Byzantium Fork Rules

.travis.yml

@@ -7,11 +7,12 @@ env:
   global:
     - PYTEST_ADDOPTS="-n 2"
   matrix:
+    # byzantium goes first because it takes the longest.
+    - TOX_POSARGS="-e py35-state-byzantium"
     - TOX_POSARGS="-e py35-state-frontier"
     - TOX_POSARGS="-e py35-state-homestead"
     - TOX_POSARGS="-e py35-state-eip150"
     - TOX_POSARGS="-e py35-state-eip158"
-    #- TOX_POSARGS="-e py35-state-byzantium"
     #- TOX_POSARGS="-e py35-state-constantinople"
     #- TOX_POSARGS="-e py35-state-metropolis"
     - TOX_POSARGS="-e py35-blockchain"

evm/chains/mainnet/__init__.py

@@ -9,6 +9,7 @@
     FrontierVM,
     HomesteadVM,
     SpuriousDragonVM,
+    ByzantiumVM,
 )
 
 
@@ -17,6 +18,7 @@
     (constants.HOMESTEAD_MAINNET_BLOCK, HomesteadVM),
     (constants.EIP150_MAINNET_BLOCK, EIP150VM),
     (constants.SPURIOUS_DRAGON_MAINNET_BLOCK, SpuriousDragonVM),
+    (constants.BYZANTIUM_MAINNET_BLOCK, ByzantiumVM),
 )
 
 

evm/constants.py

@@ -90,6 +90,12 @@
 
 GAS_ECRECOVER = 3000
 
+GAS_ECADD = 500
+GAS_ECMUL = 40000
+
+GAS_ECPAIRING_BASE = 100000
+GAS_ECPAIRING_PER_POINT = 80000
+
 
 #
 # Gas Limit
@@ -111,6 +117,7 @@
 
 FRONTIER_DIFFICULTY_ADJUSTMENT_CUTOFF = 13
 HOMESTEAD_DIFFICULTY_ADJUSTMENT_CUTOFF = 10
+BYZANTIUM_DIFFICULTY_ADJUSTMENT_CUTOFF = 9
 
 BOMB_EXPONENTIAL_PERIOD = 100000
 BOMB_EXPONENTIAL_FREE_PERIODS = 2
@@ -119,6 +126,7 @@
 # Mining
 #
 BLOCK_REWARD = 5 * denoms.ether
+EIP649_BLOCK_REWARD = 3 * denoms.ether
 
 UNCLE_DEPTH_PENALTY_FACTOR = 8
 MAX_UNCLE_DEPTH = 6
@@ -193,3 +201,11 @@
 
 # https://github.com/ethereum/EIPs/issues/170
 EIP170_CODE_SIZE_LIMIT = 24577
+
+#
+# ByzantiumVM
+#
+BYZANTIUM_MAINNET_BLOCK = 4370000
+BYZANTIUM_ROPSTEN_BLOCK = 1700000
+
+GAS_MOD_EXP_QUADRATIC_DENOMINATOR = 20

evm/exceptions.py

@@ -51,7 +51,8 @@ class VMError(PyEVMError):
     """
     Class of errors which can be raised during VM execution.
     """
-    pass
+    burns_gas = True
+    zeros_return_data = True
 
 
 class OutOfGas(VMError):
@@ -109,3 +110,27 @@ class ContractCreationCollision(VMError):
     Error signaling that there was an address collision during contract creation.
     """
     pass
+
+
+class Revert(VMError):
+    """
+    Error used by the REVERT opcode
+    """
+    burns_gas = False
+    zeros_return_data = False
+
+
+class WriteProtection(VMError):
+    """
+    Error raised if an attempt to modify the state database is made while
+    operating inside of a STATICCALL context.
+    """
+    pass
+
+
+class OutOfBoundsRead(VMError):
+    """
+    Error raised to indicate an attempt was made to read data beyond the
+    boundaries of the buffer (such as with RETURNDATACOPY)
+    """
+    pass

evm/logic/call.py

@@ -2,6 +2,7 @@
 
 from evm.exceptions import (
     OutOfGas,
+    WriteProtection,
 )
 from evm.opcode import (
     Opcode,
@@ -42,6 +43,7 @@ def __call__(self, computation):
             memory_output_start_position,
             memory_output_size,
             should_transfer_value,
+            is_static,
         ) = self.get_call_params(computation)
 
