gpg: In a list of card keys show the standard keys.

* g10/keygen.c (ask_algo): Identify the standard keys.
--

The asterisks mark the usages of a key as retruned by scd via the
$AUTHKEYID et al. attributes.

Signed-off-by: Werner Koch <[email protected]>

2 files changed, 27 insertions, 3 deletions

diff --git a/doc/help.txt b/doc/help.txt
index 38f25cd3e..4d748c4e7 100644
--- a/doc/help.txt
+++ b/doc/help.txt
@@ -133,6 +133,14 @@ encryption.  This algorithm should only be used in certain domains.
 Please consult your security expert first.
 .
 
+.gpg.keygen.cardkey
+Select which key from the card shall be used.
+
+The listing shows the selection index, the keygrip (a string of hex
+digits), the card specific key reference, the algorithm used for this
+key, and in parentheses the usage of the key (cert, sign, auth, encr).
+If known the standard usage for a key is marked with an asterisk.
+.
 
 .gpg.keygen.flags
 Toggle the capabilities of the key.
diff --git a/g10/keygen.c b/g10/keygen.c
index d9037d29d..bd02b631f 100644
--- a/g10/keygen.c
+++ b/g10/keygen.c
@@ -2268,6 +2268,12 @@ ask_algo (ctrl_t ctrl, int addmode, int *r_subkey_algo, unsigned int *r_usage,
 
           do
             {
+              char *authkeyref, *encrkeyref, *signkeyref;
+
+              agent_scd_getattr_one ("$AUTHKEYID", &authkeyref);
+              agent_scd_getattr_one ("$ENCRKEYID", &encrkeyref);
+              agent_scd_getattr_one ("$SIGNKEYID", &signkeyref);
+
               tty_printf (_("Available keys:\n"));
               for (count=1,sl=keypairlist; sl; sl = sl->next, count++)
                 {
@@ -2308,17 +2314,23 @@ ask_algo (ctrl_t ctrl, int addmode, int *r_subkey_algo, unsigned int *r_usage,
                     }
                   if ((sl->flags & GCRY_PK_USAGE_SIGN))
                     {
-                      tty_printf ("%ssign", any?",":" (");
+                      tty_printf ("%ssign%s", any?",":" (",
+                                  (signkeyref && keyref
+                                   && !strcmp (signkeyref, keyref))? "*":"");
                       any = 1;
                     }
                   if ((sl->flags & GCRY_PK_USAGE_AUTH))
                     {
-                      tty_printf ("%sauth", any?",":" (");
+                      tty_printf ("%sauth%s", any?",":" (",
+                                  (authkeyref && keyref
+                                   && !strcmp (authkeyref, keyref))? "*":"");
                       any = 1;
                     }
                   if ((sl->flags & GCRY_PK_USAGE_ENCR))
                     {
-                      tty_printf ("%sencr", any?",":" (");
+                      tty_printf ("%sencr%s", any?",":" (",
+                                  (encrkeyref && keyref
+                                   && !strcmp (encrkeyref, keyref))? "*":"");
                       any = 1;
                     }
                   tty_printf ("%s\n", any?")":"");
@@ -2330,6 +2342,10 @@ ask_algo (ctrl_t ctrl, int addmode, int *r_subkey_algo, unsigned int *r_usage,
               cpr_kill_prompt ();
               trim_spaces (answer);
               selection = atoi (answer);
+              xfree (authkeyref);
+              xfree (encrkeyref);
+              xfree (signkeyref);
+
             }
           while (!(selection > 0 && selection < count));