ecdh.c File Reference

Synchronous wrapper around lib/ecc.h for the EDHOC implementation. More...

#include "contiki.h"
#include "dev/watchdog.h"
#include "ecdh.h"
#include "edhoc-config.h"
#include "lib/ecc.h"
#include "lib/ecc-curve.h"
#include "sys/process-mutex.h"
#include "sys/pt.h"
#include <string.h>
#include "sys/log.h"

Go to the source code of this file.

Functions
bool	ecdh_generate_keypair (uint8_t curve_id, uint8_t *pub_x, uint8_t *pub_y, uint8_t *priv)
	Generates a fresh ECDH key pair.
bool	ecdh_generate_ikm (uint8_t curve_id, const uint8_t *peer_x, const uint8_t *private_key, uint8_t *ikm)
	Computes an ECDH shared secret.
bool	ecc_sign_hash (uint8_t curve_id, const uint8_t *hash, const uint8_t *private_key, uint8_t *signature)
	Generates an ECDSA signature for a message hash.
bool	ecc_verify_hash (uint8_t curve_id, const uint8_t *hash, const uint8_t *public_key, const uint8_t *signature)
	Verifies an ECDSA signature of a message hash.

Detailed Description

Synchronous wrapper around lib/ecc.h for the EDHOC implementation.

The Contiki-NG ECC driver exposes long-running operations as protothreads so that other protothreads may make progress while the cryptographic operation is in flight. The current EDHOC protocol implementation is synchronous, so we busy-wait the underlying protothread to completion. This still deduplicates the per-backend wrappers EDHOC used to ship.

Author

Lidia Pocero pocer.nosp@m.o@is.nosp@m.i.gr, Peter A Jonsson, Rikard Höglund, Marco Tiloca, Nicolas Tsiftes

Definition in file ecdh.c.

Function Documentation

ecc_sign_hash()

bool ecc_sign_hash	(	uint8_t	curve_id,
		const uint8_t *	hash,
		const uint8_t *	private_key,
		uint8_t *	signature )

Generates an ECDSA signature for a message hash.

Parameters

curve_id	The EDHOC curve identifier (e.g. EDHOC_CURVE_P256).
hash	The message hash (ECC_KEY_LEN bytes).
private_key	The signer's private key (ECC_KEY_LEN bytes).
signature	Output buffer for the signature (2*ECC_KEY_LEN bytes).

Returns

true on success, false on error.

Definition at line 174 of file ecdh.c.

References ecc_disable(), ecc_get_protothread(), ecc_sign(), PT_INIT, PT_SCHEDULE, and watchdog_periodic().

Referenced by cose_sign1_sign().

ecc_verify_hash()

bool ecc_verify_hash	(	uint8_t	curve_id,
		const uint8_t *	hash,
		const uint8_t *	public_key,
		const uint8_t *	signature )

Verifies an ECDSA signature of a message hash.

Parameters

curve_id	The EDHOC curve identifier (e.g. EDHOC_CURVE_P256).
hash	The message hash (ECC_KEY_LEN bytes).
public_key	The signer's public key (2*ECC_KEY_LEN bytes).
signature	The signature to verify (2*ECC_KEY_LEN bytes).

Returns

true if the signature is valid, false otherwise.

Definition at line 203 of file ecdh.c.

References ecc_disable(), ecc_get_protothread(), ecc_verify(), PT_INIT, PT_SCHEDULE, and watchdog_periodic().

Referenced by cose_sign1_verify().

ecdh_generate_ikm()

bool ecdh_generate_ikm	(	uint8_t	curve_id,
		const uint8_t *	peer_x,
		const uint8_t *	private_key,
		uint8_t *	ikm )

Computes an ECDH shared secret.

Parameters

curve_id	The EDHOC curve identifier (e.g. EDHOC_CURVE_P256).
peer_x	The peer's public-key x-coordinate (ECC_KEY_LEN bytes). The y-coordinate is recovered from peer_x using point decompression (odd-y branch), so EDHOC's x-only on-wire encoding can be passed in directly.
private_key	Our private key (ECC_KEY_LEN bytes).
ikm	Output buffer for the shared secret (ECC_KEY_LEN bytes).

Returns

true on success, false on error.

Definition at line 123 of file ecdh.c.

References ecc_decompress_public_key(), ecc_disable(), ecc_generate_shared_secret(), ecc_get_protothread(), PT_INIT, PT_SCHEDULE, and watchdog_periodic().

Referenced by edhoc_generate_prk_2e().

ecdh_generate_keypair()

bool ecdh_generate_keypair	(	uint8_t	curve_id,
		uint8_t *	pub_x,
		uint8_t *	pub_y,
		uint8_t *	priv )

Generates a fresh ECDH key pair.

Parameters

curve_id	The EDHOC curve identifier (e.g. EDHOC_CURVE_P256).
pub_x	Output buffer for the x-coordinate (ECC_KEY_LEN bytes).
pub_y	Output buffer for the y-coordinate (ECC_KEY_LEN bytes).
priv	Output buffer for the private key (ECC_KEY_LEN bytes).

Returns

true on success, false on error.

Definition at line 91 of file ecdh.c.

References ecc_disable(), ecc_generate_key_pair(), ecc_get_protothread(), PT_INIT, PT_SCHEDULE, and watchdog_periodic().