Difference between pages "Write Blockers" and "Mac OS X"

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'''Write blockers''' are devices that allow acquisition of information on a [[hard drive|drive]] without creating the possibility of accidentally damaging the drive contents. They do this by allowing read commands to pass but by blocking write commands, hence their name.
+
{{Expand}}
  
There are two ways to build a write-blocker: the blocker can allow all commands to pass from the computer to the drive except for those that are on a particular list. Alternatively, the blocker can specifically block the write commands and let everything else through.
+
Apple Inc.'s Macintosh OS X (pronounced "'''OS Ten'''") is the operating system distributed with Apple computers. It includes heavily used several programs by default, including [[Apple Mail]], a web browser called [[Apple Safari | Safari]], and an [[Apple Address Book]], and [[iCal]].  
  
Write blockers may also include drive protection which will limit the speed of a drive attached to the blocker. Drives that run at higher speed work harder(the head moves back and forth more often due to read errors). This added protection could allow drives that can not be read at high speed (UDMA modes) to be read at the slower modes (PIO).  
+
== EFI boot ==
 +
The firmware is responsible for initializing the hardware and performing a POST (Power-On Self Test).
  
There are two types of write blockers, Native and Tailgate. A Native device uses the same interface on for both in and out, for example a IDE to IDE write block. A Tailgate device uses one interface for one side and a different one for the other, for example a Firewire to SATA write block.  
+
The default boot volume is stored in NVRAM and can be configured through the "Startup Disk" preference pane or the nvram command line utility [https://developer.apple.com/library/mac/documentation/Darwin/Reference/Manpages/man8/nvram.8.html]. E.g. to print all of the firmware variables.
 +
<pre>
 +
nvram -p
 +
</pre>
  
Steve Bress and Mark Menz invented hard drive write blocking (US Patent 6,813,682).  
+
Additional boot arguments can be provided via the "boot-args" value [http://www.cnet.com/news/boot-argument-options-in-os-x/].
  
There are both hardware and software write blockers. Some software write blockers are designed for a specific operating system. One designed for Windows will not work on Linux. Most hardware write blockers are software independent.  
+
Mac OS X extends EFI with a read-only HFS+ driver. According to [http://refit.sourceforge.net/info/boot_process.html] HFS+ volume header fields are used to point to a "blessed file" to be loaded as an EFI application. Though it is not clear which header field the source is referring to but likely related to the "bless" utility [https://developer.apple.com/library/mac/documentation/Darwin/Reference/Manpages/man8/bless.8.html].
  
= Hardware Write Blockers =
+
The firmware start the Mac OS X boot loader (boot.efi). The bootloader displays a dark grey Apple logo on the screen and loads the Darwin kernel from disk, as well as the essential driver extensions.
  
'''Hardware write blockers''' can be either [[IDE]]-to-IDE or [[Firewire]]/[[USB]]-to-IDE. Simson prefers the IDE-to-IDE because they deal better with errors on the drive and make it easier to access special information that is only accessible over the IDE interface. You may feel differently.
+
The bootloader can be eithe a MZ-PE/COFF or EFI fat binary type [[Executable|executables]] and is commonly stored in:
 +
<pre>
 +
/com.apple.recovery.boot/boot.efi
 +
/System/Library/CoreServices/boot.efi
 +
/usr/standalone/i386/boot.efi
 +
</pre>
  
NIST test results are here: http://www.nist.gov/itl/ssd/cs/cftt/cftt-hardware-write-block.cfm
+
The behavior of the bootloader can be configured in the com.apple.Boot.plist [https://developer.apple.com/library/mac/documentation/Darwin/Reference/ManPages/man5/com.apple.Boot.plist.5.html] which can be found in:
 +
<pre>
 +
/Library/Preferences/SystemConfiguration/
 +
</pre>
  
== Commercial ==
+
== Disk image types ==
  
; [[ICS Drive Lock]]
+
Mac OS X has support for various disk image types build-in, some of which are:
: http://www.ics-iq.com/Super-DriveLock-Write-Blocker-Write-Protector-p/f.gr-0028-0000.htm
+
* read-write disk image (.dmg) some of which use the [[Raw Image Format]]
 +
* [[Sparse Image format|Sparse disk image (.spareimage)]]
 +
* [[Sparse Bundle Image format|Sparse bundle disk image (.sparsebundle)]]
  
; MyKey Technology, Inc. NoWrite FPU and FlashBlock II
+
== Burn Folder ==
: 1.8"/2.5"/3.5"/ IDE to IDE, FireWire/USB to IDE & SATA, all media types - NIST Ver. 2 accepted 
+
: http://www.mykeytech.com/
+
  
