DES being deprecated is hopefully well-established enough that no one is
going start complaining our implementation isn't constant-time. But I
think this is the only non-constant-time code left without a warning, so
add one for completeness.
(It is possible to implement DES with bitslicing, but 3DES TLS ciphers
are too slow as it is and hopefully not long for the world.)
Change-Id: I6b0de915e89ffe2d11372f7109642fcff44b11bf
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/43244
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
David Benjamin
Adam Langley