diff options
Diffstat (limited to 'scd/app.c')
| -rw-r--r-- | scd/app.c | 46 |
1 files changed, 44 insertions, 2 deletions
@@ -1435,6 +1435,46 @@ run_reselect (ctrl_t ctrl, card_t c, app_t a, app_t a_prev) } +/* + * Check external interference before each use of the application on + * card. Returns -1 when detecting some external interference. + * Returns 0 if not. + * + * Note: This kind of detection can't be perfect. At most, it may be + * possibly useful kludge, in some limited situations. + */ +static int +check_external_interference (app_t app, ctrl_t ctrl) +{ + /* + * Only when a user is using Yubikey with pcsc-shared configuration, + * we need this detection. Otherwise, the card/token is under full + * control of scdaemon, there's no problem at all. + */ + if (!opt.pcsc_shared || app->card->cardtype != CARDTYPE_YUBIKEY) + return 0; + + if (app->fnc.check_aid) + { + unsigned char *aid; + size_t aidlen; + gpg_error_t err; + int slot = app_get_slot (app); + + err = iso7816_get_data (slot, 0, 0x004F, &aid, &aidlen); + if (err) + return -1; + + err = app->fnc.check_aid (app, ctrl, aid, aidlen); + xfree (aid); + if (err) + return -1; + } + + return 0; +} + + /* Check that the card has been initialized and whether we need to * switch to another application on the same card. Switching means * that the new active app will be moved to the head of the list at @@ -1490,7 +1530,8 @@ maybe_switch_app (ctrl_t ctrl, card_t card, const char *keyref) if (app->apptype == apptype) break; if (!app_prev && ctrl->current_apptype == card->app->apptype) - return 0; /* Already the first app - no need to switch. */ + if (check_external_interference (app, ctrl) == 0) + return 0; /* Already the first app - no need to switch. */ } else if (strlen (keyref) == 40) { @@ -1503,7 +1544,8 @@ maybe_switch_app (ctrl_t ctrl, card_t card, const char *keyref) KEYGRIP_ACTION_LOOKUP, keyref, 0)) break; if (!app_prev && ctrl->current_apptype == card->app->apptype) - return 0; /* Already the first app - no need to switch. */ + if (check_external_interference (app, ctrl) == 0) + return 0; /* Already the first app - no need to switch. */ } } |