From 456cdf30919bc014f13961764a8819a8d125f868 Mon Sep 17 00:00:00 2001
From: Abtin Keshavarzian <abtink@google.com>
Date: Wed, 27 May 2020 21:38:50 -0700
Subject: [PATCH] [mle] add constant kMleSecurityTagSize for MLE security tag
 size (#5015)

---
 src/core/thread/mle.cpp | 6 +++---
 src/core/thread/mle.hpp | 3 ++-
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/core/thread/mle.cpp b/src/core/thread/mle.cpp
index ec2269d7f..a5c3d9c6c 100644
--- a/src/core/thread/mle.cpp
+++ b/src/core/thread/mle.cpp
@@ -2520,7 +2520,7 @@ otError Mle::SendMessage(Message &aMessage, const Ip6::Address &aDestination)
     Header           header;
     uint32_t         keySequence;
     uint8_t          nonce[Crypto::AesCcm::kNonceSize];
-    uint8_t          tag[4];
+    uint8_t          tag[kMleSecurityTagSize];
     Crypto::AesCcm   aesCcm;
     uint8_t          buf[64];
     uint16_t         length;
@@ -2605,14 +2605,14 @@ void Mle::HandleUdpReceive(Message &aMessage, const Ip6::MessageInfo &aMessageIn
     uint32_t        keySequence;
     const Key *     mleKey;
     uint32_t        frameCounter;
-    uint8_t         messageTag[4];
+    uint8_t         messageTag[kMleSecurityTagSize];
     uint8_t         nonce[Crypto::AesCcm::kNonceSize];
     Mac::ExtAddress macAddr;
     Crypto::AesCcm  aesCcm;
     uint16_t        mleOffset;
     uint8_t         buf[64];
     uint16_t        length;
-    uint8_t         tag[4];
+    uint8_t         tag[kMleSecurityTagSize];
     uint8_t         command;
     Neighbor *      neighbor;
 
diff --git a/src/core/thread/mle.hpp b/src/core/thread/mle.hpp
index 98ea3387a..bf7860bfb 100644
--- a/src/core/thread/mle.hpp
+++ b/src/core/thread/mle.hpp
@@ -1650,7 +1650,8 @@ protected:
 private:
     enum
     {
-        kMleHopLimit = 255,
+        kMleHopLimit        = 255,
+        kMleSecurityTagSize = 4, // Security tag size in bytes.
 
         // Parameters related to "periodic parent search" feature (CONFIG_ENABLE_PERIODIC_PARENT_SEARCH).
         // All timer intervals are converted to milliseconds.