Validate key_to_wrap length in aes_key_wrap_with_padding#14665
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reaperhulk merged 1 commit intopyca:mainfrom Apr 15, 2026
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Validate key_to_wrap length in aes_key_wrap_with_padding#14665reaperhulk merged 1 commit intopyca:mainfrom
key_to_wrap length in aes_key_wrap_with_padding#14665reaperhulk merged 1 commit intopyca:mainfrom
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Can you add a direct unit test for this as well? (Sent from my $work github) |
RFC 5649 specifies that the plaintext must be between 1 and 2^32 octets. Previously, passing an empty key_to_wrap would cause _wrap_core to be called with r=[], which skips all AES operations and returns an invalid wrapped key.
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Hi,
this PR resolves #14664:
RFC 5649 specifies that the plaintext must be between 1 and 2^32 octets. Previously, passing an empty key_to_wrap would cause _wrap_core to be called with r=[], which skips all AES operations and just returns an invalid wrapped key.
Wycheproof has a test for this that is marked as "invalid":
https://github.com/C2SP/wycheproof/blob/75ede73a39b8517b2a06c8115dfbcd364479796c/testvectors_v1/aes_kwp_test.json#L839-L849
I've updated the testing harness to allow
aes_key_wrap_with_paddingto return an error in this case. The initial CI run failed in that case. Unfortunately there doesn't seem to be a way to tell if unwrapping or wrapping the key should fail, which is why this wasn't caught by the wycheproof test and why the new logic is somewhat sloppy.Thanks!