Adding routine for pressing button to test required user presence.

Signed-off-by: Pol Henarejos <pol.henarejos@cttc.es>

src/fido/fido.c

@@ -22,6 +22,7 @@
 #include "u2f.h"
 #include "files.h"
 #include "file.h"
+#include "usb.h"
 #include "random.h"
 #include "mbedtls/ecdsa.h"
 #include "mbedtls/x509_crt.h"
@@ -186,6 +187,15 @@ void init_fido() {
     scan_all();
 }
 
+bool wait_button_pressed() {
+    uint32_t val = EV_PRESS_BUTTON;
+    queue_try_add(&card_to_usb_q, &val);
+    do {
+        queue_remove_blocking(&usb_to_card_q, &val);
+    } while (val != EV_BUTTON_PRESSED && val != EV_BUTTON_TIMEOUT);
+    return val == EV_BUTTON_TIMEOUT;
+}
+
 typedef struct cmd
 {
   uint8_t ins;

src/fido/fido.h

@@ -30,5 +30,6 @@
 
 extern int scan_files();
 extern int derive_key(const uint8_t *app_id, bool new_key, uint8_t *key_handle, mbedtls_ecdsa_context *key);
+extern bool wait_button_pressed();
 
 #endif //_FIDO_H