feat(nano): Add salt to tokens created by contracts

hathor/nanocontracts/blueprint_env.py

@@ -249,14 +249,17 @@ def create_deposit_token(
         amount: int,
         mint_authority: bool = True,
         melt_authority: bool = True,
+        *,
+        salt: bytes = b'',
     ) -> TokenUid:
         """Create a new deposit-based token."""
         return self.__runner.syscall_create_child_deposit_token(
-            token_name,
-            token_symbol,
-            amount,
-            mint_authority,
-            melt_authority
+            salt=salt,
+            token_name=token_name,
+            token_symbol=token_symbol,
+            amount=amount,
+            mint_authority=mint_authority,
+            melt_authority=melt_authority,
         )
 
     # XXX: temporary alias
@@ -270,14 +273,17 @@ def create_fee_token(
         amount: int,
         mint_authority: bool = True,
         melt_authority: bool = True,
+        *,
+        salt: bytes = b'',
     ) -> TokenUid:
         """Create a new fee-based token."""
         return self.__runner.syscall_create_child_fee_token(
-            token_name,
-            token_symbol,
-            amount,
-            mint_authority,
-            melt_authority
+            salt=salt,
+            token_name=token_name,
+            token_symbol=token_symbol,
+            amount=amount,
+            mint_authority=mint_authority,
+            melt_authority=melt_authority,
         )
 
     @final

hathor/nanocontracts/runner/runner.py

@@ -1022,6 +1022,8 @@ def _create_blueprint_instance(self, blueprint_id: BlueprintId, changes_tracker:
     @_forbid_syscall_from_view('create_deposit_token')
     def syscall_create_child_deposit_token(
         self,
+        *,
+        salt: bytes,
         token_name: str,
         token_symbol: str,
         amount: int,
@@ -1037,7 +1039,7 @@ def syscall_create_child_deposit_token(
         last_call_record = self.get_current_call_record()
         parent_id = last_call_record.contract_id
         cleaned_token_symbol = clean_token_string(token_symbol)
-        token_id = derive_child_token_id(parent_id, cleaned_token_symbol)
+        token_id = derive_child_token_id(parent_id, cleaned_token_symbol, salt=salt)
 
         token_amount = amount
         htr_amount = get_deposit_token_deposit_amount(self._settings, token_amount)
@@ -1071,6 +1073,8 @@ def syscall_create_child_deposit_token(
     @_forbid_syscall_from_view('create_fee_token')
     def syscall_create_child_fee_token(
         self,
+        *,
+        salt: bytes,
         token_name: str,
         token_symbol: str,
         amount: int,

hathor/nanocontracts/utils.py

@@ -80,11 +80,12 @@ def derive_child_contract_id(parent_id: ContractId, salt: bytes, blueprint_id: B
     return ContractId(VertexId(h.digest()))
 
 
-def derive_child_token_id(parent_id: ContractId, token_symbol: str) -> TokenUid:
+def derive_child_token_id(parent_id: ContractId, token_symbol: str, *, salt: bytes = b'') -> TokenUid:
     """Derive the token id for a token created by a (parent) contract."""
     h = hashlib.sha256()
     h.update(CHILD_TOKEN_ID_PREFIX)
     h.update(parent_id)
+    h.update(salt)
     h.update(token_symbol.encode('utf-8'))
     return TokenUid(VertexId(h.digest()))
 

tests/nanocontracts/test_token_creation.py

@@ -34,13 +34,14 @@ def withdraw(self, ctx: Context) -> None:
     def create_deposit_token(
         self,
         ctx: Context,
+        salt: bytes,
         token_name: str,
         token_symbol: str,
         amount: int,
         mint_authority: bool,
         melt_authority: bool,
     ) -> None:
-        self.syscall.create_deposit_token(token_name, token_symbol, amount, mint_authority, melt_authority)
+        self.syscall.create_deposit_token(token_name, token_symbol, amount, mint_authority, melt_authority, salt=salt)
 
 
 class NCNanoContractTestCase(unittest.TestCase):
@@ -164,6 +165,8 @@ def test_token_creation_by_vertex(self) -> None:
 
     def test_token_creation_by_contract(self) -> None:
         token_symbol = 'TKA'
+        salt0 = b'\0'
+        salt1 = b'\1'
 
         dag_builder = TestDAGBuilder.from_manager(self.manager)
         vertices = dag_builder.build_from_str(f'''
@@ -174,23 +177,28 @@ def test_token_creation_by_contract(self) -> None:
             tx1.nc_method = initialize()
 
             tx2.nc_id = tx1
-            tx2.nc_method = create_deposit_token("MyToken", "{token_symbol}", 100, false, false)
+            tx2.nc_method = create_deposit_token("{salt0.hex()}", "MyToken", "{token_symbol}", 100, false, false)
             tx2.nc_deposit = 3 HTR
 
             tx3.nc_id = tx1
-            tx3.nc_method = create_deposit_token("MyToken (2)", "{token_symbol}", 50, true, false)
+            tx3.nc_method = create_deposit_token("{salt0.hex()}", "MyToken (2)", "{token_symbol}", 50, true, false)
             tx3.nc_deposit = 1 HTR
 
