I wrote something similar, a couple of years ago[0], but it doesn't include encryption; it merely gives a place to add encryption. I didn't want to deal with the legalities of included encryption, and I think others can do far better than I (but it is quite secure, nonetheless[1]). It was really done, just to "retool" my architectural and engineering skills, as I was pivoting from being a manager, back to being a developer.
I am now using it as a backend for an app under development (currently closed-source). It has been working a treat.
But after the app has been released, I may encourage the folks to look at alternatives for the backend. I am not really into maintaining a server system. I like to stay on the app side of things.
The deal with mine, is the encryption is left to the client. The server just stores a binary "thing." That "thing" can be an encrypted envelope, managed by the client[s]. Since it's a closed-loop system, then a key could be shared programmatically, outside the purview of the server.
I don't think Firefox sync makes it very easy for devs to build other encrypted applications. Even if they did however, there are a lot of challenges with encrypted applications that they just don't take care of. Not to mention that they are very we centric and don't have developer APIs in many languages.
I wrote something similar, a couple of years ago[0], but it doesn't include encryption; it merely gives a place to add encryption. I didn't want to deal with the legalities of included encryption, and I think others can do far better than I (but it is quite secure, nonetheless[1]). It was really done, just to "retool" my architectural and engineering skills, as I was pivoting from being a manager, back to being a developer.
I am now using it as a backend for an app under development (currently closed-source). It has been working a treat.
But after the app has been released, I may encourage the folks to look at alternatives for the backend. I am not really into maintaining a server system. I like to stay on the app side of things.
[0] https://riftvalleysoftware.com/work/open-source-projects/#ba...
[1] https://riftvalleysoftware.com/BAOBAB/PDFs/Security.pdf (Downloads a PDF)