firmware-password
I couldn't find an Apple doc stating Firmware Password complexity limitations, e.g. length and allowed special characters.
Does anyone know if Apple states this information somewhere?
I don't want to be in a situation where I try to enable a complex password to find out that for some reason I'm locked out and I need to turn to Apple.
To reset the firmware password it looks like you have to take it in for service at your nearest Apple Support location as noted in the following Apple Support Article MacBook Air (Late 2010) and later, MacBook Pro (Early 2011) and later, iMac (Mid 2011) and later, Mac mini (Mid 2011): Recovering a lost firmware password
Symptoms
Learn what to do if you no longer remember the firmware password that you've set or if you see a password dialog when you try to select a startup volume on a MacBook Air (Late 2010) and later, MacBook Pro (Early 2011) and later, iMac (Mid 2011) and later, or Mac mini (Mid 2011) computer.
Resolution
Only Apple retail stores or Apple Authorized Service Providers can unlock these computers protected by a firmware password.
If you cannot remember the firmware password for your Mac, schedule a service appointment with either an Apple Retail Store or an Apple Authorized Service Provider. If you plan to visit an Apple Retail store, please make a reservation at the Genius Bar using http://www.apple.com/retail/geniusbar/ (available in some countries only).
As a side note you will need the original proof of purchase.
If you mount the hidden "Recovery HD" partition in Terminal:
sudo diskutil mount Recovery\ HD
and then again mount the "BaseSystem.dmg" by double clicking it:
then you should be able to use the setregproptool, located inside "Firmware Password Utility.app":
To get to the folder containing setregproptool right-click (or Control click) "Firmware Password Utility.app", select "Show Package Contents" and navigate to Contents/Resources.
Alternatively to the description in this link:
Set a firmware password from the command line - (see post from "Sep 13, '11 05:04:00AM ")
you can copy the "Firmware Password Utility.app" to a more acceptable location (for example on your local drive) and then use it from there.
These are the options of setregproptool:
$ sudo Firmware\ Password\ Utility.app/Contents/Resources/setregproptool -h
Password:
setregproptool v 2.0 (9) Aug 24 2013
Copyright (C) 2001-2010 Apple Inc.
All Rights Reserved.
Usage: setregproptool [-c] [-d [-o <old password>]] [[-m <mode> -p <password>] -o <old password>]
-c Check whether password is enabled.
Sets return status of 0 if set, 1 otherwise.
-d Delete current password/mode.
Requires current password on some machines.
-p Set password.
Requires current password on some machines.
-m Set security mode.
Requires current password on some machines.
Mode can be either "full" or "command".
Full mode requires entry of the password on
every boot, command mode only requires entry
of the password if the boot picker is invoked
to select a different boot device.
When enabling the Firmware Password for the first
time, both the password and mode must be provided.
Once the firmware password has been enabled, providing
the mode or password alone will change that parameter
only.
-o Old password.
Only required on certain machines to disable
or change password or mode. Optional, if not
provided the tool will prompt for the password.
Best Answer
Apple Support Document HT1352 states:
I assume from this statement that OF ignores the 9th and succeeding characters in the chosen password, but I haven't tested to see if this is the case. Further down in the document, an image of the Firmware Password Utility window states unambiguously that passwords composed of letters and numbers only should be entered: