Please Excuse My Lack of Understanding: Verifying ISO(SOLVED)

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Please Excuse My Lack of Understanding: Verifying ISO(SOLVED)

Post by Wentworth » Fri Oct 07, 2016 9:25 am

I've downloaded Mint 18 Cinammon 64bit. I tried to follow the ISO verification instructions but I've come a little stuck.

Here's what I've done so far:

Downloaded the ISO
Imported the Signing Key

I went to the links for the sha256sum.txt and the sha256sum.txt.gpg files which show these:

3fb60a7698f5d80e68526016da3e4455d8a19be6b1cb0eeb5b59dbdd8cf1ffb3 *linuxmint-18-cinnamon-32bit.iso
2238dca5b51f9e2674a7e31c46f19141fbdecff6e44c06ecbc9a7bb59b75a816 *linuxmint-18-cinnamon-64bit.iso
ff8bacc631e7955fc6b0f86c9014ce27aa455e3ee0913de0b2bc6c366b63c693 *linuxmint-18-kde-32bit.iso
87d834c13fb3e03a9c1111a9f3cec50a65c05d36247bfb6c36442c2d8a2b2484 *linuxmint-18-kde-64bit.iso
d064397cd185fa4a91fd6db4ff42f105c121a7607691797325323135713a8810 *linuxmint-18-mate-32bit.iso
c634f48b248489eef782067484a04978f046e9ccd507d9df35c798a1db9bef22 *linuxmint-18-mate-64bit.iso
9f3a4040181dcfbc027910ead361dbaf7cc3e90949ebeac0722c7e7d55fda837 *linuxmint-18-xfce-32bit.iso
2151852abb34bd62350fab807acc04b3f337d928c7c8092aebea7d0524587acf *linuxmint-18-xfce-64bit.iso

Version: GnuPG v1


The instructions say I should download the relevant file from the first output ie 2nd line ending a816 and also, I think, the whole of the second output.

This is the first time I think it's been recommended this way; it seemed easier for Mint 17. Could someone help by telling me how I download these two different values?

Many thanks
Last edited by Wentworth on Sat Oct 08, 2016 2:40 am, edited 2 times in total.

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Re: Please Excuse My Lack of Understanding: Verifying ISO

Post by austin.texas » Fri Oct 07, 2016 9:39 am

To verify the sha256sum for Mint 18 Cinnamon 64bit:
If the Mint 18 Cinnamon .iso is in your Downloads folder.
(You can substitute a different Mint 18 desktop .iso (other than Cinnamon 64bit), or a different download folder - but all files should be downloaded to one folder.)
Open a terminal and cd to your Downloads folder:

Code: Select all

cd ~/Downloads
Import the signing key:

Code: Select all

gpg --keyserver --recv-key "27DE B156 44C6 B3CF 3BD7 D291 300F 846B A25B AE09"
It should report that the signature is "Good". You can ignore any warning about "not certified".

Download the Mint 18 sha256 sum txt files:
(This is all one command on one line.)

Code: Select all

Verify the signiture on the two sha256 sum text files:

Code: Select all

gpg --verify sha256sum.txt.gpg sha256sum.txt
To compare the sha256 sum of your ISO image and the original Mint sha256 sum, enter:

Code: Select all

sha256sum -b linuxmint-18-cinnamon-64bit.iso && echo Compare the previous generated number with these: && cat sha256sum.txt
It will take a few seconds to do the computation.
Mint 18.2 Cinnamon, Quad core AMD A8-3870 with Radeon HD Graphics 6550D, 8GB DDR3, Ralink RT2561/RT61 802.11g PCI
Linux Linx 2018

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Re: Please Excuse My Lack of Understanding: Verifying ISO

Post by slipstick » Fri Oct 07, 2016 9:45 am

You want to download three files into the same folder:
1. the .iso file (which you have already done)
2. the sha256sum.txt file which has checksum values for all of the .iso files
3. the sha256sum.txt.gpg file which is the signature verification of the sha256sum.txt file

You will then use the signature file to verify the sha256sum.txt file - this verifies the checksums for all the different .iso files, even though you are only interested in one of these. You then compute the checksum of the .iso file which you have downloaded and compare it to the appropriate one in the sha256sum.txt file.

A better explanation is here:
(He first computes and compares the checksums, then uses the signature file to verify the sha256sum.txt file.)
In theory, theory and practice are the same. In practice, they ain't.

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Re: Please Excuse My Lack of Understanding: Verifying ISO

Post by phd21 » Fri Oct 07, 2016 11:00 am

Hi "Wentworth",

I just read your post and the good replies to it. Here are my thoughts on this as well.

Here is another link on "How to verify your Linux Mint iso file."

Hope this helps ...
Phd21: Mint KDE 18.3 & 19, 64-bit Awesome OS, Ancient Dell OptiPlex 780 Core2Duo E8400 3GHz,4gb Ram,256gb SDD, Video: Intel 4 Graphics, DVD Lightscribe. Why I use KDE?:

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Re: Please Excuse My Lack of Understanding: Verifying ISO

Post by Wentworth » Sat Oct 08, 2016 2:39 am

Many thanks to all, managed to get it sorted :)

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