feat(core/bitcoin): use path schemas

core/src/apps/bitcoin/addresses.py

@@ -4,7 +4,7 @@ from trezor.crypto.hashlib import sha256
 from trezor.messages import InputScriptType
 from trezor.messages.MultisigRedeemScriptType import MultisigRedeemScriptType
 
-from apps.common import HARDENED, address_type
+from apps.common import address_type
 from apps.common.coininfo import CoinInfo
 
 from .common import ecdsa_hash_pubkey, encode_bech32_address
@@ -155,82 +155,3 @@ def address_short(coin: CoinInfo, address: str) -> str:
         return address[len(coin.cashaddr_prefix) + 1 :]
     else:
         return address
-
-
-def validate_full_path(
-    path: list,
-    coin: CoinInfo,
-    script_type: EnumTypeInputScriptType,
-    validate_script_type: bool = True,
-) -> bool:
-    """
-    Validates derivation path to fit Bitcoin-like coins. We mostly use
-    44', but for segwit-enabled coins we use either 49' (P2WPKH-nested-in-P2SH)
-    or 84' (native P2WPKH). Electrum uses m/45' for legacy addresses and
-    m/48' for segwit, so those two are allowed as well.
-
-    See docs/coins for what paths are allowed. Please note that this is not
-    a comprehensive check, some nuances are omitted for simplification.
-    """
-    if len(path) not in (4, 5, 6):
-        return False
-
-    if not validate_purpose(path[0], coin):
-        return False
-    if validate_script_type and not validate_purpose_against_script_type(
-        path[0], script_type
-    ):
-        return False
-
-    if path[1] > 20 and path[1] != coin.slip44 | HARDENED:
-        return False
-    if (20 < path[2] < HARDENED) or path[2] > 20 | HARDENED:
-        return False
-    if path[3] not in (0, 1, 0 | HARDENED, 1 | HARDENED, 2 | HARDENED):
-        return False
-    if len(path) > 4 and path[4] > 1000000:
-        return False
-    if len(path) > 5 and path[5] > 1000000:
-        return False
-    return True
-
-
-def validate_purpose(purpose: int, coin: CoinInfo) -> bool:
-    if purpose not in (
-        44 | HARDENED,
-        45 | HARDENED,
-        48 | HARDENED,
-        49 | HARDENED,
-        84 | HARDENED,
-    ):
-        return False
-    if not coin.segwit and purpose not in (44 | HARDENED, 45 | HARDENED, 48 | HARDENED):
-        return False
-    return True
-
-
-def validate_purpose_against_script_type(
-    purpose: int, script_type: EnumTypeInputScriptType
-) -> bool:
-    """
-    Validates purpose against provided input's script type:
-    - 44 for spending address (script_type == SPENDADDRESS)
-    - 45, 48 for multisig (script_type == SPENDMULTISIG)
-    - 49 for p2wsh-nested-in-p2sh spend (script_type == SPENDP2SHWITNESS)
-    - 84 for p2wsh native segwit spend (script_type == SPENDWITNESS)
-    """
-    if purpose == 44 | HARDENED and script_type != InputScriptType.SPENDADDRESS:
-        return False
-    if purpose == 45 | HARDENED and script_type != InputScriptType.SPENDMULTISIG:
-        return False
-    if purpose == 48 | HARDENED and script_type not in (
-        InputScriptType.SPENDMULTISIG,
-        InputScriptType.SPENDP2SHWITNESS,
-        InputScriptType.SPENDWITNESS,
-    ):
-        return False
-    if purpose == 49 | HARDENED and script_type != InputScriptType.SPENDP2SHWITNESS:
-        return False
-    if purpose == 84 | HARDENED and script_type != InputScriptType.SPENDWITNESS:
-        return False
-    return True

core/src/apps/bitcoin/authorize_coinjoin.py

@@ -10,10 +10,9 @@ from apps.base import set_authorization
 from apps.common.confirm import require_confirm, require_hold_to_confirm
 from apps.common.paths import validate_path
 
-from . import addresses
 from .authorization import FEE_PER_ANONYMITY_DECIMALS, CoinJoinAuthorization
 from .common import BIP32_WALLET_DEPTH
-from .keychain import get_keychain_for_coin
+from .keychain import get_keychain_for_coin, validate_path_against_script_type
 
 if False:
     from trezor import wire
@@ -36,14 +35,14 @@ async def authorize_coinjoin(ctx: wire.Context, msg: AuthorizeCoinJoin) -> Succe
         if not msg.address_n:
             raise wire.DataError("Empty path not allowed.")
 
