#region License

// The MIT License
//
// Copyright (c) 2006-2008 DevDefined Limited.
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#endregion

namespace DevDefined.OAuth.Utility
{
	public static class StringUtility
	{
		public static bool EqualsInConstantTime(this string value, string other)
		{
			if (value == null ^ other == null) return false;
			if (value == null) return true;
			if (value.Length != other.Length) return false;

			return CompareStringsInConstantTime(value, other);
		}

		static bool CompareStringsInConstantTime(string value, string other)
		{
			int result = 0;

			for (int i = 0; i < value.Length; i++)
			{
				result |= value[i] ^ other[i];
			}

			return result == 0;
		}
	}
}