Services::WebGetCommon.cpp

/***
  Whenever in the Warframe API they perform an important POST action they send what they call an Signed POST
  Those task are from getting profile data, updating inventory, creating a clan, and many more...
  
  sSignSalt is an static char[64] variable.
  sSignSaltArray is an static char *[5] variable. It's statically initialized to:
  {
    "0DqsRt5PGQScH3W59Y7l4uzSBP5TkEa7sqmXwmYzdwQgxairOORGYaQTeYoH",
    "ndzkZyDRTNlrcs2XYhOpp2c2VzignWUpWAujHuyiGbZWIu5QanVr4MRDHYh1",
    "ODZG0DpTHhEOZe0g4dgtSBKJ4bbhQAZ13niCU5Gjsg4MQfSTldsc58407IaD",
    "bFch8Wl6gJdMMF319woJAU5ytRCBaMn8mxuoiStHNoCEOH3frP4zTeRPWRC3",
    "yMHqXkmONKrEzaGpjmANYzZwoFDLQKJCuth9PNEPpagIf4ZE9amDt6Em2IBn",
  }
  
  Util::Whirlpool is the crypto-utility class used by DE to create Whirlpool hashes.
  Util::BinaryTextConvert::Base64 is the utility function used by DE convert binary data to Base64.
***/

/***
  This function generates a signed payload used by certain Warframe HTTP API POST requests.
  @param uri POST Uri
  @param payload POST payload
  @return POST payload signed
  @note I don't know the actual name of this function. I called it this way
        as within the game code an exception is thrown from Services/WebGetCommon.cpp:106
        and one LUA API function which is called Engine.SignPost, calls this function.
  
  @note String class is just like regular std::string but implemented with their own allocators.
        For the purpose they have equal functionality, the only thing it would change is the way
        it reserves memory from the game heap.
  
  @note sSignSalt is 1 of 5 possible salts. Which salt it is used depends on the game status.
        Warframe game uses Services::WebGetCommon::SetSignSalt for that purpose
***/

String Services::WebGetCommon::SignPostData(const String &uri, String &payload)
{
  offset_t pos;
  String base64_hash;
  Util::Whirlpool hash;
  char time_buffer[0x40];
  const char *pSignSalt = GetSignSalt();
  String signed_payload = payload + '\n';
  
  sprintf_s(time_buffer, sizeof(time_buffer), "%u.", time(NULL))
  signed_payload += time_buffer;
  
  hash.Update(pSignSalt, strlen(pSignSalt))
  
  if((pos = uri.find("//")) == String::npos)
    throw Exception(__FILE__, __LINE__);

  if((pos = uri.find('/', pos + 2)) == String::npos)
    throw Exception(__FILE__, __LINE__);
    
  hash.Update(&uri.c_str()[pos], uri.length() - pos);
  hash.Update(signed_payload.c_str(), signed_payload.length());
  Util::BinaryTextConvert::Base64(&base64_hash, hash.GetDigest(), Util::Whirlpool::HASH_SIZE, 0);
  
  signed_payload+=base64_hash;
  return signed_payload;
}

/***
  This function returns the signing salt value
  @return Signing salt value
  @note If signing salt isn't initialized, then signing salt is set to its default value
***/
const char *Services::WebGetCommon::GetSignSalt()
{
  if(!*sSignSalt)
    Services::WebGetCommon::SetSignSalt(0);
    
  return sSignSalt;
}

void Services::WebGetCommon::SetSignSalt(uint32 id)
{
  if(id >= 5)
    throw Exception(__FILE__, __LINE__);
  
  strcpy_s(sSignSalt, sizeof(sSignSalt), sSignSaltArray[id]);
}