Adds a hasSecret assertion holding contentKey locked by secret via
method (the reference's add_secret), for an envelope whose subject was
encrypted with contentKey.
EnvelopeError InvalidParameter for a value outside
KeyDerivationMethod; Components when components cannot lock the key
(KeyDerivationMethod.SSHAgent needs an agent: see lockSubjectWith)
Adds a
hasSecretassertion holdingcontentKeylocked bysecretviamethod(the reference'sadd_secret), for an envelope whose subject was encrypted withcontentKey.