public override object GetEntity(Uri absoluteUri, string role, Type ofObjectToReturn)
{
if (absoluteUri == null)
{
throw new ArgumentNullException("absoluteUri");
}
if (absoluteUri.Scheme == "http" && (ofObjectToReturn == null || ofObjectToReturn == typeof(Stream)))
{
try {
return(GetResponse(absoluteUri));
} catch (Exception e) {
if (WebProxyService.ProxyAuthenticationRequired(e))
{
WebProxyState state = ps.PrepareWebProxy(this.GetProxy(), absoluteUri.AbsoluteUri, WebProxyState.DefaultCredentials, true);
if (state != WebProxyState.Abort)
{
// try again...
return(GetResponse(absoluteUri));
}
}
throw;
}
}
else
{
return(base.GetEntity(absoluteUri, role, ofObjectToReturn));
}
}
/// <summary>
/// This method attaches credentials to the web proxy object.
/// </summary>
/// <param name="proxy">The proxy to attach credentials to.</param>
/// <param name="webCallUrl">The url for the web call.</param>
/// <param name="oldProxyState">The current state fo the web call.</param>
/// <param name="newProxyState">The new state for the web call.</param>
/// <param name="okToPrompt">Prompt user for credentials if they are not available.</param>
public WebProxyState PrepareWebProxy(IWebProxy proxy, string webCallUrl, WebProxyState oldProxyState, bool okToPrompt)
{
WebProxyState newProxyState = WebProxyState.Abort;
if (string.IsNullOrEmpty(webCallUrl)) {
Debug.Fail("PrepareWebProxy called with an empty WebCallUrl.");
webCallUrl = "http://go.microsoft.com/fwlink/?LinkId=81947";
}
// Get the web proxy url for the the current web call.
Uri webCallProxy = null;
if (proxy != null) {
webCallProxy = proxy.GetProxy(new Uri(webCallUrl));
}
if ((proxy != null) && (webCallProxy != null)) {
// get proxy url.
string proxyUrl = webCallProxy.Host;
if (string.IsNullOrEmpty(currentProxyUrl)) {
currentProxyUrl = proxyUrl;
}
switch (oldProxyState) {
case WebProxyState.NoCredentials:
// Add the default credentials only if there aren't any credentials attached to
// the DefaultWebProxy. If the first calls attaches the correct credentials, the
// second call will just use them, instead of overwriting it with the default credentials.
// This avoids multiple web calls. Note that state is transitioned to DefaultCredentials
// instead of CachedCredentials. This ensures that web calls be tried with the
// cached credentials if the currently attached credentials don't result in successful web call.
if ((proxy.Credentials == null)) {
proxy.Credentials = CredentialCache.DefaultCredentials;
}
newProxyState = WebProxyState.DefaultCredentials;
break;
case WebProxyState.DefaultCredentials:
// Fetch cached credentials if they are null or if the proxy url has changed.
if ((cachedCredentials == null) ||
!string.Equals(currentProxyUrl, proxyUrl, StringComparison.OrdinalIgnoreCase)) {
cachedCredentials = GetCachedCredentials(proxyUrl);
}
if (cachedCredentials != null) {
proxy.Credentials = cachedCredentials;
newProxyState = WebProxyState.CachedCredentials;
break;
}
// Proceed to next step if cached credentials are not available.
goto case WebProxyState.CachedCredentials;
case WebProxyState.CachedCredentials:
case WebProxyState.PromptForCredentials:
if (okToPrompt) {
if (DialogResult.OK == PromptForCredentials(proxyUrl)) {
proxy.Credentials = cachedCredentials;
newProxyState = WebProxyState.PromptForCredentials;
} else {
newProxyState = WebProxyState.Abort;
}
} else {
newProxyState = WebProxyState.Abort;
}
break;
case WebProxyState.Abort:
throw new InvalidOperationException();
default:
throw new ArgumentException(string.Empty, "oldProxyState");
}
} else {
// No proxy for the webCallUrl scenario.
if (oldProxyState == WebProxyState.NoCredentials) {
// if it is the first call, change the state and let the web call proceed.
newProxyState = WebProxyState.DefaultCredentials;
} else {
Debug.Fail("This method is called a second time when 407 occurs. A 407 shouldn't have occurred as there is no default proxy.");
// We dont have a good idea of the circumstances under which
// WebProxy might be null for a url. To be safe, for VS 2005 SP1,
// we will just return the abort state, instead of throwing
// an exception. Abort state will ensure that no further procesing
// occurs and we will not bring down the app.
