add support for ciphered authentication response

lib/include/srslte/asn1/liblte_mme.h

@@ -2814,6 +2814,8 @@ typedef struct{
 }LIBLTE_MME_AUTHENTICATION_RESPONSE_MSG_STRUCT;
 // Functions
 LIBLTE_ERROR_ENUM liblte_mme_pack_authentication_response_msg(LIBLTE_MME_AUTHENTICATION_RESPONSE_MSG_STRUCT *auth_resp,
+                                                              uint8                                         sec_hdr_type,
+                                                              uint32                                        count,
                                                               LIBLTE_BYTE_MSG_STRUCT                        *msg);
 LIBLTE_ERROR_ENUM liblte_mme_unpack_authentication_response_msg(LIBLTE_BYTE_MSG_STRUCT                        *msg,
                                                                 LIBLTE_MME_AUTHENTICATION_RESPONSE_MSG_STRUCT *auth_resp);

lib/src/asn1/liblte_mme.cc

@@ -6180,6 +6180,8 @@ LIBLTE_ERROR_ENUM liblte_mme_unpack_authentication_request_msg(LIBLTE_BYTE_MSG_S
     Document Reference: 24.301 v10.2.0 Section 8.2.8
 *********************************************************************/
 LIBLTE_ERROR_ENUM liblte_mme_pack_authentication_response_msg(LIBLTE_MME_AUTHENTICATION_RESPONSE_MSG_STRUCT *auth_resp,
+                                                              uint8                                         sec_hdr_type,
+                                                              uint32                                        count,
                                                               LIBLTE_BYTE_MSG_STRUCT                        *msg)
 {
     LIBLTE_ERROR_ENUM  err     = LIBLTE_ERROR_INVALID_INPUTS;
@@ -6188,6 +6190,21 @@ LIBLTE_ERROR_ENUM liblte_mme_pack_authentication_response_msg(LIBLTE_MME_AUTHENT
     if(auth_resp != NULL &&
        msg       != NULL)
     {
+
+        if(LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS != sec_hdr_type)
+        {
+            // Protocol Discriminator and Security Header Type
+            *msg_ptr = (sec_hdr_type << 4) | (LIBLTE_MME_PD_EPS_MOBILITY_MANAGEMENT);
+            msg_ptr++;
+
+            // MAC will be filled in later
+            msg_ptr += 4;
+
+            // Sequence Number
+            *msg_ptr = count & 0xFF;
+            msg_ptr++;
+        }
+
         // Protocol Discriminator and Security Header Type
         *msg_ptr = (LIBLTE_MME_SECURITY_HDR_TYPE_PLAIN_NAS << 4) | (LIBLTE_MME_PD_EPS_MOBILITY_MANAGEMENT);
         msg_ptr++;

srsue/hdr/upper/nas.h

@@ -166,7 +166,7 @@ private:
   // Parsers
   void parse_attach_accept(uint32_t lcid, byte_buffer_t *pdu);
   void parse_attach_reject(uint32_t lcid, byte_buffer_t *pdu);
-  void parse_authentication_request(uint32_t lcid, byte_buffer_t *pdu);
+  void parse_authentication_request(uint32_t lcid, byte_buffer_t *pdu, const uint8_t sec_hdr_type);
   void parse_authentication_reject(uint32_t lcid, byte_buffer_t *pdu);
   void parse_identity_request(uint32_t lcid, byte_buffer_t *pdu);
   void parse_security_mode_command(uint32_t lcid, byte_buffer_t *pdu);
@@ -182,7 +182,7 @@ private:
   void send_identity_response();
   void send_service_request();
   void send_esm_information_response(const uint8 proc_transaction_id);
-  void send_authentication_response(const uint8_t* res, const size_t res_len);
+  void send_authentication_response(const uint8_t* res, const size_t res_len, const uint8_t sec_hdr_type);
   void send_authentication_failure(const uint8_t cause, const uint8_t* auth_fail_param);
   void gen_pdn_connectivity_request(LIBLTE_BYTE_MSG_STRUCT *msg);
   void send_security_mode_reject(uint8_t cause);

