Problem of TLS connection of the tasmota device with its server

[songhellobulter]

Our server has SSL.com certificate like in the attached.

We generated the certificate data and saved them in local_ca_descriptor.h, local_ca_data.h
and #define INCLUDE_LOCAL_CERT in the user_config_override.h

Now we have TLS connection error 296.

Have we missed anything. Could anyone please suggest? Thank you very much.

[s-hadinger]

Error 296 is SSL3_ALERT_HANDSHAKE_FAILURE

This makes me believe that you server is expecting a certificate based authentication from the client, which we have very limited support.

[songhellobulter]

Thank you for s-hadinger for your answer.
The server works fine with our other product with a same ESP32 chip which includes the same certificate data. Should it work OK with the tasmota one?
From the server certificate, it is RSA and supports ECDHE_RSA_WITH_AES_128_GCM_SHA256. What else should we need?

[s-hadinger]

By the way, if you want to test with bearssl on a laptop, compile bearssl and try:

./brssl client <ip_or_domain>:<port> -cs ECDHE_RSA_WITH_AES_128_GCM_SHA256