core: add exception to GetPublicKey for PSBT master fingerprint (fixes #999)

core/src/apps/bitcoin/get_public_key.py

@@ -18,6 +18,7 @@ async def get_keychain_for_curve(ctx: wire.Context, curve_name: str) -> seed.Key
 
 
 async def get_public_key(ctx, msg):
+    coin_name = msg.coin_name or "Bitcoin"
     script_type = msg.script_type or InputScriptType.SPENDADDRESS
 
     if msg.ecdsa_curve_name is not None:
@@ -34,6 +35,15 @@ async def get_public_key(ctx, msg):
         # only allow SLIP-13/17 namespaces
         keychain = await get_keychain_for_curve(ctx, msg.ecdsa_curve_name)
 
+    elif (
+        coin_name == "Bitcoin"
+        and script_type is InputScriptType.SPENDADDRESS
+        and msg.address_n == [HARDENED]
+    ):
+        # allow extracting PSBT master fingerprinty by calling GetPublicKey(m/0')
+        coin = coins.by_name("Bitcoin")
+        keychain = await seed.get_keychain(ctx, [("secp256k1", [HARDENED])])
+
     else:
         # select curve and namespaces based on the requested coin properties
         keychain, coin = await get_keychain_for_coin(ctx, msg.coin_name)

tests/device_tests/test_msg_getpublickey.py

@@ -17,10 +17,13 @@
 import pytest
 
 from trezorlib import btc, messages
+from trezorlib.exceptions import TrezorFailure
 from trezorlib.tools import parse_path
 
 from .. import bip32
 
+pytestmark = pytest.mark.skip_ui
+
 VECTORS_BITCOIN = (  # coin_name, xpub_magic, path, xpub
     (
         "Bitcoin",
@@ -58,35 +61,53 @@ VECTORS_BITCOIN = (  # coin_name, xpub_magic, path, xpub
         parse_path("m/44h/1h/0h/0/0"),
         "tpubDGwNSs8z8jZU2EcUiubR4frGvKqddvLBqCDNknnWhmoUd6EHrRWrqXmDaWBNddWzM5Yqh4e4TUYFK9hGCEnSrMKgV6cthRhArfZpwzihdw7",
     ),
-)
+    (  # PSBT master fingerprint retrieval
-
+        "Bitcoin",
-VECTORS_ALTCOINS = (
+        0x0488B21E,
-    (
+        parse_path("m/0h"),
+        "xpub68Zyu13qjcQvJXTsnmhH2h2TyPiXAama5bTU8u9iRXyYtS9X9yWvSKij6YGt7JJ2nr5rSGi4KLUW5Z8bTKHqXhbLwqb7smG3Y8j2wy4rmf3",
+    ),
+    pytest.param(
         "Litecoin",
         0x019DA462,
         parse_path("m/44h/2h/0h"),
         "Ltub2Y8PyEMWQVgiX4L4gVzU8PakBTQ2WBxFdS6tJARQeasUUfXmBut2jGShnQyD3jgyBf7mmvs5jPNgmgXad5J6M8a8FiZK78dbT21fYtTAC9a",
+        marks=pytest.mark.altcoin,
     ),
-    (
+    pytest.param(
         "Litecoin",
         0x019DA462,
         parse_path("m/44h/2h/10h"),
         "Ltub2Y8PyEMWQVgiy8Zio1XrKWkGL6ZmCZB9W5ShbvbzZ14irCrAb62YEoMafTAM5a2A6x6XNcyDdCNW7NVgES9jtQqyUZcBUFTimS7VVJ8tbpE",
+        marks=pytest.mark.altcoin,
     ),
-    (
+    pytest.param(
         "Litecoin",
         0x019DA462,
         parse_path("m/44h/2h/0h/0/0"),
         "Ltub2dTvwC4v7GNeR6UEaywQ6j72wHi4dwRo3oDDzvXAwb4CrXVQEUTbxC4hEfULiKByiUMEmYLhuMo1YMYmBBjKJ8kyk9ia5gZaVNWq5rVLom4",
+        marks=pytest.mark.altcoin,
     ),
-    (
+    pytest.param(
         "Litecoin",
         0x019DA462,
         parse_path("m/44h/2h/10h/1/100"),
         "Ltub2dcb6Nghj3kwaC2g3TtPgFzMSm7LXfe4mijFYsvEtxXu18vicTB4kYc9z6jGVMpdYhMScNhVY1naQYALnM2x4fvaGzAAGgcuZ89nFyyLhiK",
+        marks=pytest.mark.altcoin,
     ),
 )
 
