// CheckNonSecuredEndpointForRedirect
// This function does an unauthenticated GET request to a non-https
// URL to see if the server will respond with a 302 redirect. If so, it will
// attempt to use the value of the Location header to perform Autodiscover.
//
// Parameters:
// useSoapEndpoints: Indicates whether SOAP endpoints should be tried.
//
// Returns:
// A Dictionary object that contains the settings returned by the
// Autodiscover process. If null, either the redirect failed or the URL failed.
//
private Dictionary <string, string> CheckNonSecuredEndpointForRedirect(bool useSoapEndpoints)
{
// Get the non-https URL, or "last ditch" URL.
string nonHttpsEndpoint = UrlList.GetLastDitchUrl(EmailAddress);
Tracing.WriteLine("Sending non-authenticated GET to " + nonHttpsEndpoint);
HttpWebRequest getRequest = (HttpWebRequest)WebRequest.Create(nonHttpsEndpoint);
getRequest.Method = "GET";
getRequest.AllowAutoRedirect = false;
getRequest.PreAuthenticate = false;
try
{
HttpWebResponse getResponse = (HttpWebResponse)getRequest.GetResponse();
if (getResponse != null)
{
if (getResponse.StatusCode == HttpStatusCode.Redirect ||
getResponse.StatusCode == HttpStatusCode.Moved ||
getResponse.StatusCode == HttpStatusCode.RedirectKeepVerb ||
getResponse.StatusCode == HttpStatusCode.RedirectMethod)
{
Tracing.WriteLine("Received a redirect status: " + getResponse.StatusCode.ToString());
string redirectUrl = getResponse.Headers["Location"].ToString();
Tracing.WriteLine("Location header: " +
(string.IsNullOrEmpty(redirectUrl) ? "MISSING" : redirectUrl));
if (IsValidRedirectUrl(redirectUrl))
{
// You got a valid redirect; try it.
UrlRedirects++;
return(TryAutodiscoverUrl(AutodiscoverUrlList.NormalizeAutodiscoverUrl(redirectUrl),
useSoapEndpoints));
}
else
{
Tracing.WriteLine("Redirect returned missing or invalid URL, unable to proceed.");
}
}
else
{
Tracing.WriteLine("Received a non-redirect status: " + getResponse.StatusCode.ToString());
}
}
}
catch (WebException e)
{
Tracing.WriteLine("Unable to connect.");
Tracing.WriteLine(e.ToString());
}
return(null);
}
// TryPoxAutodiscoverUrl
// This function trys a URL as a POX endpoint.
//
// Parameters:
// url: The URL to try. Note that this value is a POX URL, meaning
// it has a .xml file extension. ("https://contoso.com/autodiscover/autodiscover.xml")
// useSoapEndpoints: Indicates whether SOAP endpoints should be tried.
//
// Returns:
// A Dictionary object that contains the settings returned by the
// Autodiscover process. If null, the URL failed.
//
private Dictionary <string, string> TryPoxAutodiscoverUrl(string url, bool useSoapEndpoints)
{
Tracing.WriteLine("Trying " + url);
Dictionary <string, string> settingsDictionary = null;
// Generate the POX request.
XElement autodiscover = new XElement(PoxXmlStrings.Autodiscover,
new XElement(PoxXmlStrings.Request,
new XElement(PoxXmlStrings.EMailAddress, EmailAddress),
new XElement(PoxXmlStrings.AcceptableResponseSchema, "http://schemas.microsoft.com/exchange/autodiscover/outlook/responseschema/2006a")
)
);
Tracing.WriteLine("POX Request:");
PrintElement(autodiscover);
try
{
HttpWebRequest poxRequest = (HttpWebRequest)WebRequest.Create(url);
poxRequest.AllowAutoRedirect = false;
poxRequest.Credentials = this.Credentials;
poxRequest.Method = "POST";
poxRequest.ContentType = "text/xml";
Stream requestStream = poxRequest.GetRequestStream();
autodiscover.Save(requestStream);
requestStream.Close();
HttpWebResponse poxResponse = (HttpWebResponse)poxRequest.GetResponse();
if (poxResponse.StatusCode == HttpStatusCode.OK)
{
// Successful response.
Stream responseStream = poxResponse.GetResponseStream();
XElement responseAutodiscover = XElement.Load(responseStream);
if (responseAutodiscover != null)
{
Tracing.WriteLine("Response:");
PrintElement(responseAutodiscover);
// If no errors, it is safe to proceed.
string error = CheckPoxResponseForError(responseAutodiscover);
if (error == "NoError")
{
// Check Action value.
XElement action = FindFirstDescendant(responseAutodiscover, PoxXmlStrings.Action);
if (action != null)
{
if (action.Value == "settings")
{
settingsDictionary = new Dictionary <string, string>();
IEnumerable <XElement> protocols = from protocol in responseAutodiscover.Descendants
(PoxXmlStrings.Protocol)
select protocol;
foreach (XElement protocol in protocols)
{
XElement type = protocol.Element(PoxXmlStrings.Type);
if (type != null && type.Value == "EXCH")
{
// You found what you are looking for.
