Secure login on your domain with Google App Engine

We are starting a very large web based service project. We are trying to decide what hosting environment to use. We would really like to use Google App Engine for scalability reasons and to eliminate the need to deal with servers ourselves.

Secure logins/registrations is very important to us, as well as using our own domain. Our target audience is not very computer savvy. For this reason, we don't want to have the users have to sign up with OpenID as this can't be done within our site. We also do not want to force our customers to sign up with Google.

As far as I can see, I am out of luck. I am hoping to have a definite answ开发者_JS百科er to this question. Can I have an encrypted login to our site accessed via our domain, without having to send the customers to another site for the login (OpenID/Google).

Thanks.

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The hardest part is getting around the cookie issue. While you can do secure and custom logins against https://yourdomain.appspot.com, you cannot set a cookie there that will work on http://yourdomain.com.

Here is what I propose:

When you need to log the user in, send them to https://yourdomain.appspot.com. If they enter the credentials properly, create a one-time token and place it either in the datastore or in memcache. Give it a lifetime of a few seconds.

Then redirect the user back to http://yourdomain.com/authenticate?token=mytoken (obviously substitute the names as appropriate), check to make sure that the token is valid and has not expired, and if all is clear, set the appropriate cookies and expire the token.

I think that'd work just fine. Hope it helps!

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As of June 27, 2012, App Engine supports SSL for custom domains.

http://googleappengine.blogspot.com/2012/06/google-app-engine-170-released-at.html

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There is nothing stopping you from creating your own authentication/registration mechanism with Google App Engine. The only problem is that Google App Engine currently only supports HTTPS via https://yourid.appspot.com and not your Google Apps Domain (i.e. https://www.foobar.com). However, this is on the product roadmap for future support (SSL for third-party domains). Note, also on the product roadmap is built-in support for OAuth & OpenID.

Update: Another option may be to use a proxy server (like Apache with mod_proxy) and map your domain to the proxy server and then the proxy server can proxy the HTTP and HTTPS requests to Google App Engine. The requests could be proxied to the appspot.com domain behind the scenes. I haven't actually done this, but I believe it should work. However, this would give you a single point of failure at the proxy server which basically defeats the purpose of Google App Engine's high-availability and scalability. This would definitely just be a short-term solution until Google supports SSL for third-party domains or OpenID.

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Depending on whether your threat model can accept a non-encrypted link on the "last hop" to GAE, you can use a proxy to handle SSL from the browser. Here's a HOWTO I wrote up on using CloudFlare to get always-on SSL:

http://blorn.com/post/20185054195/ssl-for-your-domain-on-google-app-engine

This isn't structurally any different than the way SSL from Google will work, it's just that Google-provided SSL will terminate within G's network rather than just outside it. If you're trying to protect against Firesheep, CloudFlare (or any other SSL proxy) will do fine. If you're worried about snoops on the trunk connection between CF and Google, you may want a more sophisticated solution.