jade: use Jade's native PSBT signing if the firmware version supports it

If Jade is running firmware 0.1.47 or later use native PSBT signing,
otherwise continue to use the existing legacy-format tx signing.

Author: JamieDriver

hwilib/devices/jade.py

@@ -52,6 +52,7 @@
     parse_multisig
 )
 
+import base64
 import logging
 import semver
 import os
@@ -90,6 +91,7 @@ def func(*args: Any, **kwargs: Any) -> Any:
 # This class extends the HardwareWalletClient for Blockstream Jade specific things
 class JadeClient(HardwareWalletClient):
     MIN_SUPPORTED_FW_VERSION = semver.VersionInfo(0, 1, 32)
+    PSBT_SUPPORTED_FW_VERSION = semver.VersionInfo(0, 1, 47)
 
     NETWORKS = {Chain.MAIN: 'mainnet',
                 Chain.TEST: 'testnet',
@@ -131,12 +133,12 @@ def __init__(self, path: str, password: Optional[str] = None, expert: bool = Fal
         self.jade.connect()
 
         verinfo = self.jade.get_version_info()
+        self.fw_version = semver.parse_version_info(verinfo['JADE_VERSION'])
         uninitialized = verinfo['JADE_STATE'] not in ['READY', 'TEMP']
 
         # Check minimum supported firmware version (ignore candidate/build parts)
-        fw_version = semver.parse_version_info(verinfo['JADE_VERSION'])
-        if self.MIN_SUPPORTED_FW_VERSION > fw_version.finalize_version():
-            raise DeviceNotReadyError(f'Jade fw version: {fw_version} - minimum required version: {self.MIN_SUPPORTED_FW_VERSION}. '
+        if self.MIN_SUPPORTED_FW_VERSION > self.fw_version.finalize_version():
+            raise DeviceNotReadyError(f'Jade fw version: {self.fw_version} - minimum required version: {self.MIN_SUPPORTED_FW_VERSION}. '
                                       'Please update using a Blockstream Green companion app')
         if path == SIMULATOR_PATH:
             if uninitialized:
@@ -165,10 +167,9 @@ def get_pubkey_at_path(self, bip32_path: str) -> ExtendedKey:
         ext_key = ExtendedKey.deserialize(xpub)
         return ext_key
 
-    # Walk the PSBT looking for inputs we can sign.  Push any signatures into the
-    # 'partial_sigs' map in the input, and return the updated PSBT.
-    @jade_exception
-    def sign_tx(self, tx: PSBT) -> PSBT:
+    # Old firmware does not have native PSBT handling - walk the PSBT looking for inputs we can sign.
+    # Push any signatures into the 'partial_sigs' map in the input, and return the updated PSBT.
+    def legacy_sign_tx(self, tx: PSBT) -> PSBT:
         """
         Sign a transaction with the Blockstream Jade.
         """
@@ -366,6 +367,29 @@ def _split_at_last_hardened_element(path: Sequence[int]) -> Tuple[Sequence[int],
         # Return the updated psbt
         return tx
 
+    # Sign tx PSBT - newer Jade firmware supports native PSBT signing, but old firmwares require
+    # mapping to the legacy 'sign_tx' structures.
+    @jade_exception
+    def sign_tx(self, tx: PSBT) -> PSBT:
+        """
+        Sign a transaction with the Blockstream Jade.
+        """
+        # Old firmware does not have native PSBT handling - use legacy method
+        if self.PSBT_SUPPORTED_FW_VERSION > self.fw_version.finalize_version():
+            return self.legacy_sign_tx(tx)
+
+        # Firmware 0.1.47 (March 2023) and later support native PSBT signing
+        psbt_b64 = tx.serialize()
+        psbt_bytes = base64.b64decode(psbt_b64.strip())
+
+        # NOTE: sign_psbt() does not use AE signatures, so sticks with default (rfc6979)
+        psbt_bytes = self.jade.sign_psbt(self._network(), psbt_bytes)
+        psbt_b64 = base64.b64encode(psbt_bytes).decode()
+
+        psbt_signed = PSBT()
+        psbt_signed.deserialize(psbt_b64)
+        return psbt_signed
+
     # Sign message, confirmed on device
     @jade_exception
     def sign_message(self, message: Union[str, bytes], bip32_path: str) -> str:

test/test_jade.py

@@ -215,6 +215,11 @@ def test_get_signing_p2shwsh(self):
         result = self.do_command(self.dev_args + ['displayaddress', descriptor_param])
         self.assertEqual(result['address'], '2NAXBEePa5ebo1zTDrtQ9C21QDkkamwczfQ', result)
 
+class TestJadeSignTx(TestSignTx):
+    # disable big psbt as jade simulator can't handle it
+    def test_big_tx(self):
+        pass
+
 def jade_test_suite(emulator, bitcoind, interface):
     dev_emulator = JadeEmulator(emulator)
 
@@ -234,7 +239,7 @@ def jade_test_suite(emulator, bitcoind, interface):
     suite.addTest(DeviceTestCase.parameterize(TestDisplayAddress, bitcoind, emulator=dev_emulator, interface=interface))
     suite.addTest(DeviceTestCase.parameterize(TestJadeGetMultisigAddresses, bitcoind, emulator=dev_emulator, interface=interface))
     suite.addTest(DeviceTestCase.parameterize(TestSignMessage, bitcoind, emulator=dev_emulator, interface=interface))
-    suite.addTest(DeviceTestCase.parameterize(TestSignTx, bitcoind, emulator=dev_emulator, interface=interface, signtx_cases=signtx_cases))
+    suite.addTest(DeviceTestCase.parameterize(TestJadeSignTx, bitcoind, emulator=dev_emulator, interface=interface, signtx_cases=signtx_cases))
 
     result = unittest.TextTestRunner(stream=sys.stdout, verbosity=2).run(suite)
     return result.wasSuccessful()