/*
* Computes scalar point multiplication pointQ = k1 * G + k2 * pointP for
* the curve whose parameters are encoded in params with base point G.
*/
SECStatus
ec_points_mul(const ECParams *params, const mp_int *k1, const mp_int *k2,
const SECItem *pointP, SECItem *pointQ)
{
mp_int Px, Py, Qx, Qy;
mp_int Gx, Gy, order, irreducible, a, b;
#if 0 /* currently don't support non-named curves */
unsigned int irr_arr[5];
#endif
ECGroup *group = NULL;
SECStatus rv = SECFailure;
mp_err err = MP_OKAY;
int len;
#if EC_DEBUG
int i;
char mpstr[256];
printf("ec_points_mul: params [len=%d]:", params->DEREncoding.len);
for (i = 0; i < params->DEREncoding.len; i++)
printf("%02x:", params->DEREncoding.data[i]);
printf("\n");
if (k1 != NULL) {
mp_tohex(k1, mpstr);
printf("ec_points_mul: scalar k1: %s\n", mpstr);
mp_todecimal(k1, mpstr);
printf("ec_points_mul: scalar k1: %s (dec)\n", mpstr);
}
if (k2 != NULL) {
mp_tohex(k2, mpstr);
printf("ec_points_mul: scalar k2: %s\n", mpstr);
mp_todecimal(k2, mpstr);
printf("ec_points_mul: scalar k2: %s (dec)\n", mpstr);
}
if (pointP != NULL) {
printf("ec_points_mul: pointP [len=%d]:", pointP->len);
for (i = 0; i < pointP->len; i++)
printf("%02x:", pointP->data[i]);
printf("\n");
}
#endif
/* NOTE: We only support uncompressed points for now */
len = (params->fieldID.size + 7) >> 3;
if (pointP != NULL) {
if ((pointP->data[0] != EC_POINT_FORM_UNCOMPRESSED) ||
(pointP->len != (2 * len + 1))) {
PORT_SetError(SEC_ERROR_UNSUPPORTED_EC_POINT_FORM);
return SECFailure;
};
}
MP_DIGITS(&Px) = 0;
MP_DIGITS(&Py) = 0;
MP_DIGITS(&Qx) = 0;
MP_DIGITS(&Qy) = 0;
MP_DIGITS(&Gx) = 0;
MP_DIGITS(&Gy) = 0;
MP_DIGITS(&order) = 0;
MP_DIGITS(&irreducible) = 0;
MP_DIGITS(&a) = 0;
MP_DIGITS(&b) = 0;
CHECK_MPI_OK( mp_init(&Px) );
CHECK_MPI_OK( mp_init(&Py) );
CHECK_MPI_OK( mp_init(&Qx) );
CHECK_MPI_OK( mp_init(&Qy) );
CHECK_MPI_OK( mp_init(&Gx) );
CHECK_MPI_OK( mp_init(&Gy) );
CHECK_MPI_OK( mp_init(&order) );
CHECK_MPI_OK( mp_init(&irreducible) );
CHECK_MPI_OK( mp_init(&a) );
CHECK_MPI_OK( mp_init(&b) );
if ((k2 != NULL) && (pointP != NULL)) {
/* Initialize Px and Py */
CHECK_MPI_OK( mp_read_unsigned_octets(&Px, pointP->data + 1, (mp_size) len) );
CHECK_MPI_OK( mp_read_unsigned_octets(&Py, pointP->data + 1 + len, (mp_size) len) );
}
/* construct from named params, if possible */
if (params->name != ECCurve_noName) {
group = ECGroup_fromName(params->name);
}
#if 0 /* currently don't support non-named curves */
if (group == NULL) {
/* Set up mp_ints containing the curve coefficients */
CHECK_MPI_OK( mp_read_unsigned_octets(&Gx, params->base.data + 1,
(mp_size) len) );
CHECK_MPI_OK( mp_read_unsigned_octets(&Gy, params->base.data + 1 + len,
(mp_size) len) );
SECITEM_TO_MPINT( params->order, &order );
SECITEM_TO_MPINT( params->curve.a, &a );
