Authenticating ChatBot (Microsoft Bot Framework) using cookies from different website in same domain?

I need to authenticate my user in chatbot ,using cookies in my website eg. I have a website "portal.b.com" hosted on an azure Virtual Machine ,

So when my user logs into my website I cookies are stored When he/she clicks On the bot , the bot should be aware about the user details.

eg. Hi "User_Name"

1) I have apis to get the user details , 2) I just dont want to ask user to sign in separately into the bot. 3) I use a session id and other cookies in my website 4) I have currently implemented the bot in Node JS

How can I implement above scenario?

Thanks

via anurag Raj