From dac2e8c79e670b81f5a80edbf93307df01c88c47 Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Thu, 26 Nov 2015 09:48:06 -0500
Subject: [PATCH] use left sift instead multipilication by 2
---
Signature.cpp | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)
diff --git a/Signature.cpp b/Signature.cpp
index 13151508..30c81a94 100644
--- a/Signature.cpp
+++ b/Signature.cpp
@@ -13,19 +13,16 @@ namespace crypto
Ed25519 ()
{
BN_CTX * ctx = BN_CTX_new ();
- BIGNUM * two = BN_new (), * tmp = BN_new ();
- BN_set_word (two, 2);
+ BIGNUM * tmp = BN_new ();
q = BN_new ();
// 2^255-19
- BN_set_word (tmp, 255);
- BN_exp (q, two, tmp, ctx);
+ BN_set_bit (q, 255); // 2^255
BN_sub_word (q, 19);
l = BN_new ();
// 2^252 + 27742317777372353535851937790883648493
- BN_set_word (tmp, 252);
- BN_exp (l, two, tmp, ctx);
+ BN_set_bit (l, 252);
two_252_2 = BN_dup (l);
BN_dec2bn (&tmp, "27742317777372353535851937790883648493");
BN_add (l, l, tmp);
@@ -45,9 +42,8 @@ namespace crypto
tmp = BN_dup (q);
BN_sub_word (tmp, 1);
BN_div_word (tmp, 4);
- BN_mod_exp (I, two, tmp, q, ctx);
-
- BN_free (two);
+ BN_set_word (I, 2);
+ BN_mod_exp (I, I, tmp, q, ctx);
BN_free (tmp);
// 4*inv(5)
@@ -208,7 +204,7 @@ namespace crypto
BIGNUM * E = BN_new (), * F = BN_new (), * G = BN_new (), * H = BN_new ();
// E = (x+y)*(x+y)-A-B = x^2+y^2+2xy-A-B = 2xy
BN_mul (E, p.x, p.y, ctx);
- BN_mul_word (E, 2); // E =2*x*y
+ BN_lshift1 (E, E); // E =2*x*y
BN_sub (F, z2, t2); // F = D - C
BN_add (G, z2, t2); // G = D + C
BN_add (H, y2, x2); // H = B + A
@@ -387,7 +383,7 @@ namespace crypto
// Bi16[0][0] = B, base point
};
- static std::unique_ptr<Ed25519> g_Ed25519;
+ static thread_local std::unique_ptr<Ed25519> g_Ed25519;
std::unique_ptr<Ed25519>& GetEd25519 ()
{
if (!g_Ed25519)