scd:piv: Implement PIN cache.

* scd/command.c (pincache_put): Add arg pinlen and change all callers
to provide it.
* scd/app-piv.c (cache_pin): New.
(pin_from_cache): New.
(ask_and_prepare_chv): Add args no_cache and r_unpaddedpinlen.  Take
PIN from the cache.  Return the unpadded length.
(verify_chv): Add arg ctrl.  Cache the PIN.
(do_change_chv): Clear PIN cache.
--

The PIV pins are padded but we want to store the unpadded PIN.  Thus
the changes to the function.

Code has has been tested by commenting the no_cache parameter because
we the current test certificate was created for PIV.9C which requires
a verification for each use.  More testing is required.

GnuPG-bug-id: 4791
Signed-off-by: Werner Koch <[email protected]>

1 files changed, 2 insertions, 2 deletions

diff --git a/scd/app.c b/scd/app.c
index cc2a549a5..5fa500ad2 100644
--- a/scd/app.c
+++ b/scd/app.c
@@ -664,7 +664,7 @@ select_application (ctrl_t ctrl, const char *name, card_t *r_card,
 
           if (err)
             {
-              pincache_put (ctrl, slot, NULL, NULL, NULL);
+              pincache_put (ctrl, slot, NULL, NULL, NULL, 0);
               apdu_close_reader (slot);
             }
         }
@@ -1919,7 +1919,7 @@ scd_update_reader_status_file (void)
           if (status == 0)
             {
               log_debug ("Removal of a card: %d\n", card->slot);
-              pincache_put (NULL, card->slot, NULL, NULL, NULL);
+              pincache_put (NULL, card->slot, NULL, NULL, NULL, 0);
               apdu_close_reader (card->slot);
               deallocate_card (card);
             }