# For RHEL 7, for domain abc.com
openssl req \
    -newkey rsa:2048 \
    -x509 \
    -nodes \
    -keyout server.key \
    -new \
    -out server.crt \
    -subj /CN=abc.com \
    -reqexts SAN \
    -extensions SAN \
    -config <(cat /etc/pki/tls/openssl.cnf && printf '[SAN]\nsubjectAltName=DNS:abc.com') \
    -sha256 \
    -days 3650

# For Mac OSX replace /etc/pki/tls/openssl.cnf with /System/Library/OpenSSL/openssl.cnf