Thoughts on Reverse Engineering 8FC8 suffix logic..

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  • nix30101
    Member
    • Dec 2019
    • 20
    • United States

    #1

    Thoughts on Reverse Engineering 8FC8 suffix logic..

    Greetings i am in the process of reverse engineering the bios logic for the 8FC8 suffix so far I have found most of the bios functions related to the suffix from a bios dump and I have verified inputs and outputs to test with plus the chartable for the 8FC8 suffix.
  • black0hackers
    Badcaps Veteran
    • Jul 2020
    • 365
    • USA

    #2
    [QUOTE=nix30101;n3529696]Greetings i am in the process of reverse engineering the bios logic for the 8FC8 suffix so far I have found most of the bios functions related to the suffix from a bios dump and I have verified inputs and outputs to test with plus the chartable for the 8FC8 suffix.[/Q
    how good!

    Comment

    • kuiri
      Member
      • Jun 2024
      • 11
      • USA

      #3
      I just thought about it, and decided to give it a good 'ol google search... and comes along your post on the 3rd result lol
      Have you had any progress? I mean it shouldn't be impossible or if I could take a guess at least, something that has been done before.

      I found there's people on the fleabay selling you a master password for 75 dollars, and has over 180 combined sales so far... Also in the BIOS of all of these newer models the "Master Password Lockout" option still exists. Which means they have a master password.

      Just my 2 cents.

      Comment

      • LBTT1121
        Badcaps Veteran
        • Nov 2024
        • 455
        • Việt Nam

        #4
        Originally posted by kuiri
        I just thought about it, and decided to give it a good 'ol google search... and comes along your post on the 3rd result lol
        Have you had any progress? I mean it shouldn't be impossible or if I could take a guess at least, something that has been done before.

        I found there's people on the fleabay selling you a master password for 75 dollars, and has over 180 combined sales so far... Also in the BIOS of all of these newer models the "Master Password Lockout" option still exists. Which means they have a master password.

        Just my 2 cents.
        Search REX 8FC8 Done 100%

        Comment

        • nix30101
          Member
          • Dec 2019
          • 20
          • United States

          #5
          RE still in the works, but in the meantime, the next best thing is the updated Python script
          https://github.com/chromebreakerdev/DellBIOSTools.git based on REX 8FC8. You can download just the raw Python file "dell_bios_tools.pyw" if you prefer. It has the 8FC8 patcher tool and old Dell master password generator combined.

          Comment

          • kuiri
            Member
            • Jun 2024
            • 11
            • USA

            #6
            Originally posted by LBTT1121

            Search REX 8FC8 Done 100%
            I am aware of REX's patch, it works wonderfully; but I meant reverse engineer the master password... not modify the contents of the BIOS flash chip.

            Comment

            • nix30101
              Member
              • Dec 2019
              • 20
              • United States

              #7
              Originally posted by kuiri

              I am aware of REX's patch, it works wonderfully; but I meant reverse engineer the master password... not modify the contents of the BIOS flash chip.
              Yes, the master password algorithm is present on "8FC8" devices, just like in older BIOS versions.

              Comment

              • talhoid
                New Member
                • May 2025
                • 2
                • United States

                #8
                Originally posted by nix30101
                Greetings i am in the process of reverse engineering the bios logic for the 8FC8 suffix so far I have found most of the bios functions related to the suffix from a bios dump and I have verified inputs and outputs to test with plus the chartable for the 8FC8 suffix.
                which UEFI module are you looking in to find the logic? can you share the bios dump? the bios i've dumped from the update exe files only contain the logic for the E7A8 suffix.

                ive looked in SystemPwSmm and PasswordMgrDxe. they seem to be related.

                Comment

                • vidvansh
                  Member
                  • Mar 2025
                  • 19
                  • Australia

                  #9
                  I have seen there are some sellers on ebay which are charging 120 aud for the master password. I am also interested in learning and reverse engineering about it but i have no idea where to start from.

                  Comment

                  • nix30101
                    Member
                    • Dec 2019
                    • 20
                    • United States

                    #10
                    Originally posted by talhoid

                    which UEFI module are you looking in to find the logic? can you share the bios dump? the bios i've dumped from the update exe files only contain the logic for the E7A8 suffix.

                    ive looked in SystemPwSmm and PasswordMgrDxe. they seem to be related.
                    Using Ghidra, I've extracted the chartables for the 8FC8 suffix. The BIOS is the full BIOS 16M file, not the update. I've dump quite few 8FC8 bios's they all have the same functions in Ghidra, which point to functions used in 8FC8 logic. I've exhausted the static references and will be doing more work with live bios dumps via binwalk etc.

                    Comment

                    • nix30101
                      Member
                      • Dec 2019
                      • 20
                      • United States

                      #11
                      Originally posted by vidvansh
                      I have seen there are some sellers on ebay which are charging 120 aud for the master password. I am also interested in learning and reverse engineering about it but i have no idea where to start from.
                      That's nuts. Just use a BIOS programmer and the apps.

                      Comment

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