Added usim features for key derivation

lib/include/srslte/common/security.h

@@ -60,6 +60,10 @@ struct k_enb_context_t {
   uint32_t ncc;
 };
 
+struct k_gnb_context_t {
+  as_key_t sk_gnb;
+};
+
 struct as_security_config_t {
   as_key_t                    k_rrc_int;
   as_key_t                    k_rrc_enc;

lib/include/srslte/interfaces/ue_interfaces.h

@@ -280,6 +280,13 @@ public:
   virtual bool is_config_pending()                                               = 0;
 };
 
+class usim_interface_rrc_nr
+{
+public:
+  virtual void generate_nr_context(uint16_t sk_counter, srslte::as_security_config_t* sec_cfg) = 0;
+  virtual void update_nr_context(srslte::as_security_config_t* sec_cfg)                        = 0;
+};
+
 // PDCP interface for RLC
 class pdcp_interface_rlc
 {

srsue/hdr/stack/rrc/rrc_nr.h

@@ -55,6 +55,7 @@ public:
             pdcp_interface_rrc*         pdcp_,
             gw_interface_rrc*           gw_,
             rrc_eutra_interface_rrc_nr* rrc_eutra_,
+            usim_interface_rrc_nr*      usim_,
             srslte::timer_handler*      timers_,
             stack_interface_rrc*        stack_,
             const rrc_nr_args_t&        args_);
@@ -110,6 +111,7 @@ public:
                            uint32_t            sk_counter_r15,
                            bool                nr_radio_bearer_cfg1_r15_present,
                            asn1::dyn_octstring nr_radio_bearer_cfg1_r15);
+  void configure_sk_counter(uint16_t sk_counter);
   bool is_config_pending();
   // STACK interface
   void cell_search_completed(const rrc_interface_phy_lte::cell_search_ret_t& cs_ret, const phy_cell_t& found_cell);
@@ -131,6 +133,7 @@ private:
   pdcp_interface_rrc*         pdcp      = nullptr;
   gw_interface_rrc*           gw        = nullptr;
   rrc_eutra_interface_rrc_nr* rrc_eutra = nullptr;
+  usim_interface_rrc_nr*      usim      = nullptr;
   stack_interface_rrc*        stack     = nullptr;
 
   srslte::log_ref log_h;
@@ -185,6 +188,7 @@ private:
     srslte::proc_outcome_t init(const bool                              endc_release_and_add_r15,
                                 const asn1::rrc_nr::rrc_recfg_s&        rrc_recfg,
                                 const asn1::rrc_nr::cell_group_cfg_s&   cell_group_cfg,
+                                bool                                    sk_counter_r15_present,
                                 const uint32_t                          sk_counter_r15,
                                 const asn1::rrc_nr::radio_bearer_cfg_s& radio_bearer_cfg);
     srslte::proc_outcome_t step() { return srslte::proc_outcome_t::yield; }

srsue/hdr/stack/upper/usim_base.h

@@ -54,7 +54,7 @@ public:
   std::string reader;
 };
 
-class usim_base : public usim_interface_nas, public usim_interface_rrc
+class usim_base : public usim_interface_nas, public usim_interface_rrc, public usim_interface_rrc_nr
 {
 public:
   usim_base(srslte::log* log_);
@@ -92,6 +92,10 @@ public:
   void store_keys_before_ho(const srslte::as_security_config_t& as_ctx) final;
   void restore_keys_from_failed_ho(srslte::as_security_config_t* as_ctx) final;
 
+  // NR RRC interface
+  void generate_nr_context(uint16_t sk_counter, srslte::as_security_config_t* sec_cfg) final;
+  void update_nr_context(srslte::as_security_config_t* sec_cfg) final;
+
   // Helpers
   std::string         get_mcc_str(const uint8_t* imsi_vec);
   virtual std::string get_mnc_str(const uint8_t* imsi_vec, std::string mcc_str) = 0;
@@ -120,6 +124,7 @@ protected:
 
   // Current K_eNB context (K_eNB, NH and NCC)
   srslte::k_enb_context_t k_enb_ctx = {};
+  srslte::k_gnb_context_t k_gnb_ctx = {};
 
   // Helpers to restore security context if HO fails
   srslte::k_enb_context_t      old_k_enb_ctx = {};

srsue/src/stack/rrc/rrc_nr.cc

@@ -12,6 +12,7 @@
 
 #include "srsue/hdr/stack/rrc/rrc_nr.h"
 #include "srslte/common/security.h"
+#include "srsue/hdr/stack/upper/usim.h"
 
