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/*-
* MIT License
* -
* Copyright (c) 2020 Luis Rivera-Zamarripa, Jesús-Javier Chi-Domínguez, Billy Bob Brumley
* -
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
* -
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
* -
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#undef RADIX
#include "ecp.h"
#include "ecp_secp521r1.h"
#include "mpi-priv.h"
#include "mplogic.h"
/*-
* reverse bytes -- total hack
*/
#define MP_BE2LE(a) \
do { \
unsigned char z_bswap; \
z_bswap = a[0]; \
a[0] = a[65]; \
a[65] = z_bswap; \
z_bswap = a[1]; \
a[1] = a[64]; \
a[64] = z_bswap; \
z_bswap = a[2]; \
a[2] = a[63]; \
a[63] = z_bswap; \
z_bswap = a[3]; \
a[3] = a[62]; \
a[62] = z_bswap; \
z_bswap = a[4]; \
a[4] = a[61]; \
a[61] = z_bswap; \
z_bswap = a[5]; \
a[5] = a[60]; \
a[60] = z_bswap; \
z_bswap = a[6]; \
a[6] = a[59]; \
a[59] = z_bswap; \
z_bswap = a[7]; \
a[7] = a[58]; \
a[58] = z_bswap; \
z_bswap = a[8]; \
a[8] = a[57]; \
a[57] = z_bswap; \
z_bswap = a[9]; \
a[9] = a[56]; \
a[56] = z_bswap; \
z_bswap = a[10]; \
a[10] = a[55]; \
a[55] = z_bswap; \
z_bswap = a[11]; \
a[11] = a[54]; \
a[54] = z_bswap; \
z_bswap = a[12]; \
a[12] = a[53]; \
a[53] = z_bswap; \
z_bswap = a[13]; \
a[13] = a[52]; \
a[52] = z_bswap; \
z_bswap = a[14]; \
a[14] = a[51]; \
a[51] = z_bswap; \
z_bswap = a[15]; \
a[15] = a[50]; \
a[50] = z_bswap; \
z_bswap = a[16]; \
a[16] = a[49]; \
a[49] = z_bswap; \
z_bswap = a[17]; \
a[17] = a[48]; \
a[48] = z_bswap; \
z_bswap = a[18]; \
a[18] = a[47]; \
a[47] = z_bswap; \
z_bswap = a[19]; \
a[19] = a[46]; \
a[46] = z_bswap; \
z_bswap = a[20]; \
a[20] = a[45]; \
a[45] = z_bswap; \
z_bswap = a[21]; \
a[21] = a[44]; \
a[44] = z_bswap; \
z_bswap = a[22]; \
a[22] = a[43]; \
a[43] = z_bswap; \
z_bswap = a[23]; \
a[23] = a[42]; \
a[42] = z_bswap; \
z_bswap = a[24]; \
a[24] = a[41]; \
a[41] = z_bswap; \
z_bswap = a[25]; \
a[25] = a[40]; \
a[40] = z_bswap; \
z_bswap = a[26]; \
a[26] = a[39]; \
a[39] = z_bswap; \
z_bswap = a[27]; \
a[27] = a[38]; \
a[38] = z_bswap; \
z_bswap = a[28]; \
a[28] = a[37]; \
a[37] = z_bswap; \
z_bswap = a[29]; \
a[29] = a[36]; \
a[36] = z_bswap; \
z_bswap = a[30]; \
a[30] = a[35]; \
a[35] = z_bswap; \
z_bswap = a[31]; \
a[31] = a[34]; \
a[34] = z_bswap; \
z_bswap = a[32]; \
a[32] = a[33]; \
a[33] = z_bswap; \
} while (0)
static mp_err
point_mul_g_secp521r1_wrap(const mp_int *n, mp_int *out_x,
mp_int *out_y, const ECGroup *group)
{
unsigned char b_x[66];
unsigned char b_y[66];
unsigned char b_n[66];
mp_err res;
ARGCHK(n != NULL && out_x != NULL && out_y != NULL, MP_BADARG);
/* fail on out of range scalars */
if (mpl_significant_bits(n) > 521 || mp_cmp_z(n) != MP_GT)
return MP_RANGE;