         computation.extend_memory(memory_input_start_position, memory_input_size)
@@ -62,6 +64,7 @@ def __call__(self, computation):
         stack_too_deep = computation.msg.depth + 1 > constants.STACK_DEPTH_LIMIT
 
         if insufficient_funds or stack_too_deep:
+            computation.return_data = b''
             if insufficient_funds:
                 err_message = "Insufficient Funds: have: {0} | need: {1}".format(
                     sender_balance,
@@ -94,6 +97,7 @@ def __call__(self, computation):
                 'code': code,
                 'code_address': code_address,
                 'should_transfer_value': should_transfer_value,
+                'is_static': is_static,
             }
             if sender is not None:
                 child_msg_kwargs['sender'] = sender
@@ -105,14 +109,18 @@ def __call__(self, computation):
             if child_computation.error:
                 computation.stack.push(0)
             else:
+                computation.stack.push(1)
+
+            if not child_computation.error or not child_computation.error.zeros_return_data:
                 actual_output_size = min(memory_output_size, len(child_computation.output))
-                computation.gas_meter.return_gas(child_computation.gas_meter.gas_remaining)
                 computation.memory.write(
                     memory_output_start_position,
                     actual_output_size,
                     child_computation.output[:actual_output_size],
                 )
-                computation.stack.push(1)
+
+            if not child_computation.error or not child_computation.error.burns_gas:
+                computation.gas_meter.return_gas(child_computation.gas_meter.gas_remaining)
 
 
 class Call(BaseCall):
@@ -146,6 +154,7 @@ def get_call_params(self, computation):
             memory_output_start_position,
             memory_output_size,
             True,  # should_transfer_value,
+            computation.msg.is_static,
         )
 
 
@@ -179,6 +188,7 @@ def get_call_params(self, computation):
             memory_output_start_position,
             memory_output_size,
             True,  # should_transfer_value,
+            computation.msg.is_static,
         )
 
 
@@ -215,6 +225,7 @@ def get_call_params(self, computation):
             memory_output_start_position,
             memory_output_size,
             False,  # should_transfer_value,
+            computation.msg.is_static,
         )
 
 
@@ -279,3 +290,42 @@ def compute_msg_extra_gas(self, computation, gas, to, value):
         transfer_gas_fee = constants.GAS_CALLVALUE if value else 0
         create_gas_fee = constants.GAS_NEWACCOUNT if (account_is_dead and value) else 0
         return transfer_gas_fee + create_gas_fee
+
+
+#
+# Byzantium
+#
+class StaticCall(CallEIP161):
+    def get_call_params(self, computation):
+        gas = computation.stack.pop(type_hint=constants.UINT256)
+        to = force_bytes_to_address(computation.stack.pop(type_hint=constants.BYTES))
+
+        (
+            memory_input_start_position,
+            memory_input_size,
+            memory_output_start_position,
+            memory_output_size,
+        ) = computation.stack.pop(num_items=4, type_hint=constants.UINT256)
+
+        return (
+            gas,
+            0,  # value
+            to,
+            None,  # sender
+            None,  # code_address
+            memory_input_start_position,
+            memory_input_size,
+            memory_output_start_position,
+            memory_output_size,
+            False,  # should_transfer_value,
+            True,  # is_static
+        )
+
+
+class CallByzantium(CallEIP161):
+    def get_call_params(self, computation):
+        call_params = super(CallByzantium, self).get_call_params(computation)
+        value = call_params[1]
+        if computation.msg.is_static and value != 0:
+            raise WriteProtection("Cannot modify state while inside of a STATICCALL context")
+        return call_params

evm/logic/context.py

@@ -1,4 +1,7 @@
 from evm import constants
+from evm.exceptions import (
+    OutOfBoundsRead,
+)
 
 from evm.utils.address import (
     force_bytes_to_address,
@@ -138,3 +141,38 @@ def extcodecopy(computation):
     padded_code_bytes = pad_right(code_bytes, size, b'\x00')
 
