Fixes

public MAX_CHUNK_SIZE, total_size check, BASE_KEY_SCRIPT, Ledger link, remove multisig case

core/src/apps/cardano/addresses.py

@@ -48,8 +48,9 @@
 
 ADDRESS_TYPES_MESSAGE = (
     CardanoAddressType.BASE,
+    CardanoAddressType.BASE_KEY_SCRIPT,
     CardanoAddressType.ENTERPRISE,
-    CardanoAddressType.REWARD
+    CardanoAddressType.REWARD,
 )
 
 ADDRESS_TYPES_PAYMENT = ADDRESS_TYPES_PAYMENT_KEY + ADDRESS_TYPES_PAYMENT_SCRIPT
@@ -247,8 +248,9 @@ def validate_cvote_payment_address_parameters(
     validate_address_parameters(parameters)
     assert_params_cond(parameters.address_type in ADDRESS_TYPES_SHELLEY)
 
+
 def validate_message_address_parameters(
-        parameters: messages.CardanoAddressParametersType,
+    parameters: messages.CardanoAddressParametersType,
 ) -> None:
     validate_address_parameters(parameters)
     assert_params_cond(parameters.address_type in ADDRESS_TYPES_MESSAGE)

core/src/apps/cardano/helpers/chunks.py

@@ -20,13 +20,13 @@
     Generic = (object,)
     C = Chunk = 0
 
-_MAX_CHUNK_SIZE = const(1024)
+MAX_CHUNK_SIZE = const(1024)
 
 
 def _get_chunks_count(size: int) -> int:
-    """Integer-only version of `ceil(size / _MAX_CHUNK_SIZE)`."""
+    """Integer-only version of `ceil(size / MAX_CHUNK_SIZE)`."""
     assert size >= 0
-    return 0 if size == 0 else (size - 1) // _MAX_CHUNK_SIZE + 1
+    return 0 if size == 0 else (size - 1) // MAX_CHUNK_SIZE + 1
 
 
 def _validate_chunk(
@@ -39,15 +39,19 @@ def _validate_chunk(
 
     chunk_name = chunk.__class__.__name__
 
-    if len(chunk.data) > _MAX_CHUNK_SIZE:
+    if len(chunk.data) > MAX_CHUNK_SIZE:
         raise ProcessError(f"Invalid {chunk_name}: Too large")
 
     is_last_chunk = chunk_index == chunks_count - 1
 
-    if not is_last_chunk and len(chunk.data) < _MAX_CHUNK_SIZE:
+    if not is_last_chunk and len(chunk.data) < MAX_CHUNK_SIZE:
         raise ProcessError(f"Invalid intermediate {chunk_name}: Too small")
 
-    if is_last_chunk and len(chunk.data) != total_size % _MAX_CHUNK_SIZE:
+    if (
+        is_last_chunk
+        # check whether this chunk and preceding chunks add up to the supposed size
+        and len(chunk.data) + MAX_CHUNK_SIZE * (chunks_count - 1) != total_size
+    ):
         raise ProcessError(
             f"Invalid last {chunk_name}: Size inconsistent with total bytes"
         )

core/src/apps/cardano/helpers/utils.py

@@ -121,27 +121,31 @@ def is_printable_ascii(bytestring: bytes) -> bool:
 
 
 def is_unambiguous_ascii(bytestring: bytes) -> bool:
-    """Checks whether the bytestring can be printed as ASCII without confusion."""
-    # empty string is unambiguous
-    # because text consisting only of spaces gets rejected later in this function
+    """
+    Checks whether the bytestring can be printed as ASCII without confusion.
+    Based on https://github.com/vacuumlabs/ledger-app-cardano-shelley/blob/6ddc60e8fdff13e35bff5cdf108b84b81a79f10c/src/textUtils.c#L274
+    """
+    # no empty strings
     if len(bytestring) == 0:
-        return True
+        return False
 
     # no non-printable ascii except spaces
     if not is_printable_ascii(bytestring):
         return False
 
+    SPACE = ord(" ")
+
     # no leading space
-    if bytestring[0] == ord(" "):
+    if bytestring[0] == SPACE:
         return False
 
