Merge pull request #81 from frzsombor/token-patch-1

Token generation fixes, cleanup, and making things more clear

Author: Stichoza

src/Stichoza/GoogleTranslate/Tokens/GoogleTokenGenerator.php

@@ -50,8 +50,8 @@ private function TL($a)
                         $d[$e++] = $g >> 12 & 63 | 128;
                     } else {
                         $d[$e++] = $g >> 12 | 224;
-                        $d[$e++] = $g >> 6 & 63 | 128;
                     }
+                    $d[$e++] = $g >> 6 & 63 | 128;
                 }
                 $d[$e++] = $g & 63 | 128;
             }
@@ -62,7 +62,7 @@ private function TL($a)
             $a = $this->RL($a, '+-a^+6');
         }
         $a = $this->RL($a, '+-3^+b+-f');
-        $a ^= $tkk[1];
+        $a ^= $tkk[1] ? $tkk[1] + 0 : 0;
         if (0 > $a) {
             $a = ($a & 2147483647) + 2147483648;
         }
@@ -81,51 +81,60 @@ private function TKK()
 
     /**
      * Process token data by applying multiple operations.
+     * (Params are safe, no need for multibyte functions)
      *
-     * @param $a
-     * @param $b
+     * @param int $a
+     * @param string $b
      *
      * @return int
      */
     private function RL($a, $b)
     {
         for ($c = 0; $c < strlen($b) - 2; $c += 3) {
-            $d = $b{$c + 2};
-            $d = $d >= 'a' ? $this->charCodeAt($d, 0) - 87 : intval($d);
-            $d = $b{$c + 1}
-            == '+' ? $this->shr32($a, $d) : $a << $d;
-            $a = $b{$c}
-            == '+' ? ($a + $d & 4294967295) : $a ^ $d;
+            $d = $b[$c + 2];
+            $d = 'a' <= $d ? ord($d[0]) - 87 : intval($d);
+            $d = '+' == $b[$c + 1] ? $this->unsignedRightShift($a, $d) : $a << $d;
+            $a = '+' == $b[$c] ? ($a + $d & 4294967295) : $a ^ $d;
         }
 
         return $a;
     }
 
     /**
-     * Crypto function.
+     * Unsigned right shift implementation
+     * https://msdn.microsoft.com/en-us/library/342xfs5s(v=vs.94).aspx
+     * http://stackoverflow.com/a/43359819/2953830
      *
-     * @param $x
-     * @param $bits
+     * @param $a
+     * @param $b
      *
      * @return number
      */
-    private function shr32($x, $bits)
+    private function unsignedRightShift($a, $b)
     {
-        if ($bits <= 0) {
-            return $x;
+        if ($b >= 32 || $b < -32) {
+            $m = (int)($b / 32);
+            $b = $b - ($m * 32);
         }
-        if ($bits >= 32) {
-            return 0;
+
+        if ($b < 0) {
+            $b = 32 + $b;
         }
-        $bin = decbin($x);
-        $l = strlen($bin);
-        if ($l > 32) {
-            $bin = substr($bin, $l - 32, 32);
-        } elseif ($l < 32) {
-            $bin = str_pad($bin, 32, '0', STR_PAD_LEFT);
+
+        if ($b == 0) {
+            return (($a >> 1) & 0x7fffffff) * 2 + (($a >> $b) & 1);
+        }
+
+        if ($a < 0) {
+            $a = ($a >> 1);
+            $a &= 2147483647;
+            $a |= 0x40000000;
+            $a = ($a >> ($b - 1));
+        } else { 
+            $a = ($a >> $b);
         }
 
-        return bindec(str_pad(substr($bin, 0, 32 - $bits), 32, '0', STR_PAD_LEFT));
+        return $a;
     }
 
     /**