//---------------------------------------------------------------------------
unsigned int PPEngine::Encode(byte *dest, word type)
{
dword offsets[] = { 15, 14, 12, 9, 5, 0 };
dword hashData = Call16( serverMapSync, clientSync, clientAccId, type );
unsigned int packetLength = 0;
int iterations = 5;
// pad_2
for( int iter = 0; iter <= iterations; iter++) {
packetLength = (1 + inputKeys.GetSize()) * 4;
dword intCtr = 5;
byte *writePtr = pktBuffer + 4;
for( unsigned int pass = 0; pass < inputKeys.GetSize(); pass++ ) {
dword magic = ((intCtr * (dword)pass) + (hashData - offsets[iter])) % 0x27;
packetLength += magic;
intCtr += 3;
writePtr += (4 + magic);
*((dword*)writePtr - 1) = inputKeys[pass] + iter - 5;
}
}
pktBuffer[2] = (byte)packetLength;
*(word*)pktBuffer = (word)type;
// Reset input keys for next generation
inputKeys.Reset();
memcpy(dest, pktBuffer, packetLength);
return packetLength;
}
//---------------------------------------------------------------------------
void PPEngine::Decode(byte *src, unsigned int keys)
{
// Reset output keys
outputKeys.Reset();
dword hashData = Call16( serverMapSync, clientSync, clientAccId, *(word*)src );
dword intCtr = 5;
byte *readPtr = src + 4;
for( unsigned int pass = 0; pass < keys; pass++ ) {
dword magic = ((intCtr * (dword)pass) + hashData) % 0x27;
intCtr += 3;
readPtr += (4 + magic);
outputKeys.Add( *((dword*)readPtr - 1) );
}
}
VOID
Int32Call(IN PCALLBACK16 Context,
IN BYTE IntNumber)
{
/*
* TODO: This function has almost the same code as RunCallback16.
* Something that may be nice is to have a common interface to
* build the trampoline...
*/
PUCHAR TrampolineBase = (PUCHAR)FAR_POINTER(Context->TrampolineFarPtr);
PUCHAR Trampoline = TrampolineBase;
UCHAR OldTrampoline[INT16_TRAMPOLINE_SIZE];
DPRINT("Int32Call(0x%02X)\n", IntNumber);
ASSERT(Context->TrampolineSize == INT16_TRAMPOLINE_SIZE);
/* Save the old trampoline */
((PULONGLONG)&OldTrampoline)[0] = ((PULONGLONG)TrampolineBase)[0];
/* Build the generic entry-point for 16-bit calls */
if (IntNumber == 0x03)
{
/* We are redefining for INT 03h */
*Trampoline++ = 0xCC; // Call INT 03h
/** *Trampoline++ = 0x90; // nop **/
}
else
{
/* Normal interrupt */
*Trampoline++ = 0xCD; // Call INT XXh
*Trampoline++ = IntNumber;
}
UnSimulate16(Trampoline);
/* Perform the call */
Call16(HIWORD(Context->TrampolineFarPtr),
LOWORD(Context->TrampolineFarPtr));
/* Restore the old trampoline */
((PULONGLONG)TrampolineBase)[0] = ((PULONGLONG)&OldTrampoline)[0];
}
