Starting to integrity check all Uplink NAS Transport messages.

master
Pedro Alvarez 7 years ago
parent 3f7bea1af6
commit 26f782d8a4

@ -74,7 +74,7 @@ s1ap::init(s1ap_args_t s1ap_args, srslte::log_filter *s1ap_log)
m_s1ap_args = s1ap_args;
srslte::s1ap_mccmnc_to_plmn(s1ap_args.mcc, s1ap_args.mnc, &m_plmn);
m_next_m_tmsi = rand();
m_next_m_tmsi = 0xF000;
//Init log
m_s1ap_log = s1ap_log;
@ -517,7 +517,7 @@ s1ap::allocate_m_tmsi(uint64_t imsi)
{
uint32_t m_tmsi = m_next_m_tmsi++;
m_tmsi_to_imsi.insert(std::pair<uint32_t,uint64_t>(m_tmsi,imsi));
m_s1ap_log->info("Allocated M-TMSI %d,\n");
m_s1ap_log->info("Allocated M-TMSI 0x%x,\n",m_tmsi);
//uint32_t m_tmsi = 0x0123;
return m_tmsi;
}

@ -117,37 +117,101 @@ s1ap_nas_transport::handle_initial_ue_message(LIBLTE_S1AP_MESSAGE_INITIALUEMESSA
bool
s1ap_nas_transport::handle_uplink_nas_transport(LIBLTE_S1AP_MESSAGE_UPLINKNASTRANSPORT_STRUCT *ul_xport, struct sctp_sndrcvinfo *enb_sri, srslte::byte_buffer_t *reply_buffer, bool *reply_flag)
{
bool ue_valid = true;
uint8_t pd, msg_type, sec_hdr_type;
uint32_t enb_ue_s1ap_id = ul_xport->eNB_UE_S1AP_ID.ENB_UE_S1AP_ID;
uint32_t mme_ue_s1ap_id = ul_xport->MME_UE_S1AP_ID.MME_UE_S1AP_ID;
ue_emm_ctx_t *ue_emm_ctx = NULL;
bool mac_valid = false;
//Get UE ECM context
ue_ecm_ctx_t *ue_ecm_ctx = m_s1ap->find_ue_ecm_ctx_from_mme_ue_s1ap_id(mme_ue_s1ap_id);
if(ue_ecm_ctx == NULL)
{
m_s1ap_log->warning("Received uplink NAS, but could not find UE ECM context. MME-UE S1AP id: %lu\n",mme_ue_s1ap_id);
return false;
}
m_s1ap_log->debug("Received uplink NAS and found UE. MME-UE S1AP id: %lu\n",mme_ue_s1ap_id);
//Get NAS message type
uint8_t pd, msg_type;
srslte::byte_buffer_t *nas_msg = m_pool->allocate();
m_s1ap_log->debug("Received uplink NAS and found UE ECM context. MME-UE S1AP id: %lu\n",mme_ue_s1ap_id);
//Parse NAS message header
srslte::byte_buffer_t *nas_msg = m_pool->allocate();
memcpy(nas_msg->msg, &ul_xport->NAS_PDU.buffer, ul_xport->NAS_PDU.n_octets);
nas_msg->N_bytes = ul_xport->NAS_PDU.n_octets;
liblte_mme_parse_msg_header((LIBLTE_BYTE_MSG_STRUCT *) nas_msg, &pd, &msg_type);
switch (msg_type) {
// Parse the message security header
liblte_mme_parse_msg_sec_header((LIBLTE_BYTE_MSG_STRUCT*)nas_msg, &pd, &sec_hdr_type);
//Find UE EMM context if message is security protected.
if(sec_hdr_type != LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS)
{
//Get EMM context to do integrity check/de-chiphering
ue_emm_ctx = m_s1ap->find_ue_emm_ctx_from_imsi(ue_ecm_ctx->imsi);
if(ue_emm_ctx == NULL)
{
m_s1ap_log->warning("Uplink NAS: could not find security context for integrity protected message. MME-UE S1AP id: %lu\n",mme_ue_s1ap_id);
m_pool->deallocate(nas_msg);
return false;
}
}
if(sec_hdr_type == LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS)
{
//Plain NAS, only identity response is valid.
switch(msg_type)
{
case LIBLTE_MME_MSG_TYPE_IDENTITY_RESPONSE:
m_s1ap_log->info("Uplink NAS: Received Identity Response\n");
m_s1ap_log->console("Uplink NAS: Received Identity Response\n");
handle_identity_response(nas_msg, ue_ecm_ctx, reply_buffer, reply_flag);
break;
case LIBLTE_MME_MSG_TYPE_AUTHENTICATION_RESPONSE:
m_s1ap_log->info("Uplink NAS: Received Authentication Response\n");
m_s1ap_log->console("Uplink NAS: Received Authentication Response\n");
handle_nas_authentication_response(nas_msg, ue_ecm_ctx, reply_buffer, reply_flag);
break;
case LIBLTE_MME_MSG_TYPE_SECURITY_MODE_COMPLETE:
default:
m_s1ap_log->warning("Unhandled Plain NAS message 0x%x\n", msg_type );
m_s1ap_log->console("Unhandled Plain NAS message 0x%x\n", msg_type );
m_pool->deallocate(nas_msg);
return false;
}
}
else if(sec_hdr_type == LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_WITH_NEW_EPS_SECURITY_CONTEXT || sec_hdr_type == LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED_WITH_NEW_EPS_SECURITY_CONTEXT)
{
switch (msg_type) {
case LIBLTE_MME_MSG_TYPE_SECURITY_MODE_COMPLETE:
m_s1ap_log->info("Uplink NAS: Received Security Mode Complete\n");