+        validation_path = msg.address_n + [0] * BIP32_WALLET_DEPTH
         await validate_path(
             ctx,
-            addresses.validate_full_path,
             keychain,
-            msg.address_n + [0] * BIP32_WALLET_DEPTH,
+            validation_path,
-            coin.curve_name,
+            validate_path_against_script_type(
-            coin=coin,
+                coin, address_n=validation_path, script_type=msg.script_type
-            script_type=msg.script_type,
+            ),
         )
 
         text = Text("Authorize CoinJoin", ui.ICON_RECOVERY)

core/src/apps/bitcoin/get_address.py

@@ -6,7 +6,7 @@ from apps.common.layout import address_n_to_str, show_address, show_qr, show_xpu
 from apps.common.paths import validate_path
 
 from . import addresses
-from .keychain import with_keychain
+from .keychain import validate_path_against_script_type, with_keychain
 from .multisig import multisig_pubkey_index
 
 if False:
@@ -45,12 +45,9 @@ async def get_address(
 ) -> Address:
     await validate_path(
         ctx,
-        addresses.validate_full_path,
         keychain,
         msg.address_n,
-        coin.curve_name,
+        validate_path_against_script_type(coin, msg),
-        coin=coin,
-        script_type=msg.script_type,
     )
 
     node = keychain.derive(msg.address_n)

core/src/apps/bitcoin/get_ownership_id.py

@@ -5,7 +5,7 @@ from trezor.messages.OwnershipId import OwnershipId
 from apps.common.paths import validate_path
 
 from . import addresses, common, scripts
-from .keychain import with_keychain
+from .keychain import validate_path_against_script_type, with_keychain
 from .ownership import get_identifier
 
 if False:
@@ -19,12 +19,9 @@ async def get_ownership_id(
 ) -> OwnershipId:
     await validate_path(
         ctx,
-        addresses.validate_full_path,
         keychain,
         msg.address_n,
-        coin.curve_name,
+        validate_path_against_script_type(coin, msg),
-        coin=coin,
-        script_type=msg.script_type,
     )
 
     if msg.script_type not in common.INTERNAL_INPUT_SCRIPT_TYPES:

core/src/apps/bitcoin/get_ownership_proof.py

@@ -9,7 +9,7 @@ from apps.common.confirm import require_confirm
 from apps.common.paths import validate_path
 
 from . import addresses, common, scripts
-from .keychain import with_keychain
+from .keychain import validate_path_against_script_type, with_keychain
 from .ownership import generate_proof, get_identifier
 
 if False:
@@ -36,12 +36,9 @@ async def get_ownership_proof(
     else:
         await validate_path(
             ctx,
-            addresses.validate_full_path,
             keychain,
             msg.address_n,
-            coin.curve_name,
+            validate_path_against_script_type(coin, msg),
-            coin=coin,
-            script_type=msg.script_type,
         )
 
     if msg.script_type not in common.INTERNAL_INPUT_SCRIPT_TYPES:

core/src/apps/bitcoin/get_public_key.py

@@ -3,7 +3,7 @@ from trezor.messages import InputScriptType
 from trezor.messages.HDNodeType import HDNodeType
 from trezor.messages.PublicKey import PublicKey
 
-from apps.common import coins, layout
+from apps.common import coins, layout, paths
 from apps.common.keychain import get_keychain
 
 if False:
@@ -16,7 +16,7 @@ async def get_public_key(ctx: wire.Context, msg: GetPublicKey) -> PublicKey:
     coin = coins.by_name(coin_name)
     curve_name = msg.ecdsa_curve_name or coin.curve_name
 
-    keychain = await get_keychain(ctx, curve_name, [[]])
+    keychain = await get_keychain(ctx, curve_name, [paths.AlwaysMatchingSchema])
 
     node = keychain.derive(msg.address_n)
 

core/src/apps/bitcoin/keychain.py

@@ -1,14 +1,18 @@
 from trezor import wire
+from trezor.messages import InputScriptType as I
 
