Unit_Key_RO.inf Disc Ids

Discussion in 'AnyDVD HD (Blu-ray issues)' started by Binnerup, Sep 9, 2019.

  1. Binnerup

    Binnerup Active Member

    Hi all,

    This is mainly for James, but I cannot send a direct message.

    We have at My Movies run into a situation where apparently identical Blu-ray and 4K Ultra HD discs are getting different disc ids.

    Our disc ids are based on a SHA-1 hash of the Unit_Key_RO.inf file, either in the AACS folder, or one of the SLY!, ANY!, !ANY, ect. directories.

    When investigating this, there is an alternative way of calculating disc ids of profiles, which we have in our service named as "AACS Id" - it is a reading of bytes in the Content000.cer file.

    Question is - is AnyDVD in any way altering the Unit_Key_RO.inf, which can cause these differences?

    We will for now try to add alternative ids to our profiles based on the Content000.cer file, but since our entire database is based on the SHA-1 of Unit_Key_RO.inf, I would like to try to determine why we are seeing these differences - any inputs?

    Best regards,

    Brian Binnerup
    My Movies
     
  2. James

    James Redfox Development Team Staff Member

    AnyDVD may alter pretty much anything in the renamed AACS directories. It reuses the sectors allocated for the files for its "magic file replacement(tm)" technology.
    So yes, it may (or may not) alter these files, depending on how many spare sectors are required.
     
  3. Pete

    Pete Forum Admin Staff Member

    Yes, that can happen.Whenever AnyDVD needs to modify the JAR files - especially whenever that causes them to grow, AnyDVD uses "unused" sectors on the disc.
    Files in the AACS directory are a nice pool for that.
    We can ensure, that certain files are spared (or maybe only used as a last resort).
     
  4. Binnerup

    Binnerup Active Member

    Ok, my understanding, and perhaps how it was some years ago? was that the files in the SLY!, !SLY, !ANY, ANY!, ect. folder was a copy of the original, unaltered.

    Knowing how things are working, is it a coincidence that the AACS ids based on the Content000.cer is unaltered, if it is AnyDVD altering the Unit_Key_RO.inf, or is it because some of these files are having a higher priority before it is altered in sort of the last resort thing?

    Back in the days when AnyDVD could not return the correct CRC64 disc id, we had a solution where the disc id was written into registry - is there any chance that you guys can help us work around this issue by writing the SHA-1 hash of the Unit_Key_RO.inf into registry or another place where we can read it?
     
  5. James

    James Redfox Development Team Staff Member

    How about the disc.inf on the disc? It is a good place, because the hash would still be known, if it is a copy.
     
  6. Binnerup

    Binnerup Active Member

    It could work, surely - but is this a file you can put anything in you would like, without it having to be altered in regards to the space?
     
  7. Binnerup

    Binnerup Active Member

    We already read the disc.inf for the "playlists=" information, so it would be easy for us to read disc id from this also.
     
  8. James

    James Redfox Development Team Staff Member

    It depends on how many spare sectors AnyDVD needs. Usually MKB_R0.inf is enough. If not, other files are used.
     
  9. Binnerup

    Binnerup Active Member

    Ok, makes sense - can you see how the Unit_Key_RO.inf priorities in this compared to the Content000.cer file?
     
  10. James

    James Redfox Development Team Staff Member

    Space for the file is allocated ... you guessed it ... from the "free pool", e.g. the renamed AACS directory. So yes, there should be enough space available.
     
  11. Binnerup

    Binnerup Active Member

    Oh - makes sense :)

    I think that if this is not a huge task for you, we should move forward with writing this info the disc.inf - it would help us quite a bit.
     
  12. James

    James Redfox Development Team Staff Member

    So, you need an SHA-1 hash of the original Unit_Key_RO.inf file in the AACS directory. Correct?
    If the file does not exist, nothing will be written (non AACS "on demand" discs for example, copies).
     
  13. Binnerup

    Binnerup Active Member

    Correct, and if possible, the binary content from the Content000.cer file, but it is not as important, as this is a secondary id for us.

    The on demand discs we do not have any sort of disc id for, for the same reason - any inputs on what would make a useful disc id for those?
     
  14. Binnerup

    Binnerup Active Member

    Overall, there are as I know it three different disc ids for Blu-rays used by different players in the market.

    The one we use with the Unit_Key_RO.inf, which was adopted by some of the early decryption discussion.

    Then there is the AACS Id based on the Content000.cer - I believe it is what Gracenote uses - we store them because we helped GD3 get them several years ago, because they had customers using them.

    Then DVD Profiler has a disc id that looks visually like a CRC-64 id, but how it is generated, I do not know. Do you by any chance?
     
  15. James

    James Redfox Development Team Staff Member

    Nah, this is too big IMHO for the .inf file.

    Not really. Maybe a hash over a specific part of the movie?
     
  16. Binnerup

    Binnerup Active Member

    The Unit_Key_RO.inf should be enough - perhaps putting the Unit_Key_RO.inf down in the priority line, and doing it also with Content000.cer could be fine.

    I am not sure what DVD Profiler does - it was also just if you knew, it could be ideal for them that whatever file also was put down in priority for altering. It is not important for us how they calculate it, although we perhaps would store it if we knew, to help users who wants to import from it.

    How quick can we get the SHA-1 hash of the Unit_Key_RO.inf file into disc.inf?
     
  17. Ch3vr0n

    Ch3vr0n Translator NL & Mod

    If james is up to the task, (not that i use mymovies) wouldn't surprise me to make it into the next beta :p
     
  18. James

    James Redfox Development Team Staff Member

    Why? You get the hash in the disc.inf file.

    Ask him. I would be curious, too.

    Please try this one:
    http://sandbox.redfox.bz/SetupAnyDVD8382.exe
    Let me know, if the hash is correct / what you expect it to be.
     
  19. James

    James Redfox Development Team Staff Member

    Oh, the hash will only be calculated for AACS protected BDROM. Not BDAV or HDDVD. :)
     
  20. Ch3vr0n

    Ch3vr0n Translator NL & Mod

    I knew it, already in the next beta! @James updated the sticky for you too. No need for a new one, you rock! (even if i don't use MyMovies)