rom_ecc.c File Reference

#include "rom_ecc.h"
#include <stdbool.h>
#include <string.h>

Functions
void	ECC_initialize (ECC_State *state, uint32_t *workzone)
	Initialize elliptic curve parameters to default values and specify workzone. More...
void	ECC_init (ECC_State *state, uint32_t *workzone, uint8_t windowSize, const uint32_t *prime, const uint32_t *order, const uint32_t *a, const uint32_t *b, const uint32_t *generatorX, const uint32_t *generatorY)
	Initialize elliptic curve parameters to specified values and specify workzone. More...
uint8_t	ECC_generateKey (ECC_State *state, uint32_t *randEntropy, uint32_t *privateKey, uint32_t *publicKey_x, uint32_t *publicKey_y)
	Generate a public key. More...
uint8_t	ECC_ECDSA_sign (ECC_State *state, uint32_t *privateKey, uint32_t *hash, uint32_t *pmsn, uint32_t *r, uint32_t *s)
	Sign message digest. More...
uint8_t	ECC_ECDSA_verify (ECC_State *state, uint32_t *publicKey_x, uint32_t *publicKey_y, uint32_t *hash, uint32_t *r, uint32_t *s)
	Verify signature. More...
uint8_t	ECC_ECDH_computeSharedSecret (ECC_State *state, uint32_t *privateKey, uint32_t *publicKey_x, uint32_t *publicKey_y, uint32_t *sharedSecret_x, uint32_t *sharedSecret_y)
	Compute the shared secret. More...
uint8_t	ECC_validatePublicKey (ECC_State *state, uint32_t *publicKey_x, uint32_t *publicKey_y)
	Validate a public key against the currently set elliptic curve. More...
uint8_t	ECC_validatePrivateKey (ECC_State *state, uint32_t *privateKey)
	Validate a private key against the currently set elliptic curve. More...

Variables
const ECC_NISTP256_Param	ECC_NISTP256_generatorX
	X coordinate of the generator point of the ECC_NISTP256 curve. More...
const ECC_NISTP256_Param	ECC_NISTP256_generatorY
	Y coordinate of the generator point of the ECC_NISTP256 curve. More...
const ECC_NISTP256_Param	ECC_NISTP256_prime
	prime of the ECC_NISTP256 curve. More...
const ECC_NISTP256_Param	ECC_NISTP256_a
	a constant of the ECC_NISTP256 curve when expressed in short Weierstrass form (y^3 = x^2 + a*x + b). More...
const ECC_NISTP256_Param	ECC_NISTP256_b
	b constant of the ECC_NISTP256 curve when expressed in short Weierstrass form (y^3 = x^2 + a*x + b). More...
const ECC_NISTP256_Param	ECC_NISTP256_order
	order of the ECC_NISTP256 curve. More...
const ECC_NISTP256_Param	ECC_NISTP256_k_mont
	k in Montgomery domain of the ECC_NISTP256 curve. More...
const ECC_NISTP256_Param	ECC_NISTP256_a_mont
	a in Montgomery domain of the ECC_NISTP256 curve. More...
const ECC_NISTP256_Param	ECC_NISTP256_b_mont
	b in Montgomery domain of the ECC_NISTP256 curve. More...

Function Documentation

ECC_ECDH_computeSharedSecret()

uint8_t ECC_ECDH_computeSharedSecret	(	ECC_State *	state,
		uint32_t *	privateKey,
		uint32_t *	publicKey_x,
		uint32_t *	publicKey_y,
		uint32_t *	sharedSecret_x,
		uint32_t *	sharedSecret_y
	)

Compute the shared secret.

Parameters

[in,out]	state	Struct to keep track of the state of the operation
[in]	privateKey	Pointer to private key
[in]	publicKey_x	Pointer to public key X-coordinate
[in]	publicKey_y	Pointer to public key Y-coordinate
[out]	sharedSecret_x	Pointer to shared secret X-coordinate
[out]	sharedSecret_y	Pointer to shared secret Y-coordinate

Returns

Status

{
    return HapiECDHCommonKey(state,
                             privateKey,
                             publicKey_x,
                             publicKey_y,
                             sharedSecret_x,
                             sharedSecret_y);
}

ECC_ECDSA_sign()

uint8_t ECC_ECDSA_sign	(	ECC_State *	state,
		uint32_t *	privateKey,
		uint32_t *	hash,
		uint32_t *	pmsn,
		uint32_t *	r,
		uint32_t *	s
	)

Sign message digest.

Parameters

[in,out]	state	Struct to keep track of the state of the operation
[in]	privateKey	Pointer to the secret key
[in]	hash	Pointer to the message
[in]	pmsn	Pointer to random string
[out]	r	Pointer to r component of signature
[out]	s	Pointer to s component of signature

Returns

Status

{
    return HapiECDSASign(state, privateKey, hash, pmsn, r, s);
}

ECC_ECDSA_verify()

uint8_t ECC_ECDSA_verify	(	ECC_State *	state,
		uint32_t *	publicKey_x,
		uint32_t *	publicKey_y,
		uint32_t *	hash,
		uint32_t *	r,
		uint32_t *	s
	)

Verify signature.

