ESPMQTT SSL Sample application
Navigate to the main directory
cd main
Generate a client key and a CSR. When you are generating the CSR, do not use the default values. At a minimum, the CSR must include the Country, Organisation and Common Name fields.
openssl genrsa -out client.key
openssl req -out client.csr -key client.key -new
Paste the generated CSR in the Mosquitto test certificate signer, click Submit and copy the downloaded client.crt in the main directory.