Added test documentation & Keccak unit test

tests/unit_tests/crypto.cpp

@@ -47,6 +47,14 @@ namespace
     "8b655970153799af2aeadc9ff1add0ea6c7251d54154cfa92c173a0dd39c1f94"
     "6c7251d54154cfa92c173a0dd39c1f948b655970153799af2aeadc9ff1add0ea";
 
+  static std::uint8_t md[] = {
+    0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00
+  };
+
   template<typename T>
   bool is_formatted()
   {
@@ -61,6 +69,26 @@ namespace
     out << "BEGIN" << value << "END";  
     return out.str() == "BEGIN<" + std::string{expected, sizeof(T) * 2} + ">END";
   }
+
+  bool keccak_harness()
+  {
+    size_t inlen = sizeof(source);
+    int mdlen = (int)sizeof(md);
+    int ret = keccak(source, inlen, md, mdlen);
+
+    if (md[0] != 0x00)
+    {
+        return true;
+    }
+    else if (!ret)
+    {
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+  }
 }
 
 TEST(Crypto, Ostream)