Kiosk mode for Hasjob

[jace]

In kiosk mode, Hasjob disables the Login feature and the Apply form for jobs. Instead, it:

1. Requires the user to tap their ContactPoint NFC card to a locally attached NFC reader (using ContactPoint's localhost server),
2. Retrieves details from the ContactPoint server (which may be on the LAN, so only reachable from the client-side), and
3. Emails the candidate with instructions on how to apply from their own computer OR submits an application with a blank message (so that the employer is informed of the submission) and expects the candidate to follow up from their computer.

Since the ContactPoint interaction is entirely client-side and per-browser, enabling kiosk mode involves the following steps:

1. The user (any user of a given computer) must go to /contactpoint, a special URL
2. They must enter the URL of the local ContactPoint server and authorization key, and
3. Click the Enable button.
4. Hasjob then sets a cookie on the computer identifying it as a kiosk.
5. The home page now shows all jobs even if the user is not logged in.
6. The Login link disappears from the networkbar and jobs no longer have an Apply button.
7. Instead of Apply, the bottom section asks users to tap their cards. When a valid card is recognised, details are retrieved from the ContactPoint server, Hasjob asks for confirmation, and then sends email.

Issues:

1. In this scheme, Hasjob must authenticate itself to a ContactPoint server, but the reverse is not required. This means anyone can turn their personal laptop into a ContactPoint kiosk with their own ContactPoint server that returns arbitrary data and causes Hasjob to mail a targeted user. There needs to be reverse-authentication too, so that Hasjob can trust data coming from a ContactPoint server.

[miteshashar]

The listed issue can be handled by restricting the enablement of kiosk mode using /contactpoint only to siteadmins. So login as a siteadmin, enable kiosk mode, and log out.

[jace]

Good idea. It's a secure cookie, so the cookie can't be edited by users on their own computer.

[jace]

Also, Flask-Lastuser sessions are session-only cookies. Setting the contactpoint flag must turn it into a permanent cookie, and turning it off must change back to a session-only cookie.

[miteshashar]

Instead, why not have a separate permanent cookie for kiosk mode & contactpoint data?

[jace]

Then we lose the automatic security control of Flask's session cookie and will need to setup all that infrastructure on our own (using the itsdangerous library that Flask itself uses).

[miteshashar]

Ah, ok. Then the former suggestion makes more sense.

[jace]

Implemented in 31280e0 and subsequent commits. However, ContactPoint integration is still pending.