[Feature] Add SLIP-39 Shamir's secret sharing import support for SeedSigner

src/seedsigner/gui/screens/seed_screens.py

@@ -1631,3 +1631,221 @@ def __post_init__(self):
             screen_y=derivation_path_display.screen_y + derivation_path_display.height + 2*GUIConstants.COMPONENT_PADDING,
         )
         self.components.append(address_display)
+
+
+
+@dataclass
+class NumericEntryScreen(BaseTopNavScreen):
+    title: str = ""
+    entered_number: str = ""
+
+    def __post_init__(self):
+        super().__post_init__()
+
+        keys_number = "0123456789"
+
+        # Set up the keyboard params
+        self.right_panel_buttons_width = 56
+
+        text_entry_display_y = self.top_nav.height
+        text_entry_display_height = 30
+
+        keyboard_start_y = text_entry_display_y + text_entry_display_height + GUIConstants.COMPONENT_PADDING
+
+        self.keyboard_digits = Keyboard(
+            draw=self.renderer.draw,
+            charset=keys_number,
+            rows=3,
+            cols=5,
+            rect=(
+                GUIConstants.COMPONENT_PADDING,
+                keyboard_start_y,
+                self.canvas_width - GUIConstants.COMPONENT_PADDING - self.right_panel_buttons_width,
+                self.canvas_height - GUIConstants.EDGE_PADDING
+            ),
+            additional_keys=[
+                Keyboard.KEY_CURSOR_LEFT,
+                Keyboard.KEY_CURSOR_RIGHT,
+                Keyboard.KEY_BACKSPACE
+            ],
+            auto_wrap=[Keyboard.WRAP_LEFT, Keyboard.WRAP_RIGHT]
+        )
+
+        self.text_entry_display = TextEntryDisplay(
+            canvas=self.renderer.canvas,
+            rect=(
+                GUIConstants.EDGE_PADDING,
+                text_entry_display_y,
+                self.canvas_width - self.right_panel_buttons_width,
+                text_entry_display_y + text_entry_display_height
+            ),
+            cursor_mode=TextEntryDisplay.CURSOR_MODE__BAR,
+            is_centered=False,
+            cur_text=''.join(self.entered_number)
+        )
+
+        # Nudge the buttons off the right edge w/padding
+        hw_button_x = self.canvas_width - self.right_panel_buttons_width + GUIConstants.COMPONENT_PADDING
+
+        # Calc center button position first
+        hw_button_y = int((self.canvas_height - GUIConstants.BUTTON_HEIGHT)/2)
+
+        self.hw_button3 = IconButton(
+            icon_name=SeedSignerIconConstants.CHECK,
+            icon_color=GUIConstants.SUCCESS_COLOR,
+            width=self.right_panel_buttons_width,
+            screen_x=hw_button_x,
+            screen_y=hw_button_y + 3*GUIConstants.COMPONENT_PADDING + GUIConstants.BUTTON_HEIGHT,
+        )
+
+
+    def _render(self):
+        super()._render()
+
+        self.text_entry_display.render()
+        self.hw_button3.render()
+        self.keyboard_digits.render_keys()
+
+        self.renderer.show_image()
+
+    def _run(self):
+        cursor_position = len(self.entered_number)
+
+        cur_keyboard = self.keyboard_digits
+
+        # Start the interactive update loop
+        while True:
+            input = self.hw_inputs.wait_for(
+                HardwareButtonsConstants.ALL_KEYS,
+                check_release=True,
+                release_keys=[HardwareButtonsConstants.KEY_PRESS, HardwareButtonsConstants.KEY1, HardwareButtonsConstants.KEY2, HardwareButtonsConstants.KEY3]
+            )
+
+            keyboard_swap = False
+
+            # Check our two possible exit conditions
+            # TODO: note the unusual return value, consider refactoring to a Response object in the future
+            if input == HardwareButtonsConstants.KEY3:
+                # Save!
+                # First light up key3
+                self.hw_button3.is_selected = True
+                self.hw_button3.render()
+                self.renderer.show_image()
+                return dict(entered_number=self.entered_number)
+
+            elif input == HardwareButtonsConstants.KEY_PRESS and self.top_nav.is_selected:
+                # Back button clicked
+                return dict(entered_number=self.entered_number, is_back_button=True)
+
+
+
+
+            # Process normal input
+            if input in [HardwareButtonsConstants.KEY_UP, HardwareButtonsConstants.KEY_DOWN] and self.top_nav.is_selected:
+                # We're navigating off the previous button
+                self.top_nav.is_selected = False
+                self.top_nav.render_buttons()
