feat(core): Implement sending to taproot addresses.

core/.changelog.d/1656.added

@@ -0,0 +1 @@
+Support sending to Taproot addresses.

core/src/apps/bitcoin/addresses.py

@@ -10,7 +10,7 @@ from apps.common.coininfo import CoinInfo
 
 from .common import ecdsa_hash_pubkey, encode_bech32_address
 from .multisig import multisig_get_pubkeys, multisig_pubkey_index
-from .scripts import output_script_native_p2wpkh_or_p2wsh, write_output_script_multisig
+from .scripts import output_script_native_segwit, write_output_script_multisig
 
 if False:
     from trezor.crypto import bip32
@@ -109,13 +109,13 @@ def address_p2sh(redeem_script_hash: bytes, coin: CoinInfo) -> str:
 
 def address_p2wpkh_in_p2sh(pubkey: bytes, coin: CoinInfo) -> str:
     pubkey_hash = ecdsa_hash_pubkey(pubkey, coin)
-    redeem_script = output_script_native_p2wpkh_or_p2wsh(pubkey_hash)
+    redeem_script = output_script_native_segwit(0, pubkey_hash)
     redeem_script_hash = coin.script_hash(redeem_script).digest()
     return address_p2sh(redeem_script_hash, coin)
 
 
 def address_p2wsh_in_p2sh(witness_script_hash: bytes, coin: CoinInfo) -> str:
-    redeem_script = output_script_native_p2wpkh_or_p2wsh(witness_script_hash)
+    redeem_script = output_script_native_segwit(0, witness_script_hash)
     redeem_script_hash = coin.script_hash(redeem_script).digest()
     return address_p2sh(redeem_script_hash, coin)
 

core/src/apps/bitcoin/common.py

@@ -7,6 +7,7 @@ from trezor.enums import InputScriptType, OutputScriptType
 from trezor.utils import ensure
 
 if False:
+    from typing import Tuple
     from apps.common.coininfo import CoinInfo
     from trezor.messages import TxInput
 
@@ -84,12 +85,12 @@ def encode_bech32_address(prefix: str, witver: int, script: bytes) -> str:
     return address
 
 
-def decode_bech32_address(prefix: str, address: str) -> bytes:
+def decode_bech32_address(prefix: str, address: str) -> Tuple[int, bytes]:
     witver, raw = bech32.decode(prefix, address)
     if witver not in _BECH32_WITVERS:
         raise wire.ProcessError("Invalid address witness program")
     assert raw is not None
-    return bytes(raw)
+    return witver, bytes(raw)
 
 
 def input_is_segwit(txi: TxInput) -> bool:

core/src/apps/bitcoin/scripts.py

@@ -60,9 +60,9 @@ def write_input_script_prefixed(
             write_input_script_p2wpkh_in_p2sh(
                 w, common.ecdsa_hash_pubkey(pubkey, coin), prefixed=True
             )
-    elif script_type == InputScriptType.SPENDWITNESS:
-        # native p2wpkh or p2wsh
-        script_sig = input_script_native_p2wpkh_or_p2wsh()
+    elif script_type in (InputScriptType.SPENDWITNESS, InputScriptType.SPENDTAPROOT):
+        # native p2wpkh or p2wsh or p2tr
+        script_sig = input_script_native_segwit()
         write_bytes_prefixed(w, script_sig)
     elif script_type == InputScriptType.SPENDMULTISIG:
         # p2sh multisig
@@ -77,9 +77,9 @@ def write_input_script_prefixed(
 
 def output_derive_script(address: str, coin: CoinInfo) -> bytes:
     if coin.bech32_prefix and address.startswith(coin.bech32_prefix):
-        # p2wpkh or p2wsh
-        witprog = common.decode_bech32_address(coin.bech32_prefix, address)
-        return output_script_native_p2wpkh_or_p2wsh(witprog)
+        # p2wpkh or p2wsh or p2tr
+        witver, witprog = common.decode_bech32_address(coin.bech32_prefix, address)
+        return output_script_native_segwit(witver, witprog)
 
     if (
         not utils.BITCOIN_ONLY
@@ -205,34 +205,39 @@ def output_script_p2sh(scripthash: bytes) -> bytearray:
     return s
 
