Share the encrypted files

[radumarias]

Use cases

• Share your vault (or some files) with another user by re-encrypting the content you share with a shared secret key based on your private and the other user's public

Implementation

Setup

• The first time you start the application, it will generate private and public key

Receiver

• Use our app to get the public key
• Send it to Sender

Sender

• With a CLI arg, specify the file path you want to send to the user. THIS IS AN ABSOLUTE PATH RELATIVE TO YOUR ENCRYPTED FOLDER VIEWED AS DECRYPTED

• Decrypt the file with the original master key

• Generate a shared secret encryption key from your private and the other user's public

• Re-encrypt the file to be sent with this key

• Include our public in the encrypted file's header

• Send the file to user2. We don't handle this, it's outside of the application

Receiver

• Receive the file from user1. We don't handle this, it's outside of the application

• With a CLI arg, specify where to save the file you received. THIS IS AN ABSOLUTE PATH RELATIVE TO YOUR ENCRYPTED FOLDER VIEWED AS DECRYPTED

• Extract the other user's public key from the encrypted file

• Generate a shared secret encryption key from your private and the other user's public

• Decrypt the encrypted content with the shared secret encryption key

• Re-encrypt the file with our master key saved to the specified path

Maybe it would make sense to share also with age or OpenPGP similar to https://github.com/radumarias/rencfs/issues/233