{
expiresHeader = response.Headers["Expires"];
lastModifiedHeader = response.Headers["Last-Modified"];
using (var stream = response.GetResponseStream())
using (var reader = new StreamReader(stream, true))
{
rss = reader.ReadToEnd();
}
}
var output = this.context.Response;
output.ContentEncoding = Encoding.UTF8;
output.ContentType = "text/xml;"; // "application/rss+xml; charset=utf-8";
output.Write(rss);
var cache = output.Cache;
cache.VaryByParams["u"] = true;
DateTime expires;
var hasExpires = DateTime.TryParse(expiresHeader, out expires);
DateTime lastModified;
var hasLastModified = DateTime.TryParse(lastModifiedHeader, out lastModified);
cache.SetCacheability(HttpCacheability.Public);
cache.SetOmitVaryStar(true);
cache.SetSlidingExpiration(false);
cache.SetValidUntilExpires(true);
DateTime expireBy = DateTime.Now.AddHours(1);
if (hasExpires && expires.CompareTo(expireBy) <= 0)
{
cache.SetExpires(expires);
}
else
{
cache.SetExpires(expireBy);
}
if (hasLastModified)
{
cache.SetLastModified(lastModified);
}
}
/// <summary>
/// Do not process requests synchronously.
/// </summary>
public void ProcessRequest(HttpContext context)
{
throw new InvalidOperationException();
}
}
/// <summary>
/// Methods for matching hostnames to a list of safe hosts.
/// </summary>
public class SafeList
{
/// <summary>
/// Hard-coded list of safe hosts.
/// </summary>
private static readonly IEnumerable<string> hostnames = new string[]
{
"cnblogs.com",
"msn.com",
"163.com",
"csdn.com"
};
/// <summary>
/// Prefix each safe hostname with a period.
/// </summary>
private static readonly IEnumerable<string> dottedHostnames =
from hostname in hostnames
select string.Concat(".", hostname);
/// <summary>
/// Tests if the <paramref name="hostname" /> matches exactly or ends with a
/// hostname from the safe host list.
/// </summary>
/// <param name="hostname">Hostname to test</param>
/// <returns>True if the hostname matches</returns>
public bool IsSafe(string hostname)
{
return MatchesHostname(hostname) || MatchesDottedHostname(hostname);
}
/// <summary>
/// Tests if the <paramref name="hostname" /> ends with a hostname from the
/// safe host list.
/// </summary>
/// <param name="hostname">Hostname to test</param>
/// <returns>True if the hostname matches</returns>
private static bool MatchesDottedHostname(string hostname)
{
return dottedHostnames.Any(host => hostname.EndsWith(host, StringComparison.InvariantCultureIgnoreCase));
}
/// <summary>
/// Tests if the <paramref name="hostname" /> matches exactly with a hostname
/// from the safe host list.
