core: Fully implement the inquire callback for assuan_transact

* src/engine-assuan.c (inquire_cb): Implement returning data.

* tests/opassuan/t-command.c (inq_cb): Send some test data.
--

The old code only allowed to send an empty response which was good
enough for scdaemon's KNOWNCARDP inquire but not to send actual data.
A quick test using a test smartcard might be

 ./t-command 'scd setattr --inquire PRIVATE-DO-1'

and then reading the data back using

  gpg-connect-agent 'scd getattr PRIVATE-DO-1' /bye

Signed-off-by: Werner Koch <[email protected]>

1 files changed, 17 insertions, 8 deletions

diff --git a/src/engine-assuan.c b/src/engine-assuan.c
index b51c17e3..eb6d2a8e 100644
--- a/src/engine-assuan.c
+++ b/src/engine-assuan.c
@@ -445,7 +445,10 @@ llass_set_locale (void *engine, int category, const char *value)
 static gpgme_error_t
 inquire_cb (engine_llass_t llass, const char *keyword, const char *args)
 {
-  gpg_error_t err;
+  gpg_error_t err, err2;
+  gpgme_data_t data = NULL;
+  char buf[1024];
+  gpgme_ssize_t n;
 
   if (llass->opt.gpg_agent && !strcmp (keyword, "PINENTRY_LAUNCHED"))
     {
@@ -454,17 +457,23 @@ inquire_cb (engine_llass_t llass, const char *keyword, const char *args)
 
   if (llass->user.inq_cb)
     {
-      gpgme_data_t data = NULL;
-
       err = llass->user.inq_cb (llass->user.inq_cb_value,
                                 keyword, args, &data);
       if (!err && data)
         {
-          /* FIXME: Returning data is not yet implemented.  However we
-             need to allow the caller to cleanup his data object.
-             Thus we run the callback in finish mode immediately.  */
-          err = llass->user.inq_cb (llass->user.inq_cb_value,
-                                    NULL, NULL, &data);
+          while ((n = gpgme_data_read (data, buf, sizeof buf)) > 0)
+            {
+              err = assuan_send_data (llass->assuan_ctx, buf, n);
+              if (err)
+                break;
+            }
+          /* Tell the caller that we are finished with the data
+           * object.  The error code from assuan_send_data has
+           * priority over the one from the cleanup function. */
+          err2 = llass->user.inq_cb (llass->user.inq_cb_value,
+                                     NULL, NULL, &data);
+          if (!err)
+            err = err2;
         }
     }
   else