g10,agent: Support CONFIRM for --delete-key.

* agent/call-pinentry.c (agent_get_confirmation): Add call of
pinentry_loopback_confirm.
(agent_popup_message_start): Likewise.
(agent_popup_message_stop): Return if it's loopback mode.
* agent/command.c (pinentry_loopback_confirm): New.

* g10/call-agent.c (default_inq_cb): Support "CONFIRM" inquery
when PINENTRY_MODE_LOOPBACK mode.
(confirm_status_cb): New.
(agent_delete_key): Supply confirm_status_cb to set the description
string for confirmation.

--

In the Assuan communication, we introduce new interaction:

    [gpg]                            [gpg-agent]
            --- CMD: PKDECRYPT -->
            <-- STATUS: SETDESC "..."
            <-- STATUS: SETOK "..."
            <-- STATUS: SETNOTOK "..."
            <-- INQUERY: CONFIRM 0/1 (0 for display, 1 for user query)
	    --- INQUERY-result: -->
	    <-- RESULT: ...

GnuPG-bug-id: 3465
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>

2 files changed, 38 insertions, 1 deletions

diff --git a/agent/call-pinentry.c b/agent/call-pinentry.c
index 487b21e81..c2105cd6e 100644
--- a/agent/call-pinentry.c
+++ b/agent/call-pinentry.c
@@ -1391,6 +1391,9 @@ agent_get_confirmation (ctrl_t ctrl,
       if (ctrl->pinentry_mode == PINENTRY_MODE_CANCEL)
         return gpg_error (GPG_ERR_CANCELED);
 
+      if (ctrl->pinentry_mode == PINENTRY_MODE_LOOPBACK)
+        return pinentry_loopback_confirm (ctrl, desc, 1, ok, notok);
+
       return gpg_error (GPG_ERR_NO_PIN_ENTRY);
     }
 
@@ -1486,7 +1489,15 @@ agent_popup_message_start (ctrl_t ctrl, const char *desc, const char *ok_btn)
   int err;
 
   if (ctrl->pinentry_mode != PINENTRY_MODE_ASK)
-    return gpg_error (GPG_ERR_CANCELED);
+    {
+      if (ctrl->pinentry_mode == PINENTRY_MODE_CANCEL)
+        return gpg_error (GPG_ERR_CANCELED);
+
+      if (ctrl->pinentry_mode == PINENTRY_MODE_LOOPBACK)
+        return pinentry_loopback_confirm (ctrl, desc, 0, ok_btn, NULL);
+
+      return gpg_error (GPG_ERR_NO_PIN_ENTRY);
+    }
 
   rc = start_pinentry (ctrl);
   if (rc)
@@ -1537,6 +1548,9 @@ agent_popup_message_stop (ctrl_t ctrl)
 
   (void)ctrl;
 
+  if (ctrl->pinentry_mode == PINENTRY_MODE_LOOPBACK)
+    return;
+
   if (!popup_tid || !entry_ctx)
     {
       log_debug ("agent_popup_message_stop called with no active popup\n");
diff --git a/agent/command.c b/agent/command.c
index 3c2da183c..b59532ce5 100644
--- a/agent/command.c
+++ b/agent/command.c
@@ -3680,3 +3680,26 @@ pinentry_loopback(ctrl_t ctrl, const char *keyword,
   assuan_end_confidential (ctx);
   return rc;
 }
+
+/* Helper for the pinentry loopback mode to ask confirmation
+   or just to show message.  */
+gpg_error_t
+pinentry_loopback_confirm (ctrl_t ctrl, const char *desc,
+                           int ask_confirmation,
+                           const char *ok, const char *notok)
+{
+  gpg_error_t err = 0;
+  assuan_context_t ctx = ctrl->server_local->assuan_ctx;
+
+  if (desc)
+    err = print_assuan_status (ctx, "SETDESC", "%s", desc);
+  if (!err && ok)
+    err = print_assuan_status (ctx, "SETOK", "%s", ok);
+  if (!err && notok)
+    err = print_assuan_status (ctx, "SETNOTOK", "%s", notok);
+
+  if (!err)
+    err = assuan_inquire (ctx, ask_confirmation ? "CONFIRM 1" : "CONFIRM 0",
+                          NULL, NULL, 0);
+  return err;
+}