W3cubDocs

Class HKDFParameterSpec.ExtractThenExpand

java.lang.Object

javax.crypto.spec.HKDFParameterSpec.ExtractThenExpand

All Implemented Interfaces:: AlgorithmParameterSpec, HKDFParameterSpec

Enclosing interface:: HKDFParameterSpec

public static final class HKDFParameterSpec.ExtractThenExpand extends Object implements HKDFParameterSpec

Defines the input parameters of an Extract-then-Expand operation as defined in RFC 5869.

Since:: 25

Nested Class Summary

Nested classes/interfaces declared in interface HKDFParameterSpec

HKDFParameterSpec.Builder, HKDFParameterSpec.Expand, HKDFParameterSpec.Extract, HKDFParameterSpec.ExtractThenExpand

Method Summary

Modifier and Type	Method	Description
`List<SecretKey>`	`ikms()`	Returns an unmodifiable `List` of input keying material values in the order they were added.
`byte[]`	`info()`	Returns the optional context and application specific information.
`int`	`length()`	Returns the length of the output keying material.
`List<SecretKey>`	`salts()`	Returns an unmodifiable `List` of salt values in the order they were added.

Methods declared in class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

ikms

public List<SecretKey> ikms()

Returns an unmodifiable List of input keying material values in the order they were added. Returns an empty list if there are no input keying material values.

Input keying material values added by HKDFParameterSpec.Builder.addIKM(byte[]) are converted to a SecretKeySpec object. Empty arrays are discarded.

Implementation Note:: An HKDF implementation should concatenate the input keying materials into a single value to be used in the HKDF-Extract phase.
Returns:: the unmodifiable List of input keying material values

salts

public List<SecretKey> salts()

Returns an unmodifiable List of salt values in the order they were added. Returns an empty list if there are no salt values.

Salt values added by HKDFParameterSpec.Builder.addSalt(byte[]) are converted to a SecretKeySpec object. Empty arrays are discarded.

Implementation Note:: An HKDF implementation should concatenate the salts into a single value to be used in the HKDF-Extract phase.
Returns:: the unmodifiable List of salt values

info

public byte[] info()

Returns the optional context and application specific information.

Returns:: a clone of the optional context and application specific information, or null if not specified

length

public int length()

Returns the length of the output keying material.

Returns:: the length of the output keying material

© 1993, 2025, Oracle and/or its affiliates. All rights reserved.
Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.
https://docs.oracle.com/en/java/javase/25/docs/api/java.base/javax/crypto/spec/HKDFParameterSpec.ExtractThenExpand.html