 #define Error(fmt, ...) rrc_ptr->log_h->error("Proc \"%s\" - " fmt, name(), ##__VA_ARGS__)
 #define Warning(fmt, ...) rrc_ptr->log_h->warning("Proc \"%s\" - " fmt, name(), ##__VA_ARGS__)
@@ -35,6 +36,7 @@ void rrc_nr::init(phy_interface_rrc_nr*       phy_,
                   pdcp_interface_rrc*         pdcp_,
                   gw_interface_rrc*           gw_,
                   rrc_eutra_interface_rrc_nr* rrc_eutra_,
+                  usim_interface_rrc_nr*      usim_,
                   srslte::timer_handler*      timers_,
                   stack_interface_rrc*        stack_,
                   const rrc_nr_args_t&        args_)
@@ -45,6 +47,7 @@ void rrc_nr::init(phy_interface_rrc_nr*       phy_,
   gw        = gw_;
   mac       = mac_;
   rrc_eutra = rrc_eutra_;
+  usim      = usim_;
   timers    = timers_;
   stack     = stack_;
   args      = args_;
@@ -368,8 +371,12 @@ bool rrc_nr::rrc_reconfiguration(bool                endc_release_and_add_r15,
   }
 
   log_rrc_message("RRC NR Reconfiguration", Rx, nr_radio_bearer_cfg1_r15, radio_bearer_cfg, "Radio Bearer Config R15");
-  if (not conn_recfg_proc.launch(
+  if (not conn_recfg_proc.launch(endc_release_and_add_r15,
-          endc_release_and_add_r15, rrc_recfg, cell_group_cfg, sk_counter_r15, radio_bearer_cfg)) {
+                                 rrc_recfg,
+                                 cell_group_cfg,
+                                 sk_counter_r15_present,
+                                 sk_counter_r15,
+                                 radio_bearer_cfg)) {
     log_h->error("Unable to launch NR RRC configuration procedure\n");
     return false;
   } else {
@@ -436,6 +443,11 @@ void rrc_nr::phy_set_cells_to_meas(uint32_t carrier_freq_r15)
   fake_measurement_timer.run();
 }
 
+void rrc_nr::configure_sk_counter(uint16_t sk_counter)
+{
+  log_h->info("[NR] Configure new SK counter %d. Update Key for secondary gnb\n", sk_counter);
+  usim->generate_nr_context(sk_counter, &sec_cfg);
+}
 bool rrc_nr::is_config_pending()
 {
   if (conn_recfg_proc.is_busy()) {
@@ -600,6 +612,14 @@ bool rrc_nr::apply_drb_add_mod(const drb_to_add_mod_s& drb_cfg)
 
 bool rrc_nr::apply_security_cfg(const security_cfg_s& security_cfg)
 {
+
+  // TODO derive correct keys
+  if (security_cfg.key_to_use_present) {
+    if (security_cfg.key_to_use.value != security_cfg_s::key_to_use_opts::options::secondary) {
+      log_h->warning("Only secondary key supported yet\n");
+    }
+  }
+
   if (security_cfg.security_algorithm_cfg_present) {
     switch (security_cfg.security_algorithm_cfg.ciphering_algorithm) {
       case ciphering_algorithm_e::nea0:
@@ -638,11 +658,8 @@ bool rrc_nr::apply_security_cfg(const security_cfg_s& security_cfg)
           break;
       }
     }
+    usim->update_nr_context(&sec_cfg);
   }
-  // TODO derive correct keys
-  if (security_cfg.key_to_use_present) {
-  }
-  // TODO derive correct keys
 
   // Apply security config for all known NR lcids
   for (auto& lcid : lcid_rb) {
@@ -677,6 +694,7 @@ rrc_nr::connection_reconf_no_ho_proc::connection_reconf_no_ho_proc(rrc_nr* paren
 proc_outcome_t rrc_nr::connection_reconf_no_ho_proc::init(const bool                       endc_release_and_add_r15,
                                                           const asn1::rrc_nr::rrc_recfg_s& rrc_recfg,
                                                           const asn1::rrc_nr::cell_group_cfg_s& cell_group_cfg,
+                                                          bool                                  sk_counter_r15_present,
                                                           const uint32_t                        sk_counter_r15,
                                                           const asn1::rrc_nr::radio_bearer_cfg_s& radio_bearer_cfg)
 {
@@ -687,6 +705,11 @@ proc_outcome_t rrc_nr::connection_reconf_no_ho_proc::init(const bool
     return proc_outcome_t::error;
   }
 
+  if (sk_counter_r15_present) {
+    Info("Applying Cell Group Cfg\n");
+    rrc_ptr->configure_sk_counter((uint16_t)sk_counter_r15);
+  }
+
   Info("Applying Radio Bearer Cfg\n");
   if (!rrc_ptr->apply_radio_bearer_cfg(radio_bearer_cfg)) {
     return proc_outcome_t::error;

srsue/src/stack/ue_stack_lte.cc

@@ -125,7 +125,8 @@ int ue_stack_lte::init(const stack_args_t& args_, srslte::logger* logger_)
 #ifdef HAVE_5GNR
   mac_nr_args_t mac_nr_args;
   mac_nr.init(mac_nr_args, nullptr, &rlc);
-  rrc_nr.init(nullptr, &mac_nr, &rlc, &pdcp, gw, &rrc, task_sched.get_timer_handler(), nullptr, args.rrc_nr);
+  rrc_nr.init(
+      nullptr, &mac_nr, &rlc, &pdcp, gw, &rrc, usim.get(), task_sched.get_timer_handler(), nullptr, args.rrc_nr);
   rrc.init(phy, &mac, &rlc, &pdcp, &nas, usim.get(), gw, &rrc_nr, args.rrc);
 #else
   rrc.init(phy, &mac, &rlc, &pdcp, &nas, usim.get(), gw, args.rrc);

