diff options
Diffstat (limited to 'src/crypto/fipsmodule/ec/ec_montgomery.c')
| -rw-r--r-- | src/crypto/fipsmodule/ec/ec_montgomery.c | 36 |
1 files changed, 18 insertions, 18 deletions
diff --git a/src/crypto/fipsmodule/ec/ec_montgomery.c b/src/crypto/fipsmodule/ec/ec_montgomery.c index c2afe257..c5f240bf 100644 --- a/src/crypto/fipsmodule/ec/ec_montgomery.c +++ b/src/crypto/fipsmodule/ec/ec_montgomery.c @@ -219,7 +219,7 @@ static int ec_GFp_mont_point_get_affine_coordinates(const EC_GROUP *group, BN_CTX_start(ctx); if (BN_cmp(&point->Z, &group->one) == 0) { - /* |point| is already affine. */ + // |point| is already affine. if (x != NULL && !BN_from_montgomery(x, &point->X, group->mont, ctx)) { goto err; } @@ -227,7 +227,7 @@ static int ec_GFp_mont_point_get_affine_coordinates(const EC_GROUP *group, goto err; } } else { - /* transform (X, Y, Z) into (x, y) := (X/Z^2, Y/Z^3) */ + // transform (X, Y, Z) into (x, y) := (X/Z^2, Y/Z^3) BIGNUM *Z_1 = BN_CTX_get(ctx); BIGNUM *Z_2 = BN_CTX_get(ctx); @@ -238,18 +238,18 @@ static int ec_GFp_mont_point_get_affine_coordinates(const EC_GROUP *group, goto err; } - /* The straightforward way to calculate the inverse of a Montgomery-encoded - * value where the result is Montgomery-encoded is: - * - * |BN_from_montgomery| + invert + |BN_to_montgomery|. - * - * This is equivalent, but more efficient, because |BN_from_montgomery| - * is more efficient (at least in theory) than |BN_to_montgomery|, since it - * doesn't have to do the multiplication before the reduction. - * - * Use Fermat's Little Theorem instead of |BN_mod_inverse_odd| since this - * inversion may be done as the final step of private key operations. - * Unfortunately, this is suboptimal for ECDSA verification. */ + // The straightforward way to calculate the inverse of a Montgomery-encoded + // value where the result is Montgomery-encoded is: + // + // |BN_from_montgomery| + invert + |BN_to_montgomery|. + // + // This is equivalent, but more efficient, because |BN_from_montgomery| + // is more efficient (at least in theory) than |BN_to_montgomery|, since it + // doesn't have to do the multiplication before the reduction. + // + // Use Fermat's Little Theorem instead of |BN_mod_inverse_odd| since this + // inversion may be done as the final step of private key operations. + // Unfortunately, this is suboptimal for ECDSA verification. if (!BN_from_montgomery(Z_1, &point->Z, group->mont, ctx) || !BN_from_montgomery(Z_1, Z_1, group->mont, ctx) || !bn_mod_inverse_prime(Z_1, Z_1, &group->field, ctx, group->mont)) { @@ -260,10 +260,10 @@ static int ec_GFp_mont_point_get_affine_coordinates(const EC_GROUP *group, goto err; } - /* Instead of using |BN_from_montgomery| to convert the |x| coordinate - * and then calling |BN_from_montgomery| again to convert the |y| - * coordinate below, convert the common factor |Z_2| once now, saving one - * reduction. */ + // Instead of using |BN_from_montgomery| to convert the |x| coordinate + // and then calling |BN_from_montgomery| again to convert the |y| + // coordinate below, convert the common factor |Z_2| once now, saving one + // reduction. if (!BN_from_montgomery(Z_2, Z_2, group->mont, ctx)) { goto err; } |