Comment by hedora
What’s illegal about stubs + extracting certs?
If the certificates were used for copy protection, the DMCA might apply. If they weren’t part of the API, copyright might apply. Patent law doesn’t apply, and trade secrets don’t enjoy legal protection.
They could argue you’re in violation of their terms of service, but their remedy for that is to kick you off the services you’re actively avoiding.
Is there some other law I’m missing?
The stubs still need to use Google servers for FCM but without following their terms, is that okay? Probably a grey area at best.
Extracting the certificates used for protection is against the DMCA in the US and probably legal in the EU as part of the interoperability exceptions.