public static ICrossDomainPolicy BuildSilverlightPolicy(HttpWebResponse response)
{
// return null if no Silverlight policy was found, since we offer a second chance with a flash policy
if ((response.StatusCode != HttpStatusCode.OK) || !CheckContentType(response.ContentType))
{
return(null);
}
ICrossDomainPolicy policy = null;
try
{
policy = ClientAccessPolicy.FromStream(response.GetResponseStream());
if (policy != null)
{
AddPolicy(response.ResponseUri, policy);
}
}
catch (Exception ex)
{
Console.WriteLine(String.Format("CrossDomainAccessManager caught an exception while reading {0}: {1}",
response.ResponseUri, ex));
// and ignore.
}
return(policy);
}
static public bool CheckEndPoint(EndPoint endpoint, SocketClientAccessPolicyProtocol protocol)
{
// if needed transform the DnsEndPoint into a usable IPEndPoint
IPEndPoint ip = (endpoint as IPEndPoint);
if (ip == null)
{
throw new ArgumentException("endpoint");
}
// find the policy (cached or to be downloaded) associated with the endpoint
string address = ip.Address.ToString();
ClientAccessPolicy policy = null;
if (!socket_policies.TryGetValue(address, out policy))
{
policy = CreateForEndPoint(ip, protocol);
socket_policies.Add(address, policy);
}
// no access granted if no policy is available
if (policy == null)
{
return(false);
}
// does the policy allows access ?
return(policy.IsAllowed(ip));
}
static public ICrossDomainPolicy FromStream(Stream stream)
{
ClientAccessPolicy cap = new ClientAccessPolicy();
// Silverlight accepts whitespaces before the XML - which is invalid XML
StreamReader sr = new StreamReader(stream);
while (Char.IsWhiteSpace((char)sr.Peek()))
{
sr.Read();
}
XmlReaderSettings policy_settings = new XmlReaderSettings();
policy_settings.DtdProcessing = DtdProcessing.Ignore;
using (XmlReader reader = XmlReader.Create(sr, policy_settings))
{
reader.MoveToContent();
if (reader.IsEmptyElement)
{
reader.Skip();
return(null);
}
reader.ReadStartElement("access-policy", String.Empty);
for (reader.MoveToContent(); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent())
{
if (reader.NodeType != XmlNodeType.Element)
{
throw new XmlException(String.Format("Unexpected access-policy content: {0}", reader.NodeType));
}
if ((reader.LocalName != "cross-domain-access") || reader.IsEmptyElement)
{
reader.Skip();
continue;
}
reader.ReadStartElement("cross-domain-access", String.Empty);
for (reader.MoveToContent(); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent())
{
if (reader.NodeType != XmlNodeType.Element)
{
throw new XmlException(String.Format("Unexpected access-policy content: {0}", reader.NodeType));
}
if ((reader.Name != "policy") || reader.IsEmptyElement)
{
reader.Skip();
continue;
}
ReadPolicyElement(reader, cap);
}
reader.ReadEndElement();
}
reader.ReadEndElement();
}
return(cap);
}
static public ICrossDomainPolicy FromStream (Stream stream)
{
ClientAccessPolicy cap = new ClientAccessPolicy ();
// Silverlight accepts whitespaces before the XML - which is invalid XML
StreamReader sr = new StreamReader (stream);
while (Char.IsWhiteSpace ((char) sr.Peek ()))
sr.Read ();
XmlReaderSettings policy_settings = new XmlReaderSettings ();
policy_settings.DtdProcessing = DtdProcessing.Ignore;
using (XmlReader reader = XmlReader.Create (sr, policy_settings)) {
reader.MoveToContent ();
if (reader.IsEmptyElement) {
reader.Skip ();
return null;
}
reader.ReadStartElement ("access-policy", String.Empty);
for (reader.MoveToContent (); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent ()) {
if (reader.NodeType != XmlNodeType.Element)
throw new XmlException (String.Format ("Unexpected access-policy content: {0}", reader.NodeType));
if ((reader.LocalName != "cross-domain-access") || reader.IsEmptyElement) {
reader.Skip ();
continue;
}
reader.ReadStartElement ("cross-domain-access", String.Empty);
for (reader.MoveToContent (); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent ()) {
if (reader.NodeType != XmlNodeType.Element)
throw new XmlException (String.Format ("Unexpected access-policy content: {0}", reader.NodeType));
if ((reader.Name != "policy") || reader.IsEmptyElement) {
reader.Skip ();
continue;
}
ReadPolicyElement (reader, cap);
}
reader.ReadEndElement ();
}
reader.ReadEndElement ();
}
return cap;
}
static void ReadPolicyElement(XmlReader reader, ClientAccessPolicy cap)
{
if (reader.HasAttributes || reader.IsEmptyElement)
{
reader.Skip();
return;
}
var policy = new AccessPolicy();
bool valid = true;
reader.ReadStartElement("policy", String.Empty);
for (reader.MoveToContent(); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent())
{
if (IsNonElement(reader))
{
reader.Skip();
continue;
}
switch (reader.LocalName)
{
case "allow-from":
ReadAllowFromElement(reader, policy);
break;
case "grant-to":
ReadGrantToElement(reader, policy);
break;
default:
valid = false;
reader.Skip();
break;
}
}
if (valid)
{
cap.AccessPolicyList.Add(policy);
}
reader.ReadEndElement();
}
public static ClientAccessPolicy CreateForEndPoint(IPEndPoint endpoint, SocketClientAccessPolicyProtocol protocol)
{
Stream s = null;
switch (protocol)
{
case SocketClientAccessPolicyProtocol.Tcp:
s = GetPolicyStream(endpoint);
break;
case SocketClientAccessPolicyProtocol.Http:
// <quote>It will NOT attempt to download the policy via the custom TCP protocol if the
// policy check fails.</quote>
// http://blogs.msdn.com/ncl/archive/2010/04/15/silverlight-4-socket-policy-changes.aspx
string url = String.Format("http://{0}:80{1}", endpoint.Address.ToString(),
CrossDomainPolicyManager.ClientAccessPolicyFile);
s = GetPolicyStream(new Uri(url));
break;
}
if ((s == null) || (s.Length == 0))
{
return(null);
}
ClientAccessPolicy policy = null;
try
{
policy = (ClientAccessPolicy)ClientAccessPolicy.FromStream(s);
}
catch (Exception ex)
{
Console.WriteLine(String.Format("CrossDomainAccessManager caught an exception while reading {0}: {1}",
endpoint, ex.Message));
// and ignore.
}
return(policy);
}
static void ReadPolicyElement (XmlReader reader, ClientAccessPolicy cap)
{
if (reader.HasAttributes || reader.IsEmptyElement) {
reader.Skip ();
return;
}
var policy = new AccessPolicy ();
bool valid = true;
reader.ReadStartElement ("policy", String.Empty);
for (reader.MoveToContent (); reader.NodeType != XmlNodeType.EndElement; reader.MoveToContent ()) {
if (IsNonElement (reader)) {
reader.Skip ();
continue;
}
switch (reader.LocalName) {
case "allow-from":
ReadAllowFromElement (reader, policy);
break;
case "grant-to":
ReadGrantToElement (reader, policy);
break;
default:
valid = false;
reader.Skip ();
break;
}
}
if (valid)
cap.AccessPolicyList.Add (policy);
reader.ReadEndElement ();
}