srsue/src/stack/ue_stack_nr.cc

@@ -83,7 +83,8 @@ int ue_stack_nr::init(const stack_args_t& args_)
   rrc_args.log_hex_limit     = args.log.rrc_hex_limit;
   rrc_args.coreless.drb_lcid = 4;
   rrc_args.coreless.ip_addr  = "192.168.1.3";
-  rrc->init(phy, mac.get(), rlc.get(), pdcp.get(), gw, nullptr, task_sched.get_timer_handler(), this, rrc_args);
+  rrc->init(
+      phy, mac.get(), rlc.get(), pdcp.get(), gw, nullptr, nullptr, task_sched.get_timer_handler(), this, rrc_args);
   rrc->init_core_less();
   running = true;
   start(STACK_MAIN_THREAD_PRIO);

srsue/src/stack/upper/usim_base.cc

@@ -175,10 +175,10 @@ void usim_base::generate_as_keys(uint8_t* k_asme_, uint32_t count_ul, srslte::as
   k_enb_ctx.is_first_ncc = true;
 
   log->debug_hex(k_enb_ctx.k_enb.data(), 32, "Initial K_eNB");
-  log->debug_hex(sec_cfg->k_rrc_enc.data(), sec_cfg->k_rrc_enc.size(), "K_RRC_enc");
-  log->debug_hex(sec_cfg->k_rrc_enc.data(), sec_cfg->k_rrc_enc.size(), "K_RRC_enc");
-  log->debug_hex(sec_cfg->k_rrc_int.data(), sec_cfg->k_rrc_int.size(), "K_RRC_int");
   log->debug_hex(sec_cfg->k_rrc_int.data(), sec_cfg->k_rrc_int.size(), "K_RRC_int");
+  log->debug_hex(sec_cfg->k_rrc_enc.data(), sec_cfg->k_rrc_enc.size(), "K_RRC_enc");
+  log->debug_hex(sec_cfg->k_up_int.data(), sec_cfg->k_up_int.size(), "K_UP_int");
+  log->debug_hex(sec_cfg->k_up_enc.data(), sec_cfg->k_up_enc.size(), "K_UP_enc");
 }
 
 void usim_base::generate_as_keys_ho(uint32_t pci, uint32_t earfcn, int ncc, srslte::as_security_config_t* sec_cfg)
@@ -265,4 +265,48 @@ void usim_base::restore_keys_from_failed_ho(srslte::as_security_config_t* as_ctx
   return;
 }
 
+/*
+ *  NR RRC Interface
+ */
+
+void usim_base::generate_nr_context(uint16_t sk_counter, srslte::as_security_config_t* sec_cfg)
+{
+  if (!initiated) {
+    log->error("USIM not initiated!\n");
+    return;
+  }
+  log->info("Generating Keys. SCG Counter %d\n", sk_counter);
+
+  srslte::security_generate_sk_gnb(k_enb_ctx.k_enb.data(), k_gnb_ctx.sk_gnb.data(), sk_counter);
+  log->info_hex(k_gnb_ctx.sk_gnb.data(), 32, "k_sk_gnb");
+  update_nr_context(sec_cfg);
+}
+
+void usim_base::update_nr_context(srslte::as_security_config_t* sec_cfg)
+{
+  if (!initiated) {
+    log->error("USIM not initiated!\n");
+    return;
+  }
+  log->info_hex(k_gnb_ctx.sk_gnb.data(), 32, "k_sk_gnb");
+  // Generate K_rrc_enc and K_rrc_int
+  security_generate_k_nr_rrc(k_gnb_ctx.sk_gnb.data(),
+                             sec_cfg->cipher_algo,
+                             sec_cfg->integ_algo,
+                             sec_cfg->k_rrc_enc.data(),
+                             sec_cfg->k_rrc_int.data());
+
+  // Generate K_up_enc and K_up_int
+  security_generate_k_nr_up(k_gnb_ctx.sk_gnb.data(),
+                            sec_cfg->cipher_algo,
+                            sec_cfg->integ_algo,
+                            sec_cfg->k_up_enc.data(),
+                            sec_cfg->k_up_int.data());
+
+  log->debug_hex(sec_cfg->k_rrc_int.data(), sec_cfg->k_rrc_int.size(), "NR K_RRC_int");
+  log->debug_hex(sec_cfg->k_rrc_enc.data(), sec_cfg->k_rrc_enc.size(), "NR K_RRC_enc");
+  log->debug_hex(sec_cfg->k_up_int.data(), sec_cfg->k_up_int.size(), "NR K_UP_int");
+  log->debug_hex(sec_cfg->k_up_enc.data(), sec_cfg->k_up_enc.size(), "NR K_UP_enc");
+}
+
 } // namespace srsue