MP_CHECKOK(mp_to_fixlen_octets(n, b_n, 66));
MP_BE2LE(b_n);
point_mul_g_secp521r1(b_x, b_y, b_n);
MP_BE2LE(b_x);
MP_BE2LE(b_y);
MP_CHECKOK(mp_read_unsigned_octets(out_x, b_x, 66));
MP_CHECKOK(mp_read_unsigned_octets(out_y, b_y, 66));
CLEANUP:
return res;
}
static mp_err
point_mul_secp521r1_wrap(const mp_int *n, const mp_int *in_x,
const mp_int *in_y, mp_int *out_x,
mp_int *out_y, const ECGroup *group)
{
unsigned char b_x[66];
unsigned char b_y[66];
unsigned char b_n[66];
mp_err res;
ARGCHK(n != NULL && in_x != NULL && in_y != NULL && out_x != NULL &&
out_y != NULL,
MP_BADARG);
/* fail on out of range scalars */
if (mpl_significant_bits(n) > 521 || mp_cmp_z(n) != MP_GT)
return MP_RANGE;
MP_CHECKOK(mp_to_fixlen_octets(n, b_n, 66));
MP_CHECKOK(mp_to_fixlen_octets(in_x, b_x, 66));
MP_CHECKOK(mp_to_fixlen_octets(in_y, b_y, 66));
MP_BE2LE(b_x);
MP_BE2LE(b_y);
MP_BE2LE(b_n);
point_mul_secp521r1(b_x, b_y, b_n, b_x, b_y);
MP_BE2LE(b_x);
MP_BE2LE(b_y);
MP_CHECKOK(mp_read_unsigned_octets(out_x, b_x, 66));
MP_CHECKOK(mp_read_unsigned_octets(out_y, b_y, 66));
CLEANUP:
return res;
}
static mp_err
point_mul_two_secp521r1_wrap(const mp_int *n1, const mp_int *n2,
const mp_int *in_x,
const mp_int *in_y, mp_int *out_x,
mp_int *out_y,
const ECGroup *group)
{
unsigned char b_x[66];
unsigned char b_y[66];
unsigned char b_n1[66];
unsigned char b_n2[66];
mp_err res;
/* If n2 == NULL or 0, this is just a base-point multiplication. */
if (n2 == NULL || mp_cmp_z(n2) == MP_EQ)
return point_mul_g_secp521r1_wrap(n1, out_x, out_y, group);
/* If n1 == NULL or 0, this is just an arbitary-point multiplication. */
if (n1 == NULL || mp_cmp_z(n1) == MP_EQ)
return point_mul_secp521r1_wrap(n2, in_x, in_y, out_x, out_y, group);
ARGCHK(in_x != NULL && in_y != NULL && out_x != NULL && out_y != NULL,
MP_BADARG);
/* fail on out of range scalars */
if (mpl_significant_bits(n1) > 521 || mp_cmp_z(n1) != MP_GT ||
mpl_significant_bits(n2) > 521 || mp_cmp_z(n2) != MP_GT)
return MP_RANGE;
MP_CHECKOK(mp_to_fixlen_octets(n1, b_n1, 66));
MP_CHECKOK(mp_to_fixlen_octets(n2, b_n2, 66));
MP_CHECKOK(mp_to_fixlen_octets(in_x, b_x, 66));
MP_CHECKOK(mp_to_fixlen_octets(in_y, b_y, 66));
MP_BE2LE(b_x);
MP_BE2LE(b_y);
MP_BE2LE(b_n1);
MP_BE2LE(b_n2);
point_mul_two_secp521r1(b_x, b_y, b_n1, b_n2, b_x, b_y);
MP_BE2LE(b_x);
MP_BE2LE(b_y);
MP_CHECKOK(mp_read_unsigned_octets(out_x, b_x, 66));
MP_CHECKOK(mp_read_unsigned_octets(out_y, b_y, 66));
CLEANUP:
return res;
}
mp_err
ec_group_set_secp521r1(ECGroup *group, ECCurveName name)
{
if (name == ECCurve_NIST_P521) {
group->base_point_mul = &point_mul_g_secp521r1_wrap;
group->point_mul = &point_mul_secp521r1_wrap;
group->points_mul = &point_mul_two_secp521r1_wrap;
}
return MP_OKAY;
}