[feature] handle unsupported encryption schemes by saving directly

2 files changed, 23 insertions, 10 deletions

diff --git a/src/leap/soledad/client/_crypto.py b/src/leap/soledad/client/_crypto.py
index a0ec343c..8b0b8f81 100644
--- a/src/leap/soledad/client/_crypto.py
+++ b/src/leap/soledad/client/_crypto.py
@@ -108,6 +108,10 @@ class InvalidBlob(Exception):
     pass
 
 
+class EncryptionSchemeNotImplementedException(Exception):
+    pass
+
+
 class SoledadCrypto(object):
     """
     This class provides convenient methods for document encryption and
@@ -389,7 +393,7 @@ class BlobDecryptor(object):
         # we can refuse to process something that is in the future or
         # too far in the past (1984 would be nice, hehe)
         if preamble.scheme != ENC_SCHEME.symkey:
-            raise InvalidBlob('Invalid scheme: %s' % preamble.scheme)
+            raise EncryptionSchemeNotImplementedException(preamble.scheme)
         if preamble.method != ENC_METHOD.aes_256_gcm:
             method = preamble.method
             raise InvalidBlob('Invalid encryption scheme: %s' % method)
diff --git a/src/leap/soledad/client/_db/blobs.py b/src/leap/soledad/client/_db/blobs.py
index e95f9d9e..5334ffe5 100644
--- a/src/leap/soledad/client/_db/blobs.py
+++ b/src/leap/soledad/client/_db/blobs.py
@@ -42,6 +42,7 @@ from .._document import BlobDoc
 from .._crypto import DocInfo
 from .._crypto import BlobEncryptor
 from .._crypto import BlobDecryptor
+from .._crypto import EncryptionSchemeNotImplementedException
 from .._http import HTTPClient
 from .._pipes import TruncatedTailPipe
 from .._pipes import PreamblePipe
@@ -124,22 +125,30 @@ class DecrypterBuffer(object):
         self.secret = secret
         self.tag = tag
         self.preamble_pipe = PreamblePipe(self._make_decryptor)
+        self.decrypter = None
 
     def _make_decryptor(self, preamble):
-        self.decrypter = BlobDecryptor(
-            self.doc_info, preamble,
-            secret=self.secret,
-            armor=False,
-            start_stream=False,
-            tag=self.tag)
-        return TruncatedTailPipe(self.decrypter, tail_size=len(self.tag))
+        try:
+            self.decrypter = BlobDecryptor(
+                self.doc_info, preamble,
+                secret=self.secret,
+                armor=False,
+                start_stream=False,
+                tag=self.tag)
+            return TruncatedTailPipe(self.decrypter, tail_size=len(self.tag))
+        except EncryptionSchemeNotImplementedException:
+            self.raw_data = BytesIO()
+            return self.raw_data
 
     def write(self, data):
         self.preamble_pipe.write(data)
 
     def close(self):
-        real_size = self.decrypter.decrypted_content_size
-        return self.decrypter._end_stream(), real_size
+        if self.decrypter:
+            real_size = self.decrypter.decrypted_content_size
+            return self.decrypter._end_stream(), real_size
+        else:
+            return self.raw_data, self.raw_data.tell()
 
 
 class BlobManager(object):