[Pkg-javascript-commits] [node-browserify-aes] 21/43: aes: add doReset algorithm readability for INV_SUB_MIX

[Bastien Roucariès]

This is an automated email from the git hooks/post-receive script.

rouca pushed a commit to branch master
in repository node-browserify-aes.

commit 4c48bddcdc7df49e130c8f324720d73eebb32779
Author: Daniel Cousens <github at dcousens.com>
Date:   Fri May 19 12:53:35 2017 +1000

    aes: add doReset algorithm readability for INV_SUB_MIX
---
 aes.js | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/aes.js b/aes.js
index 576cdb4..6d4b214 100644
--- a/aes.js
+++ b/aes.js
@@ -92,7 +92,7 @@ function AES (key) {
 }
 
 AES.prototype._doReset = function () {
-  var invKsRow, keySize, keyWords, ksRow, ksRows, t
+  var keySize, keyWords, ksRow, ksRows, t
   keyWords = this._key
   keySize = keyWords.length
   this._nRounds = keySize + 6
@@ -101,12 +101,24 @@ AES.prototype._doReset = function () {
   for (ksRow = 0; ksRow < ksRows; ksRow++) {
     this._keySchedule[ksRow] = ksRow < keySize ? keyWords[ksRow] : (t = this._keySchedule[ksRow - 1], (ksRow % keySize) === 0 ? (t = (t << 8) | (t >>> 24), t = (G.SBOX[t >>> 24] << 24) | (G.SBOX[(t >>> 16) & 0xff] << 16) | (G.SBOX[(t >>> 8) & 0xff] << 8) | G.SBOX[t & 0xff], t ^= G.RCON[(ksRow / keySize) | 0] << 24) : keySize > 6 && ksRow % keySize === 4 ? t = (G.SBOX[t >>> 24] << 24) | (G.SBOX[(t >>> 16) & 0xff] << 16) | (G.SBOX[(t >>> 8) & 0xff] << 8) | G.SBOX[t & 0xff] : void 0, this._ [...]
   }
-  this._invKeySchedule = []
-  for (invKsRow = 0; invKsRow < ksRows; invKsRow++) {
-    ksRow = ksRows - invKsRow
-    t = this._keySchedule[ksRow - (invKsRow % 4 ? 0 : 4)]
-    this._invKeySchedule[invKsRow] = invKsRow < 4 || ksRow <= 4 ? t : G.INV_SUB_MIX[0][G.SBOX[t >>> 24]] ^ G.INV_SUB_MIX[1][G.SBOX[(t >>> 16) & 0xff]] ^ G.INV_SUB_MIX[2][G.SBOX[(t >>> 8) & 0xff]] ^ G.INV_SUB_MIX[3][G.SBOX[t & 0xff]]
+
+  var invKeySchedule = []
+  for (var ik = 0; ik < ksRows; ik++) {
+    var ksR = ksRows - ik
+    var tt = this._keySchedule[ksR - (ik % 4 ? 0 : 4)]
+
+    if (ik < 4 || ksR <= 4) {
+      invKeySchedule[ik] = tt
+    } else {
+      invKeySchedule[ik] =
+        G.INV_SUB_MIX[0][G.SBOX[tt >>> 24]] ^
+        G.INV_SUB_MIX[1][G.SBOX[(tt >>> 16) & 0xff]] ^
+        G.INV_SUB_MIX[2][G.SBOX[(tt >>> 8) & 0xff]] ^
+        G.INV_SUB_MIX[3][G.SBOX[tt & 0xff]]
+    }
   }
+
+  this._invKeySchedule = invKeySchedule
   return true
 }
 

-- 
Alioth's /usr/local/bin/git-commit-notice on /srv/git.debian.org/git/pkg-javascript/node-browserify-aes.git