eqemu-server/common/crc16.cpp
Knightly 7ab909ee47 Standardize Licensing
- License was intended to be GPLv3 per earlier commit of GPLv3 LICENSE FILE
- This is confirmed by the inclusion of libraries that are incompatible with GPLv2
- This is also confirmed by KLS and the agreement of KLS's predecessors
- Added GPLv3 license headers to the compilable source files
- Removed Folly licensing in strings.h since the string functions do not match the Folly functions and are standard functions - this must have been left over from previous implementations
- Removed individual contributor license headers since the project has been under the "developer" mantle for many years
- Removed comments on files that were previously automatically generated since they've been manually modified multiple times and there are no automatic scripts referencing them (removed in 2023)
2026-04-01 17:09:57 -07:00

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C++

/* EQEmu: EQEmulator
Copyright (C) 2001-2026 EQEmu Development Team
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "crc16.h"
#include "common/crc32.h"
uint16 CRC16(const unsigned char *buf, int size, int key)
{
// This is computed as the lowest 16 bits of an Ethernet CRC32 checksum
// where the key is prepended to the data in little endian order.
uint8 keyBuf[] = {(uint8)((key >> 0) & 0xff),
(uint8)((key >> 8) & 0xff),
(uint8)((key >> 16) & 0xff),
(uint8)((key >> 24) & 0xff)};
uint32 crc = CRC32::Update(keyBuf, sizeof(uint32));
crc = CRC32::Update(buf, size, crc);
return CRC32::Finish(crc) & 0xffff;
}