fix: secure pickle deserialization in IPFS storage service (issue #22)

- Introduced RestrictedUnpickler in secure_pickle.py to prevent arbitrary code execution
- Updated IPFSStorageService.retrieve_memory and decompress_memory to use safe_loads()
- Maintains pickle dumps for serialization (safe)
- Reduces risk of remote code execution via malicious pickled data

apps/coordinator-api/src/app/services/ipfs_storage_service.py

@@ -12,6 +12,7 @@ import json
 import hashlib
 import gzip
 import pickle
+from .secure_pickle import safe_loads
 from dataclasses import dataclass, asdict
 
 try:
@@ -190,8 +191,8 @@ class IPFSStorageService:
             else:
                 decompressed_data = retrieved_data
             
-            # Deserialize
-            memory_data = pickle.loads(decompressed_data)
+            # Deserialize (using safe unpickler)
+            memory_data = safe_loads(decompressed_data)
             
             logger.info(f"Retrieved memory for agent {metadata.agent_id}: CID {cid}")
             return memory_data, metadata
@@ -353,7 +354,7 @@ class MemoryCompressionService:
     def decompress_memory(compressed_data: bytes) -> Any:
         """Decompress memory data"""
         decompressed = gzip.decompress(compressed_data)
-        return pickle.loads(decompressed)
+        return safe_loads(decompressed)
     
     @staticmethod
     def calculate_similarity(data1: Any, data2: Any) -> float:

apps/coordinator-api/src/app/services/secure_pickle.py

@@ -0,0 +1,33 @@
+"""
+Secure pickle deserialization utilities to prevent arbitrary code execution.
+"""
+
+import pickle
+import io
+from typing import Any
+
+# Safe classes whitelist: builtins and common types
+SAFE_MODULES = {
+    'builtins': {
+        'list', 'dict', 'set', 'tuple', 'int', 'float', 'str', 'bytes',
+        'bool', 'NoneType', 'range', 'slice', 'memoryview', 'complex'
+    },
+    'datetime': {'datetime', 'date', 'time', 'timedelta', 'timezone'},
+    'collections': {'OrderedDict', 'defaultdict', 'Counter', 'namedtuple'},
+    'dataclasses': {'dataclass'},
+    'typing': {'Any', 'List', 'Dict', 'Tuple', 'Set', 'Optional', 'Union', 'TypeVar', 'Generic', 'NamedTuple', 'TypedDict'},
+}
+
+class RestrictedUnpickler(pickle.Unpickler):
+    """
+    Unpickler that restricts which classes can be instantiated.
+    Only allows classes from SAFE_MODULES whitelist.
+    """
+    def find_class(self, module: str, name: str) -> Any:
+        if module in SAFE_MODULES and name in SAFE_MODULES[module]:
+            return super().find_class(module, name)
+        raise pickle.UnpicklingError(f"Class {module}.{name} is not allowed for unpickling (security risk).")
+
+def safe_loads(data: bytes) -> Any:
+    """Safely deserialize a pickle byte stream."""
+    return RestrictedUnpickler(io.BytesIO(data)).load()