Unwrap (decrypt) key material with a key-encryption key.
public static byte[] KeyUnwrap( byte[] data, byte[] kek, CipherAlgorithm cipherAlg )
Public Shared Function KeyUnwrap ( _ data As Byte(), _ kek As Byte(), _ cipherAlg As CipherAlgorithm _ ) As Byte()
VB6/C equivalent: CIPHER_KeyUnwrap