RSA keys with passphrase

[catwell]

Trying to boot Iris with an RSA key protected by a passphrase results in:

Parsing RSA key from PEM format failed: asn1: structure error: length too large

Support for passphrase-protected RSA keys would be a useful feature, e.g. if you keep a RSA key on your laptop during development or for debug purpose.

[karalabe]

That's indeed a useful feature I haven't thought of (to keep a production key locally to access the service). I'll think about how to add it best :)