I have a hard time to extract session key (symmetric key) from encrypted message envelope (Bouncy Castle encrypted).
I have read that documentation where states only that
with a field of the type EncryptedKey representing the bytes making up the wrapped symmetric key used to encrypt the data enveloped in the message and the KeyEncryptionAlgorithmIdentifier representing the algorithm that was used to do the wrapping.
but it doesn't say how to decrypt message not using Bouncy Castle but when utilize own created parser and for that I need to have a session key first.