This creates a random 100 KiB buffer, and incrementally hashes
(SHA3-512) between 1 and 5 * Rate bytes in a loop, comparing the running
digest with the equivalent one shot call from the start of the buffer.
This is an eXtendable-Output Function with the following claimed
security strengths against *all* adversaries:
Collision: min(d/2, 256)
Preimage: >= min(d, 256)
2nd Preimage: min(d, 256)
where d is the amount of output used, in bits.
* DIGEST_SHA3_[256,512] added as supported algorithms, which do
exactly what is said on the tin.
* test/bench now benchmarks all of the supported digest algorithms,
so it's possible to see just how slow SHA-3 is, though the message
sizes could probably use tweaking since this is very dependent on
the message size vs the SHA-3 rate.
The digest routines use init/update/sum, where sum will automatically
copy the internal state to support calculating running digests.
The XOF routines use init/absorb/squeeze, which behave exactly as stated
on the tin.
I believe that the final SMARTLIST_DEL_CURRENT was sometimes
double-removing items that had already been removed by
connection_mark_unattached_ap or
connection_ap_handshake_attach_circuit().
The fix here is to prevent iteration over the list that other
functions might be modifying.
According to the POSIX standard the option value is a pointer to void
and the option length a socklen_t. The Windows implementation makes the
option value be a pointer to character and the option length an int.
Casting the option value to a pointer to void conforms to the POSIX
standard while the implicit cast to a pointer to character conforms to
the Windows implementation.
The casts of the option length to the socklen_t data type conforms to
the POSIX standard. The socklen_t data type is actually an alias of an
int so it also conforms to the Windows implementation.
It is AP-specific, so that's where it belongs. This shouldn't have
caused a bug, but due to #17876, we were never actually calling
connection_edge_about_to_close from connection_ap_about_to_close,
causing bug #17874 (aka bug #17752).
