Validate transaction metadata

4 years ago · 7a1e773b49
parent a5d3b63912
commit 7a1e773b49
3 changed files with 90 additions and 4 deletions
--- a/core/src/apps/cardano/helpers/init.py
+++ b/core/src/apps/cardano/helpers/init.py
@ -4,3 +4,4 @@ INVALID_ADDRESS = wire.ProcessError("Invalid address")
 NETWORK_MISMATCH = wire.ProcessError("Output address network mismatch!")
 INVALID_CERTIFICATE = wire.ProcessError("Invalid certificate")
 INVALID_WITHDRAWAL = wire.ProcessError("Invalid withdrawal")
+INVALID_METADATA = wire.ProcessError("Invalid metadata")
--- a/core/src/apps/cardano/sign_tx.py
+++ b/core/src/apps/cardano/sign_tx.py
@ -24,6 +24,7 @@ from .address import (
 from .byron_address import get_address_attributes
 from .helpers import (
    INVALID_CERTIFICATE,
+    INVALID_METADATA,
    INVALID_WITHDRAWAL,
    network_ids,
    protocol_magics,
@ -79,9 +80,7 @@ async def sign_tx(
        _validate_outputs(keychain, msg.outputs, msg.protocol_magic, msg.network_id)
        _validate_certificates(msg.certificates)
        _validate_withdrawals(msg.withdrawals)
-
-        if msg.metadata and len(msg.metadata) > MAX_METADATA_LENGTH:
-            raise wire.ProcessError("Invalid metadata")
+        _validate_metadata(msg.metadata)

        # display the transaction in UI
        await _show_tx(ctx, keychain, msg)
@ -158,6 +157,23 @@ def _validate_withdrawals(withdrawals: List[CardanoTxWithdrawalType]) -> None:
            raise INVALID_WITHDRAWAL


+def _validate_metadata(metadata: bytes) -> None:
+    if not metadata:
+        return
+
+    if len(metadata) > MAX_METADATA_LENGTH:
+        raise INVALID_METADATA
+
+    try:
+        # this also raises an error if there's some data remaining
+        decoded = cbor.decode(metadata)
+    except:
+        raise INVALID_METADATA
+
+    if not isinstance(decoded, dict):
+        raise INVALID_METADATA
+
+
 def _serialize_tx(keychain: seed.Keychain, msg: CardanoSignTx) -> Tuple[bytes, bytes]:
    tx_body = _build_tx_body(keychain, msg)
    tx_hash = _hash_tx_body(tx_body)
--- a/tests/device_tests/test_msg_cardano_sign_transaction.py
+++ b/tests/device_tests/test_msg_cardano_sign_transaction.py
@ -998,7 +998,76 @@ INVALID_VECTORS = [
        # withdrawals
        [],
        # metadata
-        "A200A11864A118C843AA00FF01A119012C590202AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
+        "a200a11864a118c843aa00ff01a119012c590202aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+        # error message
+        "Invalid metadata",
+    ),
+    # Metadata is a list
+    (
+        # protocol magic
+        PROTOCOL_MAGICS["mainnet"],
+        # network id
+        NETWORK_IDS["mainnet"],
+        # inputs
+        [SAMPLE_INPUTS["shelley_input"]],
+        # outputs
+        [SAMPLE_OUTPUTS["simple_byron_output"]],
+        # fee
+        42,
+        # ttl
+        10,
+        # certificates
+        [],
+        # withdrawals
+        [],
+        # metadata
+        "82a200a11864a118c843aa00ff01a119012c590100aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa0A",
+        # error message
+        "Invalid metadata",
+    ),
+    # Metadata is incomplete
+    (
+        # protocol magic
+        PROTOCOL_MAGICS["mainnet"],
+        # network id
+        NETWORK_IDS["mainnet"],
+        # inputs
+        [SAMPLE_INPUTS["shelley_input"]],
+        # outputs
+        [SAMPLE_OUTPUTS["simple_byron_output"]],
+        # fee
+        42,
+        # ttl
+        10,
+        # certificates
+        [],
+        # withdrawals
+        [],
+        # metadata
+        "a200a11864a118c843aa00ff01",
+        # error message
+        "Invalid metadata",
+    ),
+    # Metadata has leftover data
+    (
+        # protocol magic
+        PROTOCOL_MAGICS["mainnet"],
+        # network id
+        NETWORK_IDS["mainnet"],
+        # inputs
+        [SAMPLE_INPUTS["shelley_input"]],
+        # outputs
+        [SAMPLE_OUTPUTS["simple_byron_output"]],
+        # fee
+        42,
+        # ttl
+        10,
+        # certificates
+        [],
+        # withdrawals
+        [],
+        # metadata
+        "a200a11864a118c843aa00ff01a119012c590100aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa000000",
        # error message
        "Invalid metadata",
    ),