From 05510058871894b7ebfda50e51938740e61c6b99 Mon Sep 17 00:00:00 2001
From: Abtin Keshavarzian <abtink@google.com>
Date: Thu, 14 Nov 2024 15:02:37 -0800
Subject: [PATCH] [secure-transport] remove unused variables and methods
 (#10918)

This commit removes unused variables/methods from the `SecureTransport`
class. It also removes repeated code and implements other minor
enhancements.
---
 src/core/meshcop/secure_transport.cpp | 14 +++----------
 src/core/meshcop/secure_transport.hpp | 29 ++++++---------------------
 2 files changed, 9 insertions(+), 34 deletions(-)

diff --git a/src/core/meshcop/secure_transport.cpp b/src/core/meshcop/secure_transport.cpp
index ef0803d72..0910f32dd 100644
--- a/src/core/meshcop/secure_transport.cpp
+++ b/src/core/meshcop/secure_transport.cpp
@@ -88,7 +88,6 @@ SecureTransport::SecureTransport(Instance &aInstance, LinkSecurityMode aLayerTwo
     , mReceiveMessage(nullptr)
     , mSocket(aInstance, *this)
     , mMessageSubType(Message::kSubTypeNone)
-    , mMessageDefaultSubType(Message::kSubTypeNone)
 {
     ClearAllBytes(mPsk);
     ClearAllBytes(mSsl);
@@ -825,8 +824,7 @@ int SecureTransport::HandleMbedtlsTransmit(const unsigned char *aBuf, size_t aLe
 
     error = HandleSecureTransportSend(aBuf, static_cast<uint16_t>(aLength), mMessageSubType);
 
-    // Restore default sub type.
-    mMessageSubType = mMessageDefaultSubType;
+    mMessageSubType = Message::kSubTypeNone;
 
     switch (error)
     {
@@ -1190,8 +1188,8 @@ Error SecureTransport::HandleSecureTransportSend(const uint8_t   *aBuf,
                                                  uint16_t         aLength,
                                                  Message::SubType aMessageSubType)
 {
-    Error        error   = kErrorNone;
-    ot::Message *message = nullptr;
+    Error    error   = kErrorNone;
+    Message *message = nullptr;
 
     VerifyOrExit((message = mSocket.NewMessage()) != nullptr, error = kErrorNoBufs);
     message->SetSubType(aMessageSubType);
@@ -1199,12 +1197,6 @@ Error SecureTransport::HandleSecureTransportSend(const uint8_t   *aBuf,
 
     SuccessOrExit(error = message->AppendBytes(aBuf, aLength));
 
-    // Set message sub type in case Joiner Finalize Response is appended to the message.
-    if (aMessageSubType != Message::kSubTypeNone)
-    {
-        message->SetSubType(aMessageSubType);
-    }
-
     if (mTransportCallback.IsSet())
     {
         SuccessOrExit(error = mTransportCallback.Invoke(*message, mMessageInfo));
diff --git a/src/core/meshcop/secure_transport.hpp b/src/core/meshcop/secure_transport.hpp
index 035f2766a..207842de8 100644
--- a/src/core/meshcop/secure_transport.hpp
+++ b/src/core/meshcop/secure_transport.hpp
@@ -259,6 +259,7 @@ public:
     Error SetPsk(const uint8_t *aPsk, uint8_t aPskLength);
 
 #if OPENTHREAD_CONFIG_TLS_API_ENABLE
+
 #ifdef MBEDTLS_KEY_EXCHANGE_PSK_ENABLED
     /**
      * Sets the Pre-Shared Key (PSK) for sessions-identified by a PSK.
@@ -273,7 +274,6 @@ public:
      * @retval kErrorNone  Successfully set the PSK.
      */
     void SetPreSharedKey(const uint8_t *aPsk, uint16_t aPskLength, const uint8_t *aPskIdentity, uint16_t aPskIdLength);
-
 #endif
 
 #ifdef MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED
@@ -410,6 +410,7 @@ public:
      * @param[in]  aVerifyPeerCertificate  true, if the peer certificate should verify.
      */
     void SetSslAuthMode(bool aVerifyPeerCertificate) { mVerifyPeerCertificate = aVerifyPeerCertificate; }
+
 #endif // OPENTHREAD_CONFIG_TLS_API_ENABLE
 
 #ifdef MBEDTLS_SSL_SRV_C
@@ -435,21 +436,6 @@ public:
      */
     Error Send(Message &aMessage, uint16_t aLength);
 
-    /**
-     * Provides a received message to the SecureTransport object.
-     *
-     * @param[in]  aMessage  A reference to the message.
-     */
-    void Receive(Message &aMessage);
-
-    /**
-     * Sets the default message sub-type that will be used for all messages without defined
-     * sub-type.
-     *
-     * @param[in]  aMessageSubType  The default message sub-type.
-     */
-    void SetDefaultMessageSubType(Message::SubType aMessageSubType) { mMessageDefaultSubType = aMessageSubType; }
-
     /**
      * Returns the session's peer address.
      *
@@ -499,8 +485,7 @@ private:
         kUnspecifiedCipherSuite,
     };
 
-#if OPENTHREAD_CONFIG_TLS_API_ENABLE
-#ifdef MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED
+#if OPENTHREAD_CONFIG_TLS_API_ENABLE && defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
     struct EcdheEcdsaInfo : public Clearable<EcdheEcdsaInfo>
     {
         EcdheEcdsaInfo(void) { Clear(); }
@@ -519,7 +504,8 @@ private:
         mbedtls_pk_context mPrivateKey;
     };
 #endif
-#ifdef MBEDTLS_KEY_EXCHANGE_PSK_ENABLED
+
+#if OPENTHREAD_CONFIG_TLS_API_ENABLE && defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
     struct PskInfo : public Clearable<PskInfo>
     {
         PskInfo(void) { Clear(); }
@@ -531,7 +517,6 @@ private:
         uint16_t       mPreSharedKeyIdLength;
     };
 #endif
-#endif // OPENTHREAD_CONFIG_TLS_API_ENABLE
 
     bool IsStateClosed(void) const { return mState == kStateClosed; }
     bool IsStateOpen(void) const { return mState == kStateOpen; }
@@ -606,9 +591,9 @@ private:
     static void HandleTimer(Timer &aTimer);
     void        HandleTimer(void);
 
-    void  HandleReceive(const uint8_t *aBuf, uint16_t aLength);
     Error HandleSecureTransportSend(const uint8_t *aBuf, uint16_t aLength, Message::SubType aMessageSubType);
 
+    void Receive(Message &aMessage);
     void Process(void);
     void Disconnect(ConnectEvent aEvent);
 
@@ -678,10 +663,8 @@ private:
     TransportSocket  mSocket;
 
     Callback<TransportCallback> mTransportCallback;
-    void                       *mTransportContext;
 
     Message::SubType mMessageSubType;
-    Message::SubType mMessageDefaultSubType;
 
     ConnectEvent mConnectEvent;
 };