+VECTORS_INVALID = (  # coin_name, path
+    ("Bitcoin", parse_path("m/44h/1h/0h")),  # Testnet path on Bitcoin
+    ("Testnet", parse_path("m/44h/0h/0h")),  # Bitcoin path on Testnet
+    ("Bitcoin", parse_path("m/40h/0h/0h")),  # Unknown purpose
+    ("Bitcoin", parse_path("m/13h/0h/0h")),  # SLIP-13 path
+    # Bitcoin path on Litecoin
+    pytest.param("Litecoin", parse_path("m/44h/0h/0h"), marks=pytest.mark.altcoin),
+    # Segwit path on Bitcoin Cash
+    pytest.param("Bcash", parse_path("m/84h/145h/0h"), marks=pytest.mark.altcoin),
+)
+
 
 @pytest.mark.parametrize("coin_name, xpub_magic, path, xpub", VECTORS_BITCOIN)
 def test_get_public_node(client, coin_name, xpub_magic, path, xpub):
@@ -95,12 +116,11 @@ def test_get_public_node(client, coin_name, xpub_magic, path, xpub):
     assert bip32.serialize(res.node, xpub_magic) == xpub
 
 
-@pytest.mark.parametrize("coin_name, xpub_magic, path, xpub", VECTORS_ALTCOINS)
+@pytest.mark.skip_t1
-@pytest.mark.altcoin
+@pytest.mark.parametrize("coin_name, path", VECTORS_INVALID)
-def test_get_public_node_altcoin(client, coin_name, xpub_magic, path, xpub):
+def test_invalid_path(client, coin_name, path):
-    res = btc.get_public_node(client, path, coin_name=coin_name)
+    with pytest.raises(TrezorFailure, match="Forbidden key path"):
-    assert res.xpub == xpub
+        btc.get_public_node(client, path, coin_name=coin_name)
-    assert bip32.serialize(res.node, xpub_magic) == xpub
 
 
 VECTORS_SCRIPT_TYPES = (  # script_type, xpub

tests/ui_tests/fixtures.json

@@ -123,20 +123,6 @@
 "test_msg_getentropy.py::test_entropy[65]": "a722fa2048fa3102889ec05558d25f837a364ef2a118e85975683e10a56f1356",
 "test_msg_getentropy.py::test_entropy[8]": "a722fa2048fa3102889ec05558d25f837a364ef2a118e85975683e10a56f1356",
 "test_msg_getentropy.py::test_entropy[9]": "a722fa2048fa3102889ec05558d25f837a364ef2a118e85975683e10a56f1356",
-"test_msg_getpublickey.py::test_get_public_node[Bitcoin-76067358-path0-xpub6BiVtCpG9fQPxnPmHXG8PhtzQd": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_get_public_node[Bitcoin-76067358-path1-xpub6BiVtCpG9fQQR6cSuFeDaSvCDg": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_get_public_node[Bitcoin-76067358-path2-xpub6FVDRC1jiWNTuT3embehwSZ1bu": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_get_public_node[Bitcoin-76067358-path3-xpub6GhTNegKCjTqjYS4HNkPhXHXHN": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_get_public_node[Testnet-70617039-path4-tpubDDKn3FtHc74CaRrRbi1WFdJNaa": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_get_public_node[Testnet-70617039-path5-tpubDGwNSs8z8jZU2EcUiubR4frGvK": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_get_public_node_altcoin[Litecoin-27108450-path0-Ltub2Y8PyEMWQVgiX4L4g": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_get_public_node_altcoin[Litecoin-27108450-path1-Ltub2Y8PyEMWQVgiy8Zio": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_get_public_node_altcoin[Litecoin-27108450-path2-Ltub2dTvwC4v7GNeR6UEa": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_get_public_node_altcoin[Litecoin-27108450-path3-Ltub2dcb6Nghj3kwaC2g3": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_script_type[0-xpub6BiVtCp7ozsRo7kaoYNrCNAVJwPYTQHjoXFD3YS797S55Y42sm2": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_script_type[3-zpub6qP2VY9x7MxPVi8pUFx6cYMVesgSLeGjdkHecLDsu8BqBjgVP5M": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_script_type[4-ypub6WYmBsV2xgQueQwhduAUQTFzUuXzQ2HEidmRpwKzX7ox8dsG8RC": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
-"test_msg_getpublickey.py::test_script_type[None-xpub6BiVtCp7ozsRo7kaoYNrCNAVJwPYTQHjoXFD3YS797S55Y42": "5a80508a71a9ef64f94762b07636f90e464832f0f4a3102af8fa1a8c69e94586",
 "test_msg_lisk_getaddress.py-test_lisk_getaddress": "0063ceb48d21aecd1ddabdb083c8afd2042cdf577e4751fa3f57b2b80f619084",
 "test_msg_lisk_getpublickey.py-test_lisk_get_public_key": "e4cb8c7430c240e27a2211391ab5eba848be4f50136cf9f693142c2677a939d7",
 "test_msg_lisk_signmessage.py-test_sign": "c47a6ec147137c75903cff19da6607eaef5a1fc03ace1f840d2952744342b568",