m_s1ap_log->console("Uplink NAS: Received Security Mode Complete\n");
handle_nas_security_mode_complete(nas_msg, ue_ecm_ctx, reply_buffer, reply_flag);
ue_emm_ctx->security_ctxt.ul_nas_count = 0;
ue_emm_ctx->security_ctxt.dl_nas_count = 0;
mac_valid = integrity_check(ue_emm_ctx,nas_msg);
if(mac_valid){
handle_nas_security_mode_complete(nas_msg, ue_ecm_ctx, reply_buffer, reply_flag);
} else {
m_s1ap_log->warning("Invalid MAC in Security Mode Command Complete message.\n" );
}
break;
default:
m_s1ap_log->warning("Unhandled NAS message with new EPS security context 0x%x\n", msg_type );
m_s1ap_log->warning("Unhandled NAS message with new EPS security context 0x%x\n", msg_type );
}
}
else if(sec_hdr_type == LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY || sec_hdr_type == LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED)
{
//Integrity protected NAS message, possibly chiphered.
ue_emm_ctx->security_ctxt.ul_nas_count++;
mac_valid = integrity_check(ue_emm_ctx,nas_msg);
if(!mac_valid && msg_type != LIBLTE_MME_MSG_TYPE_AUTHENTICATION_RESPONSE){
m_s1ap_log->warning("Invalid MAC in NAS message type 0x%x.\n", msg_type);
m_pool->deallocate(nas_msg);
return false;
}
switch (msg_type) {
case LIBLTE_MME_MSG_TYPE_AUTHENTICATION_RESPONSE:
m_s1ap_log->info("Uplink NAS: Received Authentication Response\n");
m_s1ap_log->console("Uplink NAS: Received Authentication Response\n");
handle_nas_authentication_response(nas_msg, ue_ecm_ctx, reply_buffer, reply_flag);
break;
case LIBLTE_MME_MSG_TYPE_ATTACH_COMPLETE:
m_s1ap_log->info("Uplink NAS: Received Attach Complete\n");
@ -159,11 +223,6 @@ s1ap_nas_transport::handle_uplink_nas_transport(LIBLTE_S1AP_MESSAGE_UPLINKNASTRA
m_s1ap_log->console("Uplink NAS: Received ESM Information Response\n");
handle_esm_information_response(nas_msg, ue_ecm_ctx, reply_buffer, reply_flag);
break;
case LIBLTE_MME_MSG_TYPE_IDENTITY_RESPONSE:
m_s1ap_log->info("Uplink NAS: Received Identity Response\n");
m_s1ap_log->console("Uplink NAS: Received Identity Response\n");
handle_identity_response(nas_msg, ue_ecm_ctx, reply_buffer, reply_flag);
break;
case LIBLTE_MME_MSG_TYPE_TRACKING_AREA_UPDATE_REQUEST:
m_s1ap_log->info("UL NAS: Tracking Area Update Request\n");
handle_tracking_area_update_request(nas_msg, ue_ecm_ctx, reply_buffer, reply_flag);
@ -173,8 +232,16 @@ s1ap_nas_transport::handle_uplink_nas_transport(LIBLTE_S1AP_MESSAGE_UPLINKNASTRA
m_s1ap_log->console("Unhandled NAS message 0x%x\n", msg_type );
m_pool->deallocate(nas_msg);
return false;
}
}
else
{
m_s1ap_log->error("Unhandled security header type in Uplink NAS Transport: %d\n", sec_hdr_type);
m_pool->deallocate(nas_msg);
return false;
}
if(*reply_flag == true)
{
m_s1ap_log->info("DL NAS: Sent Downlink NAS message\n");
@ -221,11 +288,11 @@ s1ap_nas_transport::handle_nas_attach_request(uint32_t enb_ue_s1ap_id,
{
m_s1ap_log->console("Attach Request -- IMSI-style attach request\n");
m_s1ap_log->info("Attach Request -- IMSI-style attach request\n");
if(sec_hdr_type != LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS)
/*if(sec_hdr_type != LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS)
{
m_s1ap_log->error("Attach request -- IMSI-stlye attach request is not plain NAS\n");
return false;
}
}*/
handle_nas_imsi_attach_request(enb_ue_s1ap_id, attach_req, pdn_con_req, reply_buffer, reply_flag, enb_sri);
}
else if(attach_req.eps_mobile_id.type_of_id == LIBLTE_MME_EPS_MOBILE_ID_TYPE_GUTI)
@ -548,8 +615,6 @@ s1ap_nas_transport::handle_nas_security_mode_complete(srslte::byte_buffer_t *nas
return false;
}
//TODO Check integrity
//TODO Handle imeisv
if(sm_comp.imeisv_present)
{
@ -858,7 +923,7 @@ s1ap_nas_transport::pack_authentication_reject(srslte::byte_buffer_t *reply_msg,
if(err != LIBLTE_SUCCESS)
{
m_s1ap_log->error("Error packing Athentication Reject\n");
m_s1ap_log->console("Error packing Athentication Reject\n");
m_s1ap_log->console("Error packing Athentication Reject\n");
return false;
}

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