gpg: Let --card--status create a shadow key (card key stub).

* agent/command.c (cmd_learn): Add option --sendinfo.
* agent/learncard.c (agent_handle_learn): Add arg "send" andsend
certifciate only if that is set.
* g10/call-agent.c (agent_scd_learn): Use --sendinfo.  Make INFO
optional.
(agent_learn): Remove.
* g10/keygen.c (gen_card_key): Replace agent_learn by agent_scd_learn.
--

The requirement of using --card-status on the first use of card on a
new box is a bit annoying but the alternative of always checking
whether a card is available before a decryption starts does not sound
promising either.

Signed-off-by: Werner Koch <wk@gnupg.org>

agent/agent.h

@@ -492,7 +492,7 @@ int agent_card_scd (ctrl_t ctrl, const char *cmdline,
 
 
 /*-- learncard.c --*/
-int agent_handle_learn (ctrl_t ctrl, void *assuan_context);
+int agent_handle_learn (ctrl_t ctrl, int send, void *assuan_context);
 
 
 #endif /*AGENT_H*/

agent/command.c

@@ -1619,21 +1619,26 @@ cmd_get_confirmation (assuan_context_t ctx, char *line)
 
 
 static const char hlp_learn[] =
-  "LEARN [--send]\n"
+  "LEARN [--send][--sendinfo]\n"
   "\n"
   "Learn something about the currently inserted smartcard.  With\n"
-  "--send the new certificates are send back.";
+  "--sendinfo information about the card is returned; with --send\n"
+  "the available certificates are returned as D lines.";
 static gpg_error_t
 cmd_learn (assuan_context_t ctx, char *line)
 {
   ctrl_t ctrl = assuan_get_pointer (ctx);
-  int rc;
+  gpg_error_t err;
+  int send, sendinfo;
+
+  send = has_option (line, "--send");
+  sendinfo = send? 1 : has_option (line, "--sendinfo");
 
   if (ctrl->restricted)
     return leave_cmd (ctx, gpg_error (GPG_ERR_FORBIDDEN));
 
-  rc = agent_handle_learn (ctrl, has_option (line, "--send")? ctx : NULL);
-  return leave_cmd (ctx, rc);
+  err = agent_handle_learn (ctrl, send, sendinfo? ctx : NULL);
+  return leave_cmd (ctx, err);
 }
 
 

agent/learncard.c

@@ -296,10 +296,10 @@ send_cert_back (ctrl_t ctrl, const char *id, void *assuan_context)
   return 0;
 }
 
-/* Perform the learn operation.  If ASSUAN_CONTEXT is not NULL all new
-   certificates are send back via Assuan.  */
+/* Perform the learn operation.  If ASSUAN_CONTEXT is not NULL and
+   SEND is true all new certificates are send back via Assuan.  */
 int
-agent_handle_learn (ctrl_t ctrl, void *assuan_context)
+agent_handle_learn (ctrl_t ctrl, int send, void *assuan_context)
 {
   int rc;
 
@@ -369,7 +369,7 @@ agent_handle_learn (ctrl_t ctrl, void *assuan_context)
             log_info ("          id: %s    (type=%d)\n",
                       citem->id, citem->type);
 
-          if (assuan_context)
+          if (assuan_context && send)
             {
               rc = send_cert_back (ctrl, citem->id, assuan_context);
               if (rc)
@@ -439,9 +439,9 @@ agent_handle_learn (ctrl_t ctrl, void *assuan_context)
         }
 
       if (opt.verbose)
-        log_info ("stored\n");
+        log_info ("          id: %s - shadow key created\n", item->id);
 
-      if (assuan_context)
+      if (assuan_context && send)
         {
           CERTINFO citem;
 

g10/call-agent.c

@@ -655,6 +655,7 @@ agent_scd_learn (struct agent_card_info_s *info)
 {
   int rc;
   struct default_inq_parm_s parm;
+  struct agent_card_info_s dummyinfo;
 
   memset (&parm, 0, sizeof parm);
 
@@ -674,42 +675,25 @@ agent_scd_learn (struct agent_card_info_s *info)
   if (rc)
     return rc;
 
+  if (!info)
+    info = &dummyinfo;
+
   parm.ctx = agent_ctx;
   memset (info, 0, sizeof *info);
-  rc = assuan_transact (agent_ctx, "SCD LEARN --force",
+  rc = assuan_transact (agent_ctx, "LEARN --sendinfo",
                         dummy_data_cb, NULL, default_inq_cb, &parm,
                         learn_status_cb, info);
   /* Also try to get the key attributes.  */
   if (!rc)
     agent_scd_getattr ("KEY-ATTR", info);
 
+  if (info == &dummyinfo)
+    agent_release_card_info (info);
+
   return rc;
 }
 
 
-/* Call the agent to learn about the current smartcard.  This is
-   currently only used to have the agent create the shadow key.  */
-gpg_error_t
-agent_learn (void)
-{
-  gpg_error_t err;
-  struct default_inq_parm_s parm;
-
-  memset (&parm, 0, sizeof parm);
-
-  err = start_agent (NULL, 1);
-  if (err)
-    return err;
-
-  parm.ctx = agent_ctx;
-  err = assuan_transact (agent_ctx, "LEARN",
-                         dummy_data_cb, NULL, default_inq_cb, &parm,
-                         NULL, NULL);
-
-  return err;
-}
-
-
 int
 agent_keytocard (const char *hexgrip, int keyno, int force,
                  const char *serialno, const char *timestamp)

g10/call-agent.h

@@ -78,9 +78,6 @@ void agent_release_card_info (struct agent_card_info_s *info);
 /* Return card info. */
 int agent_scd_learn (struct agent_card_info_s *info);
 
-/* Let the agent learn about the current card.  */
-gpg_error_t agent_learn (void);
-
 /* Update INFO with the attribute NAME. */
 int agent_scd_getattr (const char *name, struct agent_card_info_s *info);
 

g10/keygen.c

@@ -4447,7 +4447,7 @@ gen_card_key (int algo, int keyno, int is_primary, kbnode_t pub_root,
   /* Send the learn command so that the agent creates a shadow key for
      card key.  We need to do that now so that we are able to create
      the self-signatures. */
-  err = agent_learn ();
+  err = agent_scd_learn (NULL);
   if (err)
     {
       /* Oops: Card removed during generation.  */