Function new_sender 

pub fn new_sender<K: Kem, D: Kdf, A: Aead>(
    mode: &Mode<'_>,
    recipient_public_key: &K::PublicKey,
    info: &[u8],
) -> Result<(K::EncappedKey, SenderContext<A, D>), HpkeError>

Sets up a sender context (draft-ietf-hpke-hpke-05 Section 5.1).

The encapsulated key must be transmitted to the recipient alongside the first message.

Errors

• HpkeError::EncapError when the recipient’s public key is invalid.
• HpkeError::ValidationError when the pre-shared key or its identifier is empty in a pre-shared key mode.
• HpkeError::Random when the operating system’s random number generator is unavailable or fails.