From e5e091b0c9a50f515fe1efd4246155ea99aef81f Mon Sep 17 00:00:00 2001 From: David Rupprecht Date: Sun, 18 Nov 2018 21:18:17 +0100 Subject: [PATCH] Minor fixes and code clean up --- srsepc/src/mme/s1ap_nas_transport.cc | 41 ++++++++++------------------ 1 file changed, 15 insertions(+), 26 deletions(-) diff --git a/srsepc/src/mme/s1ap_nas_transport.cc b/srsepc/src/mme/s1ap_nas_transport.cc index 5f34432f3..b0ef573ce 100644 --- a/srsepc/src/mme/s1ap_nas_transport.cc +++ b/srsepc/src/mme/s1ap_nas_transport.cc @@ -547,22 +547,6 @@ s1ap_nas_transport::handle_nas_guti_attach_request( uint32_t enb_ue_s1ap_id, bool* reply_flag, struct sctp_sndrcvinfo *enb_sri) { - //Parse the message security header - uint8 pd = 0; - uint8 sec_hdr_type = 0; - liblte_mme_parse_msg_sec_header((LIBLTE_BYTE_MSG_STRUCT*)nas_msg, &pd, &sec_hdr_type); - - bool integrity_valid = false; - if(sec_hdr_type != LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY) - { - m_s1ap_log->info("Attach request -- GUTI-stlye attach request is not integrity protected\n"); - m_s1ap_log->console("Attach request -- GUTI-stlye attach request is not integrity protected\n"); - } - else{ - m_s1ap_log->info("Attach request -- GUTI-stlye attach request is integrity protected\n"); - m_s1ap_log->console("Attach request -- GUTI-stlye attach request is integrity protected\n"); - } - //GUTI style attach uint32_t m_tmsi = attach_req.eps_mobile_id.guti.m_tmsi; @@ -657,6 +641,7 @@ s1ap_nas_transport::handle_nas_guti_attach_request( uint32_t enb_ue_s1ap_id, ue_ecm_ctx_t *ecm_ctx = &ue_ctx->ecm_ctx; m_s1ap_log->console("Found UE context. IMSI: %015lu, old eNB UE S1ap Id %d, old MME UE S1AP Id %d\n",emm_ctx->imsi, ecm_ctx->enb_ue_s1ap_id, ecm_ctx->mme_ue_s1ap_id); //Check NAS integrity + // Initial GUTI attach request should be always unencrypted and therefore no problem bool msg_valid = false; emm_ctx->security_ctxt.ul_nas_count++; msg_valid = integrity_check(&emm_ctx->security_ctxt, nas_msg); @@ -1224,7 +1209,7 @@ s1ap_nas_transport::handle_identity_response(srslte::byte_buffer_t *nas_msg, ue_ m_s1ap_log->console("ID Response -- IMSI: %015lu\n", imsi); //Set UE's context IMSI - emm_ctx->imsi=imsi; + emm_ctx->imsi = imsi; ecm_ctx->imsi = imsi; //Get Authentication Vectors from HSS @@ -1677,8 +1662,8 @@ s1ap_nas_transport::pack_security_mode_command(srslte::byte_buffer_t *reply_msg, sm_cmd.nonce_ue_present=false; sm_cmd.nonce_mme_present=false; - uint8_t sec_hdr_type=3; - LIBLTE_ERROR_ENUM err = liblte_mme_pack_security_mode_command_msg(&sm_cmd,sec_hdr_type, ue_emm_ctx->security_ctxt.dl_nas_count,(LIBLTE_BYTE_MSG_STRUCT *) nas_buffer); + uint8_t sec_hdr_type = LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_WITH_NEW_EPS_SECURITY_CONTEXT; + LIBLTE_ERROR_ENUM err = liblte_mme_pack_security_mode_command_msg(&sm_cmd, sec_hdr_type, ue_emm_ctx->security_ctxt.dl_nas_count,(LIBLTE_BYTE_MSG_STRUCT *) nas_buffer); if(err != LIBLTE_SUCCESS) { m_s1ap_log->console("Error packing Security Mode Command\n"); @@ -1686,7 +1671,7 @@ s1ap_nas_transport::pack_security_mode_command(srslte::byte_buffer_t *reply_msg, } //Generate EPS security context - uint8_t mac[4]; + srslte::security_generate_k_nas( ue_emm_ctx->security_ctxt.k_asme, ue_emm_ctx->security_ctxt.cipher_algo, ue_emm_ctx->security_ctxt.integ_algo, @@ -1704,9 +1689,10 @@ s1ap_nas_transport::pack_security_mode_command(srslte::byte_buffer_t *reply_msg, m_s1ap_log->info_hex(ue_emm_ctx->security_ctxt.k_enb, 32, "Key eNodeB (k_enb)\n"); //Generate MAC for integrity protection + uint8_t mac[4]; integrity_generate(&ue_emm_ctx->security_ctxt, nas_buffer, mac); - memcpy(&nas_buffer->msg[1],mac,4); + //Copy NAS PDU to Downlink NAS Trasport message buffer memcpy(dw_nas->NAS_PDU.buffer, nas_buffer->msg, nas_buffer->N_bytes); dw_nas->NAS_PDU.n_octets = nas_buffer->N_bytes; @@ -1902,16 +1888,19 @@ s1ap_nas_transport::pack_attach_accept(ue_emm_ctx_t *ue_emm_ctx, ue_ecm_ctx_t *u act_def_eps_bearer_context_req.esm_cause_present = false; act_def_eps_bearer_context_req.connectivity_type_present = false; - uint8_t sec_hdr_type =2; + uint8_t sec_hdr_type = LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED; ue_emm_ctx->security_ctxt.dl_nas_count++; liblte_mme_pack_activate_default_eps_bearer_context_request_msg(&act_def_eps_bearer_context_req, &attach_accept.esm_msg); liblte_mme_pack_attach_accept_msg(&attach_accept, sec_hdr_type, ue_emm_ctx->security_ctxt.dl_nas_count, (LIBLTE_BYTE_MSG_STRUCT *) nas_buffer); - //Integrity protect NAS message + + // Encrypt NAS message + cipher_encrypt(&ue_emm_ctx->security_ctxt, nas_buffer); + + // Integrity protect NAS message uint8_t mac[4]; integrity_generate(&ue_emm_ctx->security_ctxt, nas_buffer, mac); - memcpy(&nas_buffer->msg[1],mac,4); - m_s1ap_log->info("Packed Attach Complete\n"); + m_s1ap_log->info("Packed Attach Accept\n"); //Add nas message to context setup request erab_ctxt->nAS_PDU_present = true; @@ -2010,7 +1999,7 @@ s1ap_nas_transport::pack_emm_information( ue_ctx_t *ue_ctx, srslte::byte_buffer_ emm_info.utc_and_local_time_zone_present = false; emm_info.net_dst_present = false; - uint8_t sec_hdr_type =2; + uint8_t sec_hdr_type = LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED; emm_ctx->security_ctxt.dl_nas_count++; LIBLTE_ERROR_ENUM err = liblte_mme_pack_emm_information_msg(&emm_info, sec_hdr_type, emm_ctx->security_ctxt.dl_nas_count, (LIBLTE_BYTE_MSG_STRUCT *) nas_buffer); if(err != LIBLTE_SUCCESS)