Generate RSA keys for SaltStack master:

openssl genrsa -out /etc/salt/pki/master/master.pem 2048
openssl rsa -in /etc/salt/pki/master/master.pem -pubout -out /etc/salt/pki/master/master.pub
chmod 400 /etc/salt/pki/master/master.pem
chmod 644 /etc/salt/pki/master/master.pub

Generate RSA keys for SaltStack minion:

openssl genrsa -out /etc/salt/pki/minion/minion.pem 2048
openssl rsa -in /etc/salt/pki/minion/minion.pem -pubout -out /etc/salt/pki/minion/minion.pub
chmod 400 /etc/salt/pki/minion/minion.pem
chmod 644 /etc/salt/pki/minion/minion.pub