AddPoxSettingToDictionary(settingsDictionary, protocol, PoxXmlStrings.EwsUrl);
break;
}
}
}
else if (action.Value == "redirectAddr")
{
// The server has given you a better email address to use.
Tracing.WriteLine("Server response contains a RedirectAddr element.");
XElement redirectAddr = FindFirstDescendant(responseAutodiscover,
PoxXmlStrings.RedirectAddr);
if (redirectAddr != null &&
IsValidRedirectAddress(redirectAddr.Value, EmailAddress))
{
Tracing.WriteLine("Restarting Autodiscover with email address: " +
redirectAddr.Value);
EmailAddress = redirectAddr.Value;
UrlList.Clear();
UrlList.GenerateList(this.EmailAddress);
visitedUrls.Clear();
AddressRedirects++;
return(TryAutodiscoverUrls(useSoapEndpoints));
}
Tracing.WriteLine("Invalid or missing redirectAddr element, continuing...");
}
else if (action.Value == "redirectUrl")
{
// The server has given you a better URL
// to use. Validate that it is https and
// try it.
Tracing.Write("Server response contains a RedirectUrl element for url: ");
XElement redirectUrl = FindFirstDescendant(responseAutodiscover,
PoxXmlStrings.RedirectUrl);
if (redirectUrl != null && IsValidRedirectUrl(redirectUrl.Value.ToLower()))
{
Tracing.WriteLine(redirectUrl.Value);
UrlRedirects++;
return(TryAutodiscoverUrl(
AutodiscoverUrlList.NormalizeAutodiscoverUrl(redirectUrl.Value),
useSoapEndpoints));
}
else
{
Tracing.WriteLine("Missing or invalid RedirectUrl element, continuing...");
}
}
}
}
}
}
else if (poxResponse.StatusCode == HttpStatusCode.Redirect ||
poxResponse.StatusCode == HttpStatusCode.Moved ||
poxResponse.StatusCode == HttpStatusCode.RedirectKeepVerb ||
poxResponse.StatusCode == HttpStatusCode.RedirectMethod)
{
// Redirect HTTP status scenario.
Tracing.WriteLine("Received a redirect status: " + poxResponse.StatusCode.ToString());
string redirectUrl = poxResponse.Headers["Location"].ToString();
Tracing.WriteLine("Location header: " +
(string.IsNullOrEmpty(redirectUrl) ? "MISSING" : redirectUrl));
if (IsValidRedirectUrl(redirectUrl.ToLower()))
{
UrlRedirects++;
return(TryAutodiscoverUrl(AutodiscoverUrlList.NormalizeAutodiscoverUrl(redirectUrl),
useSoapEndpoints));
}
Tracing.WriteLine("Invalid or missing redirect URL returned. Unable to proceed.");
return(null);
}
}
catch (WebException e)
{
Tracing.WriteLine("Error connection:");
Tracing.WriteLine(e.ToString());
}
return(settingsDictionary);
}
public AutodiscoverRequest(string email, NetworkCredential creds)
{
EmailAddress = email;
Credentials = creds;
UrlList = new AutodiscoverUrlList();
}
// TrySoapAutodiscoverUrl
// This function trys a URL as a SOAP endpoint.
// NOTE: The SOAP Autodiscover service is only available in versions of Exchange starting
// with Exchange 2010, including Exchange Online.
//
// Parameters:
// url: The URL to try. Note that this value is a SOAP URL, meaning
// it has a .svc file extension. ("https://contoso.com/autodiscover/autodiscover.svc")
// useSoapEndpoints: Indicates whether SOAP endpoints should be tried.
//
// Returns:
// A Dictionary object that contains the settings returned by the
// Autodiscover process. If null, the URL failed.
//
private Dictionary <string, string> TrySoapAutodiscoverUrl(string url, bool useSoapEndpoints)
{
Tracing.WriteLine("Trying " + url);
Dictionary <string, string> settingsDictionary = null;
// Generate the SOAP request.
