feat(core/ui): T3T1 backup cannot be skipped

This commit disallows the user to exit backup flow once initiated.

It also ensurer the  intro screen is shown when initiating backup via
protobuf msg after it was previously skipped during wallet creation.

[no changelog]

core/embed/rust/src/ui/model_mercury/flow/prompt_backup.rs

@@ -97,13 +97,9 @@ pub extern "C" fn new_prompt_backup(n_args: usize, args: *const Obj, kwargs: *mu
 impl PromptBackup {
     fn new_obj(_args: &[Obj], _kwargs: &Map) -> Result<Obj, error::Error> {
         let title: TString = TR::backup__title_create_wallet_backup.into();
-        let par_array: [Paragraph<'static>; 1] = [Paragraph::new(
+        let text_intro: TString = TR::backup__it_should_be_backed_up.into();
-            &theme::TEXT_MAIN_GREY_LIGHT,
+
-            // FIXME: should be "contains X words" but the mnemonic/shares are not yet generated at
+        let paragraphs = Paragraphs::new(Paragraph::new(&theme::TEXT_MAIN_GREY_LIGHT, text_intro));
-            // this point. We might need to merge the PromptBackup and ShowShareWords flows
-            TString::from_str("Your wallet backup contains words in a specific order."),
-        )];
-        let paragraphs = Paragraphs::new(par_array);
         let content_intro = Frame::left_aligned(title, SwipeContent::new(paragraphs))
             .with_menu_button()
             .with_footer(TR::instructions__swipe_up.into(), None)

core/embed/rust/src/ui/model_mercury/flow/request_number.rs

@@ -52,7 +52,6 @@ impl FlowState for RequestNumber {
             (RequestNumber::Menu, FlowMsg::Choice(0)) => {
                 Decision::Goto(RequestNumber::Info, SwipeDirection::Left)
             }
-            (RequestNumber::Menu, FlowMsg::Choice(1)) => Decision::Return(FlowMsg::Cancelled),
             (RequestNumber::Menu, FlowMsg::Cancelled) => {
                 Decision::Goto(RequestNumber::Number, SwipeDirection::Right)
             }
@@ -119,9 +118,7 @@ impl RequestNumber {
 
         let content_menu = Frame::left_aligned(
             "".into(),
-            VerticalMenu::empty()
+            VerticalMenu::empty().item(theme::ICON_CHEVRON_RIGHT, TR::buttons__more_info.into()),
-                .item(theme::ICON_CHEVRON_RIGHT, TR::buttons__more_info.into())
-                .danger(theme::ICON_CANCEL, TR::backup__title_skip.into()),
         )
         .with_cancel_button()
         .with_swipe(SwipeDirection::Right, SwipeSettings::immediate())

core/embed/rust/src/ui/model_mercury/flow/show_share_words.rs

@@ -79,6 +79,10 @@ impl ShowShareWords {
         let subtitle: TString = kwargs.get(Qstr::MP_QSTR_subtitle)?.try_into()?;
         let share_words_obj: Obj = kwargs.get(Qstr::MP_QSTR_words)?;
         let share_words_vec: Vec<TString, 33> = util::iter_into_vec(share_words_obj)?;
+        let description: Option<TString> = kwargs
+            .get(Qstr::MP_QSTR_description)?
+            .try_into_option()?
+            .and_then(|desc: TString| if desc.is_empty() { None } else { Some(desc) });
         let text_info: Obj = kwargs.get(Qstr::MP_QSTR_text_info)?;
         let text_confirm: TString = kwargs.get(Qstr::MP_QSTR_text_confirm)?.try_into()?;
         let nwords = share_words_vec.len();
@@ -98,7 +102,7 @@ impl ShowShareWords {
             ),
         )
         .with_subtitle(TR::words__instructions.into())
-        .with_footer(TR::instructions__swipe_up.into(), None)
+        .with_footer(TR::instructions__swipe_up.into(), description)
         .with_swipe(SwipeDirection::Up, SwipeSettings::default())
         .map(|msg| matches!(msg, FrameMsg::Content(_)).then_some(FlowMsg::Confirmed))
         .one_button_request(ButtonRequestCode::ResetDevice.with_type("share_words"))

core/embed/rust/src/ui/model_mercury/layout.rs

@@ -1688,6 +1688,7 @@ pub static mp_module_trezorui2: Module = obj_module! {
     ///     title: str,
     ///     subtitle: str,
     ///     words: Iterable[str],
+    ///     description: str,
     ///     text_info: Iterable[str],
     ///     text_confirm: str,
     /// ) -> LayoutObj[UiResult]:

core/mocks/generated/trezorui2.pyi

@@ -402,6 +402,7 @@ def flow_show_share_words(
     title: str,
     subtitle: str,
     words: Iterable[str],
+    description: str,
     text_info: Iterable[str],
     text_confirm: str,
 ) -> LayoutObj[UiResult]:

core/src/apps/management/reset_device/__init__.py

@@ -126,13 +126,21 @@ async def reset_device(msg: ResetDevice) -> Success:
     return Success(message="Initialized")
 
