var defaultIV … // KeyWrap implements NIST key wrapping; it wraps a content encryption key (cek) with the given block cipher. func KeyWrap(block cipher.Block, cek []byte) ([]byte, error) { … } // KeyUnwrap implements NIST key unwrapping; it unwraps a content encryption key (cek) with the given block cipher. func KeyUnwrap(block cipher.Block, ciphertext []byte) ([]byte, error) { … }