How To perform MD5 or SHA1 check?

    I often read in http://forums.linuxmint.com many answers to helper's questions -> did you perform a md5 checksum to be sure you downloaded true and not corrupted media, file etc.?
- Huh? Whoa...? What ? What is that...?  


    That's why I suppose this could be "a must", the basic reading for all newcomers, newbies, noobs or even for all who listen the first time about checksum, md5 or sha1

    I am sure - everyone, a silly noob or a geek (gurus do that, don't they? ) must do the check, as Fred has told such cool meaning (Fred's post in the forum):

    Never ever try to use an iso that you can't get the correct md5 sum to verify. If you do, you have no idea what you are exposing your computer and data to. If you are lucky, it just won't work right. If you aren't lucky.... well.... use your imagination.

    What is md5, sha1 and other hashings? Read here for more details.
Quickly - a quotation of Boo:

"If you go to the Mint Downloads page you will notice a row "MD5" under the release name. eg Cassandra.

so for the edition of mint you have go down to the MD5 row.
this MD5 value will look like a big mess of numbers and letters.
this is a unique value for the iso file used to check if the iso you downloaded is the same as the one on the site.
some cd/dvd burning software will calculate this value for an iso you want to burn. otherwise you need an md5sum application, it is part of all linux systems. if you are using windows google for a windows md5sum application and install it."

    If you are on window$ system and downloading from win environment, I will introduce you 2 applications/programs for window$ which can check md5, sha1 and some other hashes.

    App "WinMd5Sum" Portable - is really a portable, not installing into system.
After downloading the target file "winMd5SumPortable_1.0.1.55_Rev_3_English.paf.exe" which hash md5 is "7237b0ef4872489c583250499ed9b25e" (don't forget to check it ), just run it. It will look like it's installing, but don't be afraid, it's just an executable archive and it's just extracting main executable program + some additional files, like help files, source files (if would like to compile it by yourself ).

    Once to see is 10 times better than twice to speak about it Let's see the pictures.

    All win$ programs were tested in wine of the cool LinuxMINT 9 KDE + screens were made and edited in a very cool app -> Shutter 

Just click on your downloaded file, it starts to extract...

Then just choose the location where the portable content will be extracted.

    And that's all the magic. Program extracted, it can be copied even in your flash/usb disk and just run. Remember, it's .exe - win$ program...
    Ok, so click on extracted winMd5Sum.exe (extracted into "winMd5SumPortable" folder/directory)

    Just click at the right "3 dots button" when you will browse and select the file. Immediately, after selecting file, the md5 hash is calculated and visible in the "Md5 Sum" window. The last empty window is useful to paste (Ctrl + V) hash to be compared with the file calculated

    Let's see the example with this downloaded file - winMd5SumPortable_1.0.1.55_Rev_3_English.paf.exe Click on "Compare" to see the result.

    The last win program is CyoHash which must be installed but as far as I am told, the content of installed files in the folder can be also copied to other place and that .exe - CyoHash.exe just to run. I didn't tested it, only in wine on LinuxMINT 9 KDE

    The main difference between WinMd5Sum and CyoHash is - CyoHash supports more hashes: md5, sha1, sha1-base32 and crc32.

Classic install setup...


...followed selection of destination folder...


Setup's done. Just click on the installed exe - "CyoHash.exe"

    After selecting a file, we have to choose hash algorithm and then you have to click on OK button to commit the calculation.
    After this step, another result window appears with a choice "Validate" in the left bottom corner.

Check the option, paste your string to be compare both hashes...

    As an example was chosen TorChat - a cool app and Decentral Anonymous Instant Messenger which you can download for Linux as well as Window$. Yep, the referred hash on that page (as well as other hashes are visible just after your click on desired file download) is just SHA1, not md5 that's why you can find CyoHash helpful too.

    That's all as for Window$ apps review. If you know any other on-your-opinion interesting win hash app, let us know.
 

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    The above written how-to supposes that the LinuxMINT distros are downloaded from Window$ enviro and for Win$ users.
    The md5 hashes are mentioned on each LinuxMINT exact edition -> .iso file, which is in fact the content of the boot-able CD/DVD media, which must be burned - choosing from a burner app/sw menu: Open image or Burn image followed pointing to downloaded .iso file, not as a New project and adding the .iso file to that etc. Just remember - to select the slow burning speed. I always choose 4x.

    Of course, there are also CLI applications in Windows, not only GUI.
But let's say true - most of us know very well how much are win$iees lame to use any CLI magic and they're mostly - and the only like click here, click there aka GUI users, aren't they?

    Linux newbies have much more resources which way or app to choose when calculating almost whatever hash algorithm

    Let's start for Linux noobs with IMO the best GUI app -> GtkHash 

GtkHash supports really many hash algorithms
This app is easy, no need whatever to explain

    Another way how to calculate md5 hash in KDE or Dolphin is selecting md5 (only) function from the right button click on a file.

    It's possible this way perform md5sum also in Gnome (thanks Dawgdoc) and I suppose there are some native ways in other desktops too, how to calculate at least md5, so if anyone want to share, you're welcome.

    Finally, the quickest way how to calculate almost any hash algorithm is terminal or CLI magic
Just describing some examples and sources because skilled geeks and gurus know...
However, this how-to is just for the total beginners aka newbies-noobs


    All of you have coreutils (check your Synaptic Package Manager) in the repositories. When you look up them e.g. in Synaptic, you will see that coreutils include many interesting and helpful commands:

basename cat chgrp chmod chown chroot cksum comm cp csplit cut date dd df dir dircolors dirname du echo env expand expr factor false fmt fold groups head hostid id install join link ln logname ls md5sum mkdir mkfifo mknod mktemp mv nice nl nohup od paste pathchk pinky pr printenv printf ptx pwd readlink rm rmdir sha1sum seq shred sleep sort split stat stty sum sync tac tail tee test touch tr true tsort tty uname unexpand uniq unlink users vdir wc who whoami yes

The quickest and easiest way how to use md5sum or sha1sum in terminal:

md5sum file

Result in terminal is hash string. The hash string can be stored also in a text file:

md5sum file > txtfile.md5

where you have to specify file => concrete file and txtfile.md5 => file output (name) which will be created immediately.

Just play with CLI, you will see that even CLI can be fun too


For additional studying, some meaningful resources:

http://en.wikipedia.org/wiki/Md5sum
http://en.wikipedia.org/wiki/Sha1sum
http://linux.byexamples.com/archives/19 ... sum-how-to
http://www.howtoforge.com/useful_linux_commands


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