Added in API level 24

Extension

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 java.security.cert.X509Extension which is more suitable for accessing a set of extensions.

Summary

Public methods
abstract Unit

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

Gets the extensions's object identifier.
abstract ByteArray!

Gets the extensions's DER-encoded value.
abstract Boolean

Gets the extension's criticality setting.

Public methods

encode

Added in API level 24
abstract fun encode(out: OutputStream!): Unit

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

Parameters
out OutputStream!: the output stream
Exceptions
java.io.IOException on encoding or output error.
java.lang.NullPointerException if out is null.

getId

Added in API level 24
abstract fun getId(): String!

Gets the extensions's object identifier.

Return
String! the object identifier as a String

getValue

Added in API level 24
abstract fun getValue(): ByteArray!

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.

Return
ByteArray! a copy of the extension's value, or null if no extension value is present.

isCritical

Added in API level 24
abstract fun isCritical(): Boolean

Gets the extension's criticality setting.

Return
Boolean true if this is a critical extension.