方法一 使用 snakeoil

使用 apt 安装的 nginx，默认配置文件中会有一行被注释的 include snippets/snakeoil.conf; 解除注释，通过 systemctl reload nginx 重新加载配置即可。

若重新加载失败提示

nginx: [emerg] cannot load certificate "/etc/ssl/certs/ssl-cert-snakeoil.pem": BIO_new_file() failed (SSL: 
error:02001002:system library:fopen:No such file or directory:fopen('/etc/ssl/certs/ssl-cert-snakeoil.pem','r') 
error:2006D080:BIO routines:BIO_new_file:no such file)

则需要使用 apt install ssl-cert 安装依赖，再次重新加载配置即可

方法二 使用 OpenSSL 自签名 (重点）

创建私钥

openssl genrsa -out server.key 2048

创建证书签名请求

openssl req -new -key server.key -out server.csr

此时可以根据自己需要对信息进行填写，需要注意 Common Name 必须为对应网站域名或ip地址

output and input：

You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]:**cn**
State or Province Name (full name) [Some-State]:**localhost**
Locality Name (eg, city) []:**sh**
Organization Name (eg, company) [Internet Widgits Pty Ltd]:****
Organizational Unit Name (eg, section) []:****
Common Name (e.g. server FQDN or YOUR name) []:**localhost**
Email Address []:**admin@localhost**

Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []:**nopass**
An optional company name []:**cn-ltd**

创建自签名证书

openssl x509 -req -in server.csr -signkey server.key -out server.crt

output：

Certificate request self-signature ok
subject=C = cn, ST = localhost, L = sh, O = Internet Widgits Pty Ltd, CN = localhost, emailAddress = admin@localhost

配置 nginx

server {
      listen              443 ssl;
      ssl_certificate     /path/to/server.crt
      ssl_certificate_key /path/to/server.key
      ....
}

配置完成后使用 systemctl reload nginx 来重载配置

当使用 Chrome 访问自签名证书的网站时，会提示不安全。

解决方法 就是 忽略 或者 添加到本地信任机构证书（貌似没什么卵用）

意义：

起码 你有了SSL证书 用于开发、部署测试。

copy from：

https://jackyu.cn/tech/nginx-selfsign-ssl-cert/