The certificate common name (cn) does not match with the expected cn



when I want to register my ESP8266 to mDash I get this error. Is it because mDash is only for ESP32 and not other devices?



Mongoose OS devices work with mDash regardless of the architecture.
Please share exactly the config you’re using and the returned error.


This is my output. I didn’t change anything in configuration since I just started.


Please try

mos config-set dash.server=wss://

Same thing happens. Do I need to change certificate?


The stock ca-bundle library (which delivers ca.pem file) should work fine .
Do you use an unmodified ca.pem ?


Since this device was used before, someone could have modified ca.pem, however since I am new to this stuff, I don’t know how to check it. Can you please tell me how?

  1. Make a backup of existing ca.pem mos get ca.pem >
  2. Download the stock one, curl -O
  3. Upload to the device mos put ca.pem
  4. Reboot the device mos call Sys.Reboot

Doesn’t work. I guess ca.pem was left untouched. I still get the same error.


Does your browser show the warning when you visit ?


Not at work ATM, but nope, didn’t show any warnings.


Can’t reproduce. Works fine on our side:

$ mos --port /dev/cu.wchusbserial1420 config-get dash
  "enable": true,
  "send_logs": false,
  "server": "wss://",
  "ssl_ca_cert": "ca.pem",
  "ssl_cert": "",
  "ssl_key": "",
  "token": "...."

It connects to the with no issues.
Please try on a vanilla new ESP8266 box to verify.