gpg: New export option "mode1003".
* agent/command.c (cmd_export_key): Add option --mode1003. (command_has_option): Ditto. * g10/build-packet.c (do_key): Implement mode 1003. * g10/parse-packet.c (parse_key): Ditto. * g10/options.h (EXPORT_MODE1003): New.o * g10/call-agent.c (agent_export_key): Add arg mode1003. * g10/export.c (parse_export_options): Add "mode1003" (secret_key_to_mode1003): New. (receive_seckey_from_agent): Add arg mode1003. (do_export_one_keyblock): Pass option down.
This option allows to export a secret key in GnuPG's native format.
Thus no re-encryption is required and further the public key parameters
are also authenticated if a protection passphrase has been used.
Note that --import is not yet able to handle this new mode. Although
old version of GnuPG will bail out with "invalid packet" if a mode1003
exported secret key is seen.