for certs

Returns:
  the version number, i.e. 1 or 2.

#### getIssuerDN

    public abstract Principal getIssuerDN()

Denigrated, replaced by 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 CRL. The issuer name identifies the entity that signed (and issued) the CRL.

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`.

Returns:
  a Principal whose name is the issuer distinguished name.

#### getIssuerX500Principal

    public X500Principal getIssuerX500Principal()

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

It is recommended that subclasses override this method.

Returns:
  an `X500Principal` representing the issuer distinguished name
Since:
  1.4

#### getThisUpdate

    public abstract Date getThisUpdate()

Gets the `thisUpdate` date from the CRL. The ASN.1 definition for this is:

     thisUpdate   ChoiceOfTime
     ChoiceOfTime ::= CHOICE {
         utcTime        UTCTime,
         generalTime    GeneralizedTime }

Returns:
  the `thisUpdate` date from the CRL.

#### getNextUpdate

    public abstract Date getNextUpdate()

Gets the `nextUpdate` date from the CRL.

Returns:
  the `nextUpdate` date from the CRL, or null if not present.

#### getRevokedCertificate

    public abstract X509CRLEntry getRevokedCertificate​(BigInteger serialNumber)

Gets the CRL entry, if any, with the given certificate serialNumber.

Parameters:
  `serialNumber` - the serial number of the certificate for which a CRL entry is to be looked up
Returns:
  the entry with the given serial number, or null if no such entry exists in this CRL.
See Also:
  `X509CRLEntry`

#### getRevokedCertificate

    public X509CRLEntry getRevokedCertificate​(X509Certificate certificate)

Get the CRL entry, if any, for the given certificate.

This method can be used to lookup CRL entries in indirect CRLs, that means CRLs that contain entries from issuers other than the CRL issuer. The default implementation will only return entries for certificates issued by the CRL issuer. Subclasses that wish to support indirect CRLs should override this method.

Parameters:
  `certificate` - the certificate for which a CRL entry is to be looked up
Returns:
  the entry for the given certificate, or null if no such entry exists in this CRL.
Throws:
  `NullPointerException` - if certificate is null
Since:
  1.5

#### getRevokedCertificates

    public abstract Set<? extends X509CRLEntry> getRevokedCertificates()

Gets all the entries from this CRL. This returns a Set of X509CRLEntry objects.

Returns:
  all the entries or null if there are none present.
See Also:
  `X509CRLEntry`

#### getTBSCertList

    public abstract byte[] getTBSCertList()
                                   throws CRLException

Gets the DER-encoded CRL information, the `tbsCertList` from this CRL. This can be used to verify the signature independently.

Returns:
  the DER-encoded CRL information.
Throws:
  `CRLException` - if an encoding error occurs.

#### getSignature

    public abstract byte[] getSignature()

Gets the `signature` value (the raw signature bits) from the CRL. The ASN.1 definition for this is:

     signature     BIT STRING

Returns:
  the signature.

#### getSigAlgName

    public abstract String getSigAlgName()

Gets the signature algorithm name for the CRL 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.

Returns:
  the signature algorithm name.

#### getSigAlgOID

    public abstract String getSigAlgOID()

Gets the signature algorithm OID string from the CRL. 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.

Returns:
  the signature algorithm OID string.

#### getSigAlgParams

    public abstract byte[] getSigAlgParams()

Gets the DER-encoded signature algorithm parameters from this CRL's signature algorithm. In most cases, the signature algorithm parameters are null; the parameters are usually supplied with the 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.

Returns:
  the DER-encoded signature algorithm parameters, or null if no parameters are present.