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authorAndy Polyakov <appro@openssl.org>2015-01-21 17:28:45 +0100
committerMatt Caswell <matt@openssl.org>2015-01-22 09:28:26 +0000
commit319d5c7a586a5695589494e16cb3dd5f82d753ca (patch)
tree4f7495a0e7d8029d63083db12aee8f43432b7a75
parent3807db9d91d07fd11432325cdf3c51a0c901f0b6 (diff)
ec/ecp_nistz256.c: further harmonization with latest rules.
Conflicts: crypto/ec/ecp_nistz256.c Reviewed-by: Tim Hudson <tjh@openssl.org>
-rw-r--r--crypto/ec/ecp_nistz256.c100
1 files changed, 63 insertions, 37 deletions
diff --git a/crypto/ec/ecp_nistz256.c b/crypto/ec/ecp_nistz256.c
index d8c0dae1ae..2cd6599d85 100644
--- a/crypto/ec/ecp_nistz256.c
+++ b/crypto/ec/ecp_nistz256.c
@@ -71,9 +71,11 @@ typedef P256_POINT_AFFINE PRECOMP256_ROW[64];
typedef struct ec_pre_comp_st {
const EC_GROUP *group; /* Parent EC_GROUP object */
size_t w; /* Window size */
- /* Constant time access to the X and Y coordinates of the pre-computed,
+ /*
+ * Constant time access to the X and Y coordinates of the pre-computed,
* generator multiplies, in the Montgomery domain. Pre-calculated
- * multiplies are stored in affine form. */
+ * multiplies are stored in affine form.
+ */
PRECOMP256_ROW *precomp;
void *precomp_storage;
int references;
@@ -89,15 +91,15 @@ void ecp_nistz256_div_by_2(BN_ULONG res[P256_LIMBS],
/* Modular mul by 3: res = 3*a mod P */
void ecp_nistz256_mul_by_3(BN_ULONG res[P256_LIMBS],
const BN_ULONG a[P256_LIMBS]);
-/* Modular add: res = a+b mod P */
+/* Modular add: res = a+b mod P */
void ecp_nistz256_add(BN_ULONG res[P256_LIMBS],
const BN_ULONG a[P256_LIMBS],
const BN_ULONG b[P256_LIMBS]);
-/* Modular sub: res = a-b mod P */
+/* Modular sub: res = a-b mod P */
void ecp_nistz256_sub(BN_ULONG res[P256_LIMBS],
const BN_ULONG a[P256_LIMBS],
const BN_ULONG b[P256_LIMBS]);
-/* Modular neg: res = -a mod P */
+/* Modular neg: res = -a mod P */
void ecp_nistz256_neg(BN_ULONG res[P256_LIMBS], const BN_ULONG a[P256_LIMBS]);
/* Montgomery mul: res = a*b*2^-256 mod P */
void ecp_nistz256_mul_mont(BN_ULONG res[P256_LIMBS],
@@ -275,8 +277,8 @@ static void ecp_nistz256_point_double(P256_POINT *r, const P256_POINT *a)
}
/* Point addition: r = a+b */
-static void ecp_nistz256_point_add(P256_POINT * r,
- const P256_POINT * a, const P256_POINT * b)
+static void ecp_nistz256_point_add(P256_POINT *r,
+ const P256_POINT *a, const P256_POINT *b)
{
BN_ULONG U2[P256_LIMBS], S2[P256_LIMBS];
BN_ULONG U1[P256_LIMBS], S1[P256_LIMBS];
@@ -332,8 +334,9 @@ static void ecp_nistz256_point_add(P256_POINT * r,
ecp_nistz256_mul_mont(U2, in2_x, Z1sqr); /* U2 = X2*Z1^2 */
ecp_nistz256_sub(H, U2, U1); /* H = U2 - U1 */
- /* This should not happen during sign/ecdh,
- * so no constant time violation */
+ /*
+ * This should not happen during sign/ecdh, so no constant time violation
+ */
if (is_equal(U1, U2) && !in1infty && !in2infty) {
if (is_equal(S1, S2)) {
ecp_nistz256_point_double(r, a);
@@ -400,8 +403,10 @@ static void ecp_nistz256_point_add_affine(P256_POINT *r,
const BN_ULONG *in2_x = b->X;
const BN_ULONG *in2_y = b->Y;
- /* In affine representation we encode infty as (0,0),
- * which is not on the curve, so it is OK */
+ /*
+ * In affine representation we encode infty as (0,0), which is not on the
+ * curve, so it is OK
+ */
in1infty = (in1_x[0] | in1_x[1] | in1_x[2] | in1_x[3] |
in1_y[0] | in1_y[1] | in1_y[2] | in1_y[3]);
if (P256_LIMBS == 8)
@@ -463,8 +468,10 @@ static void ecp_nistz256_point_add_affine(P256_POINT *r,
static void ecp_nistz256_mod_inverse(BN_ULONG r[P256_LIMBS],
const BN_ULONG in[P256_LIMBS])
{
- /* The poly is ffffffff 00000001 00000000 00000000 00000000 ffffffff ffffffff ffffffff
- We use FLT and used poly-2 as exponent */
+ /*
+ * The poly is ffffffff 00000001 00000000 00000000 00000000 ffffffff
+ * ffffffff ffffffff We use FLT and used poly-2 as exponent
+ */
BN_ULONG p2[P256_LIMBS];
BN_ULONG p4[P256_LIMBS];
BN_ULONG p8[P256_LIMBS];
@@ -534,10 +541,12 @@ static void ecp_nistz256_mod_inverse(BN_ULONG r[P256_LIMBS],
memcpy(r, res, sizeof(res));
}
-/* ecp_nistz256_bignum_to_field_elem copies the contents of |in| to |out| and
- * returns one if it fits. Otherwise it returns zero. */
+/*
+ * ecp_nistz256_bignum_to_field_elem copies the contents of |in| to |out| and
+ * returns one if it fits. Otherwise it returns zero.
