def __init__(self, aes_crypto):
self.cloud = Cloud(aes_crypto)
self.aes_crypto = aes_crypto
def __init__(self, aes_crypto):
self.cloud = Cloud(aes_crypto)
self.aes_crypto = aes_crypto
class PathORAM:
def __init__(self, aes_crypto):
self.cloud = Cloud(aes_crypto)
self.aes_crypto = aes_crypto
@classmethod
def get_max_oram_block_size(cls):
return int(math.pow(2, config.ORAM_LEVEL + 1) - 1)
@classmethod
def get_max_oram_storage_size(cls):
return cls.get_max_oram_block_size() * config.BLOCK_SIZE
def setup_cloud(self):
self.cloud.setup_cloud(self.get_max_oram_block_size())
# Find the path from root to leaf
# __author__: Dr. Steve Gordon
def path_to_leaf(self, leaf):
path = [0] * (config.ORAM_LEVEL + 1)
leafmin = config.LEAF_MIN
leafmax = config.LEAF_MAX
for curlevel in range(config.ORAM_LEVEL):
mid = (leafmax - leafmin) // 2 + leafmin
if leaf <= mid:
path[curlevel + 1] = path[curlevel] * 2 + 1
leafmax = mid
else:
path[curlevel + 1] = path[curlevel] * 2 + 2
leafmin = mid + 1
return path
# Find the path from leaf to root
# __author__: Dr. Steve Gordon
def path_to_root(self, leaf):
path = self.path_to_leaf(leaf)
path.reverse()
return path
def get_potential_data_ids_with_leaf(self):
potential_data_ids = Stash().get_potential_data_id()
potential_data_properties = PositionMap().get_leaf_ids(
potential_data_ids)
return potential_data_properties
def access_oram(self, path_to_root, data_id_of_interest=None):
# TODO: lock the function to be used only in one thread at the time
downloaded_data_items = self.read_path(path_to_root)
data_item = self.write_stash(downloaded_data_items,
data_id_of_interest)
self.write_path(path_to_root)
logger.info('STASH SIZE - %d' % Stash().get_stash_size())
return data_item
def read_path(self, path_to_root):
data_items = []
for node in path_to_root:
logger.info('READ PATH - download from node %d' % node)
data_item = self.read_node(node)
data_items.append(data_item)
return data_items
def write_path(self, path_to_root):
for node in path_to_root:
potential_data_properties = self.get_potential_data_ids_with_leaf()
has_potential_item = False
for potential_data_property in potential_data_properties:
potential_leaf_id = abs(potential_data_property[1])
potential_path = self.path_to_root(potential_leaf_id)
if node in potential_path:
has_potential_item = True
data_id = potential_data_property[0]
data_item = Stash().get_data_item(data_id)
self.write_node(node, data_item[1])
logger.info(
'WRITE PATH - upload to node %d data item with id %d' %
(node, data_id))
PositionMap().update_leaf_id(data_id, True)
Stash().delete_data_item(data_id)
break
if not has_potential_item:
self.write_node(node)
logger.info('WRITE PATH - upload to node %d dummy data' % node)
def decrypt_data_item(self, data_item):
return self.aes_crypto.decrypt(data_item)
def write_stash(self, downloaded_data_items, data_id_of_interest=None):
data_item_of_interest = None
for downloaded_data_item in downloaded_data_items:
try:
data_id, plaintext = self.decrypt_data_item(
downloaded_data_item)
if PositionMap().data_id_exist(data_id):
logger.info(
'WRITE STASH - downloaded data item with id %d' %
data_id)
token = self.aes_crypto.encrypt(plaintext, data_id)
Stash().add_file(data_id, token)
if data_id_of_interest is not None and data_id_of_interest == data_id:
PositionMap().choose_new_leaf_id(data_id)
data_item_of_interest = data_id, plaintext
else:
PositionMap().update_leaf_id(data_id, False)
except DummyFileFound:
logger.info('WRITE STASH - downloaded dummy file')
pass
return data_item_of_interest
def read_node(self, node):
return self.cloud.download_node(node)
def write_node(self, node, data_item=None):
self.cloud.upload_to_node(node, data_item)
def download_data_items(self, data_ids):
data_items = []
for data_id in data_ids:
leaf_id = PositionMap().get_leaf_id(data_id)
if leaf_id < 0:
data_item = Stash().get_data_item(data_id)
logger.info('PATH ORAM - access stash')
# decrypt data item
data_item = self.decrypt_data_item(data_item[1])
data_items.append(data_item)
else:
path_to_root = self.path_to_root(leaf_id)
data_item = self.access_oram(path_to_root, data_id)
data_items.append(data_item)
return data_items
def update_data(self, data_properties):
for data_property in data_properties:
