diff --git a/src/AsyncElegantOTA.h b/src/AsyncElegantOTA.h
index f7fcb5d..4950159 100644
--- a/src/AsyncElegantOTA.h
+++ b/src/AsyncElegantOTA.h
@@ -15,6 +15,7 @@
     #include "esp_task_wdt.h"
 #endif
 
+#include "Hash.h"
 #include "ESPAsyncWebServer.h"
 #include "FS.h"
 
diff --git a/src/Hash.h b/src/Hash.h
new file mode 100644
index 0000000..bb4599f
--- /dev/null
+++ b/src/Hash.h
@@ -0,0 +1,38 @@
+/**
+ * @file Hash.h
+ * @date 20.05.2015
+ * @author Markus Sattler
+ *
+ * Copyright (c) 2015 Markus Sattler. All rights reserved.
+ * This file is part of the esp8266 core for Arduino environment.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifndef HASH_H_
+#define HASH_H_
+
+//#define DEBUG_SHA1
+
+void sha1(const uint8_t* data, uint32_t size, uint8_t hash[20]);
+void sha1(const char* data, uint32_t size, uint8_t hash[20]);
+void sha1(const String& data, uint8_t hash[20]);
+
+String sha1(const uint8_t* data, uint32_t size);
+String sha1(const char* data, uint32_t size);
+String sha1(const String& data);
+
+#endif /* HASH_H_ */
\ No newline at end of file