gnutls_hpke_encap3

Arguments

gnutls_hpke_context_t ctx

The HPKE context to use for encapsulation.

const gnutls_datum_t * info

The application-specific information to be included in the key schedule (optional).

gnutls_datum_t * enc

A pointer to a gnutls_datum_t structure where the encapsulated key will be stored.

const gnutls_pubkey_t receiver_pubkey

The receiver's public key to use for encapsulation.

const gnutls_privkey_t sender_privkey

The sender's private key needed for AuthEncap operation (optional).

const gnutls_datum_t * psk

The pre-shared key (optional).

const gnutls_datum_t * psk_id

The pre-shared key identifier (optional).

Overview

This function performs the encapsulation operation of HPKE. It generates an encapsulated key ( enc ) that can be sent to the receiver, who can then use it to derive the shared secret.

The function checks that the context is properly initialized and that the provided parameters are valid. It also checks that the context is in the correct role (GNUTLS_HPKE_ROLE_SENDER) for encapsulation.

This function must be used once per HPKE context and before any calls to gnutls_hpke_seal().

The function will allocate memory for enc , and the caller is responsible for freeing this memory using gnutls_free() when it is no longer needed.

receiver_pubkey must be a valid public key that is compatible with the KEM algorithm specified in the HPKE context.

For GNUTLS_HPKE_MODE_AUTH or GNUTLS_HPKE_MODE_AUTH_PSK,
sender_privkey must be a valid private key that can be used for authentication. For GNUTLS_HPKE_MODE_PSK or GNUTLS_HPKE_MODE_AUTH_PSK, a pre-shared key ( psk ) and its identifier ( psk_id ) must be supplied.

Returns

0 on success, or a negative error code on failure

Since

3.8.13