OpenSSHの公開鍵
OpenSSHの公開鍵をSSH2形式に変換
ssh-keygen -e -f ~/.ssh/id_rsa.pub -m RFC4716
-m RFC4716は省略可能
---- BEGIN SSH2 PUBLIC KEY ----で始まる
OpenSSHの公開鍵をPKCS #1形式に変換
ssh-keygen -e -f ~/.ssh/id_rsa.pub -m PEM
-----BEGIN RSA PUBLIC KEY-----で始まる
OpenSSHの公開鍵をPKCS #8形式に変換
ssh-keygen -e -f ~/.ssh/id_rsa.pub -m PKCS8
-----BEGIN PUBLIC KEY----- で始まる