Can xorriso update the md5sum.txt file in an ISO to reflect modifications?

Question

I am using the following xorriso command from the Debian wiki to modify a Ubuntu ISO:

xorriso \
   -indev "$orig_iso" \
   -outdev "$new_iso" \
   \
   -map "$changed_isolinux" /isolinux \
   -rm /isolinux/f10.txt -- \
   \
   -boot_image any replay \
   \
   -compliance no_emul_toc \
   -padding included

Does xorriso provide a mechanism to generate a new /md5sum.txt file that reflects the modifications that were made to the image through -map and -rm? The man page contains the following section which I suspect may be what I am looking for:

make_md5 equips a data file with an MD5 sum of its content. Useful to upgrade the files in the loaded image to full MD5 coverage by the next commit with -md5 "on". E.g.: -find / -type f -not -has_md5 -exec make_md5 --

Adding the example shown to the command above does not appear to update the /md5sum.txt though.

In case xorriso does not provide this capability, then I guess I could copy the md5sum.txt out of the image and manually modify it.

Answer 1

thank you for flying xorriso.

Although xorriso's MD5 checksums use the same algorithm as Debian's and Ubuntu's, they are not stored in a file named /md5sum.txt but rather in a non-file array at the end of the ISO image. The specification is at https://dev.lovelyhq.com/libburnia/libisofs/raw/branch/master/doc/checksums.txt

You will have to extract the file /md5sum.txt and modify it so that it reflects the changes which you plan to make by the xorriso run. Then you put it back into the ISO filesystem during that run of xorriso.

Have a nice day :)

Thomas