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In this demonstration,

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we're going to walk through how to create a password

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to protect the Grub 2 configurations.

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Now the Grub 2 is a bootloader.

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And of course the bootloader is what's used initially

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to get the operating system up and running.

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It locates all the necessary resources required

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for our systems to function properly.

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So we're going to walk through how to protect this

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Grub 2 boot loader by adding a password to it, okay?

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First we need to find the grub.cfg file, config file.

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Now the thing is, it depends on if you're using a UEFI

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or a BIOS firmware.

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I'm currently using a BIOS firmware,

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which is the older type.

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But if you're using UEFI,

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then your location of this grub,

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that CFG file is going to be in a different location.

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So if you're using the UEFI, which most people probably are,

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we going to look here.

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And this is going to be the location of your grub cfg file,

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but mine is going to be in a different location.

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If you're using a BIOS system,

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it's going to be in boot/grub2.

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So we're going to walk through the process

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of making a custom configuration file,

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that will modify the grub.config file.

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Okay, let's go ahead and look and see

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what this config file looks like.

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sudo, but my mine's in the boot folder, remember,

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grub2 grub.cfg.

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Okay, a lot of this is a script.

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And what's going to happen is,

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we're going to run a make feed command here shortly.

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It's going to combine all of our custom files

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to allow us to customize the menu

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and the grub 2, once we reboot.

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And we're going to show that a little bit later.

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So again, we're about to create a password file,

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under a custom file name,

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and we're going to put it under our grub.d folder

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under the etc directory,

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and then it's going to combine everything into this one file

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which is the .cfg that we're looking at now.

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Okay, so let's go ahead and make this password.

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Okay, so we see it created a hash for a password.

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And if you were wondering the pbkdf2

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that's a hashing function that's still currently used.

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it's similar to SHA-1, SHA-256 SHA-128

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all of those different type of hashing algorithms,

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but we're going to use this one for our grub 2 file,

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that's the preferred one.

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Okay, so now we're going to adjust this config file,

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and we're going to make sure

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that it requires the password, okay.

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So we're going to go ahead and modify that custom file

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we just created.

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use the vim editor,

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better remove this entire line right here,

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both three and the password as well.

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Then we're just going to edit this.

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We're going to put a little note here, pretty much,

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password for jkelly,

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and I'm going to set myself as a super user, okay.

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Okay, so once you finish,

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your screen should look something like this.

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Now we're going to make the configuration file

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and it's going to update the current one that we already have

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with all the information that's in that

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etc grub d folder,

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the o options are specifying which file we're going to look at.

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Okay, now so again, just remember I'm using bios,

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if you're using UEFI your location

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will be somewhere different,

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it should be boot efi then slash capital EFI

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and then probably centos,

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and then you're going to use the grub.cfg.

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Okay, so let's just reboot this really quick

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and just make sure that we're going to be prompted

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for a password when we try to get into the grub.

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All right, going to click the escape,

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so that'll stop the timer.

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We're going to do e for edit.

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And you see it prompts me for my password.

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Now be very careful with this password

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because if you mess up, there's no way to come back,

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it's not a redo type of situation.

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So, all right, now we're in here.

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Again, all we did was go through,

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and we figured out how to put restrictions

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by adding a password authentication, to access the grub 2

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to protect some of our valuable boot up instructions.

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That concludes this lesson,

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and I'll see you in the next one.