This Mattermost plugin serves as a symmetric encryption and decryption layer when uploading and downloading files, respectively.
This is a work in progress and contributions are welcome!
This plugin needs a hook that is invoked when a file will be read. There is no such hook for server-side plugins in Mattermost server (as of 29.11.2019). So, I am currently working on adding a new hook named FileWillBeRead. It is a work-in-progress and can be seen here. Comments and contributions to there are also welcome!