Arm Mbed and Pelion Device Management support forum

2 ways authentication error with TLS client/server

Hi all,
i’m trying a 2 ways authentication communication between server/client on TLS over TCP, it was OK with 1 way, i’ve added differences described here:,
and i get on server error " MBEDTLS_ERR_SSL_BAD_HS_CERTIFICATE" or 0x7A00, saying “Processing of the Certificate handshake message failed”. This error is generated at ssl_handshake.

I have compared my code with ssl-server1 and client1, which inspired me.
Did i forget anything ?
Thanks in advance, Nicolas.

Hi @nicogeff
As mentioned in this post, Mbed TLS is now maintained under open governance at

It is advised you post your question in their mailing list.
Mbed Support

HI Ron,
I have no news, did i miss anything ?

Thanks, Nicolas.

Hi Nicolas,
Have you sent your question to ?

Hi Ron,
yes this is exactly what i did…