diff options
Diffstat (limited to 'client/src/leap')
| -rw-r--r-- | client/src/leap/soledad/client/_crypto.py | 32 |
1 files changed, 17 insertions, 15 deletions
diff --git a/client/src/leap/soledad/client/_crypto.py b/client/src/leap/soledad/client/_crypto.py index 923891fc..66b26521 100644 --- a/client/src/leap/soledad/client/_crypto.py +++ b/client/src/leap/soledad/client/_crypto.py @@ -328,15 +328,16 @@ class BlobDecryptor(object): self.armor = armor self._producer = None self.result = result or BytesIO() - self.sym_key = _get_sym_key_for_doc(doc_info.doc_id, secret) + sym_key = _get_sym_key_for_doc(doc_info.doc_id, secret) self.size = None - self.tag = tag + self.tag = None + preamble, iv = self._consume_preamble() assert preamble assert iv - self._aes = AESWriter(self.sym_key, iv, self.result, tag=self.tag) - self._aes.authenticate(preamble) + self._aes = AESWriter(sym_key, iv, self.result, tag=tag or self.tag) + self._aes.authenticate(preamble) if start_stream: self._start_stream() @@ -346,12 +347,18 @@ class BlobDecryptor(object): def _consume_preamble(self): self.fd.seek(0) try: - preamble, ciphertext = self.fd.getvalue().split(SEPARATOR, 1) - preamble = base64.urlsafe_b64decode(preamble) - if self.armor: - ciphertext = base64.urlsafe_b64decode(ciphertext) - tag, ciphertext = ciphertext[-16:], ciphertext[:-16] - self.tag = self.tag or tag + parts = self.fd.getvalue().split(SEPARATOR, 1) + preamble = base64.urlsafe_b64decode(parts[0]) + if len(parts) == 2: + ciphertext = parts[1] + if self.armor: + ciphertext = base64.urlsafe_b64decode(ciphertext) + self.tag, ciphertext = ciphertext[-16:], ciphertext[:-16] + self.fd.seek(0) + self.fd.write(ciphertext) + self.fd.seek(len(ciphertext)) + self.fd.truncate() + self.fd.seek(0) except (TypeError, ValueError): raise InvalidBlob @@ -387,11 +394,6 @@ class BlobDecryptor(object): if doc_id != self.doc_id: raise InvalidBlob('invalid doc id') - self.fd.seek(0) - self.fd.write(ciphertext) - self.fd.seek(len(ciphertext)) - self.fd.truncate() - self.fd.seek(0) return preamble, iv def _end_stream(self): |