Configurable sec algo preference list

srsenb/enb.conf.example

@@ -155,6 +155,8 @@ nof_ctrl_symbols = 3
 # enable_mbsfn:         Enable MBMS transmission in the eNB
 # m1u_multiaddr:        Multicast addres the M1-U socket will register to
 # m1u_if_addr:          Address of the inteferface the M1-U interface will listen for multicast packets.
+# eea_pref_list:        Ordered preference list for the selection of encryption algorithm (EEA) (default: EEA0, EEA2, EEA1). 
+# eia_pref_list:        Ordered preference list for the selection of integrity algorithm (EIA) (default: EIA2, EIA1, EIA0).
 #
 #####################################################################
 [expert]
@@ -172,3 +174,5 @@ nof_ctrl_symbols = 3
 #enable_mbsfn = false
 #m1u_multiaddr = 239.255.0.1
 #m1u_if_addr = 127.0.1.201 
+#eea_pref_list = EEA0, EEA2, EEA1
+#eia_pref_list = EIA2, EIA1, EIA0

srsenb/hdr/enb.h

@@ -47,6 +47,7 @@
 
 #include "srslte/radio/radio.h"
 
+#include "srslte/common/security.h"
 #include "srslte/common/bcd_helpers.h"
 #include "srslte/common/buffer_pool.h"
 #include "srslte/interfaces/ue_interfaces.h"
@@ -132,6 +133,8 @@ typedef struct {
   bool        print_buffer_state;
   std::string m1u_multiaddr;
   std::string m1u_if_addr;
+  std::string eia_pref_list;
+  std::string eea_pref_list;
 }expert_args_t;
 
 typedef struct { 

srsenb/hdr/upper/rrc.h

@@ -90,7 +90,11 @@ typedef struct {
   srslte_cell_t                      cell;
   bool                               enable_mbsfn;
   uint32_t                           inactivity_timeout_ms;
-}rrc_cfg_t; 
+  srslte::CIPHERING_ALGORITHM_ID_ENUM
+      eea_preference_list[srslte::CIPHERING_ALGORITHM_ID_N_ITEMS];
+  srslte::INTEGRITY_ALGORITHM_ID_ENUM
+      eia_preference_list[srslte::INTEGRITY_ALGORITHM_ID_N_ITEMS];
+} rrc_cfg_t;
 
 static const char rrc_state_text[RRC_STATE_N_ITEMS][100] = {"IDLE",
                                                             "WAIT FOR CON SETUP COMPLETE",

srsenb/src/enb.cc

@@ -179,6 +179,56 @@ bool enb::init(all_args_t *args_)
   rrc_cfg.inactivity_timeout_ms = args->expert.rrc_inactivity_timer;
   rrc_cfg.enable_mbsfn          = args->expert.enable_mbsfn;
 
+  // Parse EEA preference list
+  std::vector<std::string> eea_pref_list;
+  boost::split(eea_pref_list, args->expert.eea_pref_list,
+               boost::is_any_of(","));
+  int i = 0;
+  for (std::vector<std::string>::iterator it = eea_pref_list.begin();
+       it != eea_pref_list.end() && i < srslte::CIPHERING_ALGORITHM_ID_N_ITEMS;
+       it++) {
+    boost::trim_left(*it);
+    if ((*it).compare("EEA0") == 0) {
+      rrc_cfg.eea_preference_list[i] = srslte::CIPHERING_ALGORITHM_ID_EEA0;
+      i++;
+    } else if ((*it).compare("EEA1") == 0) {
+      rrc_cfg.eea_preference_list[i] = srslte::CIPHERING_ALGORITHM_ID_128_EEA1;
+      i++;
+    } else if ((*it).compare("EEA2") == 0) {
+      rrc_cfg.eea_preference_list[i] = srslte::CIPHERING_ALGORITHM_ID_128_EEA2;
+      i++;
+    } else {
+      fprintf(stderr, "Failed to parse EEA prefence list %s \n",
+              args->expert.eea_pref_list.c_str());
+      return false;
+    }
+  }
+
+  // Parse EIA preference list
+  std::vector<std::string> eia_pref_list;
+  boost::split(eia_pref_list, args->expert.eia_pref_list,
+               boost::is_any_of(","));
+  i = 0;
+  for (std::vector<std::string>::iterator it = eia_pref_list.begin();
+       it != eia_pref_list.end() && i < srslte::INTEGRITY_ALGORITHM_ID_N_ITEMS;
+       it++) {
+    boost::trim_left(*it);
+    if ((*it).compare("EIA0") == 0) {
+      rrc_cfg.eia_preference_list[i] = srslte::INTEGRITY_ALGORITHM_ID_EIA0;
+      i++;
+    } else if ((*it).compare("EIA1") == 0) {
+      rrc_cfg.eia_preference_list[i] = srslte::INTEGRITY_ALGORITHM_ID_128_EIA1;
+      i++;
+    } else if ((*it).compare("EIA2") == 0) {
+      rrc_cfg.eia_preference_list[i] = srslte::INTEGRITY_ALGORITHM_ID_128_EIA2;
+      i++;
+    } else {
+      fprintf(stderr, "Failed to parse EIA prefence list %s \n",
+              args->expert.eia_pref_list.c_str());
+      return false;
+    }
+  }
+
   // Copy cell struct to rrc and phy
   memcpy(&rrc_cfg.cell, &cell_cfg, sizeof(srslte_cell_t));
   memcpy(&phy_cfg.cell, &cell_cfg, sizeof(srslte_cell_t));

