From 7620473cd007c074b0625a678caa6105a4c87142 Mon Sep 17 00:00:00 2001
From: Werner Koch <wk@gnupg.org>
Date: Wed, 27 Jan 2021 18:31:12 +0100
Subject: [PATCH] scd: Define new status word

* scd/apdu.h (SW_NO_CURRENT_EF): New.
--

This merely to show better diagnostics.
Used for example by CardOS 5.3.
---
 scd/apdu.c    |  1 +
 scd/apdu.h    |  1 +
 scd/iso7816.c | 22 ++++++++++++++--------
 scd/iso7816.h |  2 +-
 4 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/scd/apdu.c b/scd/apdu.c
index 9b473d56a..fa0fb7c43 100644
--- a/scd/apdu.c
+++ b/scd/apdu.c
@@ -548,6 +548,7 @@ apdu_strerror (int rc)
     case SW_CHV_BLOCKED    : return "CHV blocked";
     case SW_REF_DATA_INV   : return "referenced data invalidated";
     case SW_USE_CONDITIONS : return "use conditions not satisfied";
+    case SW_NO_CURRENT_EF  : return "no current EF selected";
     case SW_BAD_PARAMETER  : return "bad parameter";
     case SW_NOT_SUPPORTED  : return "not supported";
     case SW_FILE_NOT_FOUND : return "file not found";
diff --git a/scd/apdu.h b/scd/apdu.h
index d042c7cde..fd03ae6f0 100644
--- a/scd/apdu.h
+++ b/scd/apdu.h
@@ -39,6 +39,7 @@ enum {
   SW_CHV_BLOCKED    = 0x6983,
   SW_REF_DATA_INV   = 0x6984, /* Referenced data invalidated. */
   SW_USE_CONDITIONS = 0x6985,
+  SW_NO_CURRENT_EF  = 0x6986, /* No current EF selected.  */
   SW_BAD_PARAMETER  = 0x6a80, /* (in the data field) */
   SW_NOT_SUPPORTED  = 0x6a81,
   SW_FILE_NOT_FOUND = 0x6a82,
diff --git a/scd/iso7816.c b/scd/iso7816.c
index c68aab075..a796553d7 100644
--- a/scd/iso7816.c
+++ b/scd/iso7816.c
@@ -63,6 +63,7 @@ map_sw (int sw)
     case SW_CHV_WRONG:      ec = GPG_ERR_BAD_PIN; break;
     case SW_CHV_BLOCKED:    ec = GPG_ERR_PIN_BLOCKED; break;
     case SW_USE_CONDITIONS: ec = GPG_ERR_USE_CONDITIONS; break;
+    case SW_NO_CURRENT_EF:  ec = GPG_ERR_ENOENT; break;
     case SW_NOT_SUPPORTED:  ec = GPG_ERR_NOT_SUPPORTED; break;
     case SW_BAD_PARAMETER:  ec = GPG_ERR_INV_VALUE; break;
     case SW_FILE_NOT_FOUND: ec = GPG_ERR_ENOENT; break;
@@ -185,27 +186,32 @@ iso7816_select_file (int slot, int tag, int is_dir)
 }
 
 
-/* Do a select file command with a direct path.  If FROM_CDF is set
- * the starting point is the current direcory file (feature depends on
- * the card). */
+/* Do a select file command with a direct path.  If TOPDF is set, the
+ * actual used path is 3f00/<topdf>/<path>.  */
 gpg_error_t
 iso7816_select_path (int slot, const unsigned short *path, size_t pathlen,
-                     int from_cdf)
+                     unsigned short topdf)
 {
   int sw, p0, p1;
   unsigned char buffer[100];
-  int buflen;
+  int buflen = 0;
 
-  if (pathlen/2 >= sizeof buffer)
+  if (pathlen*2 + 2 >= sizeof buffer)
     return gpg_error (GPG_ERR_TOO_LARGE);
 
-  for (buflen = 0; pathlen; pathlen--, path++)
+  if (topdf)
+    {
+      buffer[buflen++] = topdf >> 8;
+      buffer[buflen++] = topdf;
+    }
+
+  for (; pathlen; pathlen--, path++)
     {
       buffer[buflen++] = (*path >> 8);
       buffer[buflen++] = *path;
     }
 
-  p0 = from_cdf? 0x09 : 0x08;
+  p0 = 0x08;
   p1 = 0x0c; /* No FC return. */
   sw = apdu_send_simple (slot, 0, 0x00, CMD_SELECT_FILE,
                          p0, p1, buflen, (char*)buffer );
diff --git a/scd/iso7816.h b/scd/iso7816.h
index 06ee5eaa1..d9fd3eb69 100644
--- a/scd/iso7816.h
+++ b/scd/iso7816.h
@@ -69,7 +69,7 @@ gpg_error_t iso7816_select_mf (int slot);
 gpg_error_t iso7816_select_file (int slot, int tag, int is_dir);
 gpg_error_t iso7816_select_path (int slot,
                                  const unsigned short *path, size_t pathlen,
-                                 int from_cdf);
+                                 unsigned short topdf);
 gpg_error_t iso7816_list_directory (int slot, int list_dirs,
                                     unsigned char **result, size_t *resultlen);
 gpg_error_t iso7816_send_apdu (int slot, int extended_mode,