/*  10.5.3.2.2 Authentication Failure parameter (UMTS and EPS authentication challenge)  */
static guint16 de_auth_fail_param(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo, guint32 offset, guint len, gchar *add_string _U_, int string_len _U_)
/*  10.5.3.2.2 Authentication Failure parameter (UMTS and EPS authentication challenge)  */
static guint16 de_auth_fail_param(tvbuff_t *tvb, proto_tree *tree, packet_info *pinfo, guint32 offset, guint len, gchar *add_string _U_, int string_len _U_)
{
    proto_item *item;
    proto_tree *subtree;
    item = proto_tree_add_item(tree, hf_gsm_a_dtap_auts, tvb, offset, len, ENC_NA);
    subtree = proto_item_add_subtree(item, ett_gsm_dtap_elem[DE_AUTH_FAIL_PARAM]);
    if (len == 14)
    {
        proto_tree_add_item(subtree, hf_gsm_a_dtap_auts_sqn_ms_xor_ak, tvb, offset, 6, ENC_NA);
        proto_tree_add_item(subtree, hf_gsm_a_dtap_auts_mac_s, tvb, offset + 6, 8, ENC_NA);
    }
    else
        expert_add_info(pinfo, item, &ei_gsm_a_dtap_auts);
    return (len);
}