+
+                # Override the actual input w/an ENTER signal for the Keyboard
+                if input == HardwareButtonsConstants.KEY_DOWN:
+                    input = Keyboard.ENTER_TOP
+                else:
+                    input = Keyboard.ENTER_BOTTOM
+            elif input in [HardwareButtonsConstants.KEY_LEFT, HardwareButtonsConstants.KEY_RIGHT] and self.top_nav.is_selected:
+                # ignore
+                continue
+
+            ret_val = cur_keyboard.update_from_input(input)
+
+            # Now process the result from the keyboard
+            if ret_val in Keyboard.EXIT_DIRECTIONS:
+                self.top_nav.is_selected = True
+                self.top_nav.render_buttons()
+
+            elif ret_val in Keyboard.ADDITIONAL_KEYS and input == HardwareButtonsConstants.KEY_PRESS:
+                if ret_val == Keyboard.KEY_BACKSPACE["code"]:
+                    if cursor_position == 0:
+                        pass
+                    elif cursor_position == len(self.entered_number):
+                        self.entered_number = self.entered_number[:-1]
+                    else:
+                        self.entered_number = self.entered_number[:cursor_position - 1] + self.entered_number[cursor_position:]
+
+                    cursor_position -= 1
+
+                elif ret_val == Keyboard.KEY_CURSOR_LEFT["code"]:
+                    cursor_position -= 1
+                    if cursor_position < 0:
+                        cursor_position = 0
+
+                elif ret_val == Keyboard.KEY_CURSOR_RIGHT["code"]:
+                    cursor_position += 1
+                    if cursor_position > len(self.entered_number):
+                        cursor_position = len(self.entered_number)
+
+                elif ret_val == Keyboard.KEY_SPACE["code"]:
+                    if cursor_position == len(self.entered_number):
+                        self.entered_number += " "
+                    else:
+                        self.entered_number = self.entered_number[:cursor_position] + " " + self.entered_number[cursor_position:]
+                    cursor_position += 1
+
+                # Update the text entry display and cursor
+                self.text_entry_display.render(self.entered_number, cursor_position)
+
+            elif input == HardwareButtonsConstants.KEY_PRESS and ret_val not in Keyboard.ADDITIONAL_KEYS:
+                # User has locked in the current letter
+                if cursor_position == len(self.entered_number):
+                    self.entered_number += ret_val
+                else:
+                    self.entered_number = self.entered_number[:cursor_position] + ret_val + self.entered_number[cursor_position:]
+                cursor_position += 1
+
+                # Update the text entry display and cursor
+                self.text_entry_display.render(self.entered_number, cursor_position)
+
+            elif input in HardwareButtonsConstants.KEYS__LEFT_RIGHT_UP_DOWN or keyboard_swap:
+                # Live joystick movement; haven't locked this new letter in yet.
+                # Leave current spot blank for now. Only update the active keyboard keys
+                # when a selection has been locked in (KEY_PRESS) or removed ("del").
+                pass
+
+
+            self.renderer.show_image()
+
+
+
+@dataclass
+class SeedEntryShamirThresholdScreen(NumericEntryScreen):
+    title: str = "SLIP-39 Threshold"
+
+
+
+@dataclass
+class SeedEntryShamirShareCountScreen(NumericEntryScreen):
+    title: str = "SLIP-39 Share Count"
+
+
+
+@dataclass
+class ShamirFinalizeScreen(ButtonListScreen):
+    value_text: str = None
+    is_bottom_list: bool = True
+    button_data: list = None
+
+    def __post_init__(self):
+        self.show_back_button = False
+        self.title = _("Finalize Shamir Share")
+        super().__post_init__()
+
+        self.fingerprint_icontl = IconTextLine(
+            icon_name=SeedSignerIconConstants.FINGERPRINT,
+            icon_color=GUIConstants.INFO_COLOR,
+            icon_size=GUIConstants.ICON_FONT_SIZE + 12,
+            label_text=_("SLIP-39"),
+            value_text=self.value_text,
+            font_size=GUIConstants.get_body_font_size() + 2,
+            is_text_centered=True,
+            screen_y=self.top_nav.height + int((self.buttons[0].screen_y - self.top_nav.height) / 2) - 30
+        )
+        self.components.append(self.fingerprint_icontl)