 
+async def _backup_bip39(mnemonic: str) -> None:
+    words = mnemonic.split()
+    await layout.show_backup_intro(single_share=True, num_of_words=len(words))
+    await layout.show_and_confirm_single_share(words)
+
+
 async def _backup_slip39_single(
     encrypted_master_secret: bytes, extendable: bool
 ) -> None:
     mnemonics = _get_slip39_mnemonics(encrypted_master_secret, 1, ((1, 1),), extendable)
+    words = mnemonics[0][0].split()
 
     # for a single 1-of-1 group, we use the same layouts as for BIP39
-    await layout.show_and_confirm_mnemonic(mnemonics[0][0])
+    await layout.show_backup_intro(single_share=True, num_of_words=len(words))
+    await layout.show_and_confirm_single_share(words)
 
 
 async def _backup_slip39_basic(
@@ -140,6 +148,8 @@ async def _backup_slip39_basic(
 ) -> None:
     group_threshold = 1
 
+    await layout.show_backup_intro(single_share=False)
+
     # get number of shares
     await layout.slip39_show_checklist(0, advanced=False)
     share_count = await layout.slip39_prompt_number_of_shares()
@@ -165,6 +175,9 @@ async def _backup_slip39_basic(
 async def _backup_slip39_advanced(
     encrypted_master_secret: bytes, extendable: bool
 ) -> None:
+
+    await layout.show_backup_intro(single_share=False)
+
     # get number of groups
     await layout.slip39_show_checklist(0, advanced=True)
     groups_count = await layout.slip39_advanced_prompt_number_of_groups()
@@ -287,4 +300,4 @@ async def backup_seed(backup_type: BackupType, mnemonic_secret: bytes) -> None:
         else:
             await _backup_slip39_basic(mnemonic_secret, extendable)
     else:
-        await layout.show_and_confirm_mnemonic(mnemonic_secret.decode())
+        await _backup_bip39(mnemonic_secret.decode())

core/src/apps/management/reset_device/layout.py

@@ -3,7 +3,6 @@ from typing import Sequence
 
 from trezor import TR
 from trezor.enums import ButtonRequestType
-from trezor.ui.layouts import show_success
 from trezor.ui.layouts.reset import (  # noqa: F401
     show_share_words,
     slip39_advanced_prompt_group_threshold,
@@ -70,8 +69,8 @@ async def _share_words_confirmed(
     Return true if the words are confirmed successfully.
     """
     from trezor.ui.layouts.reset import (
-        show_share_confirmation_success,
         show_share_confirmation_failure,
+        show_share_confirmation_success,
     )
 
     if await _do_confirm_share_words(share_index, share_words, group_index):
@@ -108,6 +107,14 @@ async def _do_confirm_share_words(
     return True
 
 
+async def show_backup_intro(
+    single_share: bool, num_of_words: int | None = None
+) -> None:
+    from trezor.ui.layouts.reset import show_intro_backup
+
+    await show_intro_backup(single_share, num_of_words)
+
+
 async def show_backup_warning() -> None:
     from trezor.ui.layouts.reset import show_warning_backup
 
@@ -124,12 +131,10 @@ async def show_backup_success() -> None:
 # ===
 
 
-async def show_and_confirm_mnemonic(mnemonic: str) -> None:
+async def show_and_confirm_single_share(words: Sequence[str]) -> None:
     # warn user about mnemonic safety
     await show_backup_warning()
 
-    words = mnemonic.split()
-
     while True:
         # display paginated mnemonic on the screen
         await show_share_words(words)

core/src/trezor/ui/layouts/mercury/__init__.py

@@ -382,7 +382,6 @@ async def prompt_backup() -> bool:
         "backup_device",
         ButtonRequestType.ResetDevice,
     )
-
     return result is CONFIRMED
 
 

core/src/trezor/ui/layouts/mercury/reset.py

@@ -32,12 +32,14 @@ async def show_share_words(
             group_index + 1, share_index + 1
         )
     words_count = len(share_words)
+    description = ""
     text_info = [TR.reset__write_down_words_template.format(words_count)]
     if words_count == 20 and share_index is None:
         # 1-of-1 SLIP39: inform the user about repeated words
         text_info.append(TR.reset__words_may_repeat)
     if share_index == 0:
         # regular SLIP39, 1st share
+        description = TR.instructions__shares_start_with_1
         text_info.append(TR.reset__repeat_for_all_shares)
     text_confirm = TR.reset__words_written_down_template.format(words_count)
 
