Description of problem:
To read an image file off a burned optical disc, one needs to know the file size. If the image file is an ISO 9660-compliant ISO file, this can be determined from the Volume Space Size in the ISO header. However, some Fedora image files are not, and the size is larger than that indicated by the Volume Space Size, for example live images and some recent netinst images (and in the case of 16-Alpha.TC1, even the x86_64 DVD image) - see bug 585006. In fact, according to https://bugzilla.redhat.com/show_bug.cgi?id=585006#c89 , the padding may soon be arbitrary data and not simply zeroes, making it impossible to deduce.
The size of an image may be time-consuming or even impossible to find online (not all Fedora images are archived). Also, being able to do an external verification of a burned disc's checksum is important for the following reasons:
1) The disc's built-in mediacheck may either not exist (for example the F15 netinst images) or may not work (for example bug 692135).
2) If one gets a burned disc from someone else, to verify that the disc isn't evil they need to match the disc contents to the official checksum.
So I propose that for each "ISO" checksum line, adding a comment line giving the size in bytes, for example
# Fedora-16-Alpha.TC1-x86_64-DVD.iso: 3589275648 bytes
Another reason for considering this - not a matter of necessity, but still - one of the most common forms of download corruption is simple truncation, and when downloading with a browser (Firefox, at least) as opposed to something like wget, you can't see the target file's exact size in bytes.
Are you talking about sha256 sums in *-CHECKSUM lines? These are created by sha256sum called by pungi, not by isomd5sum. If I understand it correctly the primary purpose of md5sum implanted in DVDs is to check the integrity of actual physical medium (not of the iso image - for security purposes there is the sha256 sum)
I don't understand your question. I'm proposing that the content of the Fedora-*-*-CHECKSUM file be modified by inserting a comment containing the size for each ISO file, as shown in my example in comment 0, so for example instead of
# The image checksum(s) are generated with sha256sum.
the checksum file would be
# The image checksum(s) are generated with sha256sum.
# Fedora-16-Alpha-i386-DVD.iso: 3438059520 bytes
# Fedora-16-Alpha-i386-netinst.iso: 132194304 bytes
I don't know what software would be responsible for creating the extra comment lines (I originally assigned this bug to "distribution" and it was reassigned).
Pungi runs that for the traditional install media. It is ran by hand for the live images.
Patches welcome at this point.
I don't know Python, but it looks like the checksum lines are created by pungi-2.9/src/pypungi/__init__.py, line 978:
checkfile.write("%s *%s\n" % (checksum.replace('sha256:', ''), os.path.basename(path)))
So one could put one line before this to generate the byte size comment line. But since the checksum files are currently made by hand for live images, would it make sense to just use a little script run inside the ISO directory and call it for both install and live images, for example
echo \# The image checksum\(s\) are generated with sha256sum.
for i in *.iso ; do
echo \# "$i" : `stat -c %s "$i"` bytes
sha256sum -b "$i"
instead of doing it inside pungi? (Of course the script that calls this would have to redirect to the correct file name.)
This package has changed ownership in the Fedora Package Database. Reassigning to the new owner of this component.
This bug appears to have been reported against 'rawhide' during the Fedora 19 development cycle.
Changing version to '19'.
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pungi-4.1.13-1.fc25 has been submitted as an update to Fedora 25. https://bodhi.fedoraproject.org/updates/FEDORA-2017-803e6bacb4
pungi-4.1.13-1.fc25 has been pushed to the Fedora 25 testing repository. If problems still persist, please make note of it in this bug report.
See https://fedoraproject.org/wiki/QA:Updates_Testing for
instructions on how to install test updates.
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2017-803e6bacb4
pungi-4.1.13-1.fc25 has been pushed to the Fedora 25 stable repository. If problems still persist, please make note of it in this bug report.