Create Generate Key Routine in Java (HPKE)

Hybrid Public Key Encryption (HPKE)​ needs three things:

1. Key Encapsulation Mechanism
2. Key Derivation Function
3. Encryption Scheme

I want to create a public private Key Pair:

GenerateKeyPair() with the outputs being the public and private key.

Use OpenJDK 17+ for this.

1. Key Encapsulation Mechanism should be: Curve25519
2. Key Derivation Function: SHA2-256
3. Encryption Scheme: AES-128-GCM

These are supported natively in OpenJDK.

I will pay a maximum of $200 for this. I need it in 7 days.