csgo-2018-source/engine/checksum_engine.cpp
2021-07-24 21:11:47 -07:00

360 lines
8.2 KiB
C++

//========= Copyright © 1996-2005, Valve Corporation, All rights reserved. ============//
//
// Purpose: Engine specific CRC functions
//
//=============================================================================//
#include "checksum_engine.h"
#include "bspfile.h"
#include "filesystem.h"
#include "filesystem_engine.h"
// memdbgon must be the last include file in a .cpp file!!!
#include "tier0/memdbgon.h"
//-----------------------------------------------------------------------------
// Purpose: For proxy protecting
// Turns the passed data into a
// single byte block CRC based on current network sequence number.
// Input : *base -
// length -
// sequence -
// Output : byte COM_BlockSequenceCRCByte
//-----------------------------------------------------------------------------
byte COM_BlockSequenceCRCByte( byte *base, int length, int sequence )
{
CRC32_t crc;
byte *p;
byte chkb[60 + 4];
if (sequence < 0)
{
Sys_Error("sequence < 0, in COM_BlockSequenceCRCByte\n");
}
CRC32_t entry;
entry = CRC32_GetTableEntry( ( sequence + 1 ) % ( 256 * sizeof(CRC32_t) - 4 ) );
p = (byte *)&entry;
// Use up to the first 60 bytes of data and a 4 byte value from the
// CRC lookup table (divided into the sequence)
if (length > 60)
{
length = 60;
}
memcpy (chkb, base, length);
chkb[length+0] = p[0];
chkb[length+1] = p[1];
chkb[length+2] = p[2];
chkb[length+3] = p[3];
length += 4;
// Compute a crc based on the buffer.
CRC32_Init(&crc);
CRC32_ProcessBuffer(&crc, chkb, length);
CRC32_Final(&crc);
// Chop down to byte size
return (byte)(crc & 0xFF);
}
#if defined(_X360)
const int CRC_BUFSIZE = 16384;
#else
const int CRC_BUFSIZE = 65536;
#endif
// YWB: 5/18
/*
===================
bool CRC_File(unsigned short *crcvalue, char *pszFileName)
Computes CRC for given file. If there is an error opening/reading the file, returns false,
otherwise returns true and sets the crc value passed to it. The value should be initialized
with CRC_Init
==================
*/
bool CRC_File(CRC32_t *crcvalue, const char *pszFileName)
{
// Always re-init the CRC buffer
CRC32_Init( crcvalue );
FileHandle_t fp;
byte chunk[CRC_BUFSIZE];
int nBytesRead;
int nSize;
nSize = COM_OpenFile(pszFileName, &fp);
if ( !fp || ( nSize == -1 ) )
return FALSE;
// Now read in chunks
while (nSize > 0)
{
if (nSize > sizeof(chunk))
nBytesRead = g_pFileSystem->Read(chunk, sizeof(chunk), fp);
else
nBytesRead = g_pFileSystem->Read(chunk, nSize, fp);
// If any data was received, CRC it.
if (nBytesRead > 0)
{
nSize -= nBytesRead;
CRC32_ProcessBuffer(crcvalue, chunk, nBytesRead);
}
// We we are end of file, break loop and return
if ( g_pFileSystem->EndOfFile( fp ) )
{
g_pFileSystem->Close( fp );
fp = 0;
break;
}
// If there was a disk error, indicate failure.
else if ( !g_pFileSystem->IsOk(fp) )
{
if ( fp )
g_pFileSystem->Close(fp);
return FALSE;
}
}
if ( fp )
g_pFileSystem->Close(fp);
return TRUE;
}
static BSPHeader_t *g_pMapHeader = NULL;
int __cdecl LumpCompare( const void *pElem0, const void *pElem1 )
{
const int *pLump0 = (const int *)pElem0;
const int *pLump1 = (const int *)pElem1;
return g_pMapHeader->lumps[*pLump0].fileofs - g_pMapHeader->lumps[*pLump1].fileofs;
}
// YWB: 5/18
/*
===================
bool CRC_MapFile(unsigned short *crcvalue, char *pszFileName)
Computes CRC for given map file. If there is an error opening/reading the file, returns false,
otherwise returns true and sets the crc value passed to it. The value should be initialized
with CRC_Init
For map (.bsp) files, the entity lump is not included in the CRC.
//FIXME make this work
==================
*/
ConVar debug_map_crc( "debug_map_crc", "0", FCVAR_RELEASE, "Prints CRC for each map lump loaded" );
bool CRC_MapFile(CRC32_t *crcvalue, const char *pszFileName)
{
FileHandle_t fp;
byte chunk[CRC_BUFSIZE];
int nBytesRead;
BSPHeader_t header;
int nSize;
lump_t *curLump;
long startOfs;
nSize = COM_OpenFile(pszFileName, &fp);
if ( !fp || ( nSize == -1 ) )
return false;
startOfs = g_pFileSystem->Tell(fp);
// Don't CRC the header.
