using System;

using System.Security.Cryptography.X509Certificates;

using System.Security.Cryptography.Xml;

using System.Text;

using System.Web;

using SAML2.Config;

namespace SAML2.Protocol

{

/// <summary>

/// The handler that exposes a metadata endpoint to the other parties of the federation.

/// The handler accepts the following GET parameters :

/// - encoding : Delivers the Metadata document in the specified encoding. Example: encoding=iso-8859-1 . If the parameter is omitted, the encoding utf-8 is used.

/// - sign : A boolean parameter specifying whether to sign the metadata document. Example: sign=false. If the parameter is omitted, the document is signed.

/// </summary>

public class Saml20MetadataHandler : AbstractEndpointHandler

{

#region IHttpHandler Members

/// <summary>

/// Gets a value indicating whether this instance is reusable.

/// </summary>

/// <value>

/// <c>true</c> if this instance is reusable; otherwise, <c>false</c>.

/// </value>

public new bool IsReusable

{

get { return false; }

}

/// <summary>

/// Enables processing of HTTP Web requests by a custom HttpHandler that implements the <see cref="T:System.Web.IHttpHandler"/> interface.

/// </summary>

/// <param name="context">An <see cref="T:System.Web.HttpContext"/> object that provides references to the intrinsic server objects (for example, Request, Response, Session, and Server) used to service HTTP requests.</param>

public override void ProcessRequest(HttpContext context)

{

var encoding = context.Request.QueryString["encoding"];

try

{

if (!string.IsNullOrEmpty(encoding))

{

context.Response.ContentEncoding = Encoding.GetEncoding(encoding);

}

}

catch (ArgumentException ex)

{

Logger.ErrorFormat(ErrorMessages.UnknownEncoding, encoding);

throw new ArgumentException(string.Format(ErrorMessages.UnknownEncoding, encoding), ex);

}

var sign = true;

var param = context.Request.QueryString["sign"];

if (!string.IsNullOrEmpty(param))

{

if (!bool.TryParse(param, out sign))

{

throw new ArgumentException(ErrorMessages.MetadataSignQueryParameterInvalid);

}

}

context.Response.ContentType = Saml20Constants.MetadataMimetype;

context.Response.AddHeader("Content-Disposition", "attachment; filename=\"metadata.xml\"");

CreateMetadataDocument(context, sign);

context.Response.End();

}

#endregion

/// <summary>

/// Creates the metadata document.

/// </summary>

/// <param name="context">The context.</param>

/// <param name="sign">if set to <c>true</c> sign the document.</param>

private void CreateMetadataDocument(HttpContext context, bool sign)

{

Logger.Debug(TraceMessages.MetadataDocumentBeingCreated);

var configuration = Saml2Config.Current;

var keyinfo = new KeyInfo();

var keyClause = new KeyInfoX509Data(configuration.ServiceProvider.SigningCertificate.GetCertificate(), X509IncludeOption.EndCertOnly);

keyinfo.AddClause(keyClause);

var doc = new Saml20MetadataDocument(configuration, keyinfo, sign);

Logger.Debug(TraceMessages.MetadataDocumentCreated);

context.Response.Write(doc.ToXml(context.Response.ContentEncoding));

}

}

}