src/seedsigner/models/seed.py

@@ -4,7 +4,7 @@
 import hmac
 
 from binascii import hexlify
-from embit import bip39, bip32, bip85
+from embit import bip39, bip32, bip85, slip39
 from embit.networks import NETWORKS
 from typing import List
 
@@ -35,6 +35,8 @@ def __init__(self,
         self.seed_bytes: bytes = None
         self._generate_seed()
 
+        self._shamir_share_sets: List[(int, int, List[str], str)] = []
+
 
     @staticmethod
     def get_wordlist(wordlist_language_code: str = SettingsConstants.WORDLIST_LANGUAGE__ENGLISH) -> List[str]:
@@ -164,6 +166,33 @@ def get_bip85_child_mnemonic(self, bip85_index: int, bip85_num_words: int, netwo
         return bip85.derive_mnemonic(root, bip85_num_words, bip85_index)
 
 
+    # Shamir's Secret Sharing
+
+    @classmethod
+    def recover_from_shares(cls, shares: list[str], slip39_passphrase: str = ""):
+        mnemonic = slip39.ShareSet.recover_mnemonic(shares, slip39_passphrase.encode('utf-8'))
+        return cls(mnemonic.split(), wordlist_language_code = SettingsConstants.WORDLIST_LANGUAGE__ENGLISH)
+
+
+    @staticmethod
+    def get_slip39_wordlist(wordlist_language_code: str = SettingsConstants.WORDLIST_LANGUAGE__ENGLISH) -> List[str]:
+        if wordlist_language_code == SettingsConstants.WORDLIST_LANGUAGE__ENGLISH:
+            return slip39.SLIP39_WORDS
+        else:
+            raise Exception(f"Unrecognized wordlist_language_code {wordlist_language_code}")
+
+
+    @property
+    def slip39_wordlist(self) -> List[str]:
+        return Seed.get_slip39_wordlist(self.wordlist_language_code)
+
+
+    @property
+    def slip39_passphrase_label(self) -> str:
+        #return SettingsConstants.LABEL__BIP39_PASSPHRASE
+        return "SLIP-39 Passphrase"
+
+
     ### override operators    
     def __eq__(self, other):
         if isinstance(other, Seed):
@@ -239,3 +268,4 @@ def seedqr_supported(self) -> bool:
     @property
     def bip85_supported(self) -> bool:
         return False
+

src/seedsigner/models/seed_storage.py

@@ -10,6 +10,7 @@ def __init__(self) -> None:
         self.pending_seed: Seed = None
         self._pending_mnemonic: List[str] = []
         self._pending_is_electrum : bool = False
+        self._pending_shamir_share_set: List[str] = []
 
 
     def set_pending_seed(self, seed: Seed):
@@ -103,3 +104,49 @@ def convert_pending_mnemonic_to_pending_seed(self):
     def discard_pending_mnemonic(self):
         self._pending_mnemonic = []
         self._pending_is_electrum = False
+
+
+    # Shamir shares
+
+    def init_pending_shamir_share_set(self, num_words: int = 20, num_shares: int = 2, is_electrum: bool = False):
+        self._pending_mnemonic = [None] * num_words
+        self._pending_shamir_share_set = [None] * num_shares
+        self._pending_is_electrum = is_electrum
+
+
+    def update_pending_shamir_share_set(self, index: int):
+        """
+        Replaces the nth share in the pending shamir share.
+
+        * may specify a negative `index` (e.g. -1 is the last word).
+        """
+        if index >= len(self._pending_shamir_share_set):
+            raise Exception(f"index {index} is too high")
+        self._pending_shamir_share_set[index] = self._pending_mnemonic    
+        if index < len(self._pending_shamir_share_set) - 1:
+            self.discard_pending_mnemonic()
+            self.init_pending_mnemonic(len(self._pending_shamir_share_set[index]))
+
+
+    def get_pending_shamir_share_set_share(self, index: int) -> List[str]:
+        if index < len(self._pending_shamir_share_set):
+            return self._pending_shamir_share_set[index]
+        return None
+
+
+    @property
+    def pending_shamir_share_set_length(self) -> int:
+        return len(self._pending_shamir_share_set)
+
+
+    def discard_pending_shamir_share_set(self):
+        self._pending_shamir_share_set = []
+
+
+    def convert_pending_shamir_share_set_to_pending_seed(self, passphrase: str = '', clean: bool = True):
+        share_set_formatted = [" ".join(share) for share in self._pending_shamir_share_set]
+        self.pending_seed = Seed.recover_from_shares(share_set_formatted, passphrase)
+        if clean:
+            self.discard_pending_mnemonic()
+            self.discard_pending_shamir_share_set()
+

src/seedsigner/models/settings_definition.py

@@ -193,6 +193,7 @@ def map_network_to_embit(cls, network) -> str:
     SETTING__BIP85_CHILD_SEEDS = "bip85_child_seeds"
     SETTING__ELECTRUM_SEEDS = "electrum_seeds"
     SETTING__MESSAGE_SIGNING = "message_signing"
+    SETTING__SSS = "sss_seeds"
     SETTING__PRIVACY_WARNINGS = "privacy_warnings"
     SETTING__DIRE_WARNINGS = "dire_warnings"
     SETTING__QR_BRIGHTNESS_TIPS = "qr_brightness_tips"
@@ -515,6 +516,14 @@ class SettingsDefinition:
                       visibility=SettingsConstants.VISIBILITY__ADVANCED,
                       default_value=SettingsConstants.OPTION__DISABLED),
 
+        SettingsEntry(category=SettingsConstants.CATEGORY__FEATURES,
+                      attr_name=SettingsConstants.SETTING__SSS,
+                      abbreviated_name="sss",
+                      display_name="Shamir's Secret Sharing",
+                      help_text="Shares import only",
+                      visibility=SettingsConstants.VISIBILITY__ADVANCED,
+                      default_value=SettingsConstants.OPTION__DISABLED),
+
         SettingsEntry(category=SettingsConstants.CATEGORY__FEATURES,
                       attr_name=SettingsConstants.SETTING__PRIVACY_WARNINGS,
                       abbreviated_name="priv_warn",