LoRaKey string to byte array conversion

testLoraKey.cpp

//============================================================================
// Name        : testLoraKey.cpp
// Author      : nid
//============================================================================

#include <iostream>
#include <cstring>
#include <stdlib.h>
#include <stdio.h>

using namespace std;

void convertStringToByteArray(unsigned char* byteBuffer, const char* str)
{
  unsigned int len = strlen(str);

  for (unsigned int i = 0; i < len; i+=2)
  {
    char substr[3];
    const char* strSel = &(str[i]);
    strncpy(substr, strSel, 2);
    substr[2] = '\0';
    byteBuffer[i/2] = static_cast<unsigned int>(strtol(substr, NULL, 16));
  }
}

void prettyPrintSessionKey(const char* sessionKeyName, const char* sessionKeyString)
{
  unsigned char byteBuffer[16];

  convertStringToByteArray(byteBuffer, sessionKeyString);

  printf("%s[%u] = {", sessionKeyName, sizeof(byteBuffer));
  for (unsigned int i = 0; i < sizeof(byteBuffer); i++)
  {
    if (i != 0)
    {
      printf(",");
    }
    printf("0x%02X", byteBuffer[i]);
  }
  printf("};\n");
}

int main()
{
  const char nwkSKeyStr[] = "0123123D234A12450132413241243155";
  // static const PROGMEM u1_t NWKSKEY[16] = {0x01,0x23,0x12,0x3D,0x23,0x4A,0x12,0x45,0x01,0x32,0x41,0x32,0x41,0x24,0x31,0x55};

  const char appSKeyStr[] = "0123123D234A12450132413241243156";
  // static const u1_t PROGMEM APPSKEY[16] = {0x01,0x23,0x12,0x3D,0x23,0x4A,0x12,0x45,0x01,0x32,0x41,0x32,0x41,0x24,0x31,0x56};

  const char devAddrStr[] = "26011BF3";
  unsigned int devAddr = static_cast<unsigned int>(strtol(devAddrStr, 0, 16));

  prettyPrintSessionKey("nwkSKey", nwkSKeyStr);
  prettyPrintSessionKey("appSKey", appSKeyStr);
  printf("devAddr = 0x%08X;\n", devAddr);

  return 0;
}