Need to define the workspace buffer properly to allow compiler to handle
strict aliasing between the incoming unsigned char[64] buffer as an u32
array. The previous version built with strict aliasing enabled can
result in SHA-1 producing incorrect results and consequently, with
4-way handshake failing.
This is based on a report and patch from Dan Williams <dcbw@redhat.com>
but with a different type (the union) used as a fix to avoid needing
extra type casting.
Discovered as part of the investigation of:
https://bugzilla.redhat.com/show_bug.cgi?id=494262#c32
if sha1 is built with gcc without turning off strict aliasing, it will
fail to correctly generate the hashes and will fail its own testcases as
well.
Signed-off-by: Dan Williams <dcbw@redhat.com>
Some crypto libraries can return in these functions (e.g., if a specific
hash function is disabled), so we better provide the caller a chance to
check whether the call failed. The return values are not yet used
anywhere, but they will be needed for future changes.
