С помощью этой статьи поправил:
www.thinkplexx.com/learn/howto/security/ssl/rem...

tl;dr

  1. openssl rsa -in ~/.ssh/id_rsa -out ~/.ssh/id_rsa_new
  2. cp ~/.ssh/id_rsa ~/.ssh/id_rsa.backup
  3. rm ~/.ssh/id_rsa
  4. cp ~/.ssh/id_rsa_new ~/.ssh/id_rsa
  5. chmod 400 ~/.ssh/id_rsa