fix(mme): Replace insecure rand() with getrandom() for TMSI generation (

magma#15433) Signed-off-by: shashidhar-patil <[email protected]> Co-authored-by: panyogesh <[email protected]>
Mirantis · Jun 19, 2024 · 8792d18 · 8792d18
1 parent e8d204d
commit 8792d18
Showing 1 changed file with 8 additions and 2 deletions.
diff --git a/lte/gateway/c/core/oai/tasks/nas/api/mme/mme_api.cpp b/lte/gateway/c/core/oai/tasks/nas/api/mme/mme_api.cpp
@@ -39,6 +39,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <string.h>
+#include <sys/random.h>
 
 #ifdef __cplusplus
 extern "C" {
@@ -408,6 +409,11 @@ status_code_e mme_api_unsubscribe(bstring apn) {
 }
 
 static tmsi_t generate_random_TMSI() {
-  // note srand with seed is initialized at main
-  return (tmsi_t)rand();
+  tmsi_t tmsi = (tmsi_t)0;
+  if (getrandom(reinterpret_cast<void*>(&tmsi), sizeof(tmsi_t), 0) !=
+      sizeof(tmsi_t)) {
+    tmsi = static_cast<tmsi_t>(
+        rand());  // Fallback in case of fundamental system error
+  }
+  return tmsi;
 }