refactor(core): make 1-of-1 SLIP39 backups use same messaging as BIP39

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

@@ -121,10 +121,14 @@ async def _backup_slip39_basic(encrypted_master_secret: bytes) -> None:
     await layout.slip39_show_checklist(1, BAK_T_SLIP39_BASIC)
     share_threshold = await layout.slip39_prompt_threshold(share_count)
 
-    await _backup_slip39(
+    mnemonics = await _backup_slip39(
         encrypted_master_secret, group_threshold, [(share_threshold, share_count)]
     )
 
+    # show and confirm individual shares
+    await layout.slip39_show_checklist(2, BAK_T_SLIP39_BASIC)
+    await layout.slip39_basic_show_and_confirm_shares(mnemonics[0])
+
 
 async def _backup_slip39_advanced(encrypted_master_secret: bytes) -> None:
     # get number of groups
@@ -143,9 +147,30 @@ async def _backup_slip39_advanced(encrypted_master_secret: bytes) -> None:
         share_threshold = await layout.slip39_prompt_threshold(share_count, i)
         groups.append((share_threshold, share_count))
 
-    await _backup_slip39(encrypted_master_secret, group_threshold, groups)
+    mnemonics = await _backup_slip39(encrypted_master_secret, group_threshold, groups)
+
+    # show and confirm individual shares
+    await layout.slip39_advanced_show_and_confirm_shares(mnemonics)
 
 
+async def _backup_slip39_custom(
+    encrypted_master_secret: bytes,
+    group_threshold: int,
+    groups: Collection[tuple[int, int]],
+):
+    mnemonics = await _backup_slip39(encrypted_master_secret, group_threshold, groups)
+
+    # show and confirm individual shares
+    if len(groups) == 1 and groups[0][0] == 1 and groups[0][1] == 1:
+        # for a single 1-of-1 group, we use the same layouts as for BIP39
+        await layout.show_and_confirm_mnemonic(mnemonics[0][0])
+    else:
+        # TODO: a confirmation screen will be shown: "do you want to create a -of- Shamir backup?"
+        if len(groups) == 1:
+            await layout.slip39_basic_show_and_confirm_shares(mnemonics[0])
+        else:
+            await layout.slip39_advanced_show_and_confirm_shares(mnemonics)
+
 async def _backup_slip39(
     encrypted_master_secret: bytes,
     group_threshold: int,
@@ -157,7 +182,7 @@ async def _backup_slip39(
         raise ValueError
 
     # generate the mnemonics
-    mnemonics = slip39.split_ems(
+    return slip39.split_ems(
         group_threshold,
         groups,
         identifier,
@@ -165,13 +190,6 @@ async def _backup_slip39(
         encrypted_master_secret,
     )
 
-    # show and confirm individual shares
-    if len(groups) == 1:
-        await layout.slip39_show_checklist(2, BAK_T_SLIP39_BASIC)
-        await layout.slip39_basic_show_and_confirm_shares(mnemonics[0])
-    else:
-        await layout.slip39_advanced_show_and_confirm_shares(mnemonics)
-
 
 def _validate_reset_device(msg: ResetDevice) -> None:
     from trezor.wire import UnexpectedMessage
@@ -225,10 +243,10 @@ async def backup_seed(
     assert backup_type != BAK_T_BIP39 or group_threshold is None
 
     if group_threshold is not None:
-        await _backup_slip39(mnemonic_secret, group_threshold, groups)
+        await _backup_slip39_custom(mnemonic_secret, group_threshold, groups)
     elif backup_type == BAK_T_SLIP39_BASIC:
         await _backup_slip39_basic(mnemonic_secret)
     elif backup_type == BAK_T_SLIP39_ADVANCED:
         await _backup_slip39_advanced(mnemonic_secret)
     else:
-        await layout.bip39_show_and_confirm_mnemonic(mnemonic_secret.decode())
+        await layout.show_and_confirm_mnemonic(mnemonic_secret.decode())

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

@@ -110,7 +110,7 @@ async def _show_confirmation_success(
     num_of_shares: int | None = None,
     group_index: int | None = None,
 ) -> None:
-    if share_index is None or num_of_shares is None:  # it is a BIP39 backup
+    if share_index is None or num_of_shares is None:  # it is a BIP39 or a 1-of-1 SLIP39 backup
         subheader = TR.reset__finished_verifying_seed
         text = ""
 
@@ -150,10 +150,10 @@ async def _show_confirmation_failure() -> None:
     )
 
 
-async def show_backup_warning(slip39: bool = False) -> None:
+async def show_backup_warning() -> None:
     from trezor.ui.layouts.reset import show_warning_backup
 
-    await show_warning_backup(slip39)
+    await show_warning_backup()
 
 
 async def show_backup_success() -> None:
@@ -162,11 +162,11 @@ async def show_backup_success() -> None:
     await show_success_backup()
 
 
-# BIP39
+# Simple setups: BIP39 or SLIP39 1-of-1
 # ===
 
 
-async def bip39_show_and_confirm_mnemonic(mnemonic: str) -> None:
+async def show_and_confirm_mnemonic(mnemonic: str) -> None:
     # warn user about mnemonic safety
     await show_backup_warning()
 
@@ -181,13 +181,13 @@ async def bip39_show_and_confirm_mnemonic(mnemonic: str) -> None:
             break  # mnemonic is confirmed, go next
 
 
-# SLIP39
+# Complex setups: SLIP39, except 1-of-1
 # ===
 
 
 async def slip39_basic_show_and_confirm_shares(shares: Sequence[str]) -> None:
     # warn user about mnemonic safety
-    await show_backup_warning(True)
+    await show_backup_warning()
 
     for index, share in enumerate(shares):
         share_words = share.split(" ")
@@ -204,7 +204,7 @@ async def slip39_advanced_show_and_confirm_shares(
     shares: Sequence[Sequence[str]],
 ) -> None:
     # warn user about mnemonic safety
-    await show_backup_warning(True)
+    await show_backup_warning()
 
     for group_index, group in enumerate(shares):
         for share_index, share in enumerate(group):

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

@@ -258,7 +258,7 @@ async def slip39_advanced_prompt_group_threshold(num_of_groups: int) -> int:
     )
 
 
-async def show_warning_backup(slip39: bool) -> None:
+async def show_warning_backup() -> None:
     await show_warning(
         "backup_warning",
         TR.words__title_remember,

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

@@ -319,7 +319,7 @@ async def slip39_advanced_prompt_group_threshold(num_of_groups: int) -> int:
     )
 
 
-async def show_warning_backup(slip39: bool) -> None:
+async def show_warning_backup() -> None:
     result = await interact(
         RustLayout(
             trezorui2.show_info(