trezorlib: implement auto-creating protobuf messages from dicts

along with a convert_dict function to rename keys from camelCase
and optionally apply simple field renames

trezorlib/lisk.py

@@ -1,7 +1,8 @@
 import binascii
 
 from . import messages as proto
-from .tools import CallException, expect, normalize_nfc
+from .tools import CallException, expect, normalize_nfc, dict_from_camelcase
+from .protobuf import dict_to_proto
 
 
 @expect(proto.LiskAddress, field="address")
@@ -33,46 +34,11 @@ def verify_message(client, pubkey, signature, message):
     return isinstance(resp, proto.Success)
 
 
-def _asset_to_proto(asset):
-    msg = proto.LiskTransactionAsset()
-
-    if "votes" in asset:
-        msg.votes = asset["votes"]
-    if "data" in asset:
-        msg.data = asset["data"]
-    if "signature" in asset:
-        msg.signature = proto.LiskSignatureType()
-        msg.signature.public_key = binascii.unhexlify(asset["signature"]["publicKey"])
-    if "delegate" in asset:
-        msg.delegate = proto.LiskDelegateType()
-        msg.delegate.username = asset["delegate"]["username"]
-    if "multisignature" in asset:
-        msg.multisignature = proto.LiskMultisignatureType()
-        msg.multisignature.min = asset["multisignature"]["min"]
-        msg.multisignature.life_time = asset["multisignature"]["lifetime"]
-        msg.multisignature.keys_group = asset["multisignature"]["keysgroup"]
-    return msg
+RENAMES = {"lifetime": "life_time", "keysgroup": "keys_group"}
 
 
 @expect(proto.LiskSignedTx)
 def sign_tx(client, n, transaction):
-    msg = proto.LiskTransactionCommon()
-
-    msg.type = transaction["type"]
-    msg.fee = int(
-        transaction["fee"]
-    )  # Lisk use strings for big numbers (javascript issue)
-    msg.amount = int(transaction["amount"])  # And we convert it back to number
-    msg.timestamp = transaction["timestamp"]
-
-    if "recipientId" in transaction:
-        msg.recipient_id = transaction["recipientId"]
-    if "senderPublicKey" in transaction:
-        msg.sender_public_key = binascii.unhexlify(transaction["senderPublicKey"])
-    if "requesterPublicKey" in transaction:
-        msg.requester_public_key = binascii.unhexlify(transaction["requesterPublicKey"])
-    if "signature" in transaction:
-        msg.signature = binascii.unhexlify(transaction["signature"])
-
-    msg.asset = _asset_to_proto(transaction["asset"])
+    transaction = dict_from_camelcase(transaction, renames=RENAMES)
+    msg = dict_to_proto(proto.LiskTransactionCommon, transaction)
     return client.call(proto.LiskSignTx(address_n=n, transaction=msg))

trezorlib/protobuf.py

@@ -398,3 +398,50 @@ def format_message(
         size=pb.ByteSize(),
         content=pformat_value(pb.__dict__, indent),
     )
+
+
+def value_to_proto(ftype, value):
+    if issubclass(ftype, MessageType):
+        raise TypeError("value_to_proto only converts simple values")
+
+    if ftype in (UVarintType, SVarintType):
+        return int(value)
+
+    if ftype is BoolType:
+        return bool(value)
+
+    if ftype is UnicodeType:
+        return str(value)
+
+    if ftype is BytesType:
+        if isinstance(value, str):
+            return binascii.unhexlify(value)
+        elif isinstance(value, bytes):
+            return value
+        else:
+            raise TypeError("can't convert {} value to bytes".format(type(value)))
+
+
+def dict_to_proto(message_type, d):
+    params = {}
+    for fname, ftype, fflags in message_type.FIELDS.values():
+        repeated = fflags & FLAG_REPEATED
+        value = d.get(fname)
+        if value is None:
+            continue
+
+        if not repeated:
+            value = [value]
+
+        if issubclass(ftype, MessageType):
+            function = dict_to_proto
+        else:
+            function = value_to_proto
+
+        newvalue = [function(ftype, v) for v in value]
+
+        if not repeated:
+            newvalue = newvalue[0]
+
+        params[fname] = newvalue
+    return message_type(**params)

trezorlib/ripple.py

@@ -16,7 +16,8 @@
 
 
 from . import messages
-from .tools import expect
+from .tools import expect, dict_from_camelcase
+from .protobuf import dict_to_proto
 
 REQUIRED_FIELDS = ("Fee", "Sequence", "TransactionType", "Amount", "Destination")
 
@@ -40,16 +41,5 @@ def create_sign_tx_msg(transaction) -> messages.RippleSignTx:
     if transaction["TransactionType"] != "Payment":
         raise ValueError("Only Payment transaction type is supported")
 
-    return messages.RippleSignTx(
-        fee=transaction.get("Fee"),
-        sequence=transaction.get("Sequence"),
-        flags=transaction.get("Flags"),
-        last_ledger_sequence=transaction.get("LastLedgerSequence"),
-        payment=_create_payment(transaction),
-    )
-
-
-def _create_payment(transaction) -> messages.RipplePayment:
-    return messages.RipplePayment(
-        amount=transaction.get("Amount"), destination=transaction.get("Destination")
-    )
+    converted = dict_from_camelcase(transaction)
+    return dict_to_proto(messages.RippleSignTx, converted)

trezorlib/tools.py

@@ -16,6 +16,7 @@
 
 import functools
 import hashlib
+import re
 import struct
 import unicodedata
 from typing import List, NewType
@@ -215,3 +216,37 @@ def session(f):
             client.transport.session_end()
 
     return wrapped_f
+
+
+# de-camelcasifier
+# https://stackoverflow.com/a/1176023/222189
+
+FIRST_CAP_RE = re.compile("(.)([A-Z][a-z]+)")
+ALL_CAP_RE = re.compile("([a-z0-9])([A-Z])")
+
+
+def from_camelcase(s):
+    s = FIRST_CAP_RE.sub(r"\1_\2", s)
+    return ALL_CAP_RE.sub(r"\1_\2", s).lower()
+
+
+def dict_from_camelcase(d, renames=None):
+    if not isinstance(d, dict):
+        return d
+
+    if renames is None:
+        renames = {}
+
+    res = {}
+    for key, value in d.items():
+        newkey = from_camelcase(key)
+        renamed_key = renames.get(newkey) or renames.get(key)
+        if renamed_key:
+            newkey = renamed_key
+
+        if isinstance(value, list):
+            res[newkey] = [dict_from_camelcase(v, renames) for v in value]
+        else:
+            res[newkey] = dict_from_camelcase(value, renames)
+
+    return res