1
"Generate Pseudorandom Numbers"
Auto Assembler Script
{ Author: ParkourPenguin
Date: 27 / 03 / 2016
This script generates a pseudorandom number between [lowerBound] and
[upperBound] (inclusive) every [interval] ms. Stored in myRandomNumber.
Please note that msvcrt.rand is only guaranteed to return a number from 0
to 32767.
}
[ENABLE]
alloc(newmem,2048)
label(asTimeGoesBy)
label(lowerBound)
label(upperBound)
//label(interval)
label(myRandomNumber)
//label(shouldExit)
label(begin)
label(check) //make sure the 4 random numbers are only generated once when this code is triggered 10 times
label(freeMemory)
label(getRandomNumber)
label(setCheckToZero)
registersymbol(lowerBound)
registersymbol(upperBound)
//registersymbol(interval)
registersymbol(myRandomNumber)
//registersymbol(shouldExit)
registersymbol(check)
createthread(newmem)
newmem:
cmp [check],0 //if [check] != 0, do not generate random numbers, only do the comparison
je getRandomNumber
jmp compare
getRandomNumber:
push eax //save EAX
call kernel32.GetTickCount
push eax //push EAX for "srand"
push ecx //save ECX
push esi //save ESI before adding value to the arry
xor esi,esi //use ESI to caculate the offset in the array
call msvcrt.srand
add esp,4
asTimeGoesBy:
call msvcrt.rand
xor edx,edx
mov ebx,[lowerBound]
mov ecx,[upperBound]
cmp ecx,ebx
cmovl ecx,ebx
inc ecx
sub ecx,ebx
idiv ecx
add edx,ebx
xor ecx,ecx //set ECX to 0 for the next random number
arrayRelated: //set an array and move random numbers into it
//push eax
mov eax,[myRandomNumber] //setting up the array? I learn from somewhere, which I forgot the source
begin:
mov [eax+esi*4],edx //move the value into the array. Is it *4 or *2? It's only one byte of value.
inc esi //increase the index
cmp esi,#4 //max size of array
jl asTimeGoesBy //get the next random number until there are 4 of them
inc [check] //increase [check] by 1, so no more random number.
jmp compare //Four random numbers have been generated, go to comparison
compare:
xor edx,edx // set EDX to 0
mov eax,[myRandomNumber]
xor esi,esi //set ESI to 0
mov edx,[eax+esi*4] //move the first value in the array into edx
cmp byte ptr [ebx+04],dl //compare the first value in the array with the ID of the tribes
je setGoldToZero //if the random number equals the ID of the tribe then make the modification
inc esi //increase the index of the array
mov edx,[eax+esi*4] //move the second value into edx
cmp byte ptr [ebx+04],dl //compare the second value in the array with the ID of the tribes
je setGoldToZero
inc esi //increase the index of the array
mov edx,[eax+esi*4] //move the third value into edx
cmp byte ptr [ebx+04],dl //compare it with the ID of the tribes
je setGoldToZero
inc esi //increase the index of the array
mov edx,[eax+esi*4] //move the fourth value into edx
cmp byte ptr [ebx+04],dl //compare it with the ID of the tribes
je setGoldToZero
jmp originalcode //if not equal, then goes to the original code
setGoldToZero:
mov [ebx+4C],0
mov esi,[esi]
cmp [check],10 //if the code has been executed 10 times, set [check] to 0.
je setCheckToZero
originalcode:
mov [ebx+4C],eax
mov esi,[esi]
cmp [check],10
je setCheckToZero
setCheckToZero:
mov [check],00
freeMemory:
pop eax
push 8000
push 0
push newmem
push eax
jmp kernel32.VirtualFree
db CC CC CC CC CC CC
exit:
jmp returnhere
lowerBound:
dd #10
upperBound:
dd #20
//interval:
//dd #1000
myRandomNumber: //creating an array
dd 0 0 0 0
shouldExit:
dd 0
check:
db 0
"San13_tc.exe"+11A138:
jmp newmem
returnhere:
[DISABLE]
dealloc(newmem)
"San13_tc.exe"+11A138:
mov [ebx+4C],eax
mov esi,[esi]
unregistersymbol(lowerBound)
unregistersymbol(upperBound)
//unregistersymbol(interval)
unregistersymbol(myRandomNumber)
//unregistersymbol(shouldExit)
unregistersymbol(check)
2
"Lower Bound"
1
4 Bytes
lowerBound
3
"Upper Bound"
1
4 Bytes
upperBound
4
"Update Interval"
4 Bytes
interval
5
"Pseudorandom Number"
1
4 Bytes
myRandomNumber