In Corda, the node will look into its keystore to check if it already has an identity certificate, and if it doesn't, then it gets created automatically.
This is done by adding the following line to each node's node.conf file:
devMode : true
A hardcoded test root CA is used to sign these certificates for dev purposes.
Once the keystore and certificates have been generated, you can turn off dev mode if you want. You do this by stopping each node, setting
devMode : false
and then restarting each node.
Outside of dev mode, the node will expect the relevant certificates to already exist in its keystore, and will throw an exception if they don’t exist.