In a previous post I talked about our strategy of using scheduled console applications to perform tasks that are often performed by SharePoint timer jobs.
As we march “zealously” to the cloud we find ourselves needing to update our batch jobs so that they communicate with our SharePoint Online tenant. We must update our applications because the authentication flow between on premise SharePoint 2013 and SharePoint Online are completely different.
Fortunately for us, we found the only change needed to adapt our list accessing code was to swap instances of the NetworkCredentials class for the SharePointOnlineCredentials class.
Imagine that this is your list reading code:
using (var client = new WebClient())
{
client.Headers.Add(“X-FORMS_BASED_AUTH_ACCEPTED”, “f”);
client.Credentials = _credentials; //NetworkCredentials
client.Headers.Add(HttpRequestHeader.ContentType, “application/json;odata=nometadata”);
client.Headers.Add(HttpRequestHeader.Accept, “application/json;odata=nometadata”);
/* make the rest call */
var endpointUri = $”{_site}/_api/web/lists/getbytitle(‘{_listName}’)/Items({itemId})”;
var apiResponse= client.DownloadString(endpointUri);
/* deserielize the result */
return _deserializer.Deserialize(apiResponse);
}
The chances are your _credentials object is created like this:
_credentials= new NetworkCredentials(username,password,domain);
Here, the username and password are those of a service account specifically provisioned a for SharePoint list access.
In order to swap the NetworkCredentails class for SharePointOnlineCredentails first, you need to download and install the latest version of the SharePoint Online Client Components SDK here (https://www.microsoft.com/en-us/download/details.aspx?id=42038).
Once the SDK is installed add a reference to the Microsoft.SharePoint.Client and Microsoft.SharePoint.Client.Runtime libraries. Assuming a default installation, these binaries can be found here: C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\16\ISAPI\.
Be certain to reference the 16.0.0.0 version of the dlls. If you get the 15.0.0.0 version (which is currently the version in NUGet) your code may not work!
Now you can “new up” your _credentials like this:
_credentails = new SharePointOnlineCredentials(username,password);
But “TV Timeout!” (as a colleague likes to say after a couple brews at the pub) the password argument is a SecureString rather than the garden variety string. You will need a helper method to transform your plain old string into a SecureString. Here is how we do it:
public static SecureString GetSecureString(string myString)
{
var secureString = new SecureString();
foreach (var c in myString)
{
secureString.AppendChar(c);
}
return secureString;
}
One last thing to note; the SharePointOnlineCredentials class implements the System.Net.ICredentials interface. That’s what allows us to simple swap one class for another.
Therefore, if you are following the SOLID principles and using dependency injection then the extent of your code changes may look like this:
var securePassword = SecureStringService
.GetSecureString(settings.SPOPassword);
container.Register<ICredentials>(()
=> new SharePointOnlineCredentials(username, securePassword));
Now that is cool!
Cheers and Happy Coding!
jcclements 