srsue/src/upper/nas.cc

@@ -331,7 +331,7 @@ void nas::write_pdu(uint32_t lcid, byte_buffer_t *pdu) {
       parse_attach_reject(lcid, pdu);
       break;
     case LIBLTE_MME_MSG_TYPE_AUTHENTICATION_REQUEST:
-      parse_authentication_request(lcid, pdu);
+      parse_authentication_request(lcid, pdu, sec_hdr_type);
       break;
     case LIBLTE_MME_MSG_TYPE_AUTHENTICATION_REJECT:
       parse_authentication_reject(lcid, pdu);
@@ -722,7 +722,7 @@ void nas::parse_attach_reject(uint32_t lcid, byte_buffer_t *pdu) {
   // FIXME: Command RRC to release?
 }
 
-void nas::parse_authentication_request(uint32_t lcid, byte_buffer_t *pdu) {
+void nas::parse_authentication_request(uint32_t lcid, byte_buffer_t *pdu, const uint8_t sec_hdr_type) {
   LIBLTE_MME_AUTHENTICATION_REQUEST_MSG_STRUCT auth_req;
   bzero(&auth_req, sizeof(LIBLTE_MME_AUTHENTICATION_REQUEST_MSG_STRUCT));
 
@@ -756,7 +756,7 @@ void nas::parse_authentication_request(uint32_t lcid, byte_buffer_t *pdu) {
 
   if (auth_result == AUTH_OK) {
     nas_log->info("Network authentication successful\n");
-    send_authentication_response(res, res_len);
+    send_authentication_response(res, res_len, sec_hdr_type);
     nas_log->info("Generated k_asme=%s\n", hex_to_string(ctxt.k_asme, 32).c_str());
   } else if (auth_result == AUTH_SYNCH_FAILURE) {
     nas_log->error("Network authentication synchronization failure.\n");
@@ -1129,9 +1129,9 @@ void nas::send_security_mode_reject(uint8_t cause) {
 }
 
 
-void nas::send_authentication_response(const uint8_t* res, const size_t res_len) {
+void nas::send_authentication_response(const uint8_t* res, const size_t res_len, const uint8_t sec_hdr_type) {
-  byte_buffer_t *msg = pool_allocate;
+  byte_buffer_t *pdu = pool_allocate;
-  if (!msg) {
+  if (!pdu) {
     nas_log->error("Fatal Error: Couldn't allocate PDU in send_authentication_response().\n");
     return;
   }
@@ -1143,13 +1143,24 @@ void nas::send_authentication_response(const uint8_t* res, const size_t res_len)
     auth_res.res[i] = res[i];
   }
   auth_res.res_len = res_len;
-  liblte_mme_pack_authentication_response_msg(&auth_res, (LIBLTE_BYTE_MSG_STRUCT *)msg);
+  liblte_mme_pack_authentication_response_msg(&auth_res, sec_hdr_type, ctxt.tx_count, (LIBLTE_BYTE_MSG_STRUCT *)pdu);
 
   if(pcap != NULL) {
-    pcap->write_nas(msg->msg, msg->N_bytes);
+    pcap->write_nas(pdu->msg, pdu->N_bytes);
+  }
+
+  if (sec_hdr_type == LIBLTE_MME_SECURITY_HDR_TYPE_INTEGRITY_AND_CIPHERED && pdu->N_bytes > 5) {
+    cipher_encrypt(pdu);
+    integrity_generate(&k_nas_int[16],
+                       ctxt.tx_count,
+                       SECURITY_DIRECTION_UPLINK,
+                       &pdu->msg[5],
+                       pdu->N_bytes - 5,
+                       &pdu->msg[1]);
   }
+
   nas_log->info("Sending Authentication Response\n");
-  rrc->write_sdu(cfg.lcid, msg);
+  rrc->write_sdu(cfg.lcid, pdu);
 }