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Verify MD5 checksums for your entire CD

Posted: Sun Sep 11, 2005 3:47 pm
by jj
I ordered UBCD on CD (slow dial-up here), but I'm now skeptical about the source.
Would anyone be willing to provide an MD5 Checksum txt file for UBCD v3.3?

Or please explain how I can get the MD5 checksum value for the "ISO" (given for the downloads) off this CD.

An MD5 Checksum txt file for all files on this entire CD (or your download) can be generated via the below links.
With an easy comparison result showing any differences for individual files.
Anyone can do this for free.
Easy instructions & simple batch files found here:
http://mtz.t35.com/Checksum.html
Process uses the freeware named "FSUM" found here:
http://www.slavasoft.com/fsum/index.htm

Thanks

Verify MD5 checksums for your entire CD

Posted: Sun Sep 11, 2005 6:41 pm
by bldrdash
You can make an ISO from the CD using various utils then
check against the following:
[MD5 ] 3adcec845d446708e7c344187af2640c BASIC
[MD5 ] fa856de1804032f69d6ebd267d7c2a29 FULL

But, I'd be surprised if your own ISO extraction from a CD
came out with the same hash. In order for anyone to provide
a MD5 sum of the list of files on CD, you'll need to let us
know if your UBCD is the BASIC or FULL. (Full contains
Insert (F7))

That said, I'm not the best one to provide MD5 sums since
I rarely keep the original ISO, but if I don't see anyone
has provided this info for you in a few days, I'll download
it and let you know. Just post back what you're working with.

-- Charles

Re: Verify MD5 checksums for your entire CD

Posted: Mon Sep 12, 2005 4:03 am
by jj
Thanks bldrdash,

>>But, I'd be surprised if your own ISO extraction from a CD came out with the same hash.
Exactly. I'm guessing at a minimum it would have to have an exact name & date to match the MD5 values on the download page.

>>In order for anyone to provide a MD5 sum of the list of files on CD, you'll need to let us know if your UBCD is the BASIC or FULL.
v3.3 FULL

>>If... in a few days, I'll download it and let you know.
Thanks for being willing to help.

Hopefully others will find those links useful for identifying individual file differences.

Verify MD5 checksums for your entire CD

Posted: Tue Sep 13, 2005 7:42 am
by bldrdash
OK, I have edited this post since you are correct; looks like the list was
truncated. BTW, the method I used to create the MD5 sums is as follows:

(Note, I use Linux; it's easier for me to do stuff like this and I don't
need to burn or install special software, but here is a list of commands I ran)

## The following line verifies the MD5 of the iso I'm using:
palo:/data/bootcds/iso$ md5sum ubcd33-full.iso
fa856de1804032f69d6ebd267d7c2a29 ubcd33-full.iso

## The following line mounts the iso read-only to a directory
palo:/data/bootcds/iso$ mount -o loop ubcd33-full.iso /mnt/iso
palo:/data/bootcds/iso$ cd /mnt/iso

## Count the number of files (exclude directories)
palo:/mnt/iso$ find . -type f | wc -l
2602

## Generate MD5 sums for all files
palo:/mnt/iso$ find . -type f -print0 | xargs -0 md5sum > /tmp/ubcd33-full.md5

Looks like I'll have to find a way to get you the results.

Posted: Tue Sep 13, 2005 1:02 pm
by jj
Thanks for trying bldrdash,
But the MD5 Checksum txt file I get from my CD (from the procedure above) gets checksums for 2643 files.
This txt file is about 197KB and takes 2 to 3 minutes to generate.
The sums you provided above are of a slightly different format and are for 737 files.
Did your post get clipped?
Could I possibly get you to generate this text file and attach to a PM or to this site somewhere (if admin would permit)?
Admin are you there?

>>Note that a few files, like /boot.catalog may not show up on your CD due to being hidden...
That file shows up fine in my results (from the procedure above).

Thanks again.

