static int SRP_user_pwd_set_sv(SRP_user_pwd *vinfo, const char *s,
                               const char *v)
{
    unsigned char tmp[MAX_LEN];
    int len;

    vinfo->v = NULL;
    vinfo->s = NULL;

    len = t_fromb64(tmp, sizeof(tmp), v);
    if (len < 0)
        return 0;
    if (NULL == (vinfo->v = BN_bin2bn(tmp, len, NULL)))
        return 0;
    len = t_fromb64(tmp, sizeof(tmp), s);
    if (len < 0)
        goto err;
    vinfo->s = BN_bin2bn(tmp, len, NULL);
    if (vinfo->s == NULL)
        goto err;
    return 1;
 err:
    BN_free(vinfo->v);
    vinfo->v = NULL;
    return 0;
}