gpg: Improve decryption diagnostic for an ADSK key.

* g10/keydb.h (GET_PUBKEYBLOCK_FLAG_ADSK): New constant.
* g10/packet.h (PUBKEY_USAGE_XENC_MASK): New constant.
* g10/pubkey-enc.c (get_session_key): Consider an ADSK also as "marked
for encryption use".
(get_it): Print a note if an ADSK key was used.  Use the new
get_pubkeyblock flag.
* g10/getkey.c (struct getkey_ctx_s): Add field allow_adsk.
(get_pubkeyblock): Factor all code out to ...
(get_pubkeyblock_ext): new.
(finish_lookup): Add new arg allow_adsk and make use of it.
--

This patch solves two purposes:
- We write a note that the ADSK key was used for decryption
- We avoid running into a
  "oops: public key not found for preference check\n"
  due to ADSK keys.  The error is mostly harmless but lets gpg return
  with an exit code of 2.

1 files changed, 1 insertions, 1 deletions

diff --git a/doc/gpg.texi b/doc/gpg.texi
index 501e075d2..ae1603924 100644
--- a/doc/gpg.texi
+++ b/doc/gpg.texi
@@ -4076,7 +4076,7 @@ current home directory (@pxref{option --homedir}).
   startup.  It may contain options pertaining to all components of
   GnuPG.  Its current main use is for the "use-keyboxd" option.  If
   the default home directory @file{~/.gnupg} does not exist, GnuPG creates
-  this directory and a @file{common.conf} file with "use_keyboxd".
+  this directory and a @file{common.conf} file with "use-keyboxd".
 
 @end table