; [[Tableau]] write blockers for IDE, SATA, SCSI, USB  NIST Ver. 1 accepted
+
Mac OS X Burn Folder:
: http://www.tableau.com/index.php?pageid=products
+
<pre>
 +
$NAME.fpbf
 +
</pre>
  
; WiebeTech write-blockers for almost any disk drive: 2.5"/3.5" IDE, SCSI, SATA, ...
+
This folder normally contains [[Mac OS X Alias Files|alias files]] (similar to LNK files under Windows). Which should have the following signature.
: http://wiebetech.com/home.php?home=5  NIST Ver. 1 accepted
+
<pre>
 +
00000000  62 6f 6f 6b 00 00 00 00  6d 61 72 6b 00 00 00 00  |book....mark....|
 +
</pre>
  
; EPOS WriteProtector
+
These [[Mac OS X Alias Files|alias files]] contain additional date and time values.
; http://www.epos.ua/view.php/en/products_epos_write_protector
+
  
= Software Write Blockers =
+
Also check the following files for references to deleted .fpbf paths:
 +
<pre>
 +
/Users/$USERNAME/Library/Preferences/com.apple.finder.plist
 +
/Users/$USERNAME/Library/Preferences/com.apple.sidebarlists.plist
 +
</pre>
  
'''Software write blockers''' can be either tailored to an individual operating system or can be an independent boot disk. Their main upsides are with ease of use, since they are on a CD and do not require you to open up the case, and speed since they do not become a bottle neck.
+
Actual burning of optical media is logged in:
 +
<pre>
 +
/var/log/system.log
 +
/Users/$USERNAME/Library/Logs/DiscRecording.log
 +
/private/var/.logs_exporter/cache/Users/$USERNAME/Library/Logs/DiscRecording.log
 +
</pre>
  
== Commercial ==
+
== HFS/HFS+ date and time values ==
  
; [[SAFE Block XP]]
+
In HFS+ date and time values are stored in an unsigned 32-bit integer containing the number of seconds since January 1, 1904 at 00:00:00 (midnight) UTC (GMT). This is slightly different from HFS where the date and time value are stored using the local time. The maximum representable date is February 6, 2040 at 06:28:15 UTC (GMT). The date values do not account for leap seconds. They do include a leap day in every year that is evenly divisible by four. This is sufficient given that the range of representable dates does not contain 1900 or 2100, neither of which have leap days. Also see: [http://web.archive.org/web/20090214212148/http://developer.apple.com/technotes/tn/tn1150.html Technical Note TN1150 - HFS Plus Volume Format]
: SAFE Block XP is a software-based write blocker designed for the Windows XP Operating System. It comes in both 32 and 64 bit options. NIST Ver. 1.2 accepted
+
: http://www.forensicsoft.com/
+
  
; [[MacForensicsLab Write Controller]]
+
Converting HFS/HFS+ date and time values with Python:
: MacForensicsLab Write Controller is a software-based write blocker designed for the Mac OS X operating system.  It runs on both 32 and 64 bit versions of Mac OS X 10.4 or later.
+
<pre>
: http://www.macforensicslab.com/ProductsAndServices/index.php?main_page=product_info&cPath=1&products_id=339
+
import datetime
  
[[Category:Disk Imaging]]
+
print datetime.datetime( 1904, 1, 1 ) + datetime.timedelta( seconds=0xCBDAF25B )
 +
</pre>
 +
 
 +
== Launch Agents ==
 +
System-wide:
 +
<pre>
 +
/Library/LaunchAgents
 +
/System/Library/LaunchAgents
 +
</pre>
 +
 
 +
Per user:
 +
<pre>
 +
/Users/$USERNAME/Library/LaunchAgents
 +
</pre>
 +
 
 +
These directories contain  [[Property list (plist)]] files.
 +
 
 +
== Launch Daemons ==
 +
System-wide:
 +
<pre>
 +
/Library/LaunchDaemons
 +
/System/Library/LaunchDaemons
 +
</pre>
 +
 
 +
These directories contain [[Property list (plist)]] files.
 +
 
 +
== Startup Items ==
 +
<pre>
 +
/Library/StartupItems/
 +
/System/Library/StartupItems/
 +
</pre>
 +
 
 +
== Crash Reporter ==
 +
<pre>
 +
/Library/Application Support/CrashReporter
 +
</pre>
 +
 
 +
Contains text files named .crash, .diag, .spin
 +
 
 +
== Diagnostic Reports ==
 +
<pre>
 +
/Library/Logs/DiagnosticReports
 +
</pre>
 +
 
 +
== Internet Plug-Ins ==
 +
System-wide:
 +
<pre>
 +
/Library/Internet Plug-Ins
 +
</pre>
 +
 
