diff --git a/core/.changelog.d/4351.changed.3 b/core/.changelog.d/4351.changed.3 new file mode 100644 index 0000000000..f648168fb8 --- /dev/null +++ b/core/.changelog.d/4351.changed.3 @@ -0,0 +1 @@ +Forbidden per-node paths in multisig. diff --git a/core/src/apps/bitcoin/sign_tx/change_detector.py b/core/src/apps/bitcoin/sign_tx/change_detector.py index 374c24eb54..df1af62502 100644 --- a/core/src/apps/bitcoin/sign_tx/change_detector.py +++ b/core/src/apps/bitcoin/sign_tx/change_detector.py @@ -62,6 +62,9 @@ class ChangeDetector: if not ( self.pubkeys_order.output_matches(txo) and self.multisig_fingerprint.output_matches(txo) + and common.multisig_uses_single_path( + txo.multisig + ) # An output that uses different derivation paths for different xpubs could be difficult to discover ): return False diff --git a/tests/device_tests/bitcoin/test_multisig_change.py b/tests/device_tests/bitcoin/test_multisig_change.py index 990c92c82e..9703a9b672 100644 --- a/tests/device_tests/bitcoin/test_multisig_change.py +++ b/tests/device_tests/bitcoin/test_multisig_change.py @@ -406,6 +406,43 @@ def test_multisig_mismatch_multisig_change(client: Client): ) +# inputs match, change mismatches (second tries to be change but isn't) +@pytest.mark.models(skip="legacy", reason="Not fixed") +def test_multisig_mismatch_multisig_change_different_paths(client: Client): + multisig_out2 = messages.MultisigRedeemScriptType( + pubkeys=[ + messages.HDNodePathType(node=NODE_EXT1, address_n=[1, 0]), + messages.HDNodePathType(node=NODE_EXT2, address_n=[1, 1]), + messages.HDNodePathType(node=NODE_INT, address_n=[1, 2]), + ], + signatures=[b"", b"", b""], + m=2, + ) + + out1 = messages.TxOutputType( + address="3B23k4kFBRtu49zvpG3Z9xuFzfpHvxBcwt", + amount=40_000_000, + script_type=messages.OutputScriptType.PAYTOADDRESS, + ) + + out2 = messages.TxOutputType( + address_n=[H_(45), 0, 1, 2], + multisig=multisig_out2, + amount=44_000_000, + script_type=messages.OutputScriptType.PAYTOMULTISIG, + ) + + with client: + client.set_expected_responses(_responses(client, INP1, INP2)) + btc.sign_tx( + client, + "Bitcoin", + [INP1, INP2], + [out1, out2], + prev_txes=TX_API, + ) + + # inputs mismatch, change matches with first input def test_multisig_mismatch_inputs(client: Client): multisig_out1 = messages.MultisigRedeemScriptType(