Class Hkdf

java.lang.Object

ai.badmonkey.agentspaces.common.crypto.Hkdf

public final class Hkdf
extends Object

HKDF (RFC 5869) with HMAC-SHA-256: extract-then-expand key derivation. The sealed group-key wrap derives its AES key-encryption key from the X25519 shared secret through this function, binding the derivation to both parties' public keys through the salt.

Method Summary

Modifier and Type	Method	Description
static byte[]	derive(byte[] ikm, byte[] salt, byte[] info, int length)	Derives key material.

Methods inherited from class Object

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

Method Details

derive

public static byte[] derive(byte[] ikm,
 byte[] salt,
 byte[] info,
 int length)

Derives key material.

Parameters:

ikm - the input keying material (a shared secret)

salt - the salt; MAY be empty, SHOULD bind the context's identities

info - the application- and use-specific label

length - the number of bytes to derive, at most 255 * 32

Returns:

the derived bytes