Check that the first secret-key packet is a 'secret-key packet'
authorW. Trevor King <wking@tremily.us>
Sat, 21 Dec 2013 00:07:00 +0000 (16:07 -0800)
committerW. Trevor King <wking@tremily.us>
Mon, 23 Dec 2013 02:32:14 +0000 (18:32 -0800)
commit98dd5b53c88cca49a1f7166e2fe4f9d55a7e23b6
tree7c45b65ea6ec9be1927bfb527300266c3157ccde
parent0d7501f68c23af2c637c748d4aacfdf547f7fdfd
Check that the first secret-key packet is a 'secret-key packet'

From RFC 4880 [1]:

  The format of a transferable secret key is the same as a
  transferable public key except that secret-key and secret-subkey
  packets are used instead of the public key and public-subkey
  packets.

[1]: http://tools.ietf.org/search/rfc4880#section-11.2
gpg-migrate.py