Function fn_encrypt_handshake_opaque 

pub fn fn_encrypt_handshake_opaque(
    some_message: &OpaqueMessage,
    server_hello: &HandshakeHash,
    server_key_share: &Option<Vec<u8>>,
    psk: &Option<Vec<u8>>,
    group: &NamedGroup,
    client: &bool,
    sequence: &u64,
    client_random: &Random,
    suite: &CipherSuite,
) -> Result<OpaqueMessage, FnError>

Encrypt a handshake record that is already represented as an OpaqueMessage.

This differs from fn_encrypt_handshake, which takes a parsed TLS Message and converts it into an encrypted OpaqueMessage.

Use this variant when you already have an opaque TLS handshake record (for example, a coalesced or pre-encoded handshake flight) and just need to apply the TLS 1.3 handshake encryption.