CA callback not called in TLS 1.3

[gilles-peskine-arm]

Configuring a CA callback with mbedtls_ssl_conf_ca_cb() has no effect in TLS 1.3. This is not documented as a limitation, and there is no reason not to support it. See #7075 (comment)

The goal of this task is to support a CA callback in TLS 1.3, the same way as in TLS 1.2.

This should be tested both from the server side and the client side.

[gilles-peskine-arm]

Related: TLS currently doesn't support the X.509 certificate extension callback (only available via mbedtls_x509_crt_parse_der_with_ext_cb). Whatever method we add to make it support this, should work both for TLS 1.2 and TLS 1.3.

[adambvidex]

Is there a workaround for this bug? Our product requires it because the CA database cannot fit in RAM of the embedded device.

[ronald-cron-arm]

Is there a workaround for this bug? Our product requires it because the CA database cannot fit in RAM of the embedded device.

#9002 fixes this issue.

[ronald-cron-arm]

Closing this issue as we have rather decided to address this more generally with #9018.