1. GithubよりLet's EncryptリポジトリをCloneする
# git clone https://github.com/letsencrypt/letsencrypt.git
2. 以下のコマンドを実行する
# cd letsencrypt # ./letsencrypt-auto certonly --manual -d *.<ドメイン名> --preferred-challenges dns
<ドメイン名>は、*以下のドメインを入力する。
3. 画面の指示に従い、操作を行う
メールアドレスの登録
メールアドレスを入力して、[Enter]を押下します。
Saving debug log to /var/log/letsencrypt/letsencrypt.log Plugins selected: Authenticator manual, Installer None Enter email address (used for urgent renewal and security notices) (Enter 'c' to cancel): <メールアドレス>
規約、メールアドレスの収集、IPアドレスの収集に関する同意
a を入力し、[Enter]を押下して進めます。
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Please read the Terms of Service at https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf. You must agree in order to register with the ACME server at https://acme-v02.api.letsencrypt.org/directory - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - (A)gree/(C)ancel: A
規約、メールアドレスの収集、IPアドレスの収集に関する同意
全てy を入力し、[Enter]を押下して進めます。
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Would you be willing to share your email address with the Electronic Frontier Foundation, a founding partner of the Let's Encrypt project and the non-profit organization that develops Certbot? We'd like to send you email about our work encrypting the web, EFF news, campaigns, and ways to support digital freedom. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - (Y)es/(N)o: y Obtaining a new certificate Performing the following challenges: dns-01 challenge for <ドメイン名> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - NOTE: The IP of this machine will be publicly logged as having requested this certificate. If you're running certbot in manual mode on a machine that is not your server, please ensure you're okay with that. Are you OK with your IP being logged? - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - (Y)es/(N)o: y
4. DNS TXTレコードの登録
以下のようなメッセージが表示され、DNS TXTレコードのエントリとして指定された値の入力（登録）を求められますので、DNSサーバに対して登録を行います。
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Please deploy a DNS TXT record under the name _acme-challenge.<ドメイン名> with the following value: <TXTレコードへ入力する値> Before continuing, verify the record is deployed. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
DNSサーバへの登録後、しばらく（5分程度）時間をおいてから[Enter]を押下します。
5. 登録完了
次のようなメッセージが表示され、サーバ証明書が発行されます。
Waiting for verification... Cleaning up challenges IMPORTANT NOTES: - Congratulations! Your certificate and chain have been saved at: /etc/letsencrypt/live/<ドメイン名>/fullchain.pem Your key file has been saved at: /etc/letsencrypt/live/<ドメイン名>/privkey.pem Your cert will expire on <有効期限>. To obtain a new or tweaked version of this certificate in the future, simply run letsencrypt-auto again. To non-interactively renew *all* of your certificates, run "letsencrypt-auto renew" - Your account credentials have been saved in your Certbot configuration directory at /etc/letsencrypt. You should make a secure backup of this folder now. This configuration directory will also contain certificates and private keys obtained by Certbot so making regular backups of this folder is ideal. - If you like Certbot, please consider supporting our work by: Donating to ISRG / Let's Encrypt: https://letsencrypt.org/donate Donating to EFF: https://eff.org/donate-le
上記に表示されたディレクトリを確認すると、証明書ファイルを確認することが出来ます。
# cd /etc/letsencrypt/live/<ドメイン名>/ # ls -la total 12 drwxr-xr-x 2 root root 4096 Nov 1 08:39 . drwx------ 3 root root 4096 Nov 1 08:39 .. -rw-r--r-- 1 root root 682 Nov 1 08:39 README lrwxrwxrwx 1 root root 52 Nov 1 08:39 cert.pem -> ../../archive/<ドメイン名>/cert1.pem lrwxrwxrwx 1 root root 53 Nov 1 08:39 chain.pem -> ../../archive/<ドメイン名>/chain1.pem lrwxrwxrwx 1 root root 57 Nov 1 08:39 fullchain.pem -> ../../archive/<ドメイン名>/fullchain1.pem lrwxrwxrwx 1 root root 55 Nov 1 08:39 privkey.pem -> ../../archive/<ドメイン名>/privkey1.pem