card #227, replacing lib for debian compatibility: cryptography -> nacl

1 files changed, 9 insertions, 4 deletions

diff --git a/service/pixelated/support/encrypted_file_storage.py b/service/pixelated/support/encrypted_file_storage.py
index 5661b5e5..b859863b 100644
--- a/service/pixelated/support/encrypted_file_storage.py
+++ b/service/pixelated/support/encrypted_file_storage.py
@@ -20,14 +20,15 @@ from hashlib import sha512
 import os
 from whoosh.filedb.filestore import FileStorage
 from whoosh.filedb.structfile import StructFile, BufferFile
-from cryptography.fernet import Fernet
+from nacl.secret import SecretBox
+import nacl.utils
 from whoosh.util import random_name
 
 
 class EncryptedFileStorage(FileStorage):
     def __init__(self, path, masterkey=None):
         self.masterkey = masterkey
-        self.f = Fernet(masterkey)
+        self.secret_box = SecretBox(masterkey)
         self._tmp_storage = self.temp_storage
         self.length_cache = {}
         FileStorage.__init__(self, path, supports_mmap=False)
@@ -48,6 +49,10 @@ class EncryptedFileStorage(FileStorage):
     def file_length(self, name):
         return self.length_cache[name][0]
 
+    @property
+    def _nonce(self):
+        return nacl.utils.random(SecretBox.NONCE_SIZE)
+
     def _encrypt_index_on_close(self, name):
         def wrapper(struct_file):
             struct_file.seek(0)
@@ -56,13 +61,13 @@ class EncryptedFileStorage(FileStorage):
             if name in self.length_cache and file_hash == self.length_cache[name][1]:
                 return
             self.length_cache[name] = (len(content), file_hash)
-            encrypted_content = self.f.encrypt(content)
+            encrypted_content = self.secret_box.encrypt(content, self._nonce)
             with open(self._fpath(name), 'w+b') as f:
                 f.write(encrypted_content)
         return wrapper
 
     def _open_encrypted_file(self, name, onclose=lambda x: None):
         file_content = open(self._fpath(name), "rb").read()
-        decrypted = self.f.decrypt(file_content)
+        decrypted = self.secret_box.decrypt(file_content)
         self.length_cache[name] = (len(decrypted), sha512(decrypted).digest())
         return BufferFile(buffer(decrypted), name=name, onclose=onclose)