Parameters

[in,out]	state	Struct to keep track of the state of the operation
[in]	publicKey_x	Pointer to public key X-coordinate
[in]	publicKey_y	Pointer to public key Y-coordinate
[in]	hash	Pointer to hash of message digest
[in]	r	Pointer to r component of signature
[in]	s	Pointer to s component of signature

Returns

Status

{
    return HapiECDSAVerify(state, publicKey_x, publicKey_y, hash, r, s);
}

ECC_generateKey()

uint8_t ECC_generateKey	(	ECC_State *	state,
		uint32_t *	randEntropy,
		uint32_t *	privateKey,
		uint32_t *	publicKey_x,
		uint32_t *	publicKey_y
	)

Generate a public key.

This is used for both ECDH and ECDSA.

Parameters

[in,out]	state	Struct to keep track of the state of the operation
[in]	randEntropy	Pointer to random string
[out]	privateKey	Pointer to the private key. May be the same location as randEntropy.
[out]	publicKey_x	Pointer to public key X-coordinate
[out]	publicKey_y	Pointer to public key Y-coordinate

Returns

Status

{
    return HapiECCKeyGen(state,
                         randEntropy,
                         privateKey,
                         publicKey_x,
                         publicKey_y);

}

ECC_init()

void ECC_init	(	ECC_State *	state,
		uint32_t *	workzone,
		uint8_t	windowSize,
		const uint32_t *	prime,
		const uint32_t *	order,
		const uint32_t *	a,
		const uint32_t *	b,
		const uint32_t *	generatorX,
		const uint32_t *	generatorY
	)

Initialize elliptic curve parameters to specified values and specify workzone.

This function may be used to explicitly specify the curve parameters used by the ECC in ROM implementation.

All curve parameters must be prepended with a length word specifying the length of the parameter in 32-bit words excluding the length word itself. For NIST-P256, the length word is 8.

Parameters

state	Struct to keep track of the state of the operation.
workzone	Pointer to memory allocated for computations, input. See description at beginning of ECC section for memory requirements.
windowSize	Window size of workzone. Default value is 3.
prime	Curve prime
order	Curve order
a	Curve a value
b	Curve b value
generatorX	X coordinate of generator point
generatorY	Y coordinate of generator point

{
    state->data_Gx = generatorX;
    state->data_Gy = generatorY;
    state->data_p = prime;
    state->data_r = order;
    state->data_a = a;
    state->data_b = b;
    // TODO: change signature to accommodate in future
    state->data_a_mont = ECC_NISTP256_a_mont.word;
    state->data_b_mont = ECC_NISTP256_b_mont.word;
    state->data_k_mont = ECC_NISTP256_k_mont.word;
    state->win = windowSize;
    state->workzone = workzone;
}

ECC_initialize()

void ECC_initialize	(	ECC_State *	state,
		uint32_t *	workzone
	)

Initialize elliptic curve parameters to default values and specify workzone.

This function initializes the elliptic curve parameters to default values. The default elliptic curve used is NIST-P256.

The workzone defaults to an expected window size of 3.

This function can be called again to point the ECC workzone at a different memory buffer.

Parameters

state	Struct to keep track of the state of the operation.
workzone	Pointer to memory allocated for computations, input. See description at beginning of ECC section for memory requirements.

Returns

None

{
    state->data_Gx = ECC_NISTP256_generatorX.word;
    state->data_Gy = ECC_NISTP256_generatorY.word;
    state->data_p = ECC_NISTP256_prime.word;
    state->data_r = ECC_NISTP256_order.word;
    state->data_a = ECC_NISTP256_a.word;
    state->data_b = ECC_NISTP256_b.word;
    state->data_a_mont = ECC_NISTP256_a_mont.word;
    state->data_b_mont = ECC_NISTP256_b_mont.word;
    state->data_k_mont = ECC_NISTP256_k_mont.word;
    state->win = 3;
    state->workzone = workzone;
}

ECC_validatePrivateKey()

uint8_t ECC_validatePrivateKey	(	ECC_State *	state,
		uint32_t *	privateKey
	)

Validate a private key against the currently set elliptic curve.

Validates that private key is within [1, n-1] where n is the order of the elliptic curve.

Parameters

[in,out]	state	Struct to keep track of the state of the operation
	privateKey	Pointer to public key X-coordinate, input.

Returns

Status

{
    return HapiECCValidatePrivateKeyWeierstrass(state, privateKey);
}

ECC_validatePublicKey()

uint8_t ECC_validatePublicKey	(	ECC_State *	state,
		uint32_t *	publicKey_x,
		uint32_t *	publicKey_y
	)

Validate a public key against the currently set elliptic curve.

Parameters

[in,out]	state	Struct to keep track of the state of the operation
	publicKey_x	Pointer to public key X-coordinate, input.
	publicKey_y	Pointer to public key Y-coordinate, input.

