md5sum broken?

[Robert P. J. Day]

On Sat, 29 May 2010, Chuck Kuecker wrote:

> Hello,
>
> I am developing an embedded Linux project using Ubuntu 9.10 as a
> workstation. I need to produce an md5 checksum file of a patch I
> need to modify to make the build run. The command is:
>
> ckuecker at ckenterprises:/opt/Freescale/ltib$ md5sum
> /opt/freescale/pkgs/mtd-utils-20060302-cf-byteswap_h-1.patch >
> /opt/freescale/pkgs/mtd-utils-20060302-cf-byteswap_h-1.patch.md5
>
> Up until last week, this worked fine. Now, I get this error when I
> run my build script:
>
> Processing: mtd-utils
> =======================
> Error: corrupt md5 file:
> /opt/freescale/pkgs/mtd-utils-20060302-cf-byteswap_h-1.patch.md5,
> renamed to
> /opt/freescale/pkgs/mtd-utils-20060302-cf-byteswap_h-1.patch.md5.bad
>
> Ubuntu did an update since the last time I ran md5sum successfully.
> md5sum --v shows 7.4, and is dated in 2009.
>
> Anyone seen anything similar? I am wondering if the build script is
> accessing a different version of md5sum, and the Ubuntu version got
> updated. The build script has its' own paths, which I need to trace out.

  at the risk of giving bad advice, i'll finally try to give something
back to the list.  first, i find it unlikely that the md5sum algorithm
would have changed in any way.  the breakage that would cause would
make grown men weep.

  and second, i don't recognize the error message "corrupt md5 file".
where is that being generated?  the md5sum utility itself produces no
such diagnostic.  if you're running in check mode (md5sum -c) and the
sums don't match, you'll get:

$ md5sum -c passwd.md5
/etc/passwd: FAILED
md5sum: WARNING: 1 of 1 computed checksum did NOT match
$

and if your stored md5 file is just plain broken (literally
corrupted), you'll most likely get:

$ md5sum -c passwd.md5
md5sum: passwd.md5: no properly formatted MD5 checksum lines found
$

  so i'm assuming (unfairly?) that that "Error: corrupt md5 file"
diagnostic is being generated by your build system somewhere, yes?

  in any event, as i mentioned before, it should be trivially easy to
just look inside the .md5 file, make a note of the checksum, and
manually verify whether it's correct or not.

rday

p.s.  speculating wildly (as i am wont to do), i'm going to *guess*
that your build system is doing an MD5 check, the sums don't match for
one reason or another, and your build system is then producing that
diagnostic.  because nothing else seems to make sense.

-- 



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Robert P. J. Day                               Waterloo, Ontario, CANADA

            Linux Consulting, Training and Kernel Pedantry.

Web page:                                          http://crashcourse.ca
Twitter:                                       http://twitter.com/rpjday
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