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  • Using RCS with Google Messages on GrapheneOS

I've been on a stable RCS connection now for one week and two days, which is the longest I've ever maintained. The only thing I changed was enabling compatibility mode in the app settings.
A couple other observations:
-GrapheneOS did update once and Google Messages updated twice during this period.
-When I go to Debug -> RCS -> Report RCS Connection State, it used to say "Transport: Chat API w/ RCS". Now it says "Transport: Chat API w/ Tachygram". I have no idea what Tachygram is.

I don't know if the improved stability is due to enabling compatibility mode, the updates, or just pure luck. I'll continue to run it with compatibility enabled, and if after a month it continues to stay connected I'll disable it and see if the connection remains. I'll also add that if this is a solution to the problem, I don't know if the risk is worth the reward. Is the security vulnerability from reduced sandboxing more important than the privacy of E2EE?

    Ugh,

    It disconnected today. I did just do an update, maybe it had to do with that, but I'd done a couple updates in the last week or two without issue.
    The wording changed slightly on the RCS verify page.

    "RCS chats require a verified number".

    I'm not gonna go through the whole process again. It would be great to find out what it is about Graphene OS is preventing this from working. Is there anyway we can contribute debug logs or anything?

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    • Post #211
    • Edited

    The February patches notes say, "Messaging: update MMS configuration database based on Google Messages 20240123_01_RC02". Wonder if this will do anything. I did try to re verify my number post update. Nothing yet. Might need to do a fresh install of Google Messages, not sure.

    Edit: I have a feeling this for the stock messaging app.

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      • Post #213

      Welp GGs. I give up, haha.

      For those of you who have been unregistered, do you use aeroplane mode, disconnect from Wi-Fi and Data, or use the Block connections without VPN option?

      Ninja4694 It's weird that that's considered news. The ACS url we've been using for Verizon is already http://acs-vzw.jibe.google.com, indicating Jibe. And when I've gotten rcs to work on Verizon, I already have read receipts and stuff.

        irrenarzt That's good to know. I followed your lead and enabled compat mode on Messages, as well as Play Store and Services for good measure. I really don't think disabling gardener malloc.

        Idk about "tachygram", but I'm pretty sure Tachyon is the name of the software that does the e2ee sync between the app and any paired messages.google.com/web clients. Could be related?

          After 2 weeks mine just disconnected, so I guess compatibility mode doesn't resolve it. I was obsessively checking the RCS connection state, so I know the exact moment I was de-registered. It happened when I connected to a public wifi network that had restrictive settings and ports blocked, which prevented my VPN from connecting easily (had to use obfuscation). My guess is this wouldn't have been a problem if we could verify our numbers the way Google intends us to, but whatever is getting blocked by GrapheneOS caused it to get de-registered in this moment.

          I've gone through the process again and reconnected. This time the RCS connection state has reverted back to "Transport: Chat API w/ RCS", instead of "Tachygram". I'm still curious to know the difference.

            thed0ctor What worked for me was downloading that Messages APK (didn't need Activity Launcher) and enabling RCS. When I did this, it was stuck on "Connecting," so I updated Messages to the current version (thru the Play Store), opened it up and, it was connected. Idk if it'll work for anyone else but figured I should post just in case.

            Mine recently disconnected within the past couple days so I did this again and it worked. Might have been a Graphene update that broke it idk.

              bluesl33ves Yes. But the issue is with Google's app. Not sure what GrapheneOS developers can do if a Google app doesn't work the way it's expected to.

                  other8026 If the app registers effortlessly on stock Pixel OS, several Samsung devices, Xiaomi devices, etc., from what I have witnessed personally, does this still mean that the Google Messages app doesn't work properly? Couldn't it be a case where GrapheneOS is blocking the request for the ACS URL due to the sandbox simulation?

                      bluesl33ves I haven't personally tried to set up RCS. My guess is that Google Play Services, Google Play, or Google Phone expect to have access to some permission and/or they expect another app is installed, such as the Google app, or Assistant, or something. Maybe the app expects to be run from the owner profile. There are lots of reasons I can think of that the app will refuse to work.

                      As of right now, there's nothing to go on except "it doesn't work most of the time". Somebody needs to sit down and dig through logs and try permissions or installing apps to get to the bottom of why it doesn't work.

                          Still rocking stock Pixel7. No issues. Leads me to believe something about GrapheneOS' build is interfering with RCS

                          other8026 Permission wise, I believe a few persons have tried enabling all the possible permissions, on the primary account, and have even reset the device with no resolution. If you have other reasons, you can list them out. For me, being stuck at setting up, when I am not registered, just means that the device is not receiving the setup info. Furthermore, when trying to send the code from the Google Message deregister page, I may or may not receive the SMS message. I have never tried changing the Internet connectivity checks, Attestation key provisioning, and Widevine provisioning servers and turning off the Private DNS.

                            For what it's worth the only recent reports I've found of this happening outside of GrapheneOS are from people with other non-stock/rooted devices and their solution seems to be spoofing device integrity.

                            https://xdaforums.com/t/rcs-chat-gone-in-latest-update.4653947/#post-89312709

                            https://www.reddit.com/r/GoogleMessages/comments/1agsjh0/rcs_issues_on_devices_that_have_unlocked/