#ifndef __TC_ECC_DH_H__
#define __TC_ECC_DH_H__

#include <ecc.h>

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @brief Create a public/private key pair.
 * @return returns TC_CRYPTO_SUCCESS (1) if the key pair was generated successfully
 *         returns TC_CRYPTO_FAIL (0) if error while generating key pair
 *
 * @param p_public_key OUT -- Will be filled in with the public key. Must be at
 * least 2 * the curve size (in bytes) long. For curve secp256r1, p_public_key
 * must be 64 bytes long.
 * @param p_private_key OUT -- Will be filled in with the private key. Must be as
 * long as the curve order (for secp256r1, p_private_key must be 32 bytes long).
 *
 * @note side-channel countermeasure: algorithm strengthened against timing
 * attack.
 * @warning A cryptographically-secure PRNG function must be set (using
 * uECC_set_rng()) before calling uECC_make_key().
 */
int uECC_make_key(uint8_t *p_public_key, uint8_t *p_private_key, uECC_Curve curve);

#ifdef ENABLE_TESTS

/**
 * @brief Create a public/private key pair given a specific d.
 *
 * @note THIS FUNCTION SHOULD BE CALLED ONLY FOR TEST PURPOSES. Refer to
 * uECC_make_key() function for real applications.
 */
int uECC_make_key_with_d(uint8_t *p_public_key, uint8_t *p_private_key,
    			 unsigned int *d, uECC_Curve curve);
#endif

/**
 * @brief Compute a shared secret given your secret key and someone else's
 * public key.
 * @return returns TC_CRYPTO_SUCCESS (1) if the shared secret was computed successfully
 *         returns TC_CRYPTO_FAIL (0) otherwise
 *
 * @param p_secret OUT -- Will be filled in with the shared secret value. Must be
 * the same size as the curve size (for curve secp256r1, secret must be 32 bytes
 * long.
 * @param p_public_key IN -- The public key of the remote party.
 * @param p_private_key IN -- Your private key.
 *
 * @warning It is recommended to use the output of uECC_shared_secret() as the
 * input of a recommended Key Derivation Function (see NIST SP 800-108) in
 * order to produce a cryptographically secure symmetric key.
 */
int uECC_shared_secret(const uint8_t *p_public_key, const uint8_t *p_private_key,
		       uint8_t *p_secret, uECC_Curve curve);

#ifdef __cplusplus
}
#endif

#endif /* __TC_ECC_DH_H__ */