'L{changePassPhrase} exits when trying to change the passphrase on a
public key, and doesn\'t change the file.'

def test_changePassphrasePublicKey(self):

    filename = self.mktemp()
    FilePath(filename).setContent(publicRSA_openssh)
    error = self.assertRaises(SystemExit, changePassPhrase, {'filename': filename, 'newpass': 'pass'})
    self.assertEqual('Could    not    change    passphrase:    key    not    encrypted', str(error))
    self.assertEqual(publicRSA_openssh, FilePath(filename).getContent())