Returns

Status

{
    return HapiECCValidatePublicKeyWeierstrass(state,
                                               publicKey_x,
                                               publicKey_y);
}

Variable Documentation

ECC_NISTP256_a

const ECC_NISTP256_Param ECC_NISTP256_a

Initial value:

= {.byte = {0x08, 0x00, 0x00, 0x00,
                                                0xfc, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                                                0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00,
                                                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                                                0x01, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff}}

a constant of the ECC_NISTP256 curve when expressed in short Weierstrass form (y^3 = x^2 + a*x + b).

ECC_NISTP256_a_mont

const ECC_NISTP256_Param ECC_NISTP256_a_mont

Initial value:

= {.byte  = {
                                                0xfc, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                                                0xff, 0xff, 0xff, 0xff, 0x03, 0x00, 0x00, 0x00,
                                                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                                                0x04, 0x00, 0x00, 0x00, 0xfc, 0xff, 0xff, 0xff }}

a in Montgomery domain of the ECC_NISTP256 curve.

ECC_NISTP256_b

const ECC_NISTP256_Param ECC_NISTP256_b

Initial value:

= {.byte = {0x08, 0x00, 0x00, 0x00,
                                                0x4b, 0x60, 0xd2, 0x27, 0x3e, 0x3c, 0xce, 0x3b,
                                                0xf6, 0xb0, 0x53, 0xcc, 0xb0, 0x06, 0x1d, 0x65,
                                                0xbc, 0x86, 0x98, 0x76, 0x55, 0xbd, 0xeb, 0xb3,
                                                0xe7, 0x93, 0x3a, 0xaa, 0xd8, 0x35, 0xc6, 0x5a}}

b constant of the ECC_NISTP256 curve when expressed in short Weierstrass form (y^3 = x^2 + a*x + b).

ECC_NISTP256_b_mont

const ECC_NISTP256_Param ECC_NISTP256_b_mont

Initial value:

= {.byte  = {
                                                0xdf, 0xbd, 0xc4, 0x29, 0x62, 0xdf, 0x9c, 0xd8,
                                                0x90, 0x30, 0x84, 0x78, 0xcd, 0x05, 0xf0, 0xac,
                                                0xd6, 0x2e, 0x21, 0xf7, 0xab, 0x20, 0xa2, 0xe5,
                                                0x34, 0x48, 0x87, 0x04, 0x1d, 0x06, 0x30, 0xdc }}

b in Montgomery domain of the ECC_NISTP256 curve.

ECC_NISTP256_generatorX

const ECC_NISTP256_Param ECC_NISTP256_generatorX

Initial value:

= {.byte = {0x08, 0x00, 0x00, 0x00,
                                                0x96, 0xc2, 0x98, 0xd8, 0x45, 0x39, 0xa1, 0xf4,
                                                0xa0, 0x33, 0xeb, 0x2d, 0x81, 0x7d, 0x03, 0x77,
                                                0xf2, 0x40, 0xa4, 0x63, 0xe5, 0xe6, 0xbc, 0xf8,
                                                0x47, 0x42, 0x2c, 0xe1, 0xf2, 0xd1, 0x17, 0x6b}}

X coordinate of the generator point of the ECC_NISTP256 curve.

ECC_NISTP256_generatorY

const ECC_NISTP256_Param ECC_NISTP256_generatorY

Initial value:

= {.byte = {0x08, 0x00, 0x00, 0x00,
                                                0xf5, 0x51, 0xbf, 0x37, 0x68, 0x40, 0xb6, 0xcb,
                                                0xce, 0x5e, 0x31, 0x6b, 0x57, 0x33, 0xce, 0x2b,
                                                0x16, 0x9e, 0x0f, 0x7c, 0x4a, 0xeb, 0xe7, 0x8e,
                                                0x9b, 0x7f, 0x1a, 0xfe, 0xe2, 0x42, 0xe3, 0x4f}}

Y coordinate of the generator point of the ECC_NISTP256 curve.

ECC_NISTP256_k_mont

const ECC_NISTP256_Param ECC_NISTP256_k_mont

Initial value:

= {.byte = {
                                                0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                                                0xff, 0xff, 0xff, 0xff, 0xfb, 0xff, 0xff, 0xff,
                                                0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                                                0xfd, 0xff, 0xff, 0xff, 0x04, 0x00, 0x00, 0x00 }}

k in Montgomery domain of the ECC_NISTP256 curve.

ECC_NISTP256_order

const ECC_NISTP256_Param ECC_NISTP256_order

Initial value:

= {.byte = {0x08, 0x00, 0x00, 0x00,
                                                0x51, 0x25, 0x63, 0xfc, 0xc2, 0xca, 0xb9, 0xf3,
                                                0x84, 0x9e, 0x17, 0xa7, 0xad, 0xfa, 0xe6, 0xbc,
                                                0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                                                0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff}}

order of the ECC_NISTP256 curve.

ECC_NISTP256_prime

const ECC_NISTP256_Param ECC_NISTP256_prime

Initial value:

= {.byte = {0x08, 0x00, 0x00, 0x00,
                                                0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
                                                0xff, 0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00,
                                                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
                                                0x01, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff}}

prime of the ECC_NISTP256 curve.