From fa618d111d2da5523dfd3fc6557683eb7210d842 Mon Sep 17 00:00:00 2001 From: Joran Honig Date: Sun, 29 Apr 2018 14:14:43 +0200 Subject: [PATCH] Rename things and documentation --- .../modules/transaction_order_independence.py | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/mythril/analysis/modules/transaction_order_independence.py b/mythril/analysis/modules/transaction_order_independence.py index 9e4f3c9b..76f4d34a 100644 --- a/mythril/analysis/modules/transaction_order_independence.py +++ b/mythril/analysis/modules/transaction_order_independence.py @@ -23,7 +23,7 @@ def execute(statespace): for call in statespace.calls: # Do analysis interesting_storages = list(_get_influencing_storages(call)) - changing_sstores = list(_find_changable(statespace, interesting_storages)) + changing_sstores = list(_get_influencing_sstores(statespace, interesting_storages)) # Build issue if necessary if len(changing_sstores) > 0: @@ -41,8 +41,9 @@ def execute(statespace): return issues - +# TODO: move to __init__ or util module def _get_states_with_opcode(statespace, opcode): + """ Gets all (state, node) tuples in statespace with opcode""" for k in statespace.nodes: node = statespace.nodes[k] for state in node.states: @@ -51,6 +52,7 @@ def _get_states_with_opcode(statespace, opcode): def _dependent_on_storage(expression): + """ Checks if expression is dependent on a storage symbol and returns the influencing storages""" pattern = re.compile(r"storage_([a-z0-9_&^]+)") result = pattern.search(str(simplify(expression))) if result is not None: @@ -59,6 +61,12 @@ def _dependent_on_storage(expression): def _get_storage_variable(storage, state): + """ + Get storage z3 object given storage name and the state + :param storage: storage name example: storage_0 + :param state: state to retrieve the variable from + :return: z3 object representing storage + """ index = int(re.search('[0-9]+', storage).group()) try: return state.environment.active_account.storage[index] @@ -67,6 +75,7 @@ def _get_storage_variable(storage, state): def _can_change(constraints, variable): + """ Checks if the variable can change given some constraints """ _constraints = copy.deepcopy(constraints) model = solver.get_model(_constraints) initial_value = int(str(model.eval(variable, model_completion=True))) @@ -74,6 +83,7 @@ def _can_change(constraints, variable): def _get_influencing_storages(call): + """ Examines a Call object and returns an iterator of all storages that influence the call value or direction""" state = call.state node = call.node @@ -93,7 +103,8 @@ def _get_influencing_storages(call): yield storage -def _find_changable(statespace, interesting_storages): +def _get_influencing_sstores(statespace, interesting_storages): + """ Gets sstore (state, node) tuples that write to interesting_storages""" for sstore_state, node in _get_states_with_opcode(statespace, 'SSTORE'): index, value = sstore_state.mstate.stack[-1], sstore_state.mstate.stack[-2] try: