Remove need for additional tag data

Author: sh123

include/hal/radio_task.h

@@ -57,7 +57,7 @@ class RadioTask {
 
   static constexpr int CfgRadioTaskStack = 4096;        // task stack size
   static constexpr size_t CfgIvSize = 12;               // IV/nonce, initialization vector size
-  static constexpr size_t CfgAuthDataSize = 16;         // auth data size
+  static constexpr size_t CfgAuthTagSize = 16;          // auth tag size
 
 private:
   void setupRig(long freq, long bw, int sf, int cr, int pwr, int sync, int crcBytes);

include/settings/config.h

@@ -91,7 +91,6 @@ class Config {
   // privacy
   bool AudioEnPriv;     // enable/disable privacy
   byte AudioPrivacyKey_[32]; // privacy key
-  byte AudioPrivacyData_[16];  // privacy tag
 
   // battery monitor
   byte BatteryMonPin_;   // Battery monitor adc pin

include/settings/default_config.h

@@ -123,7 +123,4 @@
 #define CFG_AUDIO_PRIVACY_KEY \
 byte AudioPrivacyKey[32] = {0xe7,0x5c,0xf0,0x43,0x80,0xec,0x45,0x93,0xe8,0x3b,0xfb,0x72,0x22,0x40,0x19,0x57,\
                             0x6c,0xde,0x05,0x00,0xff,0x88,0x12,0x42,0x20,0xf2,0x89,0x9d,0x7f,0x57,0xee,0xd6}
-#define CFG_AUDIO_PRIVACY_DATA \
-byte AudioPrivacyData[16] = {0x00,0x9f,0x25,0x4d,0x3d,0xd1,0x70,0x0f,0xfa,0xea,0xbd,0xc2,0xe9,0x6c,0x1c,0x40}
-
 #endif // DEFAULT_CONFIG_H

src/hal/radio_task.cpp

@@ -176,7 +176,7 @@ void RadioTask::rigTask()
   rigTaskStartReceive();
 
   byte *packetBuf = new byte[CfgRadioPacketBufLen];
-  byte *tmpBuf = new byte[CfgRadioPacketBufLen + CfgIvSize + sizeof(config_->AudioPrivacyData_)];
+  byte *tmpBuf = new byte[CfgRadioPacketBufLen + CfgIvSize + CfgAuthTagSize];
 
   while (isRunning_) {
     uint32_t cmdBits = 0;
@@ -232,7 +232,7 @@ void RadioTask::rigTaskStartTransmit()
 void RadioTask::rigTaskReceive(byte *packetBuf, byte *tmpBuf) 
 {
   int packetSize = radioModule_->getPacketLength();
-  if (packetSize > CfgIvSize + CfgAuthDataSize && packetSize <= CfgRadioPacketBufLen) {
+  if (packetSize > CfgIvSize + CfgAuthTagSize && packetSize <= CfgRadioPacketBufLen) {
     // receive packet
     int state = radioModule_->readData(packetBuf, packetSize);
     bool isValidPacket = true;
@@ -307,31 +307,27 @@ void RadioTask::rigTaskTransmit(byte *packetBuf, byte *tmpBuf)
 void RadioTask::encryptPacket(byte *inBuf, byte *outBuf, int inBufSize, int& outBufSize) 
 {
   int curOutBufSize = inBufSize;
-  // add local auth data into the cipher
-  cipher_->addAuthData(config_->AudioPrivacyData_, CfgAuthDataSize);
   // generate iv and include it into payload head
   esp_fill_random(outBuf, CfgIvSize);
   cipher_->setIV(outBuf, CfgIvSize);
   // encrypt
   cipher_->encrypt(outBuf + CfgIvSize, inBuf, inBufSize);
   curOutBufSize += CfgIvSize;
   // generate auth tag and include it into payload tail
-  cipher_->computeTag(outBuf + curOutBufSize, CfgAuthDataSize);
-  curOutBufSize += CfgAuthDataSize;
+  cipher_->computeTag(outBuf + curOutBufSize, CfgAuthTagSize);
+  curOutBufSize += CfgAuthTagSize;
   outBufSize = curOutBufSize;
 }
 
 bool RadioTask::decryptPacket(byte *inBuf, byte *outBuf, int inBufSize, int& outBufSize) 
 {
-  int curOutBufSize = inBufSize - (CfgIvSize + CfgAuthDataSize);
-  // add local auth data into the cipher
-  cipher_->addAuthData(config_->AudioPrivacyData_, CfgAuthDataSize);
+  int curOutBufSize = inBufSize - (CfgIvSize + CfgAuthTagSize);
   // set iv from the packet and decrypt
   cipher_->setIV(inBuf, CfgIvSize);
   cipher_->decrypt(outBuf, inBuf + CfgIvSize, curOutBufSize);
   outBufSize = curOutBufSize;
   // check tag validity from the received packet
-  return cipher_->checkTag(inBuf + CfgIvSize + curOutBufSize, CfgAuthDataSize);
+  return cipher_->checkTag(inBuf + CfgIvSize + curOutBufSize, CfgAuthTagSize);
 }
 
 } // LoraDv

src/settings/config.cpp

@@ -5,7 +5,6 @@ namespace LoraDv {
 #define N(v) #v
 
 CFG_AUDIO_PRIVACY_KEY;
-CFG_AUDIO_PRIVACY_DATA;
 
 Config::Config()
 {
@@ -96,9 +95,8 @@ void Config::InitializeDefault()
   PmLightSleepDurationMs_ = CFG_PM_LSLEEP_DURATION_MS;
   PmLightSleepAwakeMs_ = CFG_PM_LSLEEP_AWAKE_MS;
 
-  // encryption key and auth tag data
+  // encryption key
   memcpy(AudioPrivacyKey_, AudioPrivacyKey, sizeof(AudioPrivacyKey));
-  memcpy(AudioPrivacyData_, AudioPrivacyData, sizeof(AudioPrivacyData));
 }
 
 void Config::Reset()