How does my app log into hosted Sharepoint (Sharepoint Online/Office365)?

Question

I'm new to Sharepoint generally, and need to write an app which will do some basic file management. First, though, it needs to log in.

The documentation I've found suggests that:

var clientContext = new ClientContext("https://company.sharepoint.com/");
clientContext.AuthenticationMode = ClientAuthenticationMode.FormsAuthentication;
clientContext.FormsAuthenticationLoginInfo = new FormsAuthenticationLoginInfo(username, password);

Web web = clientContext.Web;
clientContext.Load(web);
clientContext.ExecuteQuery();

should connect to the server and get some basic information.

However, I'm getting an exception: "The user's login name or password is not valid.". I'm using my own credentials, with which I've logged into Sharepoint several times in a browser.

What am I doing wrong?

Answer 1

When connecting to SharePoint Online, you should use SharePointOnlineCredentials instead of FormsAuthenticationLoginInfo.

using (var context = new ClientContext("https://contoso.sharepoint.com"))
{
    var password = new SecureString();
    foreach (var c in "Password")
    {
        secureString.AppendChar(c);
    }

    context.Credentials = new SharePointOnlineCredentials("login@contoso.onmicrosoft.com", password);

    var web = clientContext.Web;
    clientContext.Load(web);
    clientContext.ExecuteQuery();
}

Answer 2

You may want to check out this video from the Office 365 Developer Patterns and Practices Group. It enables you to achieve a similar result to using the SharePointOnlineCredentials without having to include your user name and password in the code.

Connecting to SharePoint Online from console application with Azure ADAL and PnP Core Component