another pass at constant time comparison.

neverdup · May 5, 2019 · 8696331 · 8696331
1 parent bf6c20d
commit 8696331
Showing 1 changed file with 10 additions and 4 deletions.
diff --git a/core/src/main/java/org/bouncycastle/util/Arrays.java b/core/src/main/java/org/bouncycastle/util/Arrays.java
@@ -161,17 +161,23 @@ public static boolean constantTimeAreEqual(
             return false;
         }
 
-        if (expected.length != supplied.length)
+        if (expected == supplied)
         {
-            return !Arrays.constantTimeAreEqual(expected, expected);
+            return true;
         }
 
-        int nonEqual = 0;
+        int len = (expected.length < supplied.length) ? expected.length : supplied.length;
+
+        int nonEqual = expected.length ^ supplied.length;
 
-        for (int i = 0; i != expected.length; i++)
+        for (int i = 0; i != len; i++)
         {
             nonEqual |= (expected[i] ^ supplied[i]);
         }
+        for (int i = len; i < supplied.length; i++)
+        {
+            nonEqual |= (supplied[i] ^ ~supplied[i]);
+        }
 
         return nonEqual == 0;
     }