NatTypeTester/UnitTest/XorMappedTest.cs

using Microsoft.VisualStudio.TestTools.UnitTesting;
using STUN.Enums;
using STUN.Messages.StunAttributeValues;
using System;
using System.Linq;
using System.Net;

namespace UnitTest
{
	[TestClass]
	public class XorMappedTest
	{
		private static ReadOnlySpan<byte> MagicCookieAndTransactionId => new byte[]
		{
			0x21, 0x12, 0xa4, 0x42,
			0xb7, 0xe7, 0xa7, 0x01,
			0xbc, 0x34, 0xd6, 0x86,
			0xfa, 0x87, 0xdf, 0xae
		};

		private static readonly byte[] XorPort = { 0xa1, 0x47 };
		private static readonly byte[] XorIPv4 = { 0xe1, 0x12, 0xa6, 0x43 };
		private static readonly byte[] XorIPv6 =
		{
			0x01, 0x13, 0xa9, 0xfa,
			0xa5, 0xd3, 0xf1, 0x79,
			0xbc, 0x25, 0xf4, 0xb5,
			0xbe, 0xd2, 0xb9, 0xd9
		};

		private const ushort Port = 32853;
		private readonly IPAddress IPv4 = IPAddress.Parse(@"192.0.2.1");
		private readonly IPAddress IPv6 = IPAddress.Parse(@"2001:db8:1234:5678:11:2233:4455:6677");

		private readonly byte[] _ipv4Response = new byte[] { 0x00, (byte)IpFamily.IPv4 }.Concat(XorPort).Concat(XorIPv4).ToArray();
		private readonly byte[] _ipv6Response = new byte[] { 0x00, (byte)IpFamily.IPv6 }.Concat(XorPort).Concat(XorIPv6).ToArray();

		/// <summary>
		/// https://tools.ietf.org/html/rfc5769.html
		/// </summary>
		[TestMethod]
		public void TestXorMapped()
		{
			var t = new XorMappedAddressStunAttributeValue(MagicCookieAndTransactionId)
			{
				Port = Port,
				Family = IpFamily.IPv4,
				Address = IPv4
			};
			Span<byte> temp = stackalloc byte[ushort.MaxValue];

			var length4 = t.WriteTo(temp);
			Assert.AreNotEqual(0, length4);
			Assert.IsTrue(temp[..length4].SequenceEqual(_ipv4Response));

			t = new XorMappedAddressStunAttributeValue(MagicCookieAndTransactionId);
			Assert.IsTrue(t.TryParse(_ipv4Response));
			Assert.AreEqual(t.Port, Port);
			Assert.AreEqual(t.Family, IpFamily.IPv4);
			Assert.AreEqual(t.Address, IPv4);

			t = new XorMappedAddressStunAttributeValue(MagicCookieAndTransactionId);
			Assert.IsTrue(t.TryParse(_ipv6Response));
			Assert.AreEqual(t.Port, Port);
			Assert.AreEqual(t.Family, IpFamily.IPv6);
			Assert.AreEqual(t.Address, IPv6);

			var length6 = t.WriteTo(temp);
			Assert.AreNotEqual(0, length6);
			Assert.IsTrue(temp[..length6].SequenceEqual(_ipv6Response));
		}
	}
}