Microsoft Sharepoint Products and Technologies Resource Kit eBook

718 Part VIII: Securing SharePoint Products and Technologies
3. After the URL for the logon form has been retrieved, redirect the browser to
this URL. The logon form is created by the SSOSrv service. It prompts the user
to enter credentials for the enterprise application in a number of fields. The
order, the number and the display names for these fields are configured within
the application definition under Logon Account Information. For example, if
the enterprise application uses user name and password for authentication,
two fields will be present in the logon form. For SAP, you may need five fields.
After the SSOSrv service saves the credentials, the form redirects control back
to the original Web Part.
The code in your Web Part will be similar to the following example that shows
how to redirect the user to the logon form to save credentials for an enterprise application
called SampleApp:
protected override void RenderWebPart(HtmlTextWriter writer) //RenderWebPart
{
string[] rgGetCredentialData = null;
try
{
//Try to get the credentials for this application.
//Before running this code, make sure that an individual
//application definition for application called "SampleApp"
//has been added.
Credentials.GetCredentials(1,"SampleAPP", ref rgGetCredentialData);
}
catch (SingleSignonException ssoe)
{
//This exception will be thrown if this user does not have
//credentials for the "SampleApp" application.
if(SSOReturnCodes.SSO_E_CREDS_NOT_FOUND == ssoe.LastErrorCode)
{
//Send the user to the single sign-on logon form.
//The logon form will:
//- Prompt the user for credentials for this application
//- Save credentials for this user for this application
//- Then redirect the user back to this Web Part
string strSSOLogonFormUrl = SingleSignonLocator.GetCredentialEntryUrl
("MyIndividualApplicationID");
writer.Write("Click here to save your
credentials for the Enterprise Application.");
writer.WriteLine();
}
}
}
After the user credentials for the enterprise application have been stored in the
single sign-on database, the custom code in the Web Part should retrieve the credentials
using GetCredentials method, then submit them to the enterprise application in
a manner that is relevant to this application, then retrieve the necessary data from
this application, and then finally render the data in the Web Part. Referring back to
Figure 26-1 that shows eight steps described in the section “How Single Sign-On