# cd /etc/ssl/private
# openssl req -x509 -nodes -newkey rsa:2048 -keyout /etc/ssl/private/vsftpd.pem -out /etc/ssl/private/vsftpd.pem
Generating a 2048 bit RSA private key
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writing new private key to '/etc/ssl/private/vsftpd.pem'
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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.
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Country Name (2 letter code) [AU]:JP # <= 国の略名
State or Province Name (full name) [Some-State]:Shimane # <= 都道府県名
Locality Name (eg, city) []:Matsue # <= 市区町村名
Organization Name (eg, company) [Internet Widgits Pty Ltd]:mk-mode.com # <= サイト名(何でもよい)
Organizational Unit Name (eg, section) []: # <= 部署名(空でよい)
Common Name (e.g. server FQDN or YOUR name) []:ftp.mk-mode.com # <= ホスト名
Email Address []:root@mk-mode.com # <= 管理者メールアドレス