Hello and welcome to a new section in this new session.
We are going to learn how to write external key things as we have seen in the previous lessons.
There are two types of key events.
The first one is called self keychain and this is very partially software to display the hero key and
we have completed that one and the second way is to write an external key again.
This is the way we will write separate program to implement the algorithm that creates this hero key
and extend the key yens can be either come online based on this.
In this session I'm going to show you how to write an external keychain.
There is a workflow that you can use when creating an extended keychain.
Step one bash this target software to create a self key And first why do you need to patch this over
to create yourself first.
Because that is the easier way to create Keegan and you need to have a key again in order to study the
output that way based on the observation of the output of this key from this again you will get a better
understanding of how this hierarchy is being generated.
You can also use this occasion to test your estimate key again when doing the coding
second study the disassembly and you'll get minimal instructions.
This January this year key to this assembly here is referring to the ICC for debugging debugger which
is used to DBA the software that you are targeting.
So the step here involves locating the instructions that are actually generating these Hiroki and you
will find that there are many lines of code sometimes but you need to narrow it down to only those few
lines which are actually generating the important part of the zero key.
So that is what we mean by minimal
Number Three copy those instructions out using copy to plug in.
So a copy to us and plug in is a plug in that you need to install in the SCC for the energy in order
to allow you to select regions of the disassemble code to copy to a separate file
set for paste a copy instructions to the key template key chain template has been discussed in the previous
session and this template is a simple assembly code which you can use and modify in order to become
an hysteric again for the target software that you are trying to create a key gain for Step 5 modify
the instructions of the key template.
You need to modify the variable names he addresses and a few other things as well.
Step six run and compare the zero key media circuit against Syria key.
So this is where the circle jerk becomes useful.
So after you modify your key Jen template if to paste it could you into the test it.
And how would you know then this Iraqi unity is correct.
You can compare it against the circle against Hiroki if your s to you can produce the same 0 key as
yourself.
Again it means you have correctly retain your extended key in Step Seven repeat from step two or step
five until this key matches in this circle.
So this is a ITER Retief steps and you need to repeat a few times many times maybe until you get it
right your first trial most probably you get a lot of errors and maybe even wrong key and so you need
to repeat.
Sometimes you need to repeat from Step two maybe you copy the wrong part of the code and so you have
to go back to step two and analyze again and copy on different parts or sometimes your unit and go back
to step five.
Maybe your modification that you did was not optimal or maybe even wrong.
So you may need to repeat these steps many times until your standard kitchen produces a series key that
matches units safety against Syria key.
So once you've done that it means you successfully create an external kitchen so that's all for this
a workflow explanation in this lesson is that if our protocol on how to do the standard kitchen.
Thank you very much for watching.
See you then.