SECITEM_TO_MPINT( params->curve.b, &b );
if (params->fieldID.type == ec_field_GFp) {
SECITEM_TO_MPINT( params->fieldID.u.prime, &irreducible );
group = ECGroup_consGFp(&irreducible, &a, &b, &Gx, &Gy, &order, params->cofactor);
} else {
SECITEM_TO_MPINT( params->fieldID.u.poly, &irreducible );
irr_arr[0] = params->fieldID.size;
irr_arr[1] = params->fieldID.k1;
irr_arr[2] = params->fieldID.k2;
irr_arr[3] = params->fieldID.k3;
irr_arr[4] = 0;
group = ECGroup_consGF2m(&irreducible, irr_arr, &a, &b, &Gx, &Gy, &order, params->cofactor);
}
}
#endif
if (group == NULL)
goto cleanup;
if ((k2 != NULL) && (pointP != NULL)) {
CHECK_MPI_OK( ECPoints_mul(group, k1, k2, &Px, &Py, &Qx, &Qy) );
} else {
CHECK_MPI_OK( ECPoints_mul(group, k1, NULL, NULL, NULL, &Qx, &Qy) );
}
/* Construct the SECItem representation of point Q */
pointQ->data[0] = EC_POINT_FORM_UNCOMPRESSED;
CHECK_MPI_OK( mp_to_fixlen_octets(&Qx, pointQ->data + 1,
(mp_size) len) );
CHECK_MPI_OK( mp_to_fixlen_octets(&Qy, pointQ->data + 1 + len,
(mp_size) len) );
rv = SECSuccess;
#if EC_DEBUG
printf("ec_points_mul: pointQ [len=%d]:", pointQ->len);
for (i = 0; i < pointQ->len; i++)
printf("%02x:", pointQ->data[i]);
printf("\n");
#endif
cleanup:
ECGroup_free(group);
mp_clear(&Px);
mp_clear(&Py);
mp_clear(&Qx);
mp_clear(&Qy);
mp_clear(&Gx);
mp_clear(&Gy);
mp_clear(&order);
mp_clear(&irreducible);
mp_clear(&a);
mp_clear(&b);
if (err) {
MP_TO_SEC_ERROR(err);
rv = SECFailure;
}
return rv;
}
/* Construct ECGroup from hex parameters and name, if any. Called by
* ECGroup_fromHex and ECGroup_fromName. */
ECGroup *
ecgroup_fromNameAndHex(const ECCurveName name,
const ECCurveParams * params)
{
mp_int irr, curvea, curveb, genx, geny, order;
int bits;
ECGroup *group = NULL;
mp_err res = MP_OKAY;
/* initialize values */
MP_DIGITS(&irr) = 0;
MP_DIGITS(&curvea) = 0;
MP_DIGITS(&curveb) = 0;
MP_DIGITS(&genx) = 0;
MP_DIGITS(&geny) = 0;
MP_DIGITS(&order) = 0;
MP_CHECKOK(mp_init(&irr));
MP_CHECKOK(mp_init(&curvea));
MP_CHECKOK(mp_init(&curveb));
MP_CHECKOK(mp_init(&genx));
MP_CHECKOK(mp_init(&geny));
MP_CHECKOK(mp_init(&order));
MP_CHECKOK(mp_read_radix(&irr, params->irr, 16));
MP_CHECKOK(mp_read_radix(&curvea, params->curvea, 16));
MP_CHECKOK(mp_read_radix(&curveb, params->curveb, 16));
MP_CHECKOK(mp_read_radix(&genx, params->genx, 16));
MP_CHECKOK(mp_read_radix(&geny, params->geny, 16));
MP_CHECKOK(mp_read_radix(&order, params->order, 16));
/* determine number of bits */
bits = mpl_significant_bits(&irr) - 1;
if (bits < MP_OKAY) {
res = bits;
goto CLEANUP;
}
/* determine which optimizations (if any) to use */
if (params->field == ECField_GFp) {
switch (name) {
#ifdef NSS_ECC_MORE_THAN_SUITE_B
#ifdef ECL_USE_FP
case ECCurve_SECG_PRIME_160R1:
group =
ECGroup_consGFp(&irr, &curvea, &curveb, &genx, &geny,