XElement envelope = new XElement(SoapXmlStrings.Envelope,
new XElement(SoapXmlStrings.Header,
new XElement(SoapXmlStrings.RequestedServerVersion, SoapXmlStrings.MinServerVersion),
new XElement(SoapXmlStrings.Action, "http://schemas.microsoft.com/exchange/2010/Autodiscover/Autodiscover/GetUserSettings"),
new XElement(SoapXmlStrings.To, url)
),
new XElement(SoapXmlStrings.Body,
new XElement(SoapXmlStrings.GetUserSettingsRequestMessage,
new XElement(SoapXmlStrings.Request,
new XElement(SoapXmlStrings.Users,
new XElement(SoapXmlStrings.User,
new XElement(SoapXmlStrings.Mailbox, EmailAddress)
)
),
new XElement(SoapXmlStrings.RequestedSettings,
new XElement(SoapXmlStrings.Setting, "InternalEwsUrl"),
new XElement(SoapXmlStrings.Setting, "ExternalEwsUrl"),
new XElement(SoapXmlStrings.Setting, "ExternalEwsVersion"),
new XElement(SoapXmlStrings.Setting, "EwsSupportedSchemas")
)
)
)
)
);
Tracing.WriteLine("SOAP Request:");
PrintElement(envelope);
try
{
HttpWebRequest soapRequest = (HttpWebRequest)WebRequest.Create(url);
soapRequest.AllowAutoRedirect = false;
soapRequest.Credentials = this.Credentials;
soapRequest.Method = "POST";
soapRequest.ContentType = "text/xml";
Stream requestStream = soapRequest.GetRequestStream();
envelope.Save(requestStream);
requestStream.Close();
HttpWebResponse soapResponse = (HttpWebResponse)soapRequest.GetResponse();
if (soapResponse.StatusCode == HttpStatusCode.OK)
{
// Successful response.
Stream responseStream = soapResponse.GetResponseStream();
XElement responseEnvelope = XElement.Load(responseStream);
if (responseEnvelope != null)
{
Tracing.WriteLine("Response:");
PrintElement(responseEnvelope);
// If no errors, it is safe to proceed.
string error = CheckSoapResponseForError(responseEnvelope);
if (error == "NoError")
{
settingsDictionary = new Dictionary <string, string>();
// Load settings.
IEnumerable <XElement> userSettings = from userSetting in responseEnvelope.Descendants
(SoapXmlStrings.UserSetting)
select userSetting;
foreach (XElement userSetting in userSettings)
{
XElement name = userSetting.Element(SoapXmlStrings.Name);
XElement value = userSetting.Element(SoapXmlStrings.Value);
if (name != null && value != null)
{
settingsDictionary.Add(name.Value, value.Value);
}
}
}
else if (error == "RedirectAddress")
{
// The server has given you a better email
// address to use.
Tracing.WriteLine("Server response contains a RedirectAddress error.");
XElement redirectTarget = FindFirstDescendant(responseEnvelope,
SoapXmlStrings.RedirectTarget);
if (redirectTarget != null &&
IsValidRedirectAddress(redirectTarget.Value, EmailAddress))
{
Tracing.WriteLine("Restarting Autodiscover with email address: " +
redirectTarget.Value);
EmailAddress = redirectTarget.Value;
UrlList.Clear();
UrlList.GenerateList(this.EmailAddress);
visitedUrls.Clear();
AddressRedirects++;
return(TryAutodiscoverUrls(useSoapEndpoints));
}
Tracing.WriteLine("Invalid or missing RedirectTarget element, continuing...");
}
else if (error == "RedirectUrl")
{
// The server has given you a better URL
// to use. Validate that it is https and
// try it.
Tracing.Write("Server response contains a redirect to URL: ");
XElement redirectTarget = FindFirstDescendant(responseEnvelope,
SoapXmlStrings.RedirectTarget);
if (redirectTarget != null && IsValidRedirectUrl(redirectTarget.Value.ToLower()))
{
Tracing.WriteLine(redirectTarget.Value);
UrlRedirects++;
return(TryAutodiscoverUrl(
AutodiscoverUrlList.NormalizeAutodiscoverUrl(redirectTarget.Value),
useSoapEndpoints));
}
Tracing.WriteLine("Invalid or missing RedirectTarget element, continuing...");
return(null);
}
}
}
else if (soapResponse.StatusCode == HttpStatusCode.Redirect ||
soapResponse.StatusCode == HttpStatusCode.Moved ||
soapResponse.StatusCode == HttpStatusCode.RedirectKeepVerb ||
soapResponse.StatusCode == HttpStatusCode.RedirectMethod)
{
// Redirect HTTP status scenario.
Tracing.WriteLine("Received a redirect status: " + soapResponse.StatusCode.ToString());
string redirectUrl = soapResponse.Headers["Location"].ToString();
Tracing.WriteLine("Location header: " +
(string.IsNullOrEmpty(redirectUrl) ? "MISSING" : redirectUrl));
if (IsValidRedirectUrl(redirectUrl.ToLower()))
{
UrlRedirects++;
return(TryAutodiscoverUrl(
AutodiscoverUrlList.NormalizeAutodiscoverUrl(redirectUrl),
useSoapEndpoints));
}
Tracing.WriteLine("Invalid (non-https) redirect URL returned. Unable to proceed.");
return(null);
}
}
catch (WebException e)
{
// Some errors will be exposed as WebExceptions.
// For example, 401 (Unauthorized)
// 302 should not generate a WebException and is handled above.
Tracing.WriteLine("Error connecting:");
Tracing.WriteLine(e.ToString());
}
return(settingsDictionary);
}
