# Copyright (c) 2023, NVIDIA CORPORATION. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from nvflare.apis.event_type import EventType
from nvflare.apis.fl_context import FLContext
from nvflare.app_common.abstract.model import Learnable
from nvflare.app_common.abstract.persistor_filter import PersistorFilter
from nvflare.app_opt.he.homomorphic_encrypt import (
deserialize_nested_dict,
load_tenseal_context_from_workspace,
serialize_nested_dict,
)
[docs]
class HEModelSerializeFilter(PersistorFilter):
def __init__(self, tenseal_context_file="server_context.tenseal"):
"""Used to serialize TenSEAL encrypted server models for use with
homomorphic encryption (HE) support using TenSEAL https://github.com/OpenMined/TenSEAL.
Args:
tenseal_context_file: tenseal context files containing TenSEAL context
"""
super().__init__()
self.tenseal_context = None
self.tenseal_context_file = tenseal_context_file
[docs]
def handle_event(self, event_type: str, fl_ctx: FLContext):
if event_type == EventType.START_RUN:
self.tenseal_context = load_tenseal_context_from_workspace(self.tenseal_context_file, fl_ctx)
elif event_type == EventType.END_RUN:
self.tenseal_context = None
[docs]
def process_post_load(self, learnable: Learnable, fl_ctx: FLContext) -> Learnable:
"""Filter process applied to the Learnable object after it was loaded.
Args:
learnable: Learnable
fl_ctx: FLContext
Returns:
a Learnable object
"""
return deserialize_nested_dict(learnable, self.tenseal_context)
[docs]
def process_pre_save(self, learnable: Learnable, fl_ctx: FLContext) -> Learnable:
"""Filter process applied to the Learnable object to support persisting when containing encrypted objects.
Args:
learnable: Learnable
fl_ctx: FLContext
Returns:
a Learnable object
"""
return serialize_nested_dict(learnable)
[docs]
def process_post_save(self, learnable: Learnable, fl_ctx: FLContext) -> Learnable:
"""Filter process applied to the Learnable object to support persisting when containing encrypted objects.
Args:
learnable: Learnable
fl_ctx: FLContext
Returns:
a Learnable object
"""
return deserialize_nested_dict(learnable, self.tenseal_context)
[docs]
def process_post_get(self, learnable: Learnable, fl_ctx: FLContext) -> Learnable:
"""Filter process applied to the Learnable object after it was returned.
Args:
learnable: Learnable
fl_ctx: FLContext
Returns:
a Learnable object
"""
return deserialize_nested_dict(learnable, self.tenseal_context)