Rotating User Agent

[arch-btw]

I would like to propose a rotating user agent in ElectronMail to (partially) mitigate potential accounts association in worst case scenarios.

[vladimiry]

Referencing related issue. So currently the app strips out the electron/app specifics from the user agent to make it look like a regular Chrome browser.

[arch-btw]

Thank you @vladimiry

How about something like this?

We could have them rotate through a list of random user agents on every logon.

A list of user agents can be found here: https://developers.whatismybrowser.com/useragents/explore/

[vladimiry]

Here is how to enable to option for the specific email account:

Here is the default user agents list:

ElectronMail/src/shared/util.ts

Lines 63 to 74 in 34f3ee9

	userAgents: [
	/* eslint-disable max-len */
	"Mozilla/5.0 (Windows NT 10.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.186 YaBrowser/18.3.1.1232 Yowser/2.5 Safari/537.36",
	"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36 OPR/56.0.3051.52",
	"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36",
	"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.149 Safari/537.36 Edg/80.0.361.69",
	"Mozilla/5.0 (X11; CrOS x86_64 12739.111.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.162 Safari/537.36",
	"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.87 Safari/537.36",
	"Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4102.3 Safari/537.36",
	"Mozilla/5.0 CK={} (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko",
	/* eslint-enable max-len */
	],

The list is saved in the config.json file which is located in the setting folder, so the list can be manually modified if needed. It's recommended to use Chrome-based user agents since if proton-web-client detects some browser capabilities based on the user-agent instead of using a feature-detection approach then some things might get broken since Electron comes with Chromium browser built-in.

[vladimiry]

The work-in-progress build with enabled feature is uploaded here.

[arch-btw]

@vladimiry you are so great !!!!!!! Thank you!

[User486375]

@arch-btw How exactly do you see this feature benefiting the avoidance of account association in its default state? As opposed to just blending in with the latest Chrome version for example.

[vladimiry]

Since v4.15.0 the user agent rotation feature gets replaced with an optional per account "user agent" string value. The change reduces the code complexity and overall feature understanding.