Mitigate Timing Attacks On Basic RPC Authorization

[novacoin.git] / src / util.h

diff --git a/src/util.h b/src/util.h
index 83a4012..e83f554 100644 (file)
--- a/src/util.h
+++ b/src/util.h
@@ -531,6 +531,20 @@ inline uint160 Hash160(const std::vector<unsigned char>& vch)
     return hash2;
 }
 
+/**
+ * Timing-attack-resistant comparison.
+ * Takes time proportional to length
+ * of first argument.
+ */
+template <typename T>
+bool TimingResistantEqual(const T& a, const T& b)
+{
+    if (b.size() == 0) return a.size() == 0;
+    size_t accumulator = a.size() ^ b.size();
+    for (size_t i = 0; i < a.size(); i++)
+        accumulator |= a[i] ^ b[i%b.size()];
+    return accumulator == 0;
+}
 
 /** Median filter over a stream of values.
  * Returns the median of the last N numbers