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Welcome back.

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In this video, we show you how to analyze the binary, so you click on this to open the C1 binary and

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you show you the browser, go to the functions for the military and scroll down and never click on the.

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So now you can drink this anglicised so that we can have a better view and you can see from here that

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this is the mean signature for the main function of a C program.

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I mean, anywhere except to carry this oxy, and that would be me, just refresh your memory.

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Well, see program, this is how I mean, it looks like the first barometer he's oxy.

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Oxy means how many parameters are they?

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For example, if you were to run this program.

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You can click on the map here from the window, say, initially open.

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So when we run this program, they see one.

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There are two arguments.

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This one is for argument and parameter is the second argument.

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So access to that is the meaning of oxy.

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The second parameter is this string so that the EU contains a list of the arguments.

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So in this case, example here, the first argument is the name of the binary, which is Alvie zero

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and the second parameter name of the first parameter to the argument to the binary cell.

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So if you were to use these people just now, Hoxsey nanva.

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V0 will be see one Hungwe one would be tree to tree to tree.

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OK.

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So this is how it works.

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So over here, you can see that the signature is wrong.

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It's supposed to be like this, so we have to change it.

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Just click on this edit function signature and you can change the signature that actually.

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To see how you come.

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And for the second one, we will change it to.

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Char.

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Out the.

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So the two stars they missed and this is an array of strings to correspond to this, so these two are

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equal and you can use the square bracket in the in here.

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So we need to put to stock here.

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So a nice guy he didn't to clock and you can see now he's coming and going over here, so you notice

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some other changes that reflect this thing.

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Now, if I do this, you can do it by Control Z.

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You can also undo here and redo here.

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So before I rename the signature, he was like, this hardly makes no sense when I mean, he added the

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signature to become the correct means preventing each of these things make sense.

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So you can see here the program here is comparing where they are to arguments.

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Right, if there are two arguments, then you enter the loop, enter the block here in the first thing

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and you to get the length, get the length of the password.

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This is a password that it is looking for.

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So we know that it is linked.

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So we rename it correctly.

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We numerable to Shaherkani Elche.

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Maybe I can remember something.

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So now it's easier to read then today, once he's got the line, he's going to do a string and compare.

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Strong and compact, so if you don't know what this means, you can always refer to the Gitanes point,

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a search.

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String compay.

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And you can click on the first rizza and you can read all about it and compare compares to swing swing

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on a swing to get up to the number of characters.

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So if you specify three characters, you to compare three characters here.

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And here is an example.

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So in this case, you have to string a string when it's trying to string one is lowercase A, B, C,

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D, E, F, string two is a case.

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So when you call string and compare is comparing the first four characters, string one, extreme two.

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So it is comparing A, B, C, D from here with A, B, C, D from here and returning the result even

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to the two strings matches, he will return zero as a result.

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So zero means the strings are identical.

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If the streets are not the same, either return less than zero, I'll be gone in zero.

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So this is how Street and Compare works now applying this knowledge to and then it is the street and

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convey here is comparing the user input, how everyone feels that way and is comparing for the length.

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So the line of this person is provided by Swingline.

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So the line should be one, two, three, four, five, six, seven, eight, nine, nine to nine.

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So you regret the first nine character of your input.

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How P1 and comparing it to nine characters from Hecate.

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You if they're identical, then the result will be zero.

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So we know that is the result of the extreme compay we can reliably by clicking and we need.

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Maybe you can call it a.

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Should it be easier to read and if there is zero, there is a user that they cannot possibly and so

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you would be incorrect, that password.

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Was this the whole time?

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All right, this is a format specified in C language, so whenever you see percentages, he means that

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he will substitute this variable inside here and print the original parts of it in here.

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So let's try it out now so we know the password must be this.

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So let's go to our terminal, Insana.

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So now we're going into this massive Hecate you.

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Hey, uh, did you hit enter and he correct that was you this whole time, so this string is coming

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from here and.

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Yes, he's coming from here.

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So this percentage has seized the passport itself, which is how we won.

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We ended up here, so we won and we won.

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His argument to the binary how V0 is the name of the binary.

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So if you had two parameters, then the second argument would be at we to be zero.

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I'll be one.

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How we do this is how the second barometer works, right?

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So now we saw Quami One and this is basically the technical analysis, Hindiya.

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We will try to analyze the computer code and rename the labels until it makes sense.

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So in our view, it's almost like the original lead compact of the original C program itself and is

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much easier to read than the assembly version.

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And so that's all for this video.

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Before you close on C, on C, Sehar.

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OK, so when you close this in reopening in all you relabel items are still the.

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We have not lost it, so if you go back to the functions main and reopen me, you will see that the

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reading labels are intact.

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Right.

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So this one has you in the next one.

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Thank you for watching.