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| author | Paul Kehrer <paul.l.kehrer@gmail.com> | 2018-03-20 13:33:57 -0400 |
|---|---|---|
| committer | Alex Gaynor <alex.gaynor@gmail.com> | 2018-03-20 13:33:57 -0400 |
| commit | f903da081b3eac3bc84a2e596591e7e634c3355d (patch) | |
| tree | 720fc1607b0e0ae1a3d9d9f3a88a2a49e1a3e34a /src | |
| parent | 79748a9e84b8084559e9a2794ed2d88e05259611 (diff) | |
| download | cryptography-f903da081b3eac3bc84a2e596591e7e634c3355d.tar.gz cryptography-f903da081b3eac3bc84a2e596591e7e634c3355d.tar.bz2 cryptography-f903da081b3eac3bc84a2e596591e7e634c3355d.zip | |
fix bug with n % 8 length wrapping on AESKWP (#4160)
* fix bug with n % 8 length wrapping on AESKWP
* review feedback
Diffstat (limited to 'src')
| -rw-r--r-- | src/cryptography/hazmat/primitives/keywrap.py | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/src/cryptography/hazmat/primitives/keywrap.py b/src/cryptography/hazmat/primitives/keywrap.py index 3b531318..2b7955f8 100644 --- a/src/cryptography/hazmat/primitives/keywrap.py +++ b/src/cryptography/hazmat/primitives/keywrap.py @@ -118,11 +118,16 @@ def aes_key_unwrap_with_padding(wrapping_key, wrapped_key, backend): b = (8 * n) - mli if ( not bytes_eq(a[:4], b"\xa6\x59\x59\xa6") or not - 8 * (n - 1) < mli <= 8 * n or not bytes_eq(data[-b:], b"\x00" * b) + 8 * (n - 1) < mli <= 8 * n or ( + b != 0 and not bytes_eq(data[-b:], b"\x00" * b) + ) ): raise InvalidUnwrap() - return data[:-b] + if b == 0: + return data + else: + return data[:-b] def aes_key_unwrap(wrapping_key, wrapped_key, backend): |