I talk to a lot of customers using Office 365 that would like to have granular control on who can access the hosted services and only allow access to these services from corporate owned and managed devices. Enter Azure AD Conditional Access. “Keep out.. Unless of course you meet certain conditions!”
For example, with Azure AD device access rules you can restrict access to Exchange Online to only domain joined machines.
“Wait?! What?! That sounds just like what I’m looking to do.
What does that look like?”
When a user attempts to access Outlook Web App from a personal computer, they go to the OWA URL and enter their username and password.
The conditional access policy will look to verify that the device being used to access OWA is domain joined and registered in Azure AD. Since the computer is a personal computer, the user is denied access.
After closer examination using the “More details” link, you can see the access rules set require the device to be domain joined for access. In the scenario of personal computers, this will show as Unregistered.
Your access to corporate resources was swatted away like Dikembe Mutumbo. “Not in my house!”
“Good Eric, that’s all great but how about the full Outlook client? I would really like to see what options we have to prevent our users from connecting their personal Outlook client to our corporate email.”
When a user attempts to connect the Outlook client on a non-domain machine, the Outlook client will open and prompt the user for authentication.
The user will enter their username and password and the authentication process will look for a registered device.
Once again the user will be gently reminded that they need to be on a corporate owned device.
“Wow Eric, I’m really impressed by Conditional Access and the device access restrictions available in the Microsoft security suite. Anything else we should know? What about users that want to access OWA from other browsers?”
First and foremost, under no circumstance should you ever use anything other than Microsoft technology. Ever!
But, in the event some of your users want to go against my recommendation, to access corporate resources protected with device access rules they would need to use a supported browser. Conditional access support for applications: https://azure.microsoft.com/en-us/documentation/articles/active-directory-conditional-access-supported-apps/
The behavior when attempting Outlook Web App using the Google Chrome browser would be as follows:
The user enters their username and password from a non-domain machine.
Since the user is trying to use a browser that doesn’t support conditional access, it gives the user a warning that the browser is not supported and to use Microsoft Edge or Internet Explorer.
The device based access rules are configured within Azure AD Premium and have the following options.
- Enable Access Rules – On or Off. (self-explanatory)
- Apply To – Specific groups that you want to scope the access rules to. You also have the ability to except specific users from the scope.
- Device Rules – The access rules you want to enforce for access to the corporate resources.
- Application Enforcement – “For browser and native applications” OR “For only native applications” Exchange ActiveSync – Require a compliant device to access email
For more information on Azure AD Conditional access, please read the official Microsoft blog article AzureAD Conditional Access Policies for iOS, Android and Windows are in Preview!