scd: New function send_keyinfo to assist in backporting.

* scd/command.c (send_keyinfo): New.

scd/command.c

@@ -1846,6 +1846,34 @@ scd_command_handler (ctrl_t ctrl, int fd)
 }
 
 
+
+/* Send a keyinfo string.  If DATA is true the string is emitted as a
+ * data line, else as a status line.  */
+void
+send_keyinfo (ctrl_t ctrl, int data, const char *keygrip_str,
+              const char *serialno, const char *idstr)
+{
+  char *string;
+  assuan_context_t ctx = ctrl->server_local->assuan_ctx;
+
+  string = xtryasprintf ("%s T %s %s%s", keygrip_str,
+                         serialno? serialno : "-",
+                         idstr? idstr : "-",
+                         data? "\n" : "");
+
+  if (!string)
+    return;
+
+  if (!data)
+    assuan_write_status (ctx, "KEYINFO", string);
+  else
+    assuan_send_data (ctx, string, strlen (string));
+
+  xfree (string);
+  return;
+}
+
+
 /* Send a line with status information via assuan and escape all given
    buffers. The variable elements are pairs of (char *, size_t),
    terminated with a (NULL, 0). */

scd/scdaemon.h

@@ -122,6 +122,8 @@ const char *scd_get_socket_name (void);
 /*-- command.c --*/
 gpg_error_t initialize_module_command (void);
 int  scd_command_handler (ctrl_t, int);
+void send_keyinfo (ctrl_t ctrl, int data, const char *keygrip_str,
+                   const char *serialno, const char *idstr);
 void send_status_info (ctrl_t ctrl, const char *keyword, ...)
      GPGRT_ATTR_SENTINEL(1);
 gpg_error_t send_status_direct (ctrl_t ctrl, const char *keyword,