     computation.memory.write(mem_start_position, size, padded_code_bytes)
+
+
+def returndatasize(computation):
+    size = len(computation.return_data)
+    computation.stack.push(size)
+
+
+def returndatacopy(computation):
+    (
+        mem_start_position,
+        returndata_start_position,
+        size,
+    ) = computation.stack.pop(num_items=3, type_hint=constants.UINT256)
+
+    if returndata_start_position + size > len(computation.return_data):
+        raise OutOfBoundsRead(
+            "Return data length is not sufficient to satisfy request.  Asked "
+            "for data from index {0} to {1}.  Return data is {2} bytes in "
+            "length.".format(
+                returndata_start_position,
+                returndata_start_position + size,
+                len(computation.return_data),
+            )
+        )
+
+    computation.extend_memory(mem_start_position, size)
+
+    word_count = ceil32(size) // 32
+    copy_gas_cost = word_count * constants.GAS_COPY
+
+    computation.gas_meter.consume_gas(copy_gas_cost, reason="RETURNDATACOPY fee")
+
+    value = computation.return_data[returndata_start_position: returndata_start_position + size]
+
+    computation.memory.write(mem_start_position, size, value)

evm/logic/system.py

@@ -2,6 +2,8 @@
 from evm import mnemonics
 from evm.exceptions import (
     Halt,
+    Revert,
+    WriteProtection,
 )
 
 from evm.opcode import (
@@ -28,6 +30,16 @@ def return_op(computation):
     raise Halt('RETURN')
 
 
+def revert(computation):
+    start_position, size = computation.stack.pop(num_items=2, type_hint=constants.UINT256)
+
+    computation.extend_memory(start_position, size)
+
+    output = computation.memory.read(start_position, size)
+    computation.output = bytes(output)
+    raise Revert(computation.output)
+
+
 def selfdestruct(computation):
     beneficiary = force_bytes_to_address(computation.stack.pop(type_hint=constants.BYTES))
     _selfdestruct(computation, beneficiary)
@@ -147,10 +159,17 @@ def __call__(self, computation):
         if child_computation.error:
             computation.stack.push(0)
         else:
-            computation.gas_meter.return_gas(child_computation.gas_meter.gas_remaining)
             computation.stack.push(contract_address)
+        computation.gas_meter.return_gas(child_computation.gas_meter.gas_remaining)
 
 
 class CreateEIP150(Create):
     def max_child_gas_modifier(self, gas):
         return max_child_gas_eip150(gas)
+
+
+class CreateByzantium(CreateEIP150):
+    def __call__(self, computation):
+        if computation.msg.is_static:
+            raise WriteProtection("Cannot modify state while inside of a STATICCALL context")
+        return super(CreateEIP150, self).__call__(computation)

evm/mnemonics.py

@@ -47,6 +47,8 @@
 GASPRICE = 'GASPRICE'
 EXTCODESIZE = 'EXTCODESIZE'
 EXTCODECOPY = 'EXTCODECOPY'
+RETURNDATASIZE = 'RETURNDATASIZE'
+RETURNDATACOPY = 'RETURNDATACOPY'
 #
 # Block Information
 #
@@ -71,6 +73,7 @@
 MSIZE = 'MSIZE'
 GAS = 'GAS'
 JUMPDEST = 'JUMPDEST'
+REVERT = 'REVERT'
 #
 # Push Operations
 #
@@ -158,6 +161,7 @@
 CREATE = 'CREATE'
 CALL = 'CALL'
 CALLCODE = 'CALLCODE'
+STATICCALL = 'STATICCALL'
 RETURN = 'RETURN'
 DELEGATECALL = 'DELEGATECALL'
 SELFDESTRUCT = 'SELFDESTRUCT'

evm/opcode_values.py

@@ -53,6 +53,8 @@
 GASPRICE = 0x3a
 EXTCODESIZE = 0x3b
 EXTCODECOPY = 0x3c
+RETURNDATASIZE = 0x3d
+RETURNDATACOPY = 0x3e
 
 
 #
@@ -181,4 +183,6 @@
 CALLCODE = 0xf2
 RETURN = 0xf3
 DELEGATECALL = 0xf4
+STATICCALL = 0xfa
+REVERT = 0xfd
 SELFDESTRUCT = 0xff

evm/precompiles/__init__.py

@@ -2,3 +2,7 @@
 from .identity import identity  # noqa: F401
 from .ecrecover import ecrecover  # noqa: F401
 from .ripemd160 import ripemd160  # noqa: F401
+from .modexp import modexp  # noqa: F401
+from .ecadd import ecadd  # noqa: F401
+from .ecmul import ecmul  # noqa: F401
+from .ecpairing import ecpairing  # noqa: F401