From 6d7602ddfa39ec0e798323a759827ef0f0a3d5fb Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Tue, 31 May 2016 22:58:32 -0700
Subject: [PATCH] optimize scrypt more.

---
 lib/bcoin/scrypt.js | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/lib/bcoin/scrypt.js b/lib/bcoin/scrypt.js
index 05c783c4..1abe529c 100644
--- a/lib/bcoin/scrypt.js
+++ b/lib/bcoin/scrypt.js
@@ -70,7 +70,7 @@ function scrypt(passwd, salt, N, r, p, len) {
   B = utils.pbkdf2(passwd, salt, 1, p * 128 * r, 'sha256');
 
   for (i = 0; i < p; i++)
-    smix(B.slice(i * 128 * r), r, N, V, XY);
+    smix(B, i * 128 * r, r, N, V, XY);
 
   return utils.pbkdf2(passwd, B, 1, len, 'sha256');
 }
@@ -139,7 +139,7 @@ function R(a, b) {
   return (a << b) | (a >>> (32 - b));
 }
 
-function blockmix_salsa8(B, Y, r) {
+function blockmix_salsa8(B, Y, Yo, r) {
   var X = new Buffer(64);
   var i;
 
@@ -148,40 +148,40 @@ function blockmix_salsa8(B, Y, r) {
   for (i = 0; i < 2 * r; i++) {
     blkxor(X, B, 0, i * 64, 64);
     salsa20_8(X);
-    blkcpy(Y, X, i * 64, 0, 64);
+    blkcpy(Y, X, Yo + i * 64, 0, 64);
   }
 
   for (i = 0; i < r; i++)
-    blkcpy(B, Y, i * 64, (i * 2) * 64, 64);
+    blkcpy(B, Y, i * 64, Yo + (i * 2) * 64, 64);
 
   for (i = 0; i < r; i++)
-    blkcpy(B, Y, (i + r) * 64, (i * 2 + 1) * 64, 64);
+    blkcpy(B, Y, (i + r) * 64, Yo + (i * 2 + 1) * 64, 64);
 }
 
 function integerify(B, r) {
   return B.readUInt32LE((2 * r - 1) * 64, true);
 }
 
-function smix(B, r, N, V, XY) {
+function smix(B, Bo, r, N, V, XY) {
   var X = XY;
-  var Y = XY.slice(128 * r);
+  var Y = XY;
   var i;
   var j;
 
-  blkcpy(X, B, 0, 0, 128 * r);
+  blkcpy(X, B, 0, Bo, 128 * r);
 
   for (i = 0; i < N; i++) {
     blkcpy(V, X, i * (128 * r), 0, 128 * r);
-    blockmix_salsa8(X, Y, r);
+    blockmix_salsa8(X, Y, 128 * r, r);
   }
 
   for (i = 0; i < N; i++) {
     j = integerify(X, r) & (N - 1);
     blkxor(X, V, 0, j * (128 * r), 128 * r);
-    blockmix_salsa8(X, Y, r);
+    blockmix_salsa8(X, Y, 128 * r, r);
   }
 
-  blkcpy(B, X, 0, 0, 128 * r);
+  blkcpy(B, X, Bo, 0, 128 * r);
 }
 
 function blkcpy(dest, src, s1, s2, len) {