+ */
static int ecp_nistz256_bignum_to_field_elem(BN_ULONG out[P256_LIMBS],
- const BIGNUM * in)
+ const BIGNUM *in)
{
if (in->top > P256_LIMBS)
return 0;
@@ -563,7 +572,7 @@ static void ecp_nistz256_windowed_mul(const EC_GROUP *group,
BN_ULONG tmp[P256_LIMBS];
ALIGN32 P256_POINT h;
const BIGNUM **scalars = NULL;
- P256_POINT(*table)[16] = NULL;
+ P256_POINT (*table)[16] = NULL;
void *table_storage = NULL;
if ((table_storage =
@@ -708,8 +717,10 @@ const static BN_ULONG def_yG[P256_LIMBS] = {
TOBN(0xd2e88688, 0xdd21f325), TOBN(0x8571ff18, 0x25885d85)
};
-/* ecp_nistz256_is_affine_G returns one if |generator| is the standard,
- * P-256 generator. */
+/*
+ * ecp_nistz256_is_affine_G returns one if |generator| is the standard, P-256
+ * generator.
+ */
static int ecp_nistz256_is_affine_G(const EC_POINT *generator)
{
return (generator->X.top == P256_LIMBS) &&
@@ -721,10 +732,12 @@ static int ecp_nistz256_is_affine_G(const EC_POINT *generator)
static int ecp_nistz256_mult_precompute(EC_GROUP *group, BN_CTX *ctx)
{
- /* We precompute a table for a Booth encoded exponent (wNAF) based
+ /*
+ * We precompute a table for a Booth encoded exponent (wNAF) based
* computation. Each table holds 64 values for safe access, with an
- * implicit value of infinity at index zero. We use window of size 7,
- * and therefore require ceil(256/7) = 37 tables. */
+ * implicit value of infinity at index zero. We use window of size 7, and
+ * therefore require ceil(256/7) = 37 tables.
+ */
BIGNUM *order;
EC_POINT *P = NULL, *T = NULL;
const EC_POINT *generator;
@@ -747,8 +760,10 @@ static int ecp_nistz256_mult_precompute(EC_GROUP *group, BN_CTX *ctx)
}
if (ecp_nistz256_is_affine_G(generator)) {
- /* No need to calculate tables for the standard generator
- * because we have them statically. */
+ /*
+ * No need to calculate tables for the standard generator because we
+ * have them statically.
+ */
return 1;
}
@@ -788,16 +803,20 @@ static int ecp_nistz256_mult_precompute(EC_GROUP *group, BN_CTX *ctx)
P = EC_POINT_new(group);
T = EC_POINT_new(group);
- /* The zero entry is implicitly infinity, and we skip it,
- * storing other values with -1 offset. */
+ /*
+ * The zero entry is implicitly infinity, and we skip it, storing other
+ * values with -1 offset.
+ */
EC_POINT_copy(T, generator);
for (k = 0; k < 64; k++) {
EC_POINT_copy(P, T);
for (j = 0; j < 37; j++) {
- /* It would be faster to use
+ /*
+ * It would be faster to use
* ec_GFp_simple_points_make_affine and make multiple
- * points affine at the same time. */
+ * points affine at the same time.
+ */
ec_GFp_simple_make_affine(group, P, ctx);
ecp_nistz256_bignum_to_field_elem(preComputedTable[j]
[k].X, &P->X);
@@ -886,9 +905,11 @@ static void booth_recode_w7(unsigned char *sign,
*digit = d;
}
-/* ecp_nistz256_avx2_mul_g performs multiplication by G, using only the
+/*
+ * ecp_nistz256_avx2_mul_g performs multiplication by G, using only the
* precomputed table. It does 4 affine point additions in parallel,
- * significantly speeding up point multiplication for a fixed value. */
+ * significantly speeding up point multiplication for a fixed value.
+ */
static void ecp_nistz256_avx2_mul_g(P256_POINT *r,
unsigned char p_str[33],
const P256_POINT_AFFINE(*preComputedTable)[64])
@@ -1126,9 +1147,10 @@ static int ecp_nistz256_points_mul(const EC_GROUP *group,
ecp_nistz256_pre_comp_clear_free);
if (pre_comp) {
- /* If there is a precomputed table for the generator,
- * check that it was generated with the same
- * generator. */
+ /*
+ * If there is a precomputed table for the generator, check that
+ * it was generated with the same generator.
+ */
EC_POINT *pre_comp_generator = EC_POINT_new(group);
if (pre_comp_generator == NULL)
goto err;
@@ -1144,10 +1166,12 @@ static int ecp_nistz256_points_mul(const EC_GROUP *group,
}
if (preComputedTable == NULL && ecp_nistz256_is_affine_G(generator)) {
- /* If there is no precomputed data, but the generator
+ /*
+ * If there is no precomputed data, but the generator
* is the default, a hardcoded table of precomputed
* data is used. This is because applications, such as
- * Apache, do not use EC_KEY_precompute_mult. */
+ * Apache, do not use EC_KEY_precompute_mult.
+ */
preComputedTable = (const PRECOMP256_ROW *)ecp_nistz256_precomputed;
}
@@ -1227,8 +1251,10 @@ static int ecp_nistz256_points_mul(const EC_GROUP *group,
p_is_infinity = 1;
if (no_precomp_for_generator) {
- /* Without a precomputed table for the generator, it has to be
- * handled like a normal point. */
+ /*
+ * Without a precomputed table for the generator, it has to be
+ * handled like a normal point.
+ */
const BIGNUM **new_scalars;
const EC_POINT **new_points;