feat(core): derive Cardano seed together with normal seed, if requested

core/src/apps/cardano/seed.py

@@ -1,10 +1,10 @@
 from storage import cache, device
 from trezor import wire
-from trezor.crypto import bip32
+from trezor.crypto import bip32, cardano
 
 from apps.common import mnemonic
 from apps.common.passphrase import get as get_passphrase
-from apps.common.seed import get_seed
+from apps.common.seed import get_seed, derive_and_store_roots
 
 from .helpers import paths
 
@@ -24,12 +24,19 @@ class Keychain:
     """
 
     def __init__(self, root: bip32.HDNode) -> None:
-        self.byron_root = derive_path_cardano(root, paths.BYRON_ROOT)
-        self.shelley_root = derive_path_cardano(root, paths.SHELLEY_ROOT)
-        self.multisig_root = derive_path_cardano(root, paths.MULTISIG_ROOT)
-        self.minting_root = derive_path_cardano(root, paths.MINTING_ROOT)
+        self.byron_root = self._derive_path(root, paths.BYRON_ROOT)
+        self.shelley_root = self._derive_path(root, paths.SHELLEY_ROOT)
+        self.multisig_root = self._derive_path(root, paths.MULTISIG_ROOT)
+        self.minting_root = self._derive_path(root, paths.MINTING_ROOT)
         root.__del__()
 
+    @staticmethod
+    def _derive_path(root: bip32.HDNode, path: Bip32Path) -> bip32.HDNode:
+        """Clone and derive path from the root."""
+        node = root.clone()
+        node.derive_path(path)
+        return node
+
     def verify_path(self, path: Bip32Path) -> None:
         if not self.is_in_keychain(path):
             raise wire.DataError("Forbidden key path")
@@ -67,7 +74,7 @@ class Keychain:
         suffix = node_path[len(paths.SHELLEY_ROOT) :]
 
         # derive child node from the root
-        return derive_path_cardano(path_root, suffix)
+        return self._derive_path(path_root, suffix)
 
     # XXX the root node remains in session cache so we should not delete it
     # def __del__(self) -> None:
@@ -90,28 +97,35 @@ def is_minting_path(path: Bip32Path) -> bool:
     return path[: len(paths.MINTING_ROOT)] == paths.MINTING_ROOT
 
 
-def derive_path_cardano(root: bip32.HDNode, path: Bip32Path) -> bip32.HDNode:
-    node = root.clone()
-    for i in path:
-        node.derive_cardano(i)
-    return node
+def derive_and_store_secret(passphrase: str) -> None:
+    assert device.is_initialized()
+    assert cache.get(cache.APP_COMMON_DERIVE_CARDANO)
+
+    if not mnemonic.is_bip39():
+        # nothing to do for SLIP-39, where we can derive the root from the main seed
+        return
+
+    icarus_trezor_secret = mnemonic.derive_cardano_icarus_trezor(passphrase)
+    cache.set(cache.APP_CARDANO_SECRET, icarus_trezor_secret)
 
 
-@cache.stored_async(cache.APP_CARDANO_PASSPHRASE)
-async def _get_passphrase(ctx: wire.Context) -> bytes:
-    return (await get_passphrase(ctx)).encode()
+@cache.stored_async(cache.APP_CARDANO_SECRET)
+async def _get_secret(ctx: wire.Context) -> bytes:
+    await derive_and_store_roots(ctx)
+    secret = cache.get(cache.APP_CARDANO_SECRET)
+    assert secret is not None
+    return secret
 
 
 async def _get_keychain_bip39(ctx: wire.Context) -> Keychain:
     if not device.is_initialized():
         raise wire.NotInitialized("Device is not initialized")
 
-    # ask for passphrase, loading from cache if necessary
-    passphrase = await _get_passphrase(ctx)
-    # derive the root node from mnemonic and passphrase via Cardano Icarus algorithm
-    secret_bytes = mnemonic.get_secret()
-    assert secret_bytes is not None
-    root = bip32.from_mnemonic_cardano(secret_bytes.decode(), passphrase.decode())
+    if not cache.get(cache.APP_COMMON_DERIVE_CARDANO):
+        raise wire.ProcessError("Cardano derivation is not enabled for this session")
+
+    secret = await _get_secret(ctx)
+    root = cardano.from_secret(secret)
     return Keychain(root)
 
 
@@ -121,7 +135,7 @@ async def get_keychain(ctx: wire.Context) -> Keychain:
     else:
         # derive the root node via SLIP-0023 https://github.com/satoshilabs/slips/blob/master/slip-0022.md
         seed = await get_seed(ctx)
-        return Keychain(bip32.from_seed(seed, "ed25519 cardano seed"))
+        return Keychain(cardano.from_seed_slip23(seed))
 
 
 def with_keychain(func: HandlerWithKeychain[MsgIn, MsgOut]) -> Handler[MsgIn, MsgOut]:

core/src/apps/common/mnemonic.py

@@ -26,7 +26,7 @@ def is_bip39() -> bool:
 def get_seed(passphrase: str = "", progress_bar: bool = True) -> bytes:
     mnemonic_secret = get_secret()
     if mnemonic_secret is None:
-        raise ValueError("Mnemonic not set")
+        raise ValueError  # Mnemonic not set
 
     render_func = None
     if progress_bar and not utils.DISABLE_ANIMATION:
@@ -57,6 +57,30 @@ def get_seed(passphrase: str = "", progress_bar: bool = True) -> bytes:
     return seed
 
