/// <summary>
/// Initializes a new instance of the <see cref="SslRedirectContext"/> class.
/// </summary>
/// <param name="context">The HTTP-specific information about the request.</param>
/// <param name="options">The options for the current request.</param>
public SslRedirectContext(HttpContext context, SslRedirectOptions options)
{
HttpContext = context;
Options = options.Clone();
_fwh = new Lazy <ForwardedHeader>(() => ForwardedHeader.FromHttpContext(context));
}
/// <summary>
/// Constructs a <see cref="ForwardedHeader"/> object from a <see cref="HttpContext"/>.
/// </summary>
/// <param name="context">The context to parse.</param>
/// <returns>The constructed <see cref="ForwardedHeader"/> object or <see langword="null"/>.</returns>
public static ForwardedHeader FromHttpContext(HttpContext context)
{
var headers = context?.Request.Headers ??
throw new ArgumentNullException(nameof(context));
ForwardedHeader result = null;
ForwardedHeader header()
{
if (result == null)
{
result = new ForwardedHeader();
}
return(result);
}
foreach (var pair in _xProtocolHeaders)
{
if (headers.ContainsKey(pair.Key))
{
header().Protocol =
pair.Value.Equals(headers[pair.Key], StringComparison.OrdinalIgnoreCase) ?
ProtocolType.Https : ProtocolType.Http;
}
}
if (headers.TryGetValue(HeaderNames.ForwardedFor, out var @for))
{
header().For = @for
.SelectMany(f => f.Split(new[] { ',' }, RemoveEmptyEntries))
.Select(f => f.Trim())
.ToArray();
}
else if (headers.TryGetValue(HeaderNames.ProxyUserIp, out var @ip))
{
header().For = @ip;
}
if (headers.TryGetValue(HeaderNames.ForwardedHost, out var host))
{
header().Host = host;
}
if (headers.TryGetValue(HeaderNames.ForwardedPort, out var pv))
{
if (Int32.TryParse(pv, out var port))
{
header().Port = port;
}
}
// https://tools.ietf.org/html/rfc7239
if (headers.TryGetValue(HeaderNames.Forwarded, out var fw))
{
var values = fw
.SelectMany(f => f.Split(new[] { ';', ',' }, RemoveEmptyEntries))
.Select(f => f.Split(new[] { '=' }, RemoveEmptyEntries))
.Where(f => f.Length == 2)
.ToLookup(f => f[0].Trim().ToUpperInvariant(), f => f[1].Trim());
if (values.Contains("PROTO"))
{
header().Protocol = values["PROTO"].Last().Equals("https", StringComparison.OrdinalIgnoreCase) ?
ProtocolType.Https : ProtocolType.Http;
}
if (values.Contains("FOR"))
{
header().For = values["FOR"].ToArray();
}
if (values.Contains("HOST"))
{
header().Host = values["HOST"].Last();
}
if (values.Contains("BY"))
{
header().By = values["BY"].Last();
}
}
return(result);
}