public void ToCanonical()
{
var a = new DomainName("My.EXAMPLe.ORg");
Assert.AreEqual("My.EXAMPLe.ORg", a.ToString());
Assert.AreEqual("my.example.org", a.ToCanonical().ToString());
}
/// <summary>
/// Write a domain name.
/// </summary>
/// <param name="name">
/// The name to write.
/// </param>
/// <param name="uncompressed">
/// Determines if the <paramref name="name"/> must be uncompressed. The
/// defaultl is false (allow compression).
/// <see cref="CanonicalForm"/> overrides this value.
/// </param>
/// <exception cref="ArgumentException">
/// When a label length is greater than 63 octets.
/// </exception>
/// <remarks>
/// A domain name is represented as a sequence of labels, where
/// each label consists of a length octet followed by that
/// number of octets.The domain name terminates with the
/// zero length octet for the null label of the root. Note
/// that this field may be an odd number of octets; no
/// padding is used.
/// </remarks>
public void WriteDomainName(DomainName name, bool uncompressed = false)
{
if (name == null)
{
stream.WriteByte(0); // terminating byte
++Position;
return;
}
if (CanonicalForm)
{
uncompressed = true;
name = name.ToCanonical();
}
var labels = name.Labels.ToArray();
var n = labels.Length;
for (var i = 0; i < n; ++i)
{
var label = labels[i];
if (label.Length > 63)
{
throw new ArgumentException($"Label '{label}' cannot exceed 63 octets.");
}
// Check for qualified name already used.
var qn = string.Join(".", labels, i, labels.Length - i);
if (!uncompressed && pointers.TryGetValue(qn, out int pointer))
{
WriteUInt16((ushort)(0xC000 | pointer));
return;
}
if (Position <= maxPointer)
{
pointers[qn] = Position;
}
// Add the label
var bytes = Encoding.UTF8.GetBytes(label);
WriteByteLengthPrefixedBytes(bytes);
}
stream.WriteByte(0); // terminating byte
++Position;
}
