message: remove checksum check since it wastes CPU for no benefit
diff: @@ -1914,8 +1914,10 @@ bool ProcessMessages(CNode *pfrom)
  CDataStream &vRecv = msg.vRecv;
  - // Checksum
  - // For optimization a 0 checksum means no checksum calculated -- TCP already has one.
  +#if 0 // Do not waste my CPU calculating a checksum provided by an untrusted node
  + // TCP already has one that is sufficient for network errors. The checksum does not increase security since
  + // an attacker can always provide a bad message with a good checksum.
  + // This code is removed by comment so it is clear that it is a deliberate omission.
  if (hdr.nChecksum != 0)
  {
  uint256 hash = Hash(vRecv.begin(), vRecv.begin() + nMessageSize);
  @@ -1927,6 +1929,7 @@ bool ProcessMessages(CNode *pfrom)
  continue;
  }
  }
  +#endif
  // Process message
  bool fRet = false;
  