Prototype of user-provided callback function that reseeds a user-defined RNG context.
#include "hurandom.h"
typedef int SB_CALLBACK_CALLCONV hu_RngReseedFunc(void *rngctx, size_t seedlen, const unsigned char *seed, void *sbCtx);
This function is called by hu_RngReseed(). It will be passed seeding material that the user-defined RNG can use to reseed itself.
This callback should be registered during custom RNG context creation.