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Diffstat (limited to '')
-rw-r--r-- | security/nss/lib/freebl/ecl/ecl_mult.c | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/security/nss/lib/freebl/ecl/ecl_mult.c b/security/nss/lib/freebl/ecl/ecl_mult.c new file mode 100644 index 0000000000..ffbcbf1d98 --- /dev/null +++ b/security/nss/lib/freebl/ecl/ecl_mult.c @@ -0,0 +1,305 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "mpi.h" +#include "mplogic.h" +#include "ecl.h" +#include "ecl-priv.h" +#include <stdlib.h> + +/* Elliptic curve scalar-point multiplication. Computes R(x, y) = k * P(x, + * y). If x, y = NULL, then P is assumed to be the generator (base point) + * of the group of points on the elliptic curve. Input and output values + * are assumed to be NOT field-encoded. */ +mp_err +ECPoint_mul(const ECGroup *group, const mp_int *k, const mp_int *px, + const mp_int *py, mp_int *rx, mp_int *ry) +{ + mp_err res = MP_OKAY; + mp_int kt; + + ARGCHK((k != NULL) && (group != NULL), MP_BADARG); + MP_DIGITS(&kt) = 0; + + /* want scalar to be less than or equal to group order */ + if (mp_cmp(k, &group->order) > 0) { + MP_CHECKOK(mp_init(&kt)); + MP_CHECKOK(mp_mod(k, &group->order, &kt)); + } else { + MP_SIGN(&kt) = MP_ZPOS; + MP_USED(&kt) = MP_USED(k); + MP_ALLOC(&kt) = MP_ALLOC(k); + MP_DIGITS(&kt) = MP_DIGITS(k); + } + + if ((px == NULL) || (py == NULL)) { + if (group->base_point_mul) { + MP_CHECKOK(group->base_point_mul(&kt, rx, ry, group)); + } else { + MP_CHECKOK(group->point_mul(&kt, &group->genx, &group->geny, rx, ry, + group)); + } + } else { + if (group->meth->field_enc) { + MP_CHECKOK(group->meth->field_enc(px, rx, group->meth)); + MP_CHECKOK(group->meth->field_enc(py, ry, group->meth)); + MP_CHECKOK(group->point_mul(&kt, rx, ry, rx, ry, group)); + } else { + MP_CHECKOK(group->point_mul(&kt, px, py, rx, ry, group)); + } + } + if (group->meth->field_dec) { + MP_CHECKOK(group->meth->field_dec(rx, rx, group->meth)); + MP_CHECKOK(group->meth->field_dec(ry, ry, group->meth)); + } + +CLEANUP: + if (MP_DIGITS(&kt) != MP_DIGITS(k)) { + mp_clear(&kt); + } + return res; +} + +/* Elliptic curve scalar-point multiplication. Computes R(x, y) = k1 * G + + * k2 * P(x, y), where G is the generator (base point) of the group of + * points on the elliptic curve. Allows k1 = NULL or { k2, P } = NULL. + * Input and output values are assumed to be NOT field-encoded. */ +mp_err +ec_pts_mul_basic(const mp_int *k1, const mp_int *k2, const mp_int *px, + const mp_int *py, mp_int *rx, mp_int *ry, + const ECGroup *group) +{ + mp_err res = MP_OKAY; + mp_int sx, sy; + + ARGCHK(group != NULL, MP_BADARG); + ARGCHK(!((k1 == NULL) && ((k2 == NULL) || (px == NULL) || (py == NULL))), MP_BADARG); + + /* if some arguments are not defined used ECPoint_mul */ + if (k1 == NULL) { + return ECPoint_mul(group, k2, px, py, rx, ry); + } else if ((k2 == NULL) || (px == NULL) || (py == NULL)) { + return ECPoint_mul(group, k1, NULL, NULL, rx, ry); + } + + MP_DIGITS(&sx) = 0; + MP_DIGITS(&sy) = 0; + MP_CHECKOK(mp_init(&sx)); + MP_CHECKOK(mp_init(&sy)); + + MP_CHECKOK(ECPoint_mul(group, k1, NULL, NULL, &sx, &sy)); + MP_CHECKOK(ECPoint_mul(group, k2, px, py, rx, ry)); + + if (group->meth->field_enc) { + MP_CHECKOK(group->meth->field_enc(&sx, &sx, group->meth)); + MP_CHECKOK(group->meth->field_enc(&sy, &sy, group->meth)); + MP_CHECKOK(group->meth->field_enc(rx, rx, group->meth)); + MP_CHECKOK(group->meth->field_enc(ry, ry, group->meth)); + } + + MP_CHECKOK(group->point_add(&sx, &sy, rx, ry, rx, ry, group)); + + if (group->meth->field_dec) { + MP_CHECKOK(group->meth->field_dec(rx, rx, group->meth)); + MP_CHECKOK(group->meth->field_dec(ry, ry, group->meth)); + } + +CLEANUP: + mp_clear(&sx); + mp_clear(&sy); + return res; +} + +/* Elliptic curve scalar-point multiplication. Computes R(x, y) = k1 * G + + * k2 * P(x, y), where G is the generator (base point) of the group of + * points on the elliptic curve. Allows k1 = NULL or { k2, P } = NULL. + * Input and output values are assumed to be NOT field-encoded. Uses + * algorithm 15 (simultaneous multiple point multiplication) from Brown, + * Hankerson, Lopez, Menezes. Software Implementation of the NIST + * Elliptic Curves over Prime Fields. */ +mp_err +ec_pts_mul_simul_w2(const mp_int *k1, const mp_int *k2, const mp_int *px, + const mp_int *py, mp_int *rx, mp_int *ry, + const ECGroup *group) +{ + mp_err res = MP_OKAY; + mp_int precomp[4][4][2]; + const mp_int *a, *b; + unsigned int i, j; + int ai, bi, d; + + ARGCHK(group != NULL, MP_BADARG); + ARGCHK(!((k1 == NULL) && ((k2 == NULL) || (px == NULL) || (py == NULL))), MP_BADARG); + + /* if some arguments are not defined used ECPoint_mul */ + if (k1 == NULL) { + return ECPoint_mul(group, k2, px, py, rx, ry); + } else if ((k2 == NULL) || (px == NULL) || (py == NULL)) { + return ECPoint_mul(group, k1, NULL, NULL, rx, ry); + } + + /* initialize precomputation table */ + for (i = 0; i < 4; i++) { + for (j = 0; j < 4; j++) { + MP_DIGITS(&precomp[i][j][0]) = 0; + MP_DIGITS(&precomp[i][j][1]) = 0; + } + } + for (i = 0; i < 4; i++) { + for (j = 0; j < 4; j++) { + MP_CHECKOK(mp_init_size(&precomp[i][j][0], + ECL_MAX_FIELD_SIZE_DIGITS)); + MP_CHECKOK(mp_init_size(&precomp[i][j][1], + ECL_MAX_FIELD_SIZE_DIGITS)); + } + } + + /* fill precomputation table */ + /* assign {k1, k2} = {a, b} such that len(a) >= len(b) */ + if (mpl_significant_bits(k1) < mpl_significant_bits(k2)) { + a = k2; + b = k1; + if (group->meth->field_enc) { + MP_CHECKOK(group->meth->field_enc(px, &precomp[1][0][0], group->meth)); + MP_CHECKOK(group->meth->field_enc(py, &precomp[1][0][1], group->meth)); + } else { + MP_CHECKOK(mp_copy(px, &precomp[1][0][0])); + MP_CHECKOK(mp_copy(py, &precomp[1][0][1])); + } + MP_CHECKOK(mp_copy(&group->genx, &precomp[0][1][0])); + MP_CHECKOK(mp_copy(&group->geny, &precomp[0][1][1])); + } else { + a = k1; + b = k2; + MP_CHECKOK(mp_copy(&group->genx, &precomp[1][0][0])); + MP_CHECKOK(mp_copy(&group->geny, &precomp[1][0][1])); + if (group->meth->field_enc) { + MP_CHECKOK(group->meth->field_enc(px, &precomp[0][1][0], group->meth)); + MP_CHECKOK(group->meth->field_enc(py, &precomp[0][1][1], group->meth)); + } else { + MP_CHECKOK(mp_copy(px, &precomp[0][1][0])); + MP_CHECKOK(mp_copy(py, &precomp[0][1][1])); + } + } + /* precompute [*][0][*] */ + mp_zero(&precomp[0][0][0]); + mp_zero(&precomp[0][0][1]); + MP_CHECKOK(group->point_dbl(&precomp[1][0][0], &precomp[1][0][1], + &precomp[2][0][0], &precomp[2][0][1], group)); + MP_CHECKOK(group->point_add(&precomp[1][0][0], &precomp[1][0][1], + &precomp[2][0][0], &precomp[2][0][1], + &precomp[3][0][0], &precomp[3][0][1], group)); + /* precompute [*][1][*] */ + for (i = 1; i < 4; i++) { + MP_CHECKOK(group->point_add(&precomp[0][1][0], &precomp[0][1][1], + &precomp[i][0][0], &precomp[i][0][1], + &precomp[i][1][0], &precomp[i][1][1], group)); + } + /* precompute [*][2][*] */ + MP_CHECKOK(group->point_dbl(&precomp[0][1][0], &precomp[0][1][1], + &precomp[0][2][0], &precomp[0][2][1], group)); + for (i = 1; i < 4; i++) { + MP_CHECKOK(group->point_add(&precomp[0][2][0], &precomp[0][2][1], + &precomp[i][0][0], &precomp[i][0][1], + &precomp[i][2][0], &precomp[i][2][1], group)); + } + /* precompute [*][3][*] */ + MP_CHECKOK(group->point_add(&precomp[0][1][0], &precomp[0][1][1], + &precomp[0][2][0], &precomp[0][2][1], + &precomp[0][3][0], &precomp[0][3][1], group)); + for (i = 1; i < 4; i++) { + MP_CHECKOK(group->point_add(&precomp[0][3][0], &precomp[0][3][1], + &precomp[i][0][0], &precomp[i][0][1], + &precomp[i][3][0], &precomp[i][3][1], group)); + } + + d = (mpl_significant_bits(a) + 1) / 2; + + /* R = inf */ + mp_zero(rx); + mp_zero(ry); + + for (i = d; i-- > 0;) { + ai = MP_GET_BIT(a, 2 * i + 1); + ai <<= 1; + ai |= MP_GET_BIT(a, 2 * i); + bi = MP_GET_BIT(b, 2 * i + 1); + bi <<= 1; + bi |= MP_GET_BIT(b, 2 * i); + /* R = 2^2 * R */ + MP_CHECKOK(group->point_dbl(rx, ry, rx, ry, group)); + MP_CHECKOK(group->point_dbl(rx, ry, rx, ry, group)); + /* R = R + (ai * A + bi * B) */ + MP_CHECKOK(group->point_add(rx, ry, &precomp[ai][bi][0], + &precomp[ai][bi][1], rx, ry, group)); + } + + if (group->meth->field_dec) { + MP_CHECKOK(group->meth->field_dec(rx, rx, group->meth)); + MP_CHECKOK(group->meth->field_dec(ry, ry, group->meth)); + } + +CLEANUP: + for (i = 0; i < 4; i++) { + for (j = 0; j < 4; j++) { + mp_clear(&precomp[i][j][0]); + mp_clear(&precomp[i][j][1]); + } + } + return res; +} + +/* Elliptic curve scalar-point multiplication. Computes R(x, y) = k1 * G + + * k2 * P(x, y), where G is the generator (base point) of the group of + * points on the elliptic curve. Allows k1 = NULL or { k2, P } = NULL. + * Input and output values are assumed to be NOT field-encoded. */ +mp_err +ECPoints_mul(const ECGroup *group, const mp_int *k1, const mp_int *k2, + const mp_int *px, const mp_int *py, mp_int *rx, mp_int *ry) +{ + mp_err res = MP_OKAY; + mp_int k1t, k2t; + const mp_int *k1p, *k2p; + + MP_DIGITS(&k1t) = 0; + MP_DIGITS(&k2t) = 0; + + ARGCHK(group != NULL, MP_BADARG); + + /* want scalar to be less than or equal to group order */ + if (k1 != NULL) { + if (mp_cmp(k1, &group->order) >= 0) { + MP_CHECKOK(mp_init(&k1t)); + MP_CHECKOK(mp_mod(k1, &group->order, &k1t)); + k1p = &k1t; + } else { + k1p = k1; + } + } else { + k1p = k1; + } + if (k2 != NULL) { + if (mp_cmp(k2, &group->order) >= 0) { + MP_CHECKOK(mp_init(&k2t)); + MP_CHECKOK(mp_mod(k2, &group->order, &k2t)); + k2p = &k2t; + } else { + k2p = k2; + } + } else { + k2p = k2; + } + + /* if points_mul is defined, then use it */ + if (group->points_mul) { + res = group->points_mul(k1p, k2p, px, py, rx, ry, group); + } else { + res = ec_pts_mul_simul_w2(k1p, k2p, px, py, rx, ry, group); + } + +CLEANUP: + mp_clear(&k1t); + mp_clear(&k2t); + return res; +} |