HTTPS POST failing on EC200U (CME errors (732), SSL cert issues)

IoT Modules LTE Standard Module
1

Hi Quectel team,

I’m working on HTTPS POST using:

Module: EC200U-CN
Board: 7Semi ESP32-S3 + EC200U 4G LTE Cat-1 Wi-Fi Bluetooth GNSS Smart Modem
Host MCU: ESP32-S3
Network: Airtel (India)

I am following the HTTPS AT command sequence exactly as described in the Quectel HTTP(S) Application Note.
I configured PDP, SSL, uploaded CA certificate and other two, and used AT+QHTTPPOST.

However, I am running into CME error 732.

AT command sequence I’m using

AT+QHTTPCFG=“contextid”,1
AT+QIACT?
AT+QICSGP=1,1,“airtelgprs.com”,“”,“”,1
AT+QIACT=1

AT+QIACT?
AT+QHTTPCFG=“sslctxid”,1

AT+QSSLCFG=“sslversion”,1,4
AT+QSSLCFG=“ciphersuite”,1,0xFFFF
AT+QSSLCFG=“seclevel”,1,2
AT+QSSLCFG=“cacert”,1,“UFS:cacert.pem”
AT+QSSLCFG=“clientcert”,1,“UFS:clientcert.pem”
AT+QSSLCFG=“clientkey”,1,“UFS:clientkey.pem”
AT+QSSLCFG=“ignorelocaltime”,1,1
AT+QSSLCFG=“sni”,1,1

AT+QHTTPCFG=“responseheader”,1
AT+QHTTPCFG=“contenttype”,1

AT+QHTTPURL=,80

AT+QHTTPPOST=,80,80

AT+QHTTPREAD=80

Below is the logs :

W (22480) QUECTEL: RX: AT+QFLST=“UFS:*”
+QFLST: “UFS:boot”,15004
+QFLST: “UFS:firm”,286000
+QFLST: “UFS:gnss_data”,4644
+QFLST: “UFS:gnss_loca”,47
+QFLST: “UFS:gnss_time”,21
+QFLST: “UFS:cacert.pem”,1281
+QFLST: “UFS:clientcert.pem”,1164
+QFLST: “UFS:clientkey.pem”,1704

OK

W (23460) QUECTEL: RX: AT+QFLST=“UFS:cacert.pem”
+QFLST: “UFS:cacert.pem”,1281

OK

W (26460) QUECTEL: RX: AT+QHTTPCFG=“contextid”,1
OK

W (26960) QUECTEL: RX: AT+QIACT?
OK

W (27470) QUECTEL: RX: AT+QICSGP=1,1,“airtelgprs.com”,“”,“”,1
OK

W (27970) QUECTEL: RX: AT+QIACT=1
OK

W (28460) QUECTEL: RX: AT+QIACT?
+QIACT: 1,1,1,“100.77.69.156”

OK

W (28960) QUECTEL: RX: AT+QHTTPCFG=“sslctxid”,1
OK

W (29460) QUECTEL: RX: AT+QSSLCFG=“sslversion”,1,4
OK

W (29960) QUECTEL: RX: AT+QSSLCFG=“ciphersuite”,1,0xFFFF
OK

W (30460) QUECTEL: RX: AT+QSSLCFG=“seclevel”,1,2
OK

W (30960) QUECTEL: RX: AT+QSSLCFG=“cacert”,1,“UFS:cacert.pem”
OK

W (31470) QUECTEL: RX: AT+QSSLCFG=“clientcert”,1,“UFS:clientcert.pem”
OK

W (31960) QUECTEL: RX: AT+QSSLCFG=“clientkey”,1,“UFS:clientkey.pem”
OK

W (32460) QUECTEL: RX: AT+QHTTPURL=35,80
CONNECT

URL set for POST: https://api.restful-api.dev/objects
W (32970) QUECTEL: RX:
OK

W (34960) QUECTEL: RX: AT+QHTTPPOST=31,80,80
W (36210) QUECTEL: RX:
+CME ERROR: 732

2

Hi，

  1. This may be a certificate issue. Please ask the customer to check the certificate
  2. It is possible that the server does not support POST operations.
3

Hi @Hayes , I have checked the API on postman and there it is working .
Could you help me in generating the all the certificate that is needed for https post request and if possible ,also provide the sequence of AT commands needed for https post API call.

4

Hi @Hayes,

I generated a new certificate and stopped using all three certificates (CA cert, client cert, and client key).

In most cases, an HTTPS POST API request only requires server authentication, so mutual TLS is not necessary. For this reason, I configured SSL to use server authentication only by setting:
AT+QSSLCFG=“seclevel”,1,1
and configured only the CA certificate:
AT+QSSLCFG=“cacert”,1,“UFS:cacert.pem”
After applying this configuration, the HTTPS POST request started working successfully.

Thank you for suggestions.