cleanup

mysqljs · Sep 2, 2010 · 45a240a · 45a240a
1 parent 7c06248
commit 45a240a
Showing 1 changed file with 15 additions and 57 deletions.
diff --git a/lib/mysql/auth.js b/lib/mysql/auth.js
@@ -50,19 +50,7 @@ exports.hashPassword = function(password) {
 
 		// nr^= (((nr & 63)+add)*c)+ (nr << 8);
 		// nr = xor(nr, add(mul(add(and(nr, 63), add), c), shl(nr, 8)))
-		nr = this.xor32(
-			nr,
-			this.add32(
-				this.mul32(
-					this.add32(
-						this.and32(nr, [0,63]),
-						[0,add]
-					),
-					[0,c]
-				),
-				this.shl32(nr, 8)
-			)
-		);
+		nr = this.xor32(nr, this.add32(this.mul32(this.add32(this.and32(nr, [0,63]), [0,add]), [0,c]), this.shl32(nr, 8)));
 
 		// nr2+=(nr2 << 8) ^ nr;
 		// nr2 = add(nr2, xor(shl(nr2, 8), nr))
@@ -72,8 +60,8 @@ exports.hashPassword = function(password) {
 		add += c;
 	}
 
-	this.int32Write2(result, nr, 0);
-	this.int32Write2(result, nr2, 4);
+	this.int31Write(result, nr, 0);
+	this.int31Write(result, nr2, 4);
 
 	return result;
 }
@@ -96,34 +84,17 @@ exports.xor32 = function(a,b){
 }
 
 exports.add32 = function(a,b){
-
-	var low = a[1] + b[1];
-	var rem = (low & 0xFFFF0000) >> 16;
-	var high = a[0] + b[0] + rem;
-
-	return [high & 0xFFFF, low & 0xFFFF];
+	var w1 = a[1] + b[1];
+	var w2 = a[0] + b[0] + ((w1 & 0xFFFF0000) >> 16);
+	return [w2 & 0xFFFF, w1 & 0xFFFF];
 }
 
 exports.mul32 = function(a,b){
-
-	var x = a[1] * b[1];
-	var y = a[0] * b[1];
-	var z = a[1] * b[0];
-	var w = a[0] * b[0];
-
-	var col1 = x & 0xFFFF;
-	var col2 = ((x >> 16) & 0xFFFF) + (y & 0xFFFF) + (z & 0xFFFF);
-	var col3 = ((y >> 16) & 0xFFFF) + ((z >> 16) & 0xFFFF) + (w & 0xFFFF);
-	var col4 = ((w >> 16) & 0xFFFF);
-
-	var w1 = col1;
-	var w2 = col2 & 0xFFFF;
-	var col2_over = ((col2 >> 16) & 0xFFFF);
-	var w3 = (col3 + col2_over) & 0xFFFF;
-	var col3_over = ((w3 >> 16) & 0xFFFF);
-	var w4 = (col4 + col3_over) & 0xFFFF;
-
-	return [w2, w1];
+	// based on this example of multiplying 32b ints using 16b
+	// http://www.dsprelated.com/showmessage/89790/1.php
+	var w1 = a[1] * b[1];
+	var w2 = (((a[1] * b[1]) >> 16) & 0xFFFF) + ((a[0] * b[1]) & 0xFFFF) + (a[1] * b[0] & 0xFFFF);
+	return [w2 & 0xFFFF, w1 & 0xFFFF];
 }
 
 exports.and32 = function(a,b){
@@ -132,22 +103,9 @@ exports.and32 = function(a,b){
 
 exports.shl32 = function(a,b){
 	// assume b is 16 or less
-	var low = a[1] << b;
-	var rem = (low & 0xFFFF0000) >> 16;
-	var high = (a[0] << b) | rem;
-
-	return [high & 0xFFFF, low & 0xFFFF];
-}
-
-
-
-// Provided by Herbert Vojčík, needed to deal with float point precision problems in JS
-exports.multiply = function(a, b) {
-  var a1 = a >>> 16,
-      a2 = a & 0xffff;
-  // Precondition: b is in 32bit range
-
-  return ((a1 * b << 16) + a2 * b) >>> 0;
+	var w1 = a[1] << b;
+	var w2 = (a[0] << b) | ((w1 & 0xFFFF0000) >> 16);
+	return [w2 & 0xFFFF, w1 & 0xFFFF];
 }
 
 exports.int32Write = function(buffer, number, offset) {
@@ -161,7 +119,7 @@ exports.int32Write = function(buffer, number, offset) {
   buffer[offset + 3] = Math.floor(unsigned);
 };
 
-exports.int32Write2 = function(buffer, number, offset) {
+exports.int31Write = function(buffer, number, offset) {
 	buffer[offset] = (number[0] >> 8) & 0x7F;
 	buffer[offset+1] = (number[0]) & 0xFF;
 	buffer[offset+2] = (number[1] >> 8) & 0xFF;