Using RCS with Google Messages on GrapheneOS

SirBlain Only three days? That seems normal. I'm on Visible as well. Longest I had it stay connected was a week. Finally gave up on it. Seems unlikely to get fixed at this rate, but who knows.

Looks like this issue (with a generic reference to "custom ROMs" rather than GrapheneOS specifically) is getting some coverage: https://9to5google.com/2024/02/29/google-messages-rcs-rooted/. Not sure how well-researched the article is but curious if people thought this is off-base or some consensus emerging around a new restrictive approach that Google's taking.

Gramsci ugh, I have been wondering about this for a few weeks now. It does seem like Google is trying to tie RCS to hardware in a way that graphene prevents. Well I don't understand all of the technical details, it is a little understandable from the point of view of wanting to have absolute control over a device/person and wanting to prevent spoofing.

It's an uphill battle, but it's going to push me further towards third party E2EE options, and I'll just have to deal with getting my friends onto those platforms.

I suppose the other approach is that somebody could come up with a way to implement RCS outside of Google messages. I know that's been a very rocky situation.

I've successfully setup rcs.
First time it wouldn't read any section within the RCS (this device is not supported or something like this).
Then removed the app, and re-installed it (no need for Carrier for me), and gave the minimal permissions (phone, network, sms + out of convenience also for Contacts).
For Play services + GSF + Play store = only network (no phone permission)
Took the settings to use rcS without google account.

Registered within 3-5 minutes maybe.
Used LTE during registration, dc/ed from wifi.

They're likely trying to crack down on spam. They may be using the Play Integrity API failing to pass as a spam signal. Play Integrity API is unfortunately inherently anti-competitive. The correct way to approach this would be using hardware attestation, not a trivially bypassed approach. Hardware attestation supports permitting specific alternate operating systems. The reasonable way for Play Integrity API to work would be solely using hardware attestation and permitting alternate operating systems preserving the security model regardless of whether they follow an extremely arbitrary list of non-security-related rules which are often counter to the goal of privacy and security. It's unlikely Google will do this on their own, but they could be forced to do it by a regulator.

yaomtc Well 2 days after posting this RCS stopped working for me again. It now says "Setting up... Trying to verify [my phone number]". I guess the changes to Messages/Google RCS were being rolled out gradually.

Still working.
But recently checking out the mobile contract I have, it also says RCS-Chats.

RCS started working again today. I don't know why.

I use airplane mode often (which deregisters RCS after some time), and I like to enable the option to block connection without VPN (which seems to block the connection and eventually will deregister RCS as well). Unless there is a clear fix for this, I am giving RCS a break.

That's how I'm understanding it honestly. I've stopped trying to reactivate until there's some update workaround from GrapheneOS or Google

thed0ctor We can't work around services requiring Google certification via Play Integrity API.

vcavallo They may stop messing around with intermittently blocking non-Google-certified operating systems in which case it should work perfectly without repeated failures.

RCS just connected this morning out of the blue. I didn't do anything on my end. Let's see how long it lasts.

FlipSid still working. Just posting follow ups for reference.
Have you guys checkt with your carrier?
Mine excitedly states >RCS Chats<

Just came here to say I've been using Google's messenger app in hopes of using RCS, but after months stuck on "verifying phone number" I kinda doubt it will ever work

Mines working just fine on Google Fi.
I was on the same phone and phone number when I switched to GOS, I wonder if that makes difference? I don't think I had to activate it again after installing GOS.