Algorithm Tool

[JizzaBeez]

Algorithm Tool
version: 2.2.0.0
created by: JizzaBeez


How to use:

1) open a file (drag n drop, or open from menu).
2) there are 2 ways to use this tool:

1) Calculator
a) enter the [start] position/offset.
b) enter the [length], or check [select all].
c) click [calculate].

2) Brute Force
a) select the [type] from the ListView.
b) enter the [start] position/offset.
c) enter the known [value] (must be in HEX format).
d) check [retry?] if you want the [start] to advance +1 when it reaches the end of data and then start the search again.
e) select the [direction]. "forward" will increase bytes read from beginning to end and "reverse" will decrease bytes read from end to beginning.
f) click [start] to start searching. if needed, click [stop] to stop searching.
- the tool will search the data with the [type] beginning at the [start] until it reaches the end of the data or if the [length] is found. if the calculated data's sum/hash matches the [value] then it will message with the details of the calculation, if not then it will message "length not found".

Information:

[type]
- the known checksum/hash algorithm type. if unknown then select all to cycle through all available.

[value]
- the known checksum/hash value (must be in HEX format).

[start]
- the starting position/offset in the data to start calculating from.

[length]
- the length of data to calculate using the given algorithm type.

[retry?]
- when the scan reaches the end of the data it will advance the [start] +1 then restart the calculation (loop) until the end of the file.

[select all]
- selects the entire file to be calculated.

[direction]
- the direction in which to scan the file. "forward" will increase bytes read from beginning to end and "reverse" will decrease bytes read from end to beginning.

Direction Example:
[X] = Bytes Read.

Forward:
scan1 : [X]
scan2 : [X][X]
scan3 : [X][X][X]

Reverse:
scan1 : [X][X][X]
scan2 : [X][X]
scan3 : [X]

Requirements:

1) .net framework 3.5, or greater.
2) windows xp, or greater (not tested on os below xp).
3) 32bit os. may work on 64bit os.
*) Plugins.dll. This DLL is needed to run and should be included.

Updates:

1) 2.0.0.0
- completely recoded.
- new ui design/layout.

2) 2.1.0.0
- Required: "Plugins.dll" is a Plugin that holds the algorithms to use. "Plugins.dll" can be updated as needed.

Example of Plugins.dll:

The program uses System.Reflection to get the Classes and Methods from the DLL file, so as long as the DLL is built like below then the program can use it...

Namespace Algorithms



    Public Class Checksum32



        Public Function Compute(ByVal Bytes As Byte()) As Byte()

            Dim Value As UInteger = 0

            For Each b As Byte In Bytes

                Value = CUInt((Value + b) And &HFFFFFFFF)

            Next

            Dim OutBytes As Byte() = BitConverter.GetBytes(CUInt(Value))

            Array.Reverse(OutBytes)

            Return OutBytes

        End Function



    End Class



End Namespace

3) 2.2.0.0
- new design/ui (again)
- optimized code so it should scan faster now.
- included the "direction" feature for brute force.

Screenshots:

DOWNLOAD

[8Ball]

Looks like a nice piece of kit, any particular gamesaves you would recommend for someone looking to learn about detecting and repairing checksums to throw at this program?

[JizzaBeez]

Looks like a nice piece of kit, any particular gamesaves you would recommend for someone looking to learn about detecting and repairing checksums to throw at this program?

Yeah here's an easy one from After Burner Climax...

Info:
-The CRC32 checksum is at (0x8 - 0xB)
-The Length of the covered data is at (0xC - 0xF)
-The data covered is at (0x10 - Length/EOF)

[pureIso]

Yeah here's an easy one from After Burner Climax...

Info:
-The CRC32 checksum is at (0x8 - 0xB)
-The Length of the covered data is at (0xC - 0xF)
-The data covered is at (0x10 - Length/EOF)

What Algorithm Value should we be getting in the calculator? Just to know am doing it right!

Woops its ok :)

[JizzaBeez]

What Algorithm Value should we be getting in the calculator? Just to know am doing it right

On this gamesave...

Info:
-The CRC32 checksum is at (0x8 - 0xB)
-The Length of the covered data is at (0xC - 0xF)
-The data covered is at (0x10 - Length/EOF)

If Calculating:
-enter "16" as the "Calculation Start" (this is where the covered data starts at 0x10-length),
-enter "16868" as the "calculation length" (this is the length of data covered at 0xC-0xF),
-select the "CRC_32" type
-then press "calculate" ...
It should show you the checksum in the "algorithm value" box. That is the checksum on this gamesave. It is at (0x8 - 0xB).

If Brute Force:
-enter "16" as the "Calculation Start",
-select the type "CRC_32" (or "ALL"),
-enter the known checksum into "algorithm value",
-then press "start" ...
It should start searching the file, then if found show you the length of data covered in the 'calculated length" box. That is the length of covered data and on this gamesave is at (0xC - 0xF).

These exact values will not be the same for any other file just this gamesave. You have to experiment, trial and error, and sometimes just let this program run for a couple days hoping you find it... lol

The purpose/use of the brute force is - if you know the checksum value and where at but maybe not know the type or length that it covers. By brute forcing you can find these values.

[pureIso]

Hey is it possible for an update?
---------------------------------
When useing brute force - Would it be possible if you could implement algorythm selection.
Example:
Instead of brute forcing all, I want to brute force with all 32bits.
This would reduce brute forcing time.

[tinyharold]

what? Can someone explain this?

[Vincent Valentine]

A little confused on what this is, is it a calculator that calculates the offsets of the checksum and if you don't know what type it is you use brute force to find it?