openssl genrsa -out server.key 2048  
openssl req -new -key server.key -out server.csr -subj "/C=HK/ST=/L=/O=/OU=/CN=domain.com/emailAddress=admin@domain.com"

自签名

openssl req -new -x509 -days 3650 -key server.key -out server.crt -subj "/C=/ST=/L=/O=/OU=/CN=domain.com/emailAddress=admin@domain.com"