@@ -46,6 +48,7 @@ async def show_share_words(
             title=title,
             subtitle=subtitle,
             words=share_words,
+            description=description,
             text_info=text_info,
             text_confirm=text_confirm,
         )
@@ -304,6 +307,24 @@ async def slip39_advanced_prompt_group_threshold(num_of_groups: int) -> int:
     )
 
 
+async def show_intro_backup(single_share: bool, num_of_words: int | None) -> None:
+    if single_share:
+        assert num_of_words is not None
+        description = TR.backup__info_single_share_backup.format(num_of_words)
+    else:
+        description = TR.backup__info_multi_share_backup
+
+    await interact(
+        RustLayout(
+            trezorui2.show_info(
+                title=TR.backup__title_create_wallet_backup, description=description
+            )
+        ),
+        "backup_warning",
+        ButtonRequestType.ResetDevice,
+    )
+
+
 async def show_warning_backup() -> None:
     result = await interact(
         RustLayout(

core/src/trezor/ui/layouts/tr/reset.py

@@ -6,7 +6,7 @@ from trezor.enums import ButtonRequestType
 from trezor.wire import ActionCancelled
 
 from ..common import interact
-from . import RustLayout, confirm_action, show_warning, show_success
+from . import RustLayout, confirm_action, show_success, show_warning
 
 CONFIRMED = trezorui2.CONFIRMED  # global_import_cache
 
@@ -254,6 +254,23 @@ async def slip39_advanced_prompt_group_threshold(num_of_groups: int) -> int:
     )
 
 
+async def show_intro_backup(single_share: bool, num_of_words: int | None) -> None:
+    if single_share:
+        assert num_of_words is not None
+        description = TR.backup__info_single_share_backup.format(num_of_words)
+    else:
+        description = TR.backup__info_multi_share_backup
+
+    await confirm_action(
+        "backup_warning",
+        title=TR.backup__title_backup_wallet,
+        verb=TR.buttons__continue,
+        description=description,
+        verb_cancel=None,
+        br_code=ButtonRequestType.ResetDevice,
+    )
+
+
 async def show_warning_backup() -> None:
     await show_warning(
         "backup_warning",

core/src/trezor/ui/layouts/tt/reset.py

@@ -309,6 +309,27 @@ async def slip39_advanced_prompt_group_threshold(num_of_groups: int) -> int:
     )
 
 
+async def show_intro_backup(single_share: bool, num_of_words: int | None) -> None:
+    if single_share:
+        assert num_of_words is not None
+        description = TR.backup__info_single_share_backup.format(num_of_words)
+    else:
+        description = TR.backup__info_multi_share_backup
+
+    await interact(
+        RustLayout(
+            trezorui2.show_info(
+                title="",
+                button=TR.buttons__continue,
+                description=description,
+                allow_cancel=False,
+            )
+        ),
+        "backup_warning",
+        ButtonRequestType.ResetDevice,
+    )
+
+
 async def show_warning_backup() -> None:
     result = await interact(
         RustLayout(

tests/input_flows.py

@@ -1310,7 +1310,7 @@ class InputFlowBip39ResetBackup(InputFlowBase):
         # 1. Confirm Reset x3
         # 2. Backup your seed
         # 3. Confirm warning
-        yield from click_through(self.debug, screens=4, code=B.ResetDevice)
+        yield from click_through(self.debug, screens=5, code=B.ResetDevice)
 
         # mnemonic phrases and rest
         self.mnemonic = yield from get_mnemonic_and_confirm_success(self.debug)

tests/persistence_tests/test_shamir_persistence.py

@@ -138,7 +138,7 @@ def test_recovery_on_old_wallet(core_emulator: Emulator):
     words = first_share.split(" ")
 
     # start entering first share
-    assert "the first 2-4 letters" in debug.read_layout().text_content()
+    assert "Enter each word of your wallet backup" in debug.read_layout().text_content()
     debug.press_yes()
     assert debug.wait_layout().main_component() == "MnemonicKeyboard"
 
@@ -176,7 +176,7 @@ def test_recovery_multiple_resets(core_emulator: Emulator):
     def enter_shares_with_restarts(debug: DebugLink) -> None:
         shares = MNEMONIC_SLIP39_ADVANCED_20
         layout = debug.read_layout()
-        expected_text = "the first 2-4 letters"
+        expected_text = "Enter each word of your wallet backup"
         remaining = len(shares)
         for share in shares:
             assert expected_text in layout.text_content()