 
-# SegWit: Native P2WPKH or P2WSH
+# SegWit: Native P2WPKH or P2WSH or P2TR
 # ===
+#
+# P2WPKH (Pay-to-Witness-Public-Key-Hash) is native SegWit version 0 P2PKH.
+# Not backwards compatible.
 # https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki#p2wpkh
+#
+# P2WSH (Pay-to-Witness-Script-Hash) is native SegWit version 0 P2SH.
+# Not backwards compatible.
 # https://github.com/bitcoin/bips/blob/master/bip-0141.mediawiki#p2wsh
 #
-# P2WPKH (Pay-to-Witness-Public-Key-Hash) is the segwit native P2PKH.
-# Not backwards compatible.
-#
-# P2WSH (Pay-to-Witness-Script-Hash) is segwit native P2SH.
+# P2TR (Pay-to-Taproot) is native SegWit version 1.
 # Not backwards compatible.
+# https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki#script-validation-rules
 
 
-def input_script_native_p2wpkh_or_p2wsh() -> bytearray:
+def input_script_native_segwit() -> bytearray:
     # Completely replaced by the witness and therefore empty.
     return bytearray(0)
 
 
-def output_script_native_p2wpkh_or_p2wsh(witprog: bytes) -> bytearray:
+def output_script_native_segwit(witver: int, witprog: bytes) -> bytearray:
     # Either:
     # 00 14 <20-byte-key-hash>
     # 00 20 <32-byte-script-hash>
+    # 51 20 <32-byte-taproot-output-key>
     length = len(witprog)
-    utils.ensure(length == 20 or length == 32)
+    utils.ensure((length == 20 and witver == 0) or length == 32)
 
-    w = utils.empty_bytearray(3 + length)
-    w.append(0x00)  # witness version byte
-    w.append(length)  # pub key hash length is 20 (P2WPKH) or 32 (P2WSH) bytes
-    write_bytes_fixed(w, witprog, length)  # pub key hash
+    w = utils.empty_bytearray(2 + length)
+    w.append(witver + 0x50 if witver else 0)  # witness version byte (OP_witver)
+    w.append(length)  # witness program length is 20 (P2WPKH) or 32 (P2WSH, P2TR) bytes
+    write_bytes_fixed(w, witprog, length)
     return w
 
 

core/src/apps/bitcoin/verification.py

@@ -5,7 +5,7 @@ from trezor.crypto.hashlib import sha256
 
 from .common import ecdsa_hash_pubkey
 from .scripts import (
-    output_script_native_p2wpkh_or_p2wsh,
+    output_script_native_segwit,
     output_script_p2pkh,
     output_script_p2sh,
     parse_input_script_multisig,
@@ -40,14 +40,14 @@ class SignatureVerifier:
             if len(script_pubkey) == 22:  # P2WPKH
                 public_key, signature, hash_type = parse_witness_p2wpkh(witness)
                 pubkey_hash = ecdsa_hash_pubkey(public_key, coin)
-                if output_script_native_p2wpkh_or_p2wsh(pubkey_hash) != script_pubkey:
+                if output_script_native_segwit(0, pubkey_hash) != script_pubkey:
                     raise wire.DataError("Invalid public key hash")
                 self.public_keys = [public_key]
                 self.signatures = [(signature, hash_type)]
             elif len(script_pubkey) == 34:  # P2WSH
                 script, self.signatures = parse_witness_multisig(witness)
                 script_hash = sha256(script).digest()
-                if output_script_native_p2wpkh_or_p2wsh(script_hash) != script_pubkey:
+                if output_script_native_segwit(0, script_hash) != script_pubkey:
                     raise wire.DataError("Invalid script hash")
                 self.public_keys, self.threshold = parse_output_script_multisig(script)
             else: