TCP over SSL issue on HL6528RD

IoT Modules Legacy HL Series
1

Hi,

I’m trying to open a TCP socket over SSL/TLS in order to use MQTT protocol on it.
Here below the sequence of AT commands:

AT+KCERTSTORE=0,1558,0
AT+SSLCRYPTO=5,1,1,8192,64,7,1
AT+KCNXCFG=1,“gprs”,“internet”
AT+KTCPCFG=1,0,“server_url”,“server_port”,1,1,5
AT+KTCPCNX=1

Modem clock has been set via

AT+CCLK=“yy/mm/dd,hh:mm:ss+00”

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.

Thanks in advance,
Sabino

2

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?

Regards,
Sabino

3

Hi @sabinocolonna,

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.

1 Like
4

Hii @Donald

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!