-from apps.common import HARDENED, coininfo
+from apps.common import coininfo
 from apps.common.keychain import get_keychain
+from apps.common.paths import PATTERN_BIP44, PathSchema
 
 from .common import BITCOIN_NAMES
 
 if False:
-    from typing import Awaitable, Callable, Optional, Sequence, Tuple, TypeVar
+    from typing import Awaitable, Callable, Iterable, List, Optional, Tuple, TypeVar
     from typing_extensions import Protocol
 
+    from trezor.messages.TxInputType import EnumTypeInputScriptType
+
     from apps.common.keychain import Keychain, MsgOut, Handler
     from apps.common.paths import Bip32Path
 
@@ -17,54 +21,124 @@ if False:
     class MsgWithCoinName(Protocol):
         coin_name = ...  # type: str
 
+    class MsgWithAddressScriptType(Protocol):
+        # XXX should be Bip32Path but that fails
+        address_n = ...  # type: List[int]
+        script_type = ...  # type: EnumTypeInputScriptType
+
     MsgIn = TypeVar("MsgIn", bound=MsgWithCoinName)
     HandlerWithCoinInfo = Callable[..., Awaitable[MsgOut]]
 
+# common patterns
+PATTERN_BIP45 = "m/45'/[0-100]/change/address_index"
+PATTERN_PURPOSE48_LEGACY = "m/48'/coin_type'/account'/0'/change/address_index"
+PATTERN_PURPOSE48_P2SHSEGWIT = "m/48'/coin_type'/account'/1'/change/address_index"
+PATTERN_PURPOSE48_SEGWIT = "m/48'/coin_type'/account'/2'/change/address_index"
+PATTERN_BIP49 = "m/49'/coin_type'/account'/change/address_index"
+PATTERN_BIP84 = "m/84'/coin_type'/account'/change/address_index"
 
-def get_namespaces_for_coin(coin: coininfo.CoinInfo) -> Sequence[Bip32Path]:
+# compatibility patterns, will be removed in the future
-    namespaces = []
+PATTERN_GREENADDRESS_A = "m/[1,4]/address_index"
-    slip44_id = coin.slip44 | HARDENED
+PATTERN_GREENADDRESS_B = "m/3'/[1-100]'/[1,4]/address_index"
+PATTERN_GREENADDRESS_SIGN_A = "m/1195487518"
+PATTERN_GREENADDRESS_SIGN_B = "m/1195487518/6/address_index"
 
-    # BIP-44 - legacy: m/44'/slip44' (/account'/change/addr)
+PATTERN_CASA = "m/49/coin_type/account/change/address_index"
-    namespaces.append([44 | HARDENED, slip44_id])
-    # BIP-45 - multisig cosigners: m/45' (/cosigner/change/addr)
-    namespaces.append([45 | HARDENED])
-    # "purpose48" - multisig as done by Electrum
-    # m/48'/slip44' (/account'/script_type'/change/addr)
-    namespaces.append([48 | HARDENED, slip44_id])
 
-    if coin.segwit:
-        # BIP-49 - p2sh segwit: m/49'/slip44' (/account'/change/addr)
-        namespaces.append([49 | HARDENED, slip44_id])
-        # BIP-84 - native segwit: m/84'/slip44' (/account'/change/addr)
-        namespaces.append([84 | HARDENED, slip44_id])
 
+def validate_path_against_script_type(
+    coin: coininfo.CoinInfo,
+    msg: MsgWithAddressScriptType = None,
+    address_n: Bip32Path = None,
+    script_type: EnumTypeInputScriptType = None,
+    multisig: bool = False,
+) -> bool:
+    patterns = []
+
+    if msg is not None:
+        assert address_n is None and script_type is None
+        address_n = msg.address_n
+        script_type = msg.script_type or I.SPENDADDRESS
+        multisig = bool(getattr(msg, "multisig", False))
+
+    else:
+        assert address_n is not None and script_type is not None
+
+    if script_type == I.SPENDADDRESS and not multisig:
+        patterns.append(PATTERN_BIP44)
         if coin.coin_name in BITCOIN_NAMES:
-        # compatibility namespace for Casa
+            patterns.append(PATTERN_GREENADDRESS_A)
-        namespaces.append([49, coin.slip44])
+            patterns.append(PATTERN_GREENADDRESS_B)
 
