src/apps/management: implement BackupDevice message

src/apps/common/storage.py

@@ -53,6 +53,14 @@ def load_mnemonic(mnemonic: str, needs_backup: bool) -> None:
         config.set(_APP, _NEEDS_BACKUP, b'')
 
 
+def needs_backup() -> bool:
+    return bool(config.get(_APP, _NEEDS_BACKUP))
+
+
+def set_backed_up() -> None:
+    config.set(_APP, _NEEDS_BACKUP, b'')
+
+
 def load_settings(label: str=None, use_passphrase: bool=None, homescreen: bytes=None) -> None:
     if label is not None:
         config.set(_APP, _LABEL, label.encode(), True)  # public

src/apps/homescreen/homescreen.py

@@ -22,7 +22,12 @@ def display_homescreen():
     if not image:
         image = res.load('apps/homescreen/res/bg.toif')
 
-    ui.display.bar(0, 0, ui.WIDTH, ui.HEIGHT, ui.BG)
+    if storage.is_initialized() and storage.needs_backup():
+        ui.display.bar(0, 0, ui.WIDTH, 30, ui.YELLOW)
+        ui.display.text_center(120, 22, 'NEEDS BACKUP!', ui.BOLD, ui.BLACK, ui.YELLOW)
+        ui.display.bar(0, 30, ui.WIDTH, ui.HEIGHT - 30, ui.BG)
+    else:
+        ui.display.bar(0, 0, ui.WIDTH, ui.HEIGHT, ui.BG)
     ui.display.avatar(48, 48 - 10, image, ui.WHITE, ui.BLACK)
     ui.display.text_center(120, 220, label, ui.BOLD, ui.FG, ui.BG)
 

src/apps/management/__init__.py

@@ -1,7 +1,7 @@
 from trezor.wire import register, protobuf_workflow
 from trezor.utils import unimport
 from trezor.messages.wire_types import \
-    LoadDevice, ResetDevice, WipeDevice, RecoveryDevice, ApplySettings, ApplyFlags, ChangePin
+    LoadDevice, ResetDevice, BackupDevice, WipeDevice, RecoveryDevice, ApplySettings, ApplyFlags, ChangePin
 
 
 @unimport
@@ -16,6 +16,12 @@ def dispatch_ResetDevice(*args, **kwargs):
     return reset_device(*args, **kwargs)
 
 
+@unimport
+def dispatch_BackupDevice(*args, **kwargs):
+    from .backup_device import backup_device
+    return backup_device(*args, **kwargs)
+
+
 @unimport
 def dispatch_WipeDevice(*args, **kwargs):
     from .wipe_device import layout_wipe_device
@@ -51,6 +57,7 @@ def boot():
     if __debug__:
         register(LoadDevice, protobuf_workflow, dispatch_LoadDevice)
     register(ResetDevice, protobuf_workflow, dispatch_ResetDevice)
+    register(BackupDevice, protobuf_workflow, dispatch_BackupDevice)
     register(WipeDevice, protobuf_workflow, dispatch_WipeDevice)
     register(RecoveryDevice, protobuf_workflow, dispatch_RecoveryDevice)
     register(ApplySettings, protobuf_workflow, dispatch_ApplySettings)

src/apps/management/backup_device.py

@@ -0,0 +1,30 @@
+from trezor import ui, wire
+from trezor.messages.FailureType import ProcessError
+from trezor.messages.Success import Success
+from apps.common import storage
+from apps.management.reset_device import show_warning, show_mnemonic, check_mnemonic, show_wrong_entry
+
+
+@ui.layout
+async def backup_device(ctx, msg):
+
+    if not storage.is_initialized():
+        raise wire.FailureError(ProcessError, 'Device is not initialized')
+
+    if not storage.needs_backup():
+        raise wire.FailureError(ProcessError, 'Seed already backed up')
+
+    mnemonic = storage.get_mnemonic()
+
+    storage.set_backed_up()
+
+    # warn user about mnemonic safety
+    await show_warning(ctx)
+    while True:
+        # show mnemonic and require confirmation of a random word
+        await show_mnemonic(ctx, mnemonic)
+        if await check_mnemonic(ctx, mnemonic):
+            break
+        await show_wrong_entry(ctx)
+
+    return Success(message='Seed successfully backed up')

src/apps/management/reset_device.py

@@ -80,7 +80,8 @@ async def reset_device(ctx, msg):
         mnemonic=mnemonic, needs_backup=msg.skip_backup)
 
     # show success message
-    await show_success(ctx)
+    if not msg.skip_backup:
+        await show_success(ctx)
 
     return Success(message='Initialized')