Some HP/Compaq laptops only show the hash if the F2 or F12 key has been pressed prior to entering an invalid password for the last time.ĭepending on the "format" of the number code/hash (e.g.
" 3hqgo3 jqw534 0qww294e", "enable master password" shifted one up/left on the keyboard). Either way, my scripts can be used to get valid passwords.Ī few vendors have implemented obfuscation measures to hide the hash from the end user - for instance, some FSI laptops require you to enter three special passwords for the hash to show up (e.g. Other vendors just derive the master password from the serial number. Some vendors resort to storing the password in plain text onto the FlashROM, and instead of printing out just a checksum, an encrypted version of the password is shown. This password is usually a sequence of numbers generated randomly. The bypass mechanisms of other vendors work by showing a number to the user from which a master password can be derived. From such a checksum (also called "hash"), valid passwords can be found by means of brute-forcing. The dramatic 'System Disabled' message is just scare tactics: when you remove all power from the laptop and reboot it, it will work just as before.
memory timings.įor most brands, this checksum is displayed after entering an invalid password for the third time: When a laptop is locked with password, a checksum of that password is stored to a so-called FlashROM - this is a chip on the mainboard of the device which also contains the BIOS code and other settings, e.g. A set of master password generators and hands-on instructions are given to disable BIOS passwords. Trivial mechanisms have been put in place by most vendors to bypass such passwords, rendering the protection void.
Synopsis: The mechanics of BIOS password locks present in current generation laptops are briefly outlined.
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