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use original hook code which works better for this branch

This commit is contained in:
IntelOrca 2015-12-13 01:54:33 +00:00
parent 22857ae370
commit 4eee290947
1 changed files with 74 additions and 50 deletions
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124
src/hook.c
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@ -55,6 +55,73 @@ void hookfunc(int address, int newaddress, int stacksize, int registerargs[], in
int rargssize = numrargs * 4;
data[i++] = 0x50; // push eax
// move stack down for possible existing arguments
for (int j = 0; j < stacksize; j++) {
data[i++] = 0x8B; // mov eax, [esp+x]
data[i++] = 0x44;
data[i++] = 0xE4;
data[i++] = (signed char)((4 * (stacksize - j)) + 4);
data[i++] = 0x89; // mov [esp+x], eax
data[i++] = 0x44;
data[i++] = 0xE4;
data[i++] = (signed char)((4 * (stacksize - j)) - ((registerssaved + stacksize) * 4));
}
if (numrargs > 0) {
// push the registers to be on the stack to access as arguments
data[i++] = 0x83; // add esp, x
data[i++] = 0xC4;
data[i++] = -((registerssaved + stacksize) * 4) + 4;
for (signed int j = numrargs - 1; j >= 0; j--) {
switch (registerargs[j]) {
case EAX: data[i++] = 0x50; break;
case EBX: data[i++] = 0x53; break;
case ECX: data[i++] = 0x51; break;
case EDX: data[i++] = 0x52; break;
case ESI: data[i++] = 0x56; break;
case EDI: data[i++] = 0x57; break;
case EBP: data[i++] = 0x55; break;
}
}
data[i++] = 0x83; // add esp, x
data[i++] = 0xC4;
data[i++] = rargssize + ((registerssaved + stacksize) * 4) - 4;
}
data[i++] = 0xE8; // call
data[i++] = 0x00;
data[i++] = 0x00;
data[i++] = 0x00;
data[i++] = 0x00;
int sizec = i;
data[i++] = 0x8B; // push eax, [esp] - puts eip in eax
data[i++] = 0x04;
data[i++] = 0xE4;
data[i++] = 0x83; // add eax, x
data[i++] = 0xC0;
int sizeoffset = i;
data[i++] = 0; // set to returnlocation offset later
data[i++] = 0x89; // mov [esp-20h], eax - put return address on stack
data[i++] = 0x44;
data[i++] = 0xE4;
data[i++] = (signed char)(-(registerssaved * 4) - rargssize - (stacksize * 4)) + 4;
data[i++] = 0x83; // add esp, x
data[i++] = 0xC4;
data[i++] = 4;
data[i++] = 0x58; // pop eax
if (!(registersreturned & EAX)) {
data[i++] = 0x50; // push eax
}
@ -77,51 +144,15 @@ void hookfunc(int address, int newaddress, int stacksize, int registerargs[], in
data[i++] = 0x57; // push edi
}
data[i++] = 0x50; //push eax
data[i++] = 0x89; //mov eax, esp
data[i++] = 0xE0;
data[i++] = 0x83; //sub eax, (0xC + numargs*4) & 0xF
data[i++] = 0xE8;
data[i++] = (0xC + numrargs * 4) & 0xF;
data[i++] = 0x83; //and eax, 0xC
data[i++] = 0xE0;
data[i++] = 0x0C;
data[i++] = 0xA3; //mov [0x9ABDA8], eax
data[i++] = 0xA8;
data[i++] = 0xBD;
data[i++] = 0x9A;
data[i++] = 0x00;
data[i++] = 0x58; //pop eax
data[i++] = 0x2B; //sub esp, [0x9ABDA8]
data[i++] = 0x25;
data[i++] = 0xA8;
data[i++] = 0xBD;
data[i++] = 0x9A;
data[i++] = 0x00;
data[i++] = 0x83; // sub esp, x
data[i++] = 0xEC;
data[i++] = 4 + (stacksize * 4) + rargssize;
// work out distance to nearest 0xC
// (esp - numargs * 4) & 0xC
// move to align - 4
// save that amount
if (numrargs > 0) {
// push the registers to be on the stack to access as arguments
for (signed int j = numrargs - 1; j >= 0; j--) {
switch (registerargs[j]) {
case EAX: data[i++] = 0x50; break;
case EBX: data[i++] = 0x53; break;
case ECX: data[i++] = 0x51; break;
case EDX: data[i++] = 0x52; break;
case ESI: data[i++] = 0x56; break;
case EDI: data[i++] = 0x57; break;
case EBP: data[i++] = 0x55; break;
}
}
}
data[i++] = 0xE8; // call
data[i++] = 0xE9; // jmp
*((int *)&data[i]) = (newaddress - address - i - 4); i += 4;
data[sizeoffset] = i - sizec;
// returnlocation:
switch (eaxDestinationRegister) {
@ -170,13 +201,6 @@ void hookfunc(int address, int newaddress, int stacksize, int registerargs[], in
data[i++] = 0xEC;
data[i++] = (signed char)(stacksize * -4) - rargssize;
data[i++] = 0x03; //add esp, [0x9ABDA8]
data[i++] = 0x25;
data[i++] = 0xA8;
data[i++] = 0xBD;
data[i++] = 0x9A;
data[i++] = 0x00;
if (!(registersreturned & EDI)) {
data[i++] = 0x5F; // pop edi
}
@ -246,4 +270,4 @@ void addhook(int address, int newaddress, int stacksize, int registerargs[], int
void hook_setreturnregisters(registers *regs)
{
_returnRegisters = *regs;
}
}