get_boolean
retval = get_boolean(ctx, KRB5_CONF_ALLOW_WEAK_CRYPTO, 0, &tmp);
retval = get_boolean(ctx, KRB5_CONF_ALLOW_DES3, 0, &tmp);
retval = get_boolean(ctx, KRB5_CONF_ALLOW_RC4, 0, &tmp);
retval = get_boolean(ctx, KRB5_CONF_IGNORE_ACCEPTOR_HOSTNAME, 0, &tmp);
retval = get_boolean(ctx, KRB5_CONF_ENFORCE_OK_AS_DELEGATE, 0, &tmp);