Increasing the security of encrypted SSH private keysEdit

From http://martin.kleppmann.com/2013/05/24/improving-security-of-ssh-private-keys.html:

$ mv ~/.ssh/id_rsa ~/.ssh/id_rsa.old
$ openssl pkcs8 -topk8 -v2 des3 -in ~/.ssh/id_rsa.old -out ~/.ssh/id_rsa
$ chmod 600 ~/.ssh/id_rsa

After checking that the converted key works, delete the old one:

$ srm ~/.ssh/id_rsa.old

See man pkcs8 for more details.