if (g_pFileSystem->Read(&header, sizeof(BSPHeader_t), fp) == 0)
{
ConMsg("Could not read BSP header for map [%s].\n", pszFileName);
g_pFileSystem->Close(fp);
return false;
}
if ( header.m_nVersion < MINBSPVERSION || header.m_nVersion > BSPVERSION )
{
g_pFileSystem->Close(fp);
ConMsg("Map [%s] has incorrect BSP version (%i should be %i).\n", pszFileName, header.m_nVersion, BSPVERSION);
return false;
}
if ( IsX360() )
{
// 360 bsp's store the pc checksum in the flags lump header
g_pFileSystem->Close(fp);
*crcvalue = header.lumps[LUMP_MAP_FLAGS].version;
return true;
}
static char gamedir[MAX_OSPATH];
Q_FileBase( com_gamedir, gamedir, sizeof( gamedir ) );
g_pMapHeader = &header;
int lumpList[HEADER_LUMPS];
for ( int i = 0; i < HEADER_LUMPS; i++ )
{
lumpList[i] = i;
}
qsort( lumpList, HEADER_LUMPS, sizeof(lumpList[0]), LumpCompare );
CRC32_t lumpCRC;
// CRC across all lumps except for the Entities lump
for (int i = 0; i < HEADER_LUMPS; i++)
{
int l = lumpList[i];
if (l == LUMP_ENTITIES)
continue;
CRC32_Init(&lumpCRC);
// INFESTED_DLL - Alien Swarm wants a more relaxed CRC check so each client can compile the map themselves
if ( !Q_stricmp( gamedir, "infested" ) )
{
if ( l == LUMP_LIGHTING ||
l == LUMP_DISPINFO ||
l == LUMP_GAME_LUMP ||
l == LUMP_PRIMITIVES ||
l == LUMP_LEAF_AMBIENT_INDEX_HDR ||
l == LUMP_LEAF_AMBIENT_INDEX ||
l == LUMP_LEAF_AMBIENT_LIGHTING_HDR ||
l == LUMP_LEAF_AMBIENT_LIGHTING ||
l == LUMP_PAKFILE ||
l == LUMP_PHYSCOLLIDE ||
l == LUMP_TEXINFO ||
l == LUMP_PHYSDISP )
continue;
}
curLump = &header.lumps[l];
nSize = curLump->filelen;
if ( nSize <= 0 )
continue;
g_pFileSystem->Seek( fp, startOfs + curLump->fileofs, FILESYSTEM_SEEK_HEAD );
// Now read chunks
while (nSize > 0)
{
if (nSize > sizeof(chunk))
nBytesRead = g_pFileSystem->Read(chunk, sizeof(chunk), fp);
else
nBytesRead = g_pFileSystem->Read(chunk, nSize, fp);
// If any data was received, CRC it.
if (nBytesRead > 0)
{
nSize -= nBytesRead;
CRC32_ProcessBuffer(crcvalue, chunk, nBytesRead);
if ( debug_map_crc.GetBool() )
{
CRC32_ProcessBuffer(&lumpCRC, chunk, nBytesRead);
}
}
// If there was a disk error, indicate failure.
if ( !g_pFileSystem->IsOk(fp) )
{
if ( fp )
g_pFileSystem->Close(fp);
return false;
}
}
if ( debug_map_crc.GetBool() )
{
Msg( "Lump %d crc %lu\n", l, lumpCRC );
}
}
if ( fp )
g_pFileSystem->Close(fp);
if ( debug_map_crc.GetBool() )
{
Msg( "Map file '%s' CRC = %lu\n", pszFileName, *crcvalue );
}
return true;
}
//-----------------------------------------------------------------------------
// Purpose:
// Input : digest[16] -
// *pszFileName -
// bSeed -
// seed[4] -
// Output : Returns true on success, false on failure.
//-----------------------------------------------------------------------------
bool MD5_Hash_File(unsigned char digest[16], char *pszFileName, bool bSeed /* = FALSE */, unsigned int seed[4] /* = NULL */)
{
FileHandle_t fp;
byte chunk[1024];
int nBytesRead;
MD5Context_t ctx;
int nSize;
nSize = COM_OpenFile( pszFileName, &fp );
if ( !fp || ( nSize == -1 ) )
return false;
memset(&ctx, 0, sizeof(MD5Context_t));
MD5Init(&ctx);
if (bSeed)
{
// Seed the hash with the seed value
MD5Update( &ctx, (const unsigned char *)&seed[0], 16 );
}
// Now read in 1K chunks
while (nSize > 0)
{
if (nSize > 1024)
nBytesRead = g_pFileSystem->Read(chunk, 1024, fp);
else
nBytesRead = g_pFileSystem->Read(chunk, nSize, fp);
// If any data was received, CRC it.
if (nBytesRead > 0)
{
nSize -= nBytesRead;
MD5Update(&ctx, chunk, nBytesRead);
}
// We we are end of file, break loop and return
if ( g_pFileSystem->EndOfFile( fp ) )
{
g_pFileSystem->Close( fp );
fp = NULL;
break;
}
// If there was a disk error, indicate failure.
else if ( !g_pFileSystem->IsOk(fp) )
{
if ( fp )
g_pFileSystem->Close(fp);
return FALSE;
}
}
if ( fp )
g_pFileSystem->Close(fp);
MD5Final(digest, &ctx);
return TRUE;
}