Verify MD5 checksums for your entire CD

Posted: Wed Sep 14, 2005 5:42 am
by bldrdash
I've sent you a PM.

Posted: Wed Sep 14, 2005 9:55 am
by jj
Hey bldrdash,

Thanks for the info on the GNU CoreUtils package. Have to get what I've got working first before I install any more large packages.
I was able though, to convert from that Linux preferred format with my text editor and yes we have a match on 2602 files!
When I had both text wrapping and line numbering turned on, I ended up with 2643 lines / files – DOE!!

Thanks again.

Re: Verify MD5 checksums for your entire CD

Posted: Fri Sep 23, 2005 1:27 am
by Constance
jj wrote:I'm guessing at a minimum it would have to have an exact name & date to match the MD5 values on the download page.
Of course not.
Only the file contents matters, its properties in the file system where it's stored have absolutely no importance to check whether to files are the same or not, so they are not taken into consideration in the md5, crc etc... that would be a problem whenever you have to check the md5 of a file downloaded from a site, as your system gives it the current date at download time ^^

Posted: Fri Sep 23, 2005 8:33 am
by jj
Hey Constance,
Good to know. Any advise on generating an ISO from the CD contents? Which utility to use?
Nero 5.5 has several options under the ISO tab. Any idea which were used to make that downloadable ISO?
Thanks

Posted: Fri Sep 23, 2005 9:42 am
by Constance
Well i made a few attempts to generate an iso from burnt CD with IsoBuster but the file is always like 20 MB larger than the original, so of course it's not the same and md5 will be different :(

I think the program used to generate the original ISO is mkisofs as it is named on this page... but it doesn't seem to be made to recreate an ISO from an already burnt CD :/

Posted: Wed Sep 28, 2005 4:58 am
by jj
Thanks for trying Constance.
I tried using Nero's Copy function to create an ISO.
Got the same #MB, but no sum match.

Have made many, many attempts to replicate the mkisofs process on the customize page.
Ended up starting this new thread:
viewtopic.php?t=269

Hopefully someone can shed some light on this.

Posted: Wed Sep 28, 2005 9:24 am
by bldrdash
JJ:

I thought you had verified the MD5 sums via the file I provided you? Is
this still and outstanding issue or are you attempting to generate the ISO
and compare the MD5 from that?

If that's the case, it will never work. In fact, depending upon the util
used, generating an ISO on the same machine, with the same options
and content will many times end up generating ISOs with two different
checksums. This is completely normal and does not effect the integrity of
the files WITHIN the iso.

Posted: Wed Sep 28, 2005 3:45 pm
by jj
>>or are you attempting to generate the ISO and compare the MD5 from that?
Yes, to both be able to verify via the publicly offered MD5 and to have a reliable standard ISO generation process.
That's why I thought it was worth starting a new thread.

>>on the same machine, with the same options and content
OK, I've actually just used the same mkisofs batch file & mkisofs.exe with the exact same source files (pathspec) and the exact same ISO target file.
And yes several attempts (with no changes) give a 186MB ISO with different MD5s every time.

Hopefully we can still find a reliable batch file to use with mkisofs (on a windows PC) via that other thread.

Thanks

Posted: Fri Sep 30, 2005 6:56 am
by jj
Can anyone explain why the ISOs generated by mkisofs, with the exact same source and having the exact same size (195,698,688 bytes), end up with different MD5s?
Also of interest is that Nero's "Copy CD" feature generates ISOs of 195,739,804 bytes (with the same source files off from a CD) and that all of these ISOs do have the same MD5s. Not trying to promote Nero -- just an interesting comparison with something that came with my CD-ROM burner.

Posted: Sat Oct 01, 2005 4:13 pm
by Constance
jj wrote:Can anyone explain why the ISOs generated by mkisofs, with the exact same source and having the exact same size (195,698,688 bytes), end up with different MD5s?
Maybe the files were not selected in the same order to be added to the file, or maybe the ISO file includes a "compilation date" ... which is different ^^