Keep camera frame containing qr-code for safekeeping
It would be awesome if Monkeysign would, by default, keep a copy of qr-codes containing fingerprints of keys being signed.
Here's a little snippet demonstrating how to use OpenCV and zbar to do that: https://0xacab.org/snippets/4
As a bonus, it uses zbar data to visually identify the qr-code containing the fingerprint in the saved image. This probably eliminates an attack scenario where a bad qr-code would be placed behind the user in an attempt to have the wrong key signed.
Obviously, the difficult part is integrating this in a the GTK UI. Probably this will be easier after #21 is fixed.