生成RSA服务器私钥：
openssl genrsa -out server.key 4096

生成 CSR 文件
openssl req -new -x509 -key server.key -out server.crt -days 99999
Country Name (2 letter code) [AU]:CN
State or Province Name (full name) [Some-State]:省份
Locality Name (eg, city) []:城市
Organization Name (eg, company) [Internet Widgits Pty Ltd]:组织机构
Organizational Unit Name (eg, section) []:组织机构
Common Name (e.g. server FQDN or YOUR name) []:简称
Email Address []: 邮箱

删除密钥
openssl rsa -in server.key -out server_no_passwd.key

生成自签证书：
openssl x509 -req -days 3650 -in server.csr -signkey server_no_passwd.key -out server.crt

Nginx配置
讲cert和key文件放到对应的目录中。