-        # compatibility namespace for Greenaddress:
+    elif script_type in (I.SPENDADDRESS, I.SPENDMULTISIG) and multisig:
-        # m/branch/address_pointer, for branch in (1, 4)
+        patterns.append(PATTERN_BIP45)
-        namespaces.append([1])
+        patterns.append(PATTERN_PURPOSE48_LEGACY)
-        namespaces.append([4])
+        if coin.coin_name in BITCOIN_NAMES:
-        # m/3'/subaccount'/branch/address_pointer
+            patterns.append(PATTERN_GREENADDRESS_A)
-        namespaces.append([3 | HARDENED])
+            patterns.append(PATTERN_GREENADDRESS_B)
-        # sign msg:
+
-        # m/0x4741b11e
+    elif coin.segwit and script_type == I.SPENDP2SHWITNESS:
-        # m/0x4741b11e/6/pointer
+        patterns.append(PATTERN_BIP49)
-        namespaces.append([0x4741B11E])
+        if multisig:
+            patterns.append(PATTERN_PURPOSE48_P2SHSEGWIT)
+        if coin.coin_name in BITCOIN_NAMES:
+            patterns.append(PATTERN_GREENADDRESS_A)
+            patterns.append(PATTERN_GREENADDRESS_B)
+            patterns.append(PATTERN_CASA)
+
+    elif coin.segwit and script_type == I.SPENDWITNESS:
+        patterns.append(PATTERN_BIP84)
+        if multisig:
+            patterns.append(PATTERN_PURPOSE48_SEGWIT)
+        if coin.coin_name in BITCOIN_NAMES:
+            patterns.append(PATTERN_GREENADDRESS_A)
+            patterns.append(PATTERN_GREENADDRESS_B)
+
+    return any(
+        PathSchema(pattern, coin.slip44).match(address_n) for pattern in patterns
+    )
+
+
+def get_schemas_for_coin(coin: coininfo.CoinInfo) -> Iterable[PathSchema]:
+    # basic patterns
+    patterns = [
+        PATTERN_BIP44,
+        PATTERN_BIP45,
+        PATTERN_PURPOSE48_LEGACY,
+    ]
+
+    # compatibility patterns
+    if coin.coin_name in BITCOIN_NAMES:
+        patterns.extend(
+            (
+                PATTERN_GREENADDRESS_A,
+                PATTERN_GREENADDRESS_B,
+                PATTERN_GREENADDRESS_SIGN_A,
+                PATTERN_GREENADDRESS_SIGN_B,
+                PATTERN_CASA,
+            )
+        )
+
+    # segwit patterns
+    if coin.segwit:
+        patterns.extend(
+            (
+                PATTERN_BIP49,
+                PATTERN_BIP84,
+                PATTERN_PURPOSE48_P2SHSEGWIT,
+                PATTERN_PURPOSE48_SEGWIT,
+            )
+        )
+
+    schemas = [PathSchema(pattern, coin.slip44) for pattern in patterns]
 
     # some wallets such as Electron-Cash (BCH) store coins on Bitcoin paths
     # we can allow spending these coins from Bitcoin paths if the coin has
     # implemented strong replay protection via SIGHASH_FORKID
     if coin.fork_id is not None:
-        namespaces.append([44 | HARDENED, 0 | HARDENED])
+        schemas.extend(PathSchema(pattern, 0) for pattern in patterns)
-        namespaces.append([48 | HARDENED, 0 | HARDENED])
-        if coin.segwit:
-            namespaces.append([49 | HARDENED, 0 | HARDENED])
-            namespaces.append([84 | HARDENED, 0 | HARDENED])
 
-    return namespaces
+    return schemas
 
 
 def get_coin_by_name(coin_name: Optional[str]) -> coininfo.CoinInfo:
@@ -81,9 +155,9 @@ async def get_keychain_for_coin(
     ctx: wire.Context, coin_name: Optional[str]
 ) -> Tuple[Keychain, coininfo.CoinInfo]:
     coin = get_coin_by_name(coin_name)
-    namespaces = get_namespaces_for_coin(coin)
+    schemas = get_schemas_for_coin(coin)
     slip21_namespaces = [[b"SLIP-0019"]]
-    keychain = await get_keychain(ctx, coin.curve_name, namespaces, slip21_namespaces)
+    keychain = await get_keychain(ctx, coin.curve_name, schemas, slip21_namespaces)
     return keychain, coin
 