 
+if not utils.BITCOIN_ONLY:
+
+    def derive_cardano_icarus_trezor(
+        passphrase: str = "", progress_bar: bool = True
+    ) -> bytes:
+        if not is_bip39():
+            raise ValueError  # should not be called for SLIP-39
+
+        mnemonic_secret = get_secret()
+        if mnemonic_secret is None:
+            raise ValueError("Mnemonic not set")
+
+        render_func = None
+        if progress_bar and not utils.DISABLE_ANIMATION:
+            _start_progress()
+            render_func = _render_progress
+
+        from trezor.crypto import cardano
+
+        return cardano.derive_icarus_trezor(
+            mnemonic_secret, passphrase, render_func
+        )
+
+
 def _start_progress() -> None:
     from trezor.ui.layouts import draw_simple_text
 

core/src/apps/common/seed.py

@@ -1,5 +1,5 @@
 from storage import cache, device
-from trezor import wire
+from trezor import utils, wire
 from trezor.crypto import bip32, hmac
 
 from . import mnemonic
@@ -40,10 +40,48 @@ class Slip21Node:
         return Slip21Node(data=self.data)
 
 
-@cache.stored_async(cache.APP_COMMON_SEED)
-async def get_seed(ctx: wire.Context) -> bytes:
+if not utils.BITCOIN_ONLY:
+    # === Cardano variant ===
+    # We want to derive both the normal seed and the Cardano seed together, AND
+    # expose a method for Cardano to do the same
+
+    async def derive_and_store_roots(ctx: wire.Context) -> None:
         if not device.is_initialized():
             raise wire.NotInitialized("Device is not initialized")
+
+        need_seed = not cache.is_set(cache.APP_COMMON_SEED)
+        need_cardano_secret = cache.get(
+            cache.APP_COMMON_DERIVE_CARDANO
+        ) and not cache.is_set(cache.APP_CARDANO_SECRET)
+
+        if not need_seed and not need_cardano_secret:
+            return
+
+        passphrase = await get_passphrase(ctx)
+
+        if need_seed:
+            common_seed = mnemonic.get_seed(passphrase)
+            cache.set(cache.APP_COMMON_SEED, common_seed)
+
+        if need_cardano_secret:
+            from apps.cardano.seed import derive_and_store_secret
+
+            derive_and_store_secret(passphrase)
+
+    @cache.stored_async(cache.APP_COMMON_SEED)
+    async def get_seed(ctx: wire.Context) -> bytes:
+        await derive_and_store_roots(ctx)
+        common_seed = cache.get(cache.APP_COMMON_SEED)
+        assert common_seed is not None
+        return common_seed
+
+
+else:
+    # === Bitcoin-only variant ===
+    # We use the simple version of `get_seed` that never needs to derive anything else.
+
+    @cache.stored_async(cache.APP_COMMON_SEED)
+    async def get_seed(ctx: wire.Context) -> bytes:
         passphrase = await get_passphrase(ctx)
         return mnemonic.get_seed(passphrase)
 

core/src/storage/cache.py

@@ -21,7 +21,7 @@ _SESSION_ID_LENGTH = 32
 # Traditional cache keys
 APP_COMMON_SEED = 0
 APP_COMMON_DERIVE_CARDANO = 1
-APP_CARDANO_XPRV = 2
+APP_CARDANO_SECRET = 2
 APP_MONERO_LIVE_REFRESH = 3
 APP_COMMON_AUTHORIZATION_TYPE = 4
 APP_COMMON_AUTHORIZATION_DATA = 5
@@ -69,11 +69,15 @@ class DataCache:
         ...
 
     def get(self, key: int, default: T | None = None) -> bytes | T | None:  # noqa: F811
-        utils.ensure(key < len(self.fields), f"failed to load key {key}")
+        utils.ensure(key < len(self.fields))
         if self.data[key][0] != 1:
             return default
         return bytes(self.data[key][1:])
 
+    def is_set(self, key: int) -> bool:
+        utils.ensure(key < len(self.fields))
+        return self.data[key][0] == 1
+
     def delete(self, key: int) -> None:
         utils.ensure(key < len(self.fields))
         self.data[key][:] = b"\x00"
@@ -89,7 +93,7 @@ class SessionCache(DataCache):
         self.fields = (
             64,  # APP_COMMON_SEED
             1,  # APP_COMMON_DERIVE_CARDANO
-            96,  # APP_CARDANO_XPRV
+            96,  # APP_CARDANO_SECRET
             1,  # APP_MONERO_LIVE_REFRESH
             2,  # APP_COMMON_AUTHORIZATION_TYPE
             128,  # APP_COMMON_AUTHORIZATION_DATA
@@ -227,6 +231,14 @@ def get(key: int, default: T | None = None) -> bytes | T | None:  # noqa: F811
     return _SESSIONS[_active_session_idx].get(key, default)
 
 
+def is_set(key: int) -> bool:
+    if key & _SESSIONLESS_FLAG:
+        return _SESSIONLESS_CACHE.is_set(key ^ _SESSIONLESS_FLAG)
+    if _active_session_idx is None:
+        raise InvalidSessionError
+    return _SESSIONS[_active_session_idx].is_set(key)
+
+
 def delete(key: int) -> None:
     if key & _SESSIONLESS_FLAG:
         return _SESSIONLESS_CACHE.delete(key ^ _SESSIONLESS_FLAG)