1 files changed, 81 insertions, 0 deletions
diff --git a/libdevcore/UTF8.cpp b/libdevcore/UTF8.cpp
new file mode 100644
index 00000000..d742fe66
--- /dev/null
+++ b/libdevcore/UTF8.cpp
@@ -0,0 +1,81 @@
+/*
+	This file is part of cpp-ethereum.
+
+	cpp-ethereum is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	cpp-ethereum 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 General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/** @file UTF8.cpp
+ * @author Alex Beregszaszi
+ * @date 2016
+ *
+ * UTF-8 related helpers
+ */
+
+#include "UTF8.h"
+
+
+namespace dev
+{
+
+
+bool validate(std::string const& _input, size_t& _invalidPosition)
+{
+	const size_t length = _input.length();
+	bool valid = true;
+	size_t i = 0;
+
+	for (; i < length; i++)
+	{
+		if ((unsigned char)_input[i] < 0x80)
+			continue;
+
+		size_t count = 0;
+		switch(_input[i] & 0xe0) {
+			case 0xc0: count = 1; break;
+			case 0xe0: count = 2; break;
+			case 0xf0: count = 3; break;
+			default: break;
+		}
+
+		if (count == 0)
+		{
+			valid = false;
+			break;
+		}
+
+		if ((i + count) >= length)
+		{
+			valid = false;
+			break;
+		}
+
+		for (size_t j = 0; j < count; j++)
+		{
+			i++;
+			if ((_input[i] & 0xc0) != 0x80)
+			{
+				valid = false;
+				break;
+			}
+		}
+	}
+
+	if (valid)
+		return true;
+
+	_invalidPosition = i;
+	return false;
+}
+
+
+}