QuietUnrar/libunrar/encname.cpp

70 lines
1.6 KiB
C++

#include "rar.hpp"
EncodeFileName::EncodeFileName()
{
Flags=0;
FlagBits=0;
FlagsPos=0;
DestSize=0;
}
void EncodeFileName::Decode(char *Name,size_t NameSize,byte *EncName,size_t EncSize,
wchar *NameW,size_t MaxDecSize)
{
size_t EncPos=0,DecPos=0;
byte HighByte=EncPos<EncSize ? EncName[EncPos++] : 0;
while (EncPos<EncSize && DecPos<MaxDecSize)
{
if (FlagBits==0)
{
if (EncPos>=EncSize)
break;
Flags=EncName[EncPos++];
FlagBits=8;
}
switch(Flags>>6)
{
case 0:
if (EncPos>=EncSize)
break;
NameW[DecPos++]=EncName[EncPos++];
break;
case 1:
if (EncPos>=EncSize)
break;
NameW[DecPos++]=EncName[EncPos++]+(HighByte<<8);
break;
case 2:
if (EncPos+1>=EncSize)
break;
NameW[DecPos++]=EncName[EncPos]+(EncName[EncPos+1]<<8);
EncPos+=2;
break;
case 3:
{
if (EncPos>=EncSize)
break;
int Length=EncName[EncPos++];
if ((Length & 0x80)!=0)
{
if (EncPos>=EncSize)
break;
byte Correction=EncName[EncPos++];
for (Length=(Length&0x7f)+2;Length>0 && DecPos<MaxDecSize && DecPos<NameSize;Length--,DecPos++)
NameW[DecPos]=((Name[DecPos]+Correction)&0xff)+(HighByte<<8);
}
else
for (Length+=2;Length>0 && DecPos<MaxDecSize && DecPos<NameSize;Length--,DecPos++)
NameW[DecPos]=Name[DecPos];
}
break;
}
Flags<<=2;
FlagBits-=2;
}
NameW[DecPos<MaxDecSize ? DecPos:MaxDecSize-1]=0;
}