Generate SAN csr

gistfile1.txt

[ req ]
default_bits = 4096
prompt = no
encrypt_key = no
default_md = sha256
distinguished_name = dn
req_extensions = req_ext

[ dn ]
CN = example.com
emailAddress = ssl@example.com
O = Example Company
OU = Example Unit
L = City
ST = State
C = US

[ req_ext ]
subjectAltName = DNS: www.example.com, DNS: mail.example.com, DNS: files.example.com


openssl req -new -config example.com.conf -keyout example.com.key -out example.com.csr

openssl req -text -noout -verify -in example.com.csr