Added in API level 24

Extension

public interface Extension

java.security.cert.Extension

---

This interface represents an X.509 extension.

Extensions provide a means of associating additional attributes with users or public keys and for managing a certification hierarchy. The extension format also allows communities to define private extensions to carry information unique to those communities.

Each extension contains an object identifier, a criticality setting indicating whether it is a critical or a non-critical extension, and and an ASN.1 DER-encoded value. Its ASN.1 definition is:

     Extension ::= SEQUENCE {
         extnId        OBJECT IDENTIFIER,
         critical      BOOLEAN DEFAULT FALSE,
         extnValue     OCTET STRING
                 -- contains a DER encoding of a value
                 -- of the type registered for use with
                 -- the extnId object identifier value
     }

 

This interface is designed to provide access to a single extension, unlike X509Extension which is more suitable for accessing a set of extensions.

Summary

Public methods
abstract void	encode(OutputStream out) Generates the extension's DER encoding and writes it to the output stream.
abstract String	getId() Gets the extensions's object identifier.
abstract byte[]	getValue() Gets the extensions's DER-encoded value.
abstract boolean	isCritical() Gets the extension's criticality setting.

Public methods

encode

Added in API level 24

public abstract void encode (OutputStream out)

Generates the extension's DER encoding and writes it to the output stream.

Parameters
out	OutputStream: the output stream

Throws
IOException	on encoding or output error.
NullPointerException	if out is null.

getId

Added in API level 24

public abstract String getId ()

Gets the extensions's object identifier.

Returns
String	the object identifier as a String

getValue

Added in API level 24

public abstract byte[] getValue ()

Gets the extensions's DER-encoded value. Note, this is the bytes that are encoded as an OCTET STRING. It does not include the OCTET STRING tag and length.

Returns
byte[]	a copy of the extension's value, or null if no extension value is present.

isCritical

Added in API level 24

public abstract boolean isCritical ()

Gets the extension's criticality setting.

Returns
boolean	true if this is a critical extension.