LetsEncryptでSSL証明書を取得

インストール

git clone https://github.com/letsencrypt/letsencrypt.git
cd letsencrypt
./letsencrypt-auto --help

webrootを利用する場合

./letsencrypt-auto certonly --webroot --webroot-path ~/encrypt.example.com -d encrypt.example.com

standaloneを利用する場合

./letsencrypt-auto certonly --standalone -d encrypt.example.com
# - Congratulations! Your certificate and chain have been saved at
#    /etc/letsencrypt/live/encrypt.example.com/fullchain.pem. Your cert will
#    expire on 2016-03-03. To obtain a new version of the certificate in
#    the future, simply run Let's Encrypt again.
#  - If like Let's Encrypt, please consider supporting our work by:
# 
#    Donating to ISRG / Let's Encrypt:   https://letsencrypt.org/donate
#    Donating to EFF:                    https://eff.org/donate-le

証明書は /etc/letsencrypt/live/encrypt.example.com/fullchain.pem
秘密鍵は /etc/letsencrypt/live/encrypt.example.com/private.pem
に出力されている