     # no trailing space
-    if bytestring[-1] == ord(" "):
+    if bytestring[-1] == SPACE:
         return False
 
     # no consecutive spaces
     for a, b in zip(bytestring, bytestring[1:]):
-        if a == ord(" ") and b == ord(" "):
+        if a == SPACE and b == SPACE:
             return False
 
     return True

core/src/apps/cardano/layout.py

@@ -274,6 +274,17 @@ async def confirm_inline_datum(first_chunk: bytes, inline_datum_size: int) -> No
     )
 
 
+async def confirm_reference_script(
+    first_chunk: bytes, reference_script_size: int
+) -> None:
+    await _confirm_tx_data_chunk(
+        "confirm_reference_script",
+        "Reference script",
+        first_chunk,
+        reference_script_size,
+    )
+
+
 async def confirm_message_payload(
     payload_first_chunk: bytes,
     payload_hash: bytes,
@@ -283,7 +294,12 @@ async def confirm_message_payload(
 ) -> None:
     props: list[PropertyType]
 
-    if is_unambiguous_ascii(payload_first_chunk) and not prefer_hex_display:
+    if not payload_first_chunk:
+        assert payload_size == 0
+        props = _get_data_chunk_props(
+            "Empty message", payload_first_chunk, payload_size
+        )
+    elif not prefer_hex_display and is_unambiguous_ascii(payload_first_chunk):
         props = _get_data_chunk_props(
             "Message text", payload_first_chunk.decode("ascii"), payload_size
         )
@@ -300,17 +316,6 @@ async def confirm_message_payload(
     )
 
 
-async def confirm_reference_script(
-    first_chunk: bytes, reference_script_size: int
-) -> None:
-    await _confirm_tx_data_chunk(
-        "confirm_reference_script",
-        "Reference script",
-        first_chunk,
-        reference_script_size,
-    )
-
-
 def _get_data_chunk_props(
     title: str, first_chunk: bytes | str, data_size: int
 ) -> list[PropertyType]:

core/src/apps/cardano/sign_message.py

@@ -4,7 +4,7 @@
 from trezor.wire import ProcessError
 from trezor.wire.context import call as ctx_call
 
-from apps.cardano.helpers.chunks import ChunkIterator
+from apps.cardano.helpers.chunks import MAX_CHUNK_SIZE, ChunkIterator
 from apps.cardano.helpers.paths import SCHEMA_PUBKEY
 from apps.common import cbor
 
@@ -23,11 +23,9 @@
 _COSE_HEADER_ALGORITHM_KEY = const(1)
 _COSE_EDDSA_ALGORITHM_ID = const(-8)
 
-_MAX_CHUNK_SIZE = const(1024)
-
 
 def _validate_message_signing_path(path: list[int]) -> None:
-    if not (SCHEMA_PUBKEY.match(path) or seed.is_multisig_path(path)):
+    if not SCHEMA_PUBKEY.match(path):
         raise ProcessError("Invalid signing path")
 
 
@@ -46,7 +44,7 @@ def _validate_message_init(msg: CardanoSignMessageInit) -> None:
     if msg.address_parameters:
         addresses.validate_message_address_parameters(msg.address_parameters)
 
-    if msg.payload_size > _MAX_CHUNK_SIZE and not msg.hash_payload:
+    if msg.payload_size > MAX_CHUNK_SIZE and not msg.hash_payload:
         raise ProcessError("Payload too long to sign without hashing")
 
     _validate_message_signing_path(msg.signing_path)

core/src/apps/cardano/sign_tx/signer.py

@@ -11,8 +11,8 @@
 from trezor.wire import DataError, ProcessError
 from trezor.wire.context import call as ctx_call
 
-from apps.common import safety_checks
 from apps.cardano.helpers.chunks import ChunkIterator
+from apps.common import safety_checks
 
 from .. import addresses, certificates, layout, seed
 from ..helpers import INPUT_PREV_HASH_SIZE, LOVELACE_MAX_SUPPLY