Came across a small issue when trying to use keys from iPad to ssh to Ubuntu server. The application refused to do anything (2 different apps!) and one said that it needed an RSA format key file. After looking at the file formats and reading up on openssl I found that you can convert openssl file format files generated for use on Linux using the following command
openssl rsa -in server.key -out server_new.key
Simple but on the spot it makes you pause in your track.
Hope this helps someone.
