uint8_t pointers yield strict aliasing violations

[gsauthof]

The SipHash hash function signature reads:

int siphash(const uint8_t *in, const size_t inlen, const uint8_t *k,
        uint8_t *out, const size_t outlen);

That means if I need to hash - say - an integer I have to cast an integer pointer to uint8_t*.

Unfortunately, uint8_t* doesn't have the same strict aliasing implications as char*/unsigned char */void* or even std::byte*.

(Meaning the C standard just includes exceptions from the strict aliasing rules for char/void pointers but not for uint8_t pointers.)

That means that such a cast yields undefined behaviour.

Possible fix: change the type of the first argument to const void *in (such that callers don't have to cast) and cast that pointer in the function to const unsigned char * and use that for the accesses and address calculations.

[veorq]

Thanks, will fix.

[veorq]

Looks good? #35

[gsauthof]

Thank you for looking into this, I left some review comments in the pull request.