I've been attempting to do SSO for Office365 and have federated my AD with Office365. When I reach portal.microsoftonline.com and enter a username from my domain eg: user@mydomain.com, the page gets redirected to my ADFS for authentication, there after the user keys in his/her credentials.

Is there a way to do a active authentication for Office365, if I used the term correctly, where a user logs into my site which already actively authenticates a user using a HttpBinding to my ADFS then also gets authenticated for Office365?

The high level flow is as follow:

1. User signs into my website which is authenticated against the ADFS via active authentication
2. User proceeds to Office365 and should not need to log in again.