com.absio.crypto.kdf

Class KDF2Helper

java.lang.Object

com.absio.crypto.kdf.KDF2Helper

public class KDF2Helper
extends Object

Use this helper class to assist with KDF2 key derivation. It uses the JCE MessageDigest class to accomplish the digest portion of the key derivation. The digest algorithm: MessageDigestAlgorithm is defined at creation.

Constructor Summary

Constructors

Constructor and Description
KDF2Helper() Create a KDF2 helper using MessageDigestAlgorithm.DEFAULT as the digest algorithm.
KDF2Helper(MessageDigestAlgorithm algorithm) Create a KDF2 helper using the given MessageDigestAlgorithm as the digest algorithm.

Method Summary

Modifier and Type	Method and Description
byte[]	deriveKey(byte[] secret, int keySize) Derive a new key of the given size using KDF2 with the defined MessageDigestAlgorithm and the given secret.

Methods inherited from class java.lang.Object

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

Constructor Detail

KDF2Helper

public KDF2Helper()
           throws NoSuchAlgorithmException

Create a KDF2 helper using MessageDigestAlgorithm.DEFAULT as the digest algorithm.

Throws:

NoSuchAlgorithmException - thrown if the digest algorithm is not supported

KDF2Helper

public KDF2Helper(MessageDigestAlgorithm algorithm)
           throws NoSuchAlgorithmException

Create a KDF2 helper using the given MessageDigestAlgorithm as the digest algorithm.

Parameters:

algorithm - the digest algorithm for key derivation

Throws:

NoSuchAlgorithmException - thrown if the digest algorithm is not supported

Method Detail

deriveKey

public byte[] deriveKey(byte[] secret,
                        int keySize)
                 throws InvalidKeyException

Derive a new key of the given size using KDF2 with the defined MessageDigestAlgorithm and the given secret.

Parameters:

secret - the secret to derive the key from

keySize - the size of the key in bytes to derive

Returns:

the KDF2 derived key

Throws:

InvalidKeyException - thrown if there is an issue deriving the key