tc_ecc_dh.c File Reference

#include "tc_constants.h"
#include "tc_ecc.h"
#include "tc_ecc_dh.h"
#include <string.h>

Functions
int	tc_uECC_make_key_with_d (uint8_t *public_key, uint8_t *private_key, unsigned int *d, tc_uECC_Curve curve)
int	tc_uECC_make_key (uint8_t *public_key, uint8_t *private_key, tc_uECC_Curve curve)
	Create a public/private key pair. More...
int	tc_uECC_shared_secret (const uint8_t *public_key, const uint8_t *private_key, uint8_t *secret, tc_uECC_Curve curve)
	Compute a shared secret given your secret key and someone else's public key. More...

Variables
static tc_uECC_RNG_Function	g_rng_function = 0

Function Documentation

tc_uECC_make_key()

int tc_uECC_make_key	(	uint8_t *	p_public_key,
		uint8_t *	p_private_key,
		tc_uECC_Curve	curve
	)

Create a public/private key pair.

Returns

returns TC_CRYPTO_SUCCESS (1) if the key pair was generated successfully returns TC_CRYPTO_FAIL (0) if error while generating key pair

Parameters

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.
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 tc_uECC_set_rng()) before calling tc_uECC_make_key().

tc_uECC_make_key_with_d()

int tc_uECC_make_key_with_d	(	uint8_t *	public_key,
		uint8_t *	private_key,
		unsigned int *	d,
		tc_uECC_Curve	curve
	)

tc_uECC_shared_secret()

int tc_uECC_shared_secret	(	const uint8_t *	p_public_key,
		const uint8_t *	p_private_key,
		uint8_t *	p_secret,
		tc_uECC_Curve	curve
	)

Compute a shared secret given your secret key and someone else's public key.

Returns

returns TC_CRYPTO_SUCCESS (1) if the shared secret was computed successfully returns TC_CRYPTO_FAIL (0) otherwise

Parameters

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.
p_public_key	IN – The public key of the remote party.
p_private_key	IN – Your private key.

Warning

It is recommended to use the output of tc_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.

Variable Documentation

g_rng_function

tc_uECC_RNG_Function g_rng_function = 0

static