Anti-Exfil Functions
====================

.. c:function:: int wally_ae_host_commit_from_bytes(const unsigned char *entropy, size_t entropy_len, uint32_t flags, unsigned char *bytes_out, size_t len)

   
   Create the initial commitment to host randomness.
   
   :param entropy: Randomness to commit to. It must come from a cryptographically secure RNG. As per the protocol, this value must not be revealed to the client until after the host has received the client commitment.
   :param entropy_len: The length of ``entropy`` in bytes. Must be `WALLY_S2C_DATA_LEN`.
   :param flags: Must be `EC_FLAG_ECDSA`.
   :param bytes_out: Destination for the resulting compact signature.
   :param len: Size of ``bytes_out``. Must be `WALLY_HOST_COMMITMENT_LEN`.

   :return: See :ref:`error-codes`


.. c:function:: int wally_ae_signer_commit_from_bytes(const unsigned char *priv_key, size_t priv_key_len, const unsigned char *bytes, size_t bytes_len, const unsigned char *commitment, size_t commitment_len, uint32_t flags, unsigned char *s2c_opening_out, size_t s2c_opening_out_len)

   
   Compute signer's original nonce.
   
   :param priv_key: The private key used for signing.
   :param priv_key_len: The length of ``priv_key`` in bytes. Must be `EC_PRIVATE_KEY_LEN`.
   :param bytes: The message hash to be signed.
   :param bytes_len: The length of ``bytes`` in bytes. Must be `EC_MESSAGE_HASH_LEN`.
   :param commitment: Randomness commitment from the host.
   :param commitment_len: The length of ``commitment`` in bytes. Must be `WALLY_HOST_COMMITMENT_LEN`.
   :param flags: Must be `EC_FLAG_ECDSA`.
   :param s2c_opening_out: Destination for the resulting opening information.
   :param s2c_opening_out_len: Size of ``s2c_opening_out``. Must be `WALLY_S2C_OPENING_LEN`.

   :return: See :ref:`error-codes`


.. c:function:: int wally_ae_sig_from_bytes(const unsigned char *priv_key, size_t priv_key_len, const unsigned char *bytes, size_t bytes_len, const unsigned char *entropy, size_t entropy_len, uint32_t flags, unsigned char *bytes_out, size_t len)

   
   Same as `wally_ec_sig_from_bytes`, but commits to the host randomness.
   
   :param priv_key: The private key to sign with.
   :param priv_key_len: The length of ``priv_key`` in bytes. Must be `EC_PRIVATE_KEY_LEN`.
   :param bytes: The message hash to sign.
   :param bytes_len: The length of ``bytes`` in bytes. Must be `EC_MESSAGE_HASH_LEN`.
   :param entropy: Host provided randomness.
   :param entropy_len: The length of ``entropy`` in bytes. Must be `WALLY_S2C_DATA_LEN`.
   :param flags: Must be `EC_FLAG_ECDSA`.
   :param bytes_out: Destination for the resulting compact signature.
   :param len: Size of ``bytes_out``. Must be `EC_SIGNATURE_LEN`.

   :return: See :ref:`error-codes`


.. c:function:: int wally_ae_verify(const unsigned char *pub_key, size_t pub_key_len, const unsigned char *bytes, size_t bytes_len, const unsigned char *entropy, size_t entropy_len, const unsigned char *s2c_opening, size_t s2c_opening_len, uint32_t flags, const unsigned char *sig, size_t sig_len)

   
   Verify a signature was correctly constructed using the Anti-Exfil Protocol.
   
   :param pub_key: The public key to verify with.
   :param pub_key_len: The length of ``pub_key`` in bytes. Must be `EC_PUBLIC_KEY_LEN`.
   :param bytes: The message hash to verify.
   :param bytes_len: The length of ``bytes`` in bytes. Must be `EC_MESSAGE_HASH_LEN`.
   :param entropy: Randomness provided by the host.
   :param entropy_len: The length of ``entropy`` in bytes. Must be `WALLY_S2C_DATA_LEN`.
   :param s2c_opening: Opening information provided by the signer.
   :param s2c_opening_len: The length of ``s2c_opening`` in bytes. Must be `WALLY_S2C_OPENING_LEN`.
   :param flags: Must be `EC_FLAG_ECDSA`.
   :param sig: The compact signature of the message in ``bytes``.
   :param sig_len: The length of ``sig`` in bytes. Must be `EC_SIGNATURE_LEN`.

   :return: See :ref:`error-codes`


 
Anti-Exfil Constants
--------------------

.. c:macro:: WALLY_HOST_COMMITMENT_LEN
 
    The length of the commitment to the host provided randomness