// throw new InvalidOperationException();
newProxyState = WebProxyState.Abort;
}
}
return newProxyState;
}
/// <summary>
/// This method attaches credentials to the web proxy object.
/// </summary>
/// <param name="proxy">The proxy to attach credentials to.</param>
/// <param name="webCallUrl">The url for the web call.</param>
/// <param name="oldProxyState">The current state fo the web call.</param>
/// <param name="newProxyState">The new state for the web call.</param>
/// <param name="okToPrompt">Prompt user for credentials if they are not available.</param>
public WebProxyState PrepareWebProxy(IWebProxy proxy, string webCallUrl, WebProxyState oldProxyState, bool okToPrompt)
{
WebProxyState newProxyState = WebProxyState.Abort;
if (string.IsNullOrEmpty(webCallUrl))
{
Debug.Fail("PrepareWebProxy called with an empty WebCallUrl.");
webCallUrl = "http://go.microsoft.com/fwlink/?LinkId=81947";
}
// Get the web proxy url for the the current web call.
Uri webCallProxy = null;
if (proxy != null)
{
webCallProxy = proxy.GetProxy(new Uri(webCallUrl));
}
if ((proxy != null) && (webCallProxy != null))
{
// get proxy url.
string proxyUrl = webCallProxy.Host;
if (string.IsNullOrEmpty(currentProxyUrl))
{
currentProxyUrl = proxyUrl;
}
switch (oldProxyState)
{
case WebProxyState.NoCredentials:
// Add the default credentials only if there aren't any credentials attached to
// the DefaultWebProxy. If the first calls attaches the correct credentials, the
// second call will just use them, instead of overwriting it with the default credentials.
// This avoids multiple web calls. Note that state is transitioned to DefaultCredentials
// instead of CachedCredentials. This ensures that web calls be tried with the
// cached credentials if the currently attached credentials don't result in successful web call.
if ((proxy.Credentials == null))
{
proxy.Credentials = CredentialCache.DefaultCredentials;
}
newProxyState = WebProxyState.DefaultCredentials;
break;
case WebProxyState.DefaultCredentials:
// Fetch cached credentials if they are null or if the proxy url has changed.
if ((cachedCredentials == null) ||
!string.Equals(currentProxyUrl, proxyUrl, StringComparison.OrdinalIgnoreCase))
{
cachedCredentials = GetCachedCredentials(proxyUrl);
}
if (cachedCredentials != null)
{
proxy.Credentials = cachedCredentials;
newProxyState = WebProxyState.CachedCredentials;
break;
}
// Proceed to next step if cached credentials are not available.
goto case WebProxyState.CachedCredentials;
case WebProxyState.CachedCredentials:
case WebProxyState.PromptForCredentials:
if (okToPrompt)
{
if (DialogResult.OK == PromptForCredentials(proxyUrl))
{
proxy.Credentials = cachedCredentials;
newProxyState = WebProxyState.PromptForCredentials;
}
else
{
newProxyState = WebProxyState.Abort;
}
}
else
{
newProxyState = WebProxyState.Abort;
}
break;
case WebProxyState.Abort:
throw new InvalidOperationException();
default:
throw new ArgumentException(string.Empty, "oldProxyState");
}
}
else
{
// No proxy for the webCallUrl scenario.
if (oldProxyState == WebProxyState.NoCredentials)
{
// if it is the first call, change the state and let the web call proceed.
newProxyState = WebProxyState.DefaultCredentials;
}
else
{
Debug.Fail("This method is called a second time when 407 occurs. A 407 shouldn't have occurred as there is no default proxy.");
// We dont have a good idea of the circumstances under which
// WebProxy might be null for a url. To be safe, for VS 2005 SP1,
// we will just return the abort state, instead of throwing
// an exception. Abort state will ensure that no further procesing
// occurs and we will not bring down the app.
// throw new InvalidOperationException();
newProxyState = WebProxyState.Abort;
}
}
return(newProxyState);
}