-            tx2 < tx3
+            tx4.nc_id = tx1
+            tx4.nc_method = create_deposit_token("{salt1.hex()}", "MyToken", "{token_symbol}", 30, true, false)
+            tx4.nc_deposit = 1 HTR
+
+            tx2 < tx3 < tx4
 
             b31 --> tx1
             b31 --> tx2
             b32 --> tx3
+            b32 --> tx4
         ''')
 
         vertices.propagate_with(self.manager)
 
-        tx1, tx2, tx3 = vertices.get_typed_vertices(['tx1', 'tx2', 'tx3'], Transaction)
+        tx1, tx2, tx3, tx4 = vertices.get_typed_vertices(['tx1', 'tx2', 'tx3', 'tx4'], Transaction)
         b31, b32 = vertices.get_typed_vertices(['b31', 'b32'], Block)
 
         # Uncomment for debugging:
@@ -207,6 +215,9 @@ def test_token_creation_by_contract(self) -> None:
         assert tx3.get_metadata().voided_by == {tx3.hash, NC_EXECUTION_FAIL_ID}
         assert tx3.get_metadata().nc_execution is NCExecutionState.FAILURE
 
+        assert tx4.get_metadata().voided_by is None
+        assert tx4.get_metadata().nc_execution is NCExecutionState.SUCCESS
+
         assert b31.get_metadata().voided_by is None
         assert b32.get_metadata().voided_by is None
 
@@ -217,26 +228,35 @@ def test_token_creation_by_contract(self) -> None:
             reason='NCTokenAlreadyExists',
         )
 
-        child_token_id = derive_child_token_id(ContractId(VertexId(tx1.hash)), token_symbol)
-        child_token_balance_key = BalanceKey(nc_id=tx1.hash, token_uid=child_token_id)
+        child_token_id0 = derive_child_token_id(ContractId(VertexId(tx1.hash)), token_symbol, salt=salt0)
+        child_token_id1 = derive_child_token_id(ContractId(VertexId(tx1.hash)), token_symbol, salt=salt1)
+
+        child_token_balance_key0 = BalanceKey(nc_id=tx1.hash, token_uid=child_token_id0)
+        child_token_balance_key1 = BalanceKey(nc_id=tx1.hash, token_uid=child_token_id1)
         htr_balance_key = BalanceKey(nc_id=tx1.hash, token_uid=settings.HATHOR_TOKEN_UID)
 
-        block_storage = self.manager.get_nc_block_storage(b31)
-        expected_token_info = TokenDescription(
-            token_id=child_token_id,
+        block_storage = self.manager.get_nc_block_storage(b32)
+        assert block_storage.get_token_description(child_token_id0) == TokenDescription(
+            token_id=child_token_id0,
+            token_name='MyToken',
+            token_symbol=token_symbol,
+        )
+        assert block_storage.get_token_description(child_token_id1) == TokenDescription(
+            token_id=child_token_id1,
             token_name='MyToken',
             token_symbol=token_symbol,
         )
-        assert block_storage.get_token_description(child_token_id) == expected_token_info
 
         nc_storage = block_storage.get_contract_storage(tx1.hash)
         assert nc_storage.get_all_balances() == {
-            child_token_balance_key: Balance(value=100, can_mint=False, can_melt=False),
+            child_token_balance_key0: Balance(value=100, can_mint=False, can_melt=False),
+            child_token_balance_key1: Balance(value=30, can_mint=True, can_melt=False),
             htr_balance_key: Balance(value=2, can_mint=False, can_melt=False),
         }
 
         tokens_index = self.manager.tx_storage.indexes.tokens
         assert tokens_index.get_token_info(settings.HATHOR_TOKEN_UID).get_total() == (
-            settings.GENESIS_TOKENS + 40 * settings.INITIAL_TOKENS_PER_BLOCK - 1
+            settings.GENESIS_TOKENS + 40 * settings.INITIAL_TOKENS_PER_BLOCK - 2
         )
-        assert tokens_index.get_token_info(child_token_id).get_total() == 100
+        assert tokens_index.get_token_info(child_token_id0).get_total() == 100
+        assert tokens_index.get_token_info(child_token_id1).get_total() == 30