Multi-sig AccountId support

Author: Arjan Zijderveld

scalecodec/block.py

@@ -59,16 +59,7 @@ def __init__(self, data=None, sub_type=None, metadata: MetadataDecoder = None, a
 
     def generate_hash(self):
         if self.contains_transaction:
-
-            if self.extrinsic_length:
-                extrinsic_data = self.data.data
-            else:
-                # Fallback for legacy version, prefix additional Compact<u32> with length
-                extrinsic_length_type = CompactU32(ScaleBytes(bytearray()))
-                extrinsic_length_type.encode(self.data.length)
-                extrinsic_data = extrinsic_length_type.data.data + self.data.data
-
-            return blake2b(extrinsic_data, digest_size=32).digest().hex()
+            return blake2b(self.data.data, digest_size=32).digest().hex()
         else:
             return None
 

scalecodec/types.py

@@ -17,6 +17,8 @@
 # along with Polkascan. If not, see <http://www.gnu.org/licenses/>.
 
 from datetime import datetime
+from hashlib import blake2b
+
 from scalecodec.base import ScaleType, ScaleBytes
 from scalecodec.exceptions import InvalidScaleTypeValueException
 
@@ -796,9 +798,14 @@ class Linkage(Struct):
 
 class AccountId(H256):
 
+    def __init__(self, data=None, sub_type=None, metadata=None):
+        self.ss58_address = None
+        super().__init__(data, sub_type, metadata)
+
     def process_encode(self, value):
         if value[0:2] != '0x' and len(value) == 47:
             from scalecodec.utils.ss58 import ss58_decode
+            self.ss58_address = value
             value = '0x{}'.format(ss58_decode(value))
         return super().process_encode(value)
 
@@ -1949,3 +1956,28 @@ def process_encode(self, value):
 
         return data
 
+
+class MultiAccountId(AccountId):
+
+    @classmethod
+    def create_from_account_list(cls, accounts, threshold):
+        from scalecodec.utils.ss58 import ss58_decode
+
+        account_ids = []
+        for account in accounts:
+            if account[0:2] != '0x':
+                account = '0x{}'.format(ss58_decode(account))
+            account_ids.append(account)
+
+        account_list_cls = cls.get_decoder_class('Vec<AccountId>')
+        account_list_data = account_list_cls.encode(sorted(account_ids))
+        threshold_data = cls.get_decoder_class("u16").encode(threshold)
+
+        multi_account_id = "0x{}".format(blake2b(
+            b"modlpy/utilisuba" + bytes(account_list_data.data) + bytes(threshold_data.data), digest_size=32
+        ).digest().hex())
+
+        multi_account_obj = cls()
+        multi_account_obj.encode(multi_account_id)
+
+        return multi_account_obj

test/test_scale_types.py

@@ -24,6 +24,7 @@
 from scalecodec.base import ScaleDecoder, ScaleBytes, RemainingScaleBytesNotEmptyException, \
     InvalidScaleTypeValueException, RuntimeConfiguration
 from scalecodec.type_registry import load_type_registry_preset
+from scalecodec.utils.ss58 import ss58_encode
 
 
 class TestScaleTypes(unittest.TestCase):
@@ -228,5 +229,15 @@ def test_parse_subtype(self):
 
         self.assertEqual(obj.sub_type, "UncleEntryItem<BlockNumber, Hash, AccountId>".lower())
 
+    def test_create_multi_sig_address(self):
+        MultiAccountId = RuntimeConfiguration().get_decoder_class("MultiAccountId")
+
+        multi_sig_account = MultiAccountId.create_from_account_list(
+            ["CdVuGwX71W4oRbXHsLuLQxNPns23rnSSiZwZPN4etWf6XYo",
+             "J9aQobenjZjwWtU2MsnYdGomvcYbgauCnBeb8xGrcqznvJc",
+             "HvqnQxDQbi3LL2URh7WQfcmi8b2ZWfBhu7TEDmyyn5VK8e2"], 2)
+
+        multi_sig_address = ss58_encode(multi_sig_account.value.replace('0x', ''), 2)
+
+        self.assertEqual(multi_sig_address, "HFXXfXavDuKhLLBhFQTat2aaRQ5CMMw9mwswHzWi76m6iLt")
 
-    # TODO make type_index in Metadatadecoder and add tests if all types are supported