Windows Device Enrolment Process Message Flow

Overview

Windows devices are enrolled through the inbuilt application of the respective device, i.e Company app on Windows 8.0 and Workplace on Windows 8.1. The endpoints it triggers cannot be altered as required by the service developer. Therefore additional server configurations are required to manage Windows devices using WSO2 EMM.

For more information, see windows server configurations.

The high level message flow of a Windows device is shown in the below diagram. The Windows device sends requests to a Proxy server that then directs the requests to the WSO2 EMM server.

How it works

Step 1: Initiate the enrollment process

When a user signs in through the Workplace application using a Windows device, the user's email address needs to be provided as shown below:

The email address is provided in the following format: <user>@<EMAIL_DOMAIN>.
The automatic discovery service of the device uses the following fields and constructs a unique URI:
- Append the subdomain enterpriseenrollment.
- Extracts and append the domain from the username, i.e <EMAIL_DOMAIN>, that was submitted when signing in.
- Append the path /EnrollmentServer/Discovery.svc.
The constructed URI will take the following format: enterpriseenrollment.<EMAIL_DOMAIN>/EnrollmentServer/Discovery.svc
Example: If the given user name is admin@wso2.com the resulting URI would be enterpriseenrollment.wso2.com/EnrollmentServer/Discovery.svc.
The constructed URI will then be used to initiate the enrollment process of the mobile device.

Step 2: Proxy endpoint 01

URI format

http://enterpriseenrollment.<EMAIL_DOMAIN>/enrollmentserver/discovery.svc

The first Proxy endpoint known as the Discovery Service Endpoint receives the initial request from the device.

The initial request from the device is a standard HTTP GET request.
The received request is redirected by the Proxy Server to MDM endpoint 01 at the server end.

The GET request helps the device to check if the server is up and running.
Once a success message is returned to the device by MDM endpoint 01, It will move to the next step.

Step 3: MDM endpoint 01

URI format

http://<server-ip>:<server-port>/api/device-mgt/windows/v1.0/services/discovery/get

This endpoint receives the initial GET request that was redirected by the Proxy Server. It then returns a success response to the device.
When the endpoint receives the success message from the server, the device triggers a HTTPS POST request to the same proxy endpoint (Proxy endpoint 01) .
The Proxy Server redirects the request to MDM endpoint 02, which is at the server side.

Step 4: MDM endpoint 02

URI format

http://<server-ip>:<server-port>/api/device-mgt/windows/v1.0/services/discovery/post

Once the POST request from the device is received at this endpoint, the MDM server will include the following details within a response body and send to the device.
1. Authentication Policy.(Federated)
2. Proxy endpoint for the Enrollment policy. (/ENROLLMENTSERVER/PolicyEnrollmentWebservice.svc) - Proxy endpoint 02.
3. Proxy endpoint for the Enrollment Service. (/ENROLLMENTSERVER/DeviceEnrollmentWebservice.svc) - Proxy endpoint 03
4. Proxy endpoint for the Windows login page. (/emm-web-agent) - Proxy endpoint for the federated login page.

https://enterpriseenrollment.<EMAIL_DOMAIN>/emm/enrollments/windows/login-agent

After receiving the above responses, the device requests are made in the following order:
1. The device requests for the login page using the proxy endpoint URL. The proxy server will then route the request to the following EMM endpoint.
```
http://<server-ip>:<server-port>/emm-web-agent
```
2. Next the device sends a request to Proxy endpoint 2 and 3 respectively.

Step 5: Proxy endpoint 02

URI format

https://enterpriseenrollment.<EMAIL_DOMAIN>/enrollmentserver/policyenrollmentwebservice.svc

This Proxy Server routes the messages to MDM endpoint 03.

Step 6: MDM endpoint 03

URI format

http://<server-ip>:<server-port>/api/device-mgt/windows/v1.0/services/certificatepolicy/xcep

MDM Endpoint 3 responds back to the device with the Certificate Enrollment Policy.

The Certificate Enrollment Policy is an implementation of the MS-XCEP 509 protocol.
Once the certificate enrollment policy is received, the device sends the Certificate Signing Request (CSR) to Proxy endpoint 03.

Step 7: Proxy endpoint 03

URI format

https://enterpriseenrollment.<EMAIL_DOMAIN>/enrollmentserver/deviceenrollmentwebservice.svc

This Proxy Server routes the message received from MDM endpoint 03 to MDM endpoint 04.

Step 8: MDM Endpoint 04

URI format

http://<server-ip>:<server-port>/api/device-mgt/windows/v1.0/services/deviceenrolment/wstep

The service corresponding to this endpoint generates the signed certificate for the Certificate Signing Request and Root certificate.
It then responds to the device with an encoded wap-provisioning.xml file, which includes necessary certificates and other Device Management information.

The certificate enrollment is an implementation of the MS-WSTEP protocol.
The initial details provided through the POST request are used to persist the device details in the database.

At the end of this flow the device is successfully enrolled.

Step 9: Proxy Endpoint 04

URI format

https://enterpriseenrollment.<EMAIL_DOMAIN>/syncml/initialquery

This Proxy Server routes the message received to MDM endpoint 05.

Step 10: MDM Endpoint 05

URI format

http://<server-ip>:<server-port>/api/device-mgt/windows/v1.0/services/syncml/devicemanagement/request

This endpoint will handle all the device management requests and responses.

The protocol that is being used is SyncML v1.2.