srsenb/src/main.cc

@@ -155,6 +155,8 @@ void parse_args(all_args_t *args, int argc, char* argv[]) {
     ("expert.print_buffer_state", bpo::value<bool>(&args->expert.print_buffer_state)->default_value(false), "Prints on the console the buffer state every 10 seconds")
     ("expert.m1u_multiaddr", bpo::value<string>(&args->expert.m1u_multiaddr)->default_value("239.255.0.1"), "M1-U Multicast address the eNB joins.")
     ("expert.m1u_if_addr", bpo::value<string>(&args->expert.m1u_if_addr)->default_value("127.0.1.201"), "IP address of the interface the eNB will listen for M1-U traffic.")
+    ("expert.eea_pref_list", bpo::value<string>(&args->expert.eea_pref_list)->default_value("EEA0, EEA2, EEA1"), "Ordered preference list for the selection of encryption algorithm (EEA) (default: EEA0, EEA2, EEA1).")
+    ("expert.eia_pref_list", bpo::value<string>(&args->expert.eia_pref_list)->default_value("EIA2, EIA1, EIA0"), "Ordered preference list for the selection of integrity algorithm (EIA) (default: EIA2, EIA1, EIA0).")
   ;
 
   // Positional options - config file location

srsenb/src/upper/rrc.cc

@@ -1214,7 +1214,7 @@ void rrc::ue::set_security_key(uint8_t* key, uint32_t length)
   // Selects security algorithms (cipher_algo and integ_algo) based on capabilities and config preferences 
   select_security_algorithms();
 
-  parent->rrc_log->info("Selected security algorithms EEA: EEA-%d EIA: EIA-%d\n", cipher_algo, integ_algo);
+  parent->rrc_log->info("Selected security algorithms EEA: EEA%d EIA: EIA%d\n", cipher_algo, integ_algo);
   
   // Generate K_rrc_enc and K_rrc_int
   srslte::security_generate_k_rrc(k_enb, cipher_algo, integ_algo, k_rrc_enc, k_rrc_int);
@@ -1903,26 +1903,14 @@ void rrc::ue::send_ue_cap_enquiry()
 
 /********************** HELPERS ***************************/
 
-bool rrc::ue::select_security_algorithms()
+bool rrc::ue::select_security_algorithms() {
-{
-  srslte::CIPHERING_ALGORITHM_ID_ENUM
-      enc_algo_preference[srslte::CIPHERING_ALGORITHM_ID_N_ITEMS] = {
-          srslte::CIPHERING_ALGORITHM_ID_128_EEA2,
-          srslte::CIPHERING_ALGORITHM_ID_128_EEA1,
-          srslte::CIPHERING_ALGORITHM_ID_EEA0};
-
-  srslte::INTEGRITY_ALGORITHM_ID_ENUM
-      intgrity_algo_preference[srslte::INTEGRITY_ALGORITHM_ID_N_ITEMS] = {
-          srslte::INTEGRITY_ALGORITHM_ID_128_EIA2,
-          srslte::INTEGRITY_ALGORITHM_ID_128_EIA1,
-          srslte::INTEGRITY_ALGORITHM_ID_EIA0};
-
   // Each position in the bitmap represents an encryption algorithm:
   // “all bits equal to 0” – UE supports no other algorithm than EEA0,
   // “first bit” – 128-EEA1,
   // “second bit” – 128-EEA2,
   // “third bit” – 128-EEA3,
-  // other bits reserved for future use. Value ‘1’ indicates support and value ‘0’ indicates no support of the algorithm.
+  // other bits reserved for future use. Value ‘1’ indicates support and value
+  // ‘0’ indicates no support of the algorithm.
   // Algorithms are defined in TS 33.401 [15].
   // Note: information missing
 
@@ -1931,7 +1919,7 @@ bool rrc::ue::select_security_algorithms()
   bool zero_vector = true;
   int i = 0;
   for (i = 0; i < srslte::CIPHERING_ALGORITHM_ID_N_ITEMS; i++) {
-    switch (enc_algo_preference[i]) {
+    switch (parent->cfg.eea_preference_list[i]) {
     case srslte::CIPHERING_ALGORITHM_ID_EEA0:
       // “all bits equal to 0” – UE supports no other algorithm than EEA0,
       zero_vector = true;
@@ -1974,7 +1962,7 @@ bool rrc::ue::select_security_algorithms()
   }
 
   for (i = 0; i < srslte::INTEGRITY_ALGORITHM_ID_N_ITEMS; i++) {
-    switch (intgrity_algo_preference[i]) {
+    switch (parent->cfg.eia_preference_list[i]) {
     case srslte::INTEGRITY_ALGORITHM_ID_EIA0:
       // “all bits equal to 0” – UE supports no other algorithm than EEA0,
       zero_vector = true;
@@ -2015,7 +2003,7 @@ bool rrc::ue::select_security_algorithms()
     }
   }
 
-  if(integ_algo_found == false || enc_algo_found == false){
+  if (integ_algo_found == false || enc_algo_found == false) {
     // TODO: if no security algorithm found abort radio connection and issue
     // cryption-and-or-integrity-protection-algorithms-not-supported message
     return false;