If inside KTCPCFG command is 0 (client), TCP connection never works even if the certificate has been correctly stored. If is 3 (secure client), TCP connection always works even if I delete the certificate.
How to correctly setup a TCP over SSL socket with server authentication? Sequence of AT commands of a full working example should be really appreciated.
I found a possible issue. The parameter <SSL profile> inside AT+KTCPCFG command seems to work only with profile 0, so if I configure a different profile (e.g. 5) with AT+SSLCRYPTO, TCP socket will be always opened with configuration 0.
If I configure profile 0 and use it as <SSL profile> and <mode> 3 (secure client), all is working as expected.
I’m using FW 2.5.1.11CV10F49_P1.201805031654.m6261a_1: is there any known issues on this version about TCPCFG?
It can be limitation of the current firmware module. In your case, I recommend that you contact your local distributor or reseller for technical support.
It seems like the module isn’t enforcing certificate validation properly when set to secure mode. This could be a firmware limitation. To ensure server authentication works, try updating the firmware and double-check the certificate format. If it still fails, best to contact your distributor for a confirmed fix or support. Maybe it will be helpful!