SOGo VS ProtonMail Web Client

Episode 3, which I will bookmark as it lists the solutions that they have selected. I read e.g. about SOGo and Zorin OS that I didn't know of.

https://github.com/Alinto/sogo <-- Is now under the Alinto account

[1] https://github.com/inverse-inc/sogo

(See: https://github.com/inverse-inc/sogo/releases/tag/SOGo-5.5.1)

Have a look at https://sogo.nu/

> Is this password-derived key the "account key" which I see in the Proton Mail settings interface?

No, the account key is an OpenPGP key which is encrypted with a key derived from your password. The "key encryption key" is not separately visible. The address keys are in turn encrypted using the account key.

> Please clarify what key derivation function is being used.

We use bcrypt, in addition to the OpenPGP S2K (i.e. the bcrypt output is fed as the "password" to OpenPGP's key encryption).

We are in the process of rolling out OpenPGP.js v6, which supports Argon2 for the OpenPGP S2K step, after which we'll start using that - but we aren't quite yet.

> Are there instructions for verifying that all this is happening? I think a lot of folks on HN won't be convinced otherwise.

Take a look at https://github.com/ProtonMail/WebClients/blob/main/packages/..., for example. Though to be honest, if you want to verify that we aren't sending the password to the server anywhere, in principle you'd have to check the code of the entire web app. It's all open source, but it's a lot of work, of course. But you can also check the latest audit report: https://proton.me/blog/security-audit. They also verified all of this stuff.

> It's just that I'm going to create an OpenPGP identity for things like signing code commits on git, signing packages I publish. (...) So I was really hoping to be able to use Proton Mail with this identity instead of the key pair that's generated for the account.

Yeah, I understand. Though, the typical advice from a cryptographer's perspective would be, it's better to use separate keys for separate purposes; and the simplest way to do that is to generate separate OpenPGP certificates, so that's what we'd generally recommend. But, if you want to generate separate subkeys and sign them all using a common primary key, that's also reasonable enough. And, we can improve the documentation on that, although it's a bit of a niche use case (not for HN of course, but for the general audience it is).

> Thanks for reaching out here on HN. I've been a really happy Proton Mail customer and now I'm even happier.

Thanks, glad to hear! :)

The source code is here https://github.com/ProtonMail/WebClients

> Finally, in keeping with our long track record of transparency, Proton Pass is open source so anyone can review and verify our security architecture

They sure do enjoy writing that sentence without including any hyperlinks. This (https://github.com/ProtonMail/WebClients/tree/main/applicati...) appears to be the browser extension and https://github.com/ProtonMail/WebClients/tree/main/packages/... appears to look like the backend referenced in the extension's readme, but that directory's readme is zero bytes so (shrug)

Fork the frontend and make your own lightweight option

PS: I hope that we selfhosters will have a modern, efficient, easy to use mail suite one day with modern features like JMAP, good self-learning spam integration, automated checks and validations for SPF/DMARC/DKIM or whether the IP/host suddenly appears in a blocklist and integrated encryption at rest for emails. Something that isn't 30 services in a container image, with 30 different configuration styles. Maybe even with an API integrated that's compatible to the ProtonMail frontend (like the neutron server once intended to be). Anyway, I'm sorry for dreaming. ;)

And if you want to customize it further you can use Stylus to add custom CSS, Tampermonkey to add JS, or even modify the whole thing yourself from source (if you run it locally it syncs with your actual account).