static void unhook_drbg(RAND_DRBG *drbg)
{
    HOOK_CTX *ctx = get_hook_ctx(drbg);

    drbg->get_entropy = ctx->get_entropy;
    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data);
}
static void unhook_drbg(RAND_DRBG *drbg)
{
    HOOK_CTX *ctx = get_hook_ctx(drbg);

    drbg->get_entropy = ctx->get_entropy;
    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_DRBG, drbg, &drbg->ex_data);
}