[ZenFone 2 Android Development] DarnYouGoogle:
Can confirm the issue with Protonmail, but oddly enough rolling back to a version prior to the Jan 2020 update that supposedly forced TLS 1.2 still results in a crash anyways. I haven't checked the logs because I'm not sure there's anyone actually working on this anymore anyways aside from just applying upstream patches, but that would imply the issue isn't simply lack of TLS 1.2 support. Unless it's initiating a TLS connection to the server before even loading the GUI, which would be weird considering I didn't have an account for it to load anything from. I also just spent all day flashing just about every other 7.1 rom for this device and Protonmail didn't load on any of them. The issue is probably upstream, since they all seem to base on LineageOS. I couldn't find anything that wasn't based on Lineage in some way, in fact. Has anyone gotten Protonmail working in anything other than 5.1 on this device? I don't really need Protonmail personally, but one thing being this severely broken makes me wonder what else I'll find later on that doesn't work right. I'd also be interested in any information on how TLS is implemented in /system, maybe I could build a flashable zip from a ROM that does have TLS 1.2 support to test if baking that in does fix it. A forum-wide search returns a lot of people asking the same question and getting no response at all, so I guess I won't hold my breath. I did, however, learn that TLS 1.2 should be supported in all android versions beyond 5, and has been required for several usecases for years before the most recent release of even the last official Lineage build. So, why it wouldn't be in any LineageOS build/fork of 7.1 is completely beyond any reasoning I can find. Does anyone know of a debug tool to test which version of TLS is built into a given ROM's API level? Would at least save me barking up the wrong tree if that indeed isn't the issue.

TEMPORARY FIX/ANSWER:

After a ton of digging around the internet and testing, I finally got Lineage to boot a version of Protonmail. Turns out I just wasn't going old enough in my initial tests. This is definitely indicative of a serious flaw somewhere, but short of compiling the ROM myself with a different SSL provider I'm kind of out of ideas for a more permanent solution. I'll wait and see if anyone ever wants to help me fix this issue, but I think I'm out of my depth and don't have enough free hard drive space currently to install any real dev toolkits. The version of Protonmail that works is 1.11.0 and you can get it here: apkmirror . com/apk/protonmail/protonmail-encrypted-email/protonmail-encrypted-email-1-11-0-release/protonmail-encrypted-email-1-11-0-android-apk-download/ (Link borked because I'm probably not allowed to post links, but you can fix it if you can't find the apk by searching for the version number yourself)

Edit: Leaving this here in case the knowledge that it boots helps someone fix the bug, but it doesn't allow you to create an account or log in. Just crashes when it tries to do that. This is beyond me, and I can't figure out how to switch back to the 5.1 bootloader so I guess I'm stuck with maybe random apps never launching for no reason I can figure out. Thankfully the things I actually use (At least at the time of this writing, anyways) seem to work fine, and if I ever really need protonmail there is a web version.