 

core/src/apps/bitcoin/multisig.py

@@ -5,6 +5,8 @@ from trezor.messages.HDNodeType import HDNodeType
 from trezor.messages.MultisigRedeemScriptType import MultisigRedeemScriptType
 from trezor.utils import HashWriter
 
+from apps.common import paths
+
 from .writers import write_bytes_fixed, write_uint32
 
 if False:
@@ -42,7 +44,16 @@ def multisig_fingerprint(multisig: MultisigRedeemScriptType) -> bytes:
     return h.get_digest()
 
 
+def validate_multisig(multisig: MultisigRedeemScriptType) -> None:
+    if any(paths.is_hardened(n) for n in multisig.address_n):
+        raise wire.DataError("Cannot perform hardened derivation from XPUB")
+    for hd in multisig.pubkeys:
+        if any(paths.is_hardened(n) for n in hd.address_n):
+            raise wire.DataError("Cannot perform hardened derivation from XPUB")
+
+
 def multisig_pubkey_index(multisig: MultisigRedeemScriptType, pubkey: bytes) -> int:
+    validate_multisig(multisig)
     if multisig.nodes:
         for i, hd_node in enumerate(multisig.nodes):
             if multisig_get_pubkey(hd_node, multisig.address_n) == pubkey:
@@ -54,7 +65,7 @@ def multisig_pubkey_index(multisig: MultisigRedeemScriptType, pubkey: bytes) ->
     raise wire.DataError("Pubkey not found in multisig script")
 
 
-def multisig_get_pubkey(n: HDNodeType, p: list) -> bytes:
+def multisig_get_pubkey(n: HDNodeType, p: paths.Bip32Path) -> bytes:
     node = bip32.HDNode(
         depth=n.depth,
         fingerprint=n.fingerprint,
@@ -68,6 +79,7 @@ def multisig_get_pubkey(n: HDNodeType, p: list) -> bytes:
 
 
 def multisig_get_pubkeys(multisig: MultisigRedeemScriptType) -> List[bytes]:
+    validate_multisig(multisig)
     if multisig.nodes:
         return [multisig_get_pubkey(hd, multisig.address_n) for hd in multisig.nodes]
     else:

core/src/apps/bitcoin/sign_message.py

@@ -6,7 +6,7 @@ from trezor.messages.MessageSignature import MessageSignature
 from apps.common.paths import validate_path
 from apps.common.signverify import message_digest, require_confirm_sign_message
 
-from .addresses import get_address, validate_full_path
+from .addresses import get_address
 from .keychain import with_keychain
 
 if False:
@@ -25,16 +25,7 @@ async def sign_message(
     script_type = msg.script_type or 0
 
     await require_confirm_sign_message(ctx, coin.coin_shortcut, message)
-    await validate_path(
+    await validate_path(ctx, keychain, msg.address_n)
-        ctx,
-        validate_full_path,
-        keychain,
-        msg.address_n,
-        coin.curve_name,
-        coin=coin,
-        script_type=msg.script_type,
-        validate_script_type=False,
-    )
 
     node = keychain.derive(address_n)
     seckey = node.private_key()

core/src/apps/bitcoin/sign_tx/approvers.py

@@ -5,7 +5,7 @@ from trezor.messages import OutputScriptType
 
 from apps.common import safety_checks
 
-from .. import addresses
+from .. import keychain
 from ..authorization import FEE_PER_ANONYMITY_DECIMALS
 from . import helpers, tx_weight
 from .tx_info import OriginalTxInfo, TxInfo
@@ -90,7 +90,7 @@ class BasicApprover(Approver):
         self.change_count = 0  # the number of change-outputs
 
     async def add_internal_input(self, txi: TxInput) -> None:
-        if not addresses.validate_full_path(txi.address_n, self.coin, txi.script_type):
+        if not keychain.validate_path_against_script_type(self.coin, txi):
             await helpers.confirm_foreign_address(txi.address_n)
 
         await super().add_internal_input(txi)