sd2fa is NOT backed up and not restored from older backups

releases/ChangeLog.md

@@ -13,6 +13,11 @@
 - Bugfix: empty number during BIP-39 passphrase entry could cause crash.
 - Bugfix: UX: Signing with BIP39 Passphrase showed master fingerprint as integer. Fixed to show hex.
 - Bugfix: Fixed inability to generate paper wallet without secrets
+- Bugfix: SD2FA setting is cleared when seed is wiped after failed policy SD2FA enforce.
+  Prevents infinite seed wipe loop when restoring backup after 2FA MicroSD lost or damaged.
+  SD2FA is not backed up and also not restored from older backups. If SD2FA is set up,
+  it will not survive restore of backup.
+
 
 ## 5.1.2 - 2023-04-07
 

shared/backups.py

@@ -97,6 +97,7 @@ def render_backup_contents():
         if k == 'xpub': continue        # redundant, and wrong if bip39pw
         if k == 'xfp': continue         # redundant, and wrong if bip39pw
         if k == 'bkpw': continue        # confusing/circular
+        if k == 'sd2fa': continue       # do NOT backup SD 2FA (card can be lost or damaged)
         ADD('setting.' + k, v)
 
     if version.has_fatram:
@@ -171,26 +172,35 @@ def restore_from_dict_ll(vals):
             sys.print_exception(exc)
             # but keep going
 
-    # restore settings from backup file
+    # if sd2fa is encountered during backup restore - purge it
+    settings.remove_key("sd2fa")
 
-    for idx, k in enumerate(vals):
-        dis.progress_bar_show(idx / len(vals))
-        if not k.startswith('setting.'):
+    # restore settings from backup file
+    vals_len = len(vals)
+    for idx, key in enumerate(vals):
+        dis.progress_bar_show(idx / vals_len)
+        if not key[:8] == "setting.":
             continue
 
-        if k == 'xfp' or k == 'xpub': continue
+        k = key[8:]
+
+        if k == 'sd2fa':
+            # do NOT restore sd2fa as SD card can be lost or damaged
+            # new version of firmware 5.1.3+ will not back sd2fa
+            # old backups need this to function properly
+            continue
 
         if k == 'tp':
             # restore trick pins, which may involve many ops
             if version.mk_num >= 4:
                 from trick_pins import tp
                 try:
-                    tp.restore_backup(vals[k])
+                    tp.restore_backup(vals[key])
                 except Exception as exc:
                     sys.print_exception(exc)
             continue
 
-        settings.set(k[8:], vals[k])
+        settings.set(k, vals[key])
 
     # write out
     settings.save()

shared/mk4.py

@@ -96,7 +96,6 @@ def wipe_if_deltamode():
     if not pa.is_deltamode():
         return
 
-    import callgate
     callgate.fast_wipe()
 
 # EOF

shared/pwsave.py

@@ -207,6 +207,9 @@ class MicroSD2FA(PassphraseSaver):
         except:
             # die. wrong
             import callgate
+            from glob import settings
+            settings.remove_key("sd2fa")
+            settings.save()
             callgate.fast_wipe(silent=False)
 
         # proceed w/o any notice
@@ -258,6 +261,7 @@ class MicroSD2FA(PassphraseSaver):
                     fd.write(msg)
 
             # update setting as well
+            # TODO use general method that handles memory overflow
             v.append(nonce)
             settings.set('sd2fa', v)
             settings.save()
@@ -324,13 +328,15 @@ class MicroSD2FA(PassphraseSaver):
             ok = cls.authorized_card_present(cls.get_nonces())
             if ok:
                 await ux_show_story("Need a different MicroSD card. "
-                                        "This card would already be accepted.")
+                                    "This card would already be accepted.")
                 return
 
         ctx = 'this card or one of the others' if count >= 1 else 'it'
 
-        ok = await ux_confirm("Add this card to authorized set? Going forward %s must be present during login process or the seed will be wiped!" % ctx)
-
+        ok = await ux_confirm("Add this card to authorized set? Going forward %s must be "
+                              "present during login process or the seed will be wiped!" % ctx)
+        if not ok:
+            return
 
         await cls().enroll()
 

shared/trick_pins.py

@@ -512,7 +512,7 @@ class TrickPinMenu(MenuSystem):
             have.remove(existing_pin)
 
         if (new_pin == self.current_pin) or (new_pin in have):
-            await ux_show_story("That PIN (%s) is already in use. All PIN codes must be unique." % new_pin);
+            await ux_show_story("That PIN (%s) is already in use. All PIN codes must be unique." % new_pin)
             return
 
         # check if we "forgot" this pin, and read it back if we did.