// to make sure h is not collected (and finalized) before the cgo
		// call returns.
		runtime.SetFinalizer(h, (*boringHMAC).finalize)
	}
	C._goboringcrypto_HMAC_CTX_init(&h.ctx)

	if C._goboringcrypto_HMAC_Init(&h.ctx, unsafe.Pointer(base(h.key)), C.int(len(h.key)), h.md) == 0 {
		panic("boringcrypto: HMAC_Init failed")
	}
	if int(C._goboringcrypto_HMAC_size(&h.ctx)) != h.size {