1 files changed, 60 insertions, 0 deletions
diff --git a/tests/hash-target.cpp b/tests/hash-target.cpp
new file mode 100644
index 000000000..208bb04a8
--- /dev/null
+++ b/tests/hash-target.cpp
@@ -0,0 +1,60 @@
+// Copyright (c) 2012-2013 The Cryptonote developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <cstdint>
+#include <cstdlib>
+#include <cstring>
+#include <limits>
+#include "crypto/hash.h"
+#include "cryptonote_core/difficulty.h"
+
+using namespace std;
+using cryptonote::check_hash;
+
+int main(int argc, char *argv[]) {
+  crypto::hash h;
+  for (uint64_t diff = 1;; diff += 1 + (diff >> 8)) {
+    for (int b = 0; b < 256; b++) {
+      memset(&h, b, sizeof(crypto::hash));
+      if (check_hash(h, diff) != (b == 0 || diff <= 255 / b)) {
+        return 1;
+      }
+      if (b > 0) {
+        memset(&h, 0, sizeof(crypto::hash));
+        ((char *) &h)[31] = b;
+        if (check_hash(h, diff) != (diff <= 255 / b)) {
+          return 1;
+        }
+      }
+    }
+    if (diff < numeric_limits<uint64_t>::max() / 256) {
+      uint64_t val = 0;
+      for (int i = 31; i >= 0; i--) {
+        val = val * 256 + 255;
+        ((char *) &h)[i] = static_cast<char>(val / diff);
+        val %= diff;
+      }
+      if (check_hash(h, diff) != true) {
+        return 1;
+      }
+      if (diff > 1) {
+        for (int i = 0;; i++) {
+          if (i >= 32) {
+            abort();
+          }
+          if (++((char *) &h)[i] != 0) {
+            break;
+          }
+        }
+        if (check_hash(h, diff) != false) {
+          return 1;
+        }
+      }
+    }
+    if (diff + 1 + (diff >> 8) < diff) {
+      break;
+    }
+  }
+  return 0;
+}