int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags)
{
    int ret = 1;

    if (type == 0 && flags == 0) {
        type = rand_drbg_type;
        flags = rand_drbg_flags;
    }

    /* If set is called multiple times - clear the old one */
    if (drbg->type != 0 && (type != drbg->type || flags != drbg->flags)) {
        drbg->meth->uninstantiate(drbg);
        rand_pool_free(drbg->adin_pool);
        drbg->adin_pool = NULL;
    }

    drbg->state = DRBG_UNINITIALISED;
    drbg->flags = flags;
    drbg->type = type;

    switch (type) {
    default:
        drbg->type = 0;
        drbg->flags = 0;
        drbg->meth = NULL;
        RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE);
        return 0;
    case 0:
        /* Uninitialized; that's okay. */
        drbg->meth = NULL;
        return 1;
    case NID_aes_128_ctr:
    case NID_aes_192_ctr:
    case NID_aes_256_ctr:
        ret = drbg_ctr_init(drbg);
        break;
    }

    if (ret == 0) {
        drbg->state = DRBG_ERROR;
        RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_ERROR_INITIALISING_DRBG);
    }
    return ret;
}
int RAND_DRBG_set(RAND_DRBG *drbg, int type, unsigned int flags)
{
    int ret = 1;

    if (type == 0 && flags == 0) {
        type = rand_drbg_type;
        flags = rand_drbg_flags;
    }

     
    if (drbg->type != 0 && (type != drbg->type || flags != drbg->flags)) {
        drbg->meth->uninstantiate(drbg);
        rand_pool_free(drbg->adin_pool);
        drbg->adin_pool = NULL;
    }

    drbg->state = DRBG_UNINITIALISED;
    drbg->flags = flags;
    drbg->type = type;

    switch (type) {
    default:
        drbg->type = 0;
        drbg->flags = 0;
        drbg->meth = NULL;
        RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_UNSUPPORTED_DRBG_TYPE);
        return 0;
    case 0:
         
        drbg->meth = NULL;
        return 1;
    case NID_aes_128_ctr:
    case NID_aes_192_ctr:
    case NID_aes_256_ctr:
        ret = drbg_ctr_init(drbg);
        break;
    }

    if (ret == 0) {
        drbg->state = DRBG_ERROR;
        RANDerr(RAND_F_RAND_DRBG_SET, RAND_R_ERROR_INITIALISING_DRBG);
    }
    return ret;
}