leaf_id = abs(data_property[1])
path_to_root = self.path_to_root(leaf_id)
self.access_oram(path_to_root)
class PathORAM:
def __init__(self, aes_crypto):
self.cloud = Cloud(aes_crypto)
self.aes_crypto = aes_crypto
@classmethod
def get_max_oram_block_size(cls):
return int(math.pow(2, config.ORAM_LEVEL + 1) - 1)
@classmethod
def get_max_oram_storage_size(cls):
return cls.get_max_oram_block_size() * config.BLOCK_SIZE
def setup_cloud(self):
self.cloud.setup_cloud(self.get_max_oram_block_size())
# Find the path from root to leaf
# __author__: Dr. Steve Gordon
def path_to_leaf(self, leaf):
path = [0] * (config.ORAM_LEVEL + 1)
leafmin = config.LEAF_MIN
leafmax = config.LEAF_MAX
for curlevel in range(config.ORAM_LEVEL):
mid = (leafmax - leafmin) // 2 + leafmin
if leaf <= mid:
path[curlevel + 1] = path[curlevel] * 2 + 1
leafmax = mid
else:
path[curlevel + 1] = path[curlevel] * 2 + 2
leafmin = mid + 1
return path
# Find the path from leaf to root
# __author__: Dr. Steve Gordon
def path_to_root(self, leaf):
path = self.path_to_leaf(leaf)
path.reverse()
return path
def get_potential_data_ids_with_leaf(self):
potential_data_ids = Stash().get_potential_data_id()
potential_data_properties = PositionMap().get_leaf_ids(potential_data_ids)
return potential_data_properties
def access_oram(self, path_to_root, data_id_of_interest=None):
# TODO: lock the function to be used only in one thread at the time
downloaded_data_items = self.read_path(path_to_root)
data_item = self.write_stash(downloaded_data_items, data_id_of_interest)
self.write_path(path_to_root)
logger.info('STASH SIZE - %d' % Stash().get_stash_size())
return data_item
def read_path(self, path_to_root):
data_items = []
for node in path_to_root:
logger.info('READ PATH - download from node %d' % node)
data_item = self.read_node(node)
data_items.append(data_item)
return data_items
def write_path(self, path_to_root):
for node in path_to_root:
potential_data_properties = self.get_potential_data_ids_with_leaf()
has_potential_item = False
for potential_data_property in potential_data_properties:
potential_leaf_id = abs(potential_data_property[1])
potential_path = self.path_to_root(potential_leaf_id)
if node in potential_path:
has_potential_item = True
data_id = potential_data_property[0]
data_item = Stash().get_data_item(data_id)
self.write_node(node, data_item[1])
logger.info('WRITE PATH - upload to node %d data item with id %d' % (node, data_id))
PositionMap().update_leaf_id(data_id, True)
Stash().delete_data_item(data_id)
break
if not has_potential_item:
self.write_node(node)
logger.info('WRITE PATH - upload to node %d dummy data' % node)
def decrypt_data_item(self, data_item):
return self.aes_crypto.decrypt(data_item)
def write_stash(self, downloaded_data_items, data_id_of_interest=None):
data_item_of_interest = None
for downloaded_data_item in downloaded_data_items:
try:
data_id, plaintext = self.decrypt_data_item(downloaded_data_item)
if PositionMap().data_id_exist(data_id):
logger.info('WRITE STASH - downloaded data item with id %d' % data_id)
token = self.aes_crypto.encrypt(plaintext, data_id)
Stash().add_file(data_id, token)
if data_id_of_interest is not None and data_id_of_interest == data_id:
PositionMap().choose_new_leaf_id(data_id)
data_item_of_interest = data_id, plaintext
else:
PositionMap().update_leaf_id(data_id, False)
except DummyFileFound:
logger.info('WRITE STASH - downloaded dummy file')
pass
return data_item_of_interest
def read_node(self, node):
return self.cloud.download_node(node)
def write_node(self, node, data_item=None):
self.cloud.upload_to_node(node, data_item)
def download_data_items(self, data_ids):
data_items = []
for data_id in data_ids:
leaf_id = PositionMap().get_leaf_id(data_id)
if leaf_id < 0:
data_item = Stash().get_data_item(data_id)
logger.info('PATH ORAM - access stash')
# decrypt data item
data_item = self.decrypt_data_item(data_item[1])
data_items.append(data_item)
else:
path_to_root = self.path_to_root(leaf_id)
data_item = self.access_oram(path_to_root, data_id)
data_items.append(data_item)
return data_items
def update_data(self, data_properties):
for data_property in data_properties:
leaf_id = abs(data_property[1])
path_to_root = self.path_to_root(leaf_id)
self.access_oram(path_to_root)