 +
Per user:
 +
<pre>
 +
/Users/$USERNAME/Library/Internet Plug-Ins
 +
</pre>
 +
 
 +
== Quarantine event database ==
 +
See [http://menial.co.uk/blog/2011/06/16/mac-quarantine-event-database/]
 +
 
 +
Snow Leopard and earlier
 +
<pre>
 +
/Users/$USER/Library/Preferences/com.apple.LaunchServices.QuarantineEvents
 +
</pre>
 +
 
 +
<pre>
 +
SELECT datetime(LSQuarantineTimeStamp + 978307200, "unixepoch") as LSQuarantineTimeStamp, LSQuarantineAgentName, LSQuarantineOriginURLString, LSQuarantineDataURLString from LSQuarantineEvent;
 +
</pre>
 +
 
 +
Lion and later
 +
<pre>
 +
/Users/$USER/Library/Preferences/com.apple.LaunchServices.QuarantineEventsV2
 +
</pre>
 +
 
 +
== sleepimage ==
 +
This file is similar to the hibernation file on Windows.
 +
<pre>
 +
/private/var/vm/sleepimage
 +
</pre>
 +
 
 +
Also see: [http://osxdaily.com/2010/10/11/sleepimage-mac/]
 +
 
 +
== Last shutdown logs ==
 +
<pre>
 +
/private/var/log/com.apple.launchd/launchd-shutdown.system.log
 +
/private/var/log/com.apple.launchd/launchd-shutdown.system.log.1
 +
</pre>
 +
 
 +
== Package Files (.PKG) ==
 +
Package Files (.PKG) are XAR archives [http://en.wikipedia.org/wiki/Xar_(archiver)] that contain a cpio archive and metadata [http://s.sudre.free.fr/Stuff/Ivanhoe/FLAT.html].
 +
 
 +
== Also see ==
 +
* [[MacOS Process Monitoring]]
 +
* [[Acquiring a MacOS System with Target Disk Mode]]
 +
* [[Converting Binary Plists]]
 +
* [[FileVault Disk Encryption]]
 +
* [[File Vault]]
 +
 
 +
=== Formats ===
 +
* [[Basic Security Module (BSM) file format]]
 +
* [[Property list (plist)]]
 +
 
 +
== External Links ==
 +
* [http://www.apple.com/macosx/ Official website]
 +
* [http://en.wikipedia.org/wiki/OS_X Wikipedia entry on OS X]
 +
* [http://menial.co.uk/blog/2011/06/16/mac-quarantine-event-database/ Quarantine event database]
 +
* [http://www2.tech.purdue.edu/cit/Courses/cit556/readings/MacForensicsCraiger.pdf Mac Forensics: Mac OS X and the HFS+ File System] by P. Craiger
 +
* [http://web.me.com/driley/iWeb/Previous_files/Directory_Services_Overview.pdf Mac OS X Directory Services Integration including Active Directory]
 +
* [http://digitalinvestigation.wordpress.com/2012/04/04/geek-post-nskeyedarchiver-files-what-are-they-and-how-can-i-use-them/ NSKeyedArchiver files – what are they, and how can I use them?]
 +
* [http://krypted.com/mac-os-x/command-line-alf-on-mac-os-x/ Command Line ALF on Mac OS X]
 +
* [http://newosxbook.com/DMG.html Demystifying the DMG File Format]
 +
* [https://code.google.com/p/mac-security-tips/wiki/ALL_THE_TIPS mac-security-tips]
 +
 
 +
=== Apple Examiner ===
 +
* [http://www.appleexaminer.com/ The Apple Examiner]
 +
* [http://www.appleexaminer.com/MacsAndOS/Analysis/USBOSX/USBOSX.html USB Entries on OS X]
 +
* [http://www.appleexaminer.com/Downloads/MacForensics.pdf Macintosh Forensics - A Guide for the Forensically Sound Examination of a Macintosh Computer] by Ryan R. Kubasiak
 +
 
 +
=== EFI ===
 +
* [http://refit.sourceforge.net/info/boot_process.html The Intel Mac boot process], by the [[rEFIt|rEFIt project]]
 +
* [http://ho.ax/posts/2012/02/carving-up-efi-fat-binaries/ Carving up EFI fat binaries], by snare, February 24, 2012
 +
 
 +
=== iCloud ===
 +
* [http://support.apple.com/kb/HT4865?viewlocale=en_US&locale=en_US iCloud: iCloud security and privacy overview]
 +
 
 +
[[Category:Mac OS X]]
 +
[[Category:Operating systems]]

Revision as of 08:07, 25 June 2014

Information icon.png

Please help to improve this article by expanding it.
Further information might be found on the discussion page.

Apple Inc.'s Macintosh OS X (pronounced "OS Ten") is the operating system distributed with Apple computers. It includes heavily used several programs by default, including Apple Mail, a web browser called Safari, and an Apple Address Book, and iCal.

EFI boot

The firmware is responsible for initializing the hardware and performing a POST (Power-On Self Test).

The default boot volume is stored in NVRAM and can be configured through the "Startup Disk" preference pane or the nvram command line utility [1]. E.g. to print all of the firmware variables.

nvram -p

Additional boot arguments can be provided via the "boot-args" value [2].

Mac OS X extends EFI with a read-only HFS+ driver. According to [3] HFS+ volume header fields are used to point to a "blessed file" to be loaded as an EFI application. Though it is not clear which header field the source is referring to but likely related to the "bless" utility [4].

The firmware start the Mac OS X boot loader (boot.efi). The bootloader displays a dark grey Apple logo on the screen and loads the Darwin kernel from disk, as well as the essential driver extensions.

The bootloader can be eithe a MZ-PE/COFF or EFI fat binary type executables and is commonly stored in:

/com.apple.recovery.boot/boot.efi
/System/Library/CoreServices/boot.efi
/usr/standalone/i386/boot.efi

The behavior of the bootloader can be configured in the com.apple.Boot.plist [5] which can be found in:

/Library/Preferences/SystemConfiguration/

Disk image types

Mac OS X has support for various disk image types build-in, some of which are:

Burn Folder

Mac OS X Burn Folder:

$NAME.fpbf

This folder normally contains alias files (similar to LNK files under Windows). Which should have the following signature.

00000000  62 6f 6f 6b 00 00 00 00  6d 61 72 6b 00 00 00 00  |book....mark....|

These alias files contain additional date and time values.

Also check the following files for references to deleted .fpbf paths:

/Users/$USERNAME/Library/Preferences/com.apple.finder.plist
/Users/$USERNAME/Library/Preferences/com.apple.sidebarlists.plist

Actual burning of optical media is logged in:

/var/log/system.log
/Users/$USERNAME/Library/Logs/DiscRecording.log
/private/var/.logs_exporter/cache/Users/$USERNAME/Library/Logs/DiscRecording.log

HFS/HFS+ date and time values

In HFS+ date and time values are stored in an unsigned 32-bit integer containing the number of seconds since January 1, 1904 at 00:00:00 (midnight) UTC (GMT). This is slightly different from HFS where the date and time value are stored using the local time. The maximum representable date is February 6, 2040 at 06:28:15 UTC (GMT). The date values do not account for leap seconds. They do include a leap day in every year that is evenly divisible by four. This is sufficient given that the range of representable dates does not contain 1900 or 2100, neither of which have leap days. Also see: Technical Note TN1150 - HFS Plus Volume Format

Converting HFS/HFS+ date and time values with Python:

import datetime

print datetime.datetime( 1904, 1, 1 ) + datetime.timedelta( seconds=0xCBDAF25B )

Launch Agents

System-wide:

/Library/LaunchAgents
/System/Library/LaunchAgents

Per user:

/Users/$USERNAME/Library/LaunchAgents

These directories contain Property list (plist) files.

Launch Daemons

System-wide:

/Library/LaunchDaemons
/System/Library/LaunchDaemons

These directories contain Property list (plist) files.

Startup Items

/Library/StartupItems/
/System/Library/StartupItems/

Crash Reporter

/Library/Application Support/CrashReporter

Contains text files named .crash, .diag, .spin

Diagnostic Reports

/Library/Logs/DiagnosticReports

Internet Plug-Ins

System-wide:

/Library/Internet Plug-Ins

Per user:

/Users/$USERNAME/Library/Internet Plug-Ins

Quarantine event database

See [6]

Snow Leopard and earlier

/Users/$USER/Library/Preferences/com.apple.LaunchServices.QuarantineEvents
SELECT datetime(LSQuarantineTimeStamp + 978307200, "unixepoch") as LSQuarantineTimeStamp, LSQuarantineAgentName, LSQuarantineOriginURLString, LSQuarantineDataURLString from LSQuarantineEvent;

Lion and later

/Users/$USER/Library/Preferences/com.apple.LaunchServices.QuarantineEventsV2

sleepimage

This file is similar to the hibernation file on Windows.

/private/var/vm/sleepimage

Also see: [7]

Last shutdown logs

/private/var/log/com.apple.launchd/launchd-shutdown.system.log
/private/var/log/com.apple.launchd/launchd-shutdown.system.log.1

Package Files (.PKG)

Package Files (.PKG) are XAR archives [8] that contain a cpio archive and metadata [9].

Also see

Formats

External Links

Apple Examiner

EFI

iCloud