&order, params->cofactor);
if (group == NULL) {
res = MP_UNDEF;
goto CLEANUP;
}
MP_CHECKOK(ec_group_set_secp160r1_fp(group));
break;
#endif
case ECCurve_SECG_PRIME_192R1:
#ifdef ECL_USE_FP
group =
ECGroup_consGFp(&irr, &curvea, &curveb, &genx, &geny,
&order, params->cofactor);
if (group == NULL) {
res = MP_UNDEF;
goto CLEANUP;
}
MP_CHECKOK(ec_group_set_nistp192_fp(group));
#else
group =
ECGroup_consGFp(&irr, &curvea, &curveb, &genx, &geny,
&order, params->cofactor);
if (group == NULL) {
res = MP_UNDEF;
goto CLEANUP;
}
MP_CHECKOK(ec_group_set_gfp192(group, name));
#endif
break;
case ECCurve_SECG_PRIME_224R1:
#ifdef ECL_USE_FP
group =
ECGroup_consGFp(&irr, &curvea, &curveb, &genx, &geny,
&order, params->cofactor);
if (group == NULL) {
res = MP_UNDEF;
goto CLEANUP;
}
MP_CHECKOK(ec_group_set_nistp224_fp(group));
#else
group =
ECGroup_consGFp(&irr, &curvea, &curveb, &genx, &geny,
&order, params->cofactor);
if (group == NULL) {
res = MP_UNDEF;
goto CLEANUP;
}
MP_CHECKOK(ec_group_set_gfp224(group, name));
#endif
break;
#endif /* NSS_ECC_MORE_THAN_SUITE_B */
case ECCurve_SECG_PRIME_256R1:
group =
ECGroup_consGFp(&irr, &curvea, &curveb, &genx, &geny,
&order, params->cofactor);
if (group == NULL) {
res = MP_UNDEF;
goto CLEANUP;
}
MP_CHECKOK(ec_group_set_gfp256(group, name));
MP_CHECKOK(ec_group_set_gfp256_32(group, name));
break;
case ECCurve_SECG_PRIME_521R1:
group =
ECGroup_consGFp(&irr, &curvea, &curveb, &genx, &geny,
&order, params->cofactor);
if (group == NULL) {
res = MP_UNDEF;
goto CLEANUP;
}
MP_CHECKOK(ec_group_set_gfp521(group, name));
break;
default:
/* use generic arithmetic */
group =
ECGroup_consGFp_mont(&irr, &curvea, &curveb, &genx, &geny,
&order, params->cofactor);
if (group == NULL) {
res = MP_UNDEF;
goto CLEANUP;
}
}
#ifdef NSS_ECC_MORE_THAN_SUITE_B
} else if (params->field == ECField_GF2m) {
group = ECGroup_consGF2m(&irr, NULL, &curvea, &curveb, &genx, &geny, &order, params->cofactor);
if (group == NULL) {
res = MP_UNDEF;
goto CLEANUP;
}
if ((name == ECCurve_NIST_K163) ||
(name == ECCurve_NIST_B163) ||
(name == ECCurve_SECG_CHAR2_163R1)) {
MP_CHECKOK(ec_group_set_gf2m163(group, name));
} else if ((name == ECCurve_SECG_CHAR2_193R1) ||
(name == ECCurve_SECG_CHAR2_193R2)) {
MP_CHECKOK(ec_group_set_gf2m193(group, name));
} else if ((name == ECCurve_NIST_K233) ||
(name == ECCurve_NIST_B233)) {
MP_CHECKOK(ec_group_set_gf2m233(group, name));
}
#endif
} else {
res = MP_UNDEF;
goto CLEANUP;
}
/* set name, if any */
if ((group != NULL) && (params->text != NULL)) {
group->text = strdup(params->text);
if (group->text == NULL) {
res = MP_MEM;
}
}
CLEANUP:
mp_clear(&irr);
mp_clear(&curvea);
mp_clear(&curveb);
mp_clear(&genx);
mp_clear(&geny);
mp_clear(&order);
if (res != MP_OKAY) {
ECGroup_free(group);
return NULL;
}
return group;
}
