[Answered] Question regarding sha, md5 files etc..

Discussion in 'Chit Chat' started by Smokva, Jul 4, 2017.

  1. Smokva

    Smokva MDL Novice

    May 13, 2017
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    @admin Not quite sure where to post this as this is simply a general question that popped up during a download.
    I downloaded an image of Windows 7 and with it came 3 files with the same name as the image but with MD5, SHA and SFV extensions. What are they? Are they simply a byproduct of the download and can be safely deleted? Or are they files that contain the verification code? The codes themselves were shown at the download site so I was able to verify them, so I really don't understand the purpose of these files... and I have no clue how to open them to see if there is any content. Please note, I am familiar with both the purpose of hash values and the means of verifying them... I don't need any clarification there. I am simply confused about the purpose of these files with these extensions, and how to use them.

    And while I'm asking weird (and possibly stupid) questions that I don't know where to post.. is there any real difference between an .iso extension and a .iso Archive extension? I have a win 7 pro download with .iso, and a win 7 ultimate with a .iso Archive extension. I successfully burned both, but have not used the latter yet.
    Thanks for any clarification! I've spent the last hour fruitlessly searching for more info on these two items and am somewhat surprised that there isn't any info on it. Perhaps the answers are really obvious to everyone else in the world. But please... can someone just humour me?
     
  2. mxman2k

    mxman2k MDL Developer

    Jun 20, 2007
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    If the file downloaded's hash matches what was given on the website/download area where the file was shown then the extra (md5, sha, sfv) files can safely be deleted they are used just for verification that the file is the same as was uploaded and not tampered with.

    Regarding the .iso this is a standard 'archive' format much like a .zip, .rar etc its just a container of all the files that make up the cd/dvd image.

    There are variants of the .iso extension but they are used in programs such as UltraIso (.isz = compressed version), .bin, .img (CloneCD), .nrg (nero), .mdf/.mds (Alcohol).
     
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  3. Yen

    Yen Admin
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    May 6, 2007
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    #4 Yen, Jul 4, 2017
    Last edited: Jul 4, 2017
    MD5, SHA and SFV are there to get information about the integrity of an archive such as zip or rar or ISO.

    But only the latter (SFV, Simple File Verification Checksum, uses CRC32 algo) is a used file extension that contains a CRC32 checksum.

    MD5 and SHA are checksums themselves and actually no file extension. There are also firmware images which use for instance .tar.MD5 extension (a tarball with MD5 checksum included).

    I suppose the purpose of files with .MD5 and .SHA extension is to indicate that it's actually a .txt format that contains the corresponding sum.

    .SFV files can be used by flashSFV, though.

    Edit: You can try to open them with notepad, should be clear txt...
     
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  4. Smokva

    Smokva MDL Novice

    May 13, 2017
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    @LostED , @mxman2k , @Yen Thank you all for your input. I have actually successfully opened each with Notepad++, and they did indeed have their individual values in it. Which makes a lot of sense as I was surprised why there wasn't a text file included with the download to provide the values and had to go to the website to verify them with against my Hashmyfiles output. It was strange that Notepad did not work, but that is probably because my system has been wonky with a lot of programs... which of course is why I downloaded the file in the first place so I can reinstall. :)

    Never saw those files/extensions before, or the '.iso Archive' extension so really appreciate all of you taking the time to answer.
    Now if I could just figure out where the 'SOLVED' button is.....
     
  5. mxman2k

    mxman2k MDL Developer

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    #6 mxman2k, Jul 4, 2017
    Last edited: Jul 4, 2017
    on your first post at side there is 'Thread Tools' i think it called, hover pointer over that and click edit the title and put [Solved] at first part.:)

    Yeah NotePad++ opens a lot more files than we expect! Very useful.
     
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  6. Smokva

    Smokva MDL Novice

    May 13, 2017
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  7. Yen

    Yen Admin
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    Notepad++ is a far better editor than M$ notepad, should not have suggested to try it with that, lol. I presumed it's clear text, though. Notepad++ can also handle different end of line formats (CR/LF vs. LF)

    Well one can actually give the files any extension one wants. Like .yxz. I'd consider an extension as 'official' if there is at least one application associated to it.
    MD5 and SHA are sums originally. SFV isn't a sum it can be considered as 'official' extension.
     
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  8. Smokva

    Smokva MDL Novice

    May 13, 2017
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    @Yen

    You were not wrong.
    Each of those files can be opened with MS Notepad also.
    Being a somewhat anal research geek, I copied the folder to another computer and did in fact successfully open every one with MS Notepad.
    Like I said... I should have remembered that my new system (the one I am using) is acting very wonky - programs are not reliable.
    I wanted to clarify this as I couldn't find anything on the web that really addressed these basic questions, so perhaps it will help others. (And also... when one is not wrong, that should also be clarified. ;) )