Webclient connections

Outlook.com contains a webclient for MSNP. This uses a long polling sort of gateway server.

Authentication

The webclient uses cookies for authentication; these are granted by the Microsoft Account login form, both regular and OAuth. Exactly which ones are needed is unclear.

The cookies aren't sufficient for logging in: a uic value is required as well. This can be obtained by the following:

1. POST the empty string to https://go.trouter.io/v2/a. Let the response body be ra.
2. Form a JSON object: {"trouterurl": ra.url, "connectionid": ra.connId}
3. POST that object to https://skypewebexperience.live.com/v1/user/Initialization, with the Content-Type set correctly and being sure to include the cookies.
4. The response you get from that contains the uic as the value of MappingContainer.

HTTP gateway

This seems to be a variation on long polling: ie, POST things you want to send, and keep a connection open for the server to send you things.

To start a session, POST your initial MSNP messages to https://geo.gateway.messenger.live.com/gateway/gateway.dll?Version=1&Protocol=mtp&Action=open&Server=NS&IP=none. There are two additional headers to be aware of that the webclient sends:

X-MSN-Auth: Use-Cookie
X-Requested-Session-Content-Type: text/html

The response body will be whatever MSNP messages the server deems necessary to send you, and will have some interesting headers:

X-MSN-Host: <hostname>.gateway.messenger.live.com
X-MSN-Messenger: SessionID=<sid>; GW-IP=<ip>
X-MSN-SessionTimeout: 120
X-MSN-SkypeId: <username>
X-MSNSERVER: <hostname>

After this, whenever you want to send something, POST it to https://<X-MSN-Host>/gateway/gateway.dll?SessionID=<sid>. In order be able to receive something, POST the empty string to the same URL, but with the additional parameters Action=poll&Lifespan=60, and hold the connection open until the OS gets annoyed with you or you receive something. Then do it again.

I currently don't know how you tear down the connection.