void threefish256_init(void* key, void* tweak, threefish256_ctx_t* ctx);
void threefish512_init(void* key, void* tweak, threefish512_ctx_t* ctx);
void threefish256_init(void* key, void* tweak, threefish256_ctx_t* ctx);
void threefish512_init(void* key, void* tweak, threefish512_ctx_t* ctx);