g10,scd: Improve UIF support.

* g10/call-agent.c (learn_status_cb): Parse "bt" flag.
* g10/call-agent.h: New member field "bt".
* g10/card-util.c (uif): Limit its access only when it is supported.
* scd/app-openpgp.c (do_setattr): Allow access to UIF objects only
when there is a button.

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>

1 files changed, 21 insertions, 0 deletions

diff --git a/g10/card-util.c b/g10/card-util.c
index 234abcbab..5205798b6 100644
--- a/g10/card-util.c
+++ b/g10/card-util.c
@@ -2114,10 +2114,31 @@ kdf_setup (const char *args)
 static void
 uif (int arg_number, const char *arg_rest)
 {
+  struct agent_card_info_s info;
+  int feature_available;
   gpg_error_t err;
   char name[100];
   unsigned char data[2];
 
+  memset (&info, 0, sizeof info);
+
+  err = agent_scd_getattr ("EXTCAP", &info);
+  if (err)
+    {
+      log_error (_("error getting card info: %s\n"), gpg_strerror (err));
+      return;
+    }
+
+  feature_available = info.extcap.bt;
+  agent_release_card_info (&info);
+
+  if (!feature_available)
+    {
+      log_error (_("This command is not supported by this card\n"));
+      tty_printf ("\n");
+      return;
+    }
+
   snprintf (name, sizeof name, "UIF-%d", arg_number);
   if ( !strcmp (arg_rest, "off") )
     data[0] = 0x00;