protected abstract SecretKey engineGenerateSecret (String algorithm) throws IllegalStateException, NoSuchAlgorithmException, InvalidKeyException

Creates the shared secret and returns it as a secret key object of the requested algorithm type.

This method resets this KeyAgreementSpi object, so that it can be reused for further key agreements. Unless this key agreement is reinitialized with one of the engineInit methods, the same private information and algorithm parameters will be used for subsequent key agreements.

algorithm    the requested secret key algorithm

Returns:  the shared secret key

IllegalStateException    if this key agreement has not been completed yet
NoSuchAlgorithmException    if the requested secret key algorithm is not available
InvalidKeyException    if the shared secret key material cannot be used to generate a secret key of the requested algorithm type (e.g., the key material is too short)