AntiForgeryHelper class to read token from request (Asp.Net core)

AntiForgeryHelper.cs

public class AntiForgeryHelper
{
	public static string ExtractAntiForgeryToken(string htmlResponseText)
	{
		if (htmlResponseText == null) throw new ArgumentNullException("htmlResponseText");

		System.Text.RegularExpressions.Match match = Regex.Match(htmlResponseText, @"\<input name=""__RequestVerificationToken"" type=""hidden"" value=""([^""]+)"" \/\>");
		return match.Success ? match.Groups[1].Captures[0].Value : null;
	}

	public static async Task<string> ExtractAntiForgeryToken(HttpResponseMessage response)
	{
		string responseAsString = await response.Content.ReadAsStringAsync();
		return await Task.FromResult(ExtractAntiForgeryToken(responseAsString));
	}
}