When we first integrated mbedTLS, we decided not to enable
MBEDTLS_THREADING_C (which adds mutex locking to calls modifying the
state), and instead to simply create separate contexts ("states") for
each connection.
This worked fine until recently.
Sadly, mbedTLS 3 added a global state for the new PSA crypto
functionalities (which are required to support TLSv1.3).
This results in TLSv1.3 connections to access and modify the global
state concurrently when running in threads.
This commit enables MBEDTLS_THREADING_C, and MBEDTLS_THREADING_C_ALT to
provide a generic Godot implementation using the engine Mutex class.
Move library initialization to module registration functions.
Only set library debug threshold when verbose output is enabled.
TLSv1.3 functions seems to be a bit more verbose then expected, and
generate a lot of noise. Yet, some level of debugging without
recompiling the engine would be nice. We should discuss this upstream.
Our current Linux SDK for ARM32 from https://github.com/godotengine/buildroot
targets a relatively conservative baseline of neon-fp-armv8, and (at least based
on build issues I got) this doesn't seem to include hardware AES support.
Fixes#91352.
Keep module compatibility with mbedtls 2.x (old LTS branch).
A patch has been added to allow compiling after removing all the `psa_*`
files from the library folder (will look into upstreaming it).
Note: mbedTLS 3.6 finally enabled TLSv1.3 by default, but it requires
some module changes, and to enable PSA crypto (new "standard" API
specification), so it might be best done in a separate commit/PR.
This commit adds a new mbedTLS configuration header to customize the
built-in library (and can be optionally replaced by a platform-specific
one).
Currently, it disables most weak cryptographic functions (with the
notable exceptions of MD5 and SHA-1), along with removing support for
TLS versions 1.0 and 1.1 (making TLSv1.2 the only supported one).
