Update to JEP draft: Key Encapsulation Mechanism API

[Wei-Jun Wang]

Hi All,

The JEP draft was just updated again.

The KEMParameterSpec argument is moved from getInstance() to newEncapsulator() and newDecapsulator(). The reason is that when delayed provider selection happens, a KEMSpi object is only created when newEncapsulator/newDecapsulator is called. If the parameter is rejected then some kind of exception should be thrown. It looks a little strange for newEncapsulator/newDecapsulator to throw an InvalidAlgorithmParameterException since their only argument is a key. A user might also question why the exception was not thrown when getInstance() was called.

Furthermore, since the only bonus a KEMParameterSpec provides is a SecureRandom and it's useless for a decapsulator, we decided to remove the KEMParameterSpec class. User can now provide a SecureRandom and an AlgorithmParameterSpec separately when creating an encapsulator, and only an AlgorithmParameterSpec when creating a decapsulator.

    public Encapsulator newEncapsulator(PublicKey pk, AlgorithmParameterSpec spec, SecureRandom sr)
            throws InvalidAlgorithmParameterException, InvalidKeyException;

    public Decapsulator newDecapsulator(PrivateKey sk, AlgorithmParameterSpec spec)
            throws InvalidAlgorithmParameterException, InvalidKeyException;


Please take a look. The updated JEP is still at https://openjdk.org/jeps/8301034.

Thanks,
Max