chainbreaker

The chainbreaker can extract user credential in a Keychain file with Master Key or user password in forensically sound manner. Master Key candidates can be extracted from volafox or volatility keychaindump module.

Supported OS

Snow Leopard, Lion, Mountain Lion, Mavericks, Yosemite, El Capitan, (High) Sierra

Target Keychain file

User Keychain(~/Users/[username]/Library/Keychains/login.keychain) : It has user id/password about installed application, ssh/vpn, mail, contacts, calendar and so on. It has key for call history decryption too.
System Keychain(/Library/Keychains/System.keychain) : It has WiFi password registered by local machine and several certifications and public/private keys. (Detailed Info : http://forensic.n0fate.com/2014/09/system-keychain-analysis/)

How to use:

If you have only keychain file and password, command as follow:

$ python chainbreaker.py 
usage: chainbreaker.py [-h] -f FILE (-k KEY | -p PASSWORD)
chainbreaker.py: error: argument -f/--file is required

If you have memory image, you can extract master key candidates using volafox project. The volafox, memory forensic toolit for Mac OS X has been written in Python as a cross platform open source project. Of course, you can dump it using volatility.

$ python volafox.py -i [memory image] -o keychaindump
....
....
$ python chainbreaker.py -f [keychain file] -k [master key]

Example

$ python vol.py -i ~/Desktop/show/macosxml.mem -o keychaindump

[+] Find MALLOC_TINY heap range (guess)
 [-] range 0x7fef03400000-0x7fef03500000
 [-] range 0x7fef03500000-0x7fef03600000
 [-] range 0x7fef03600000-0x7fef03700000
 [-] range 0x7fef04800000-0x7fef04900000
 [-] range 0x7fef04900000-0x7fef04a00000

[*] Search for keys in range 0x7fef03400000-0x7fef03500000 complete. master key candidates : 0
[*] Search for keys in range 0x7fef03500000-0x7fef03600000 complete. master key candidates : 0
[*] Search for keys in range 0x7fef03600000-0x7fef03700000 complete. master key candidates : 0
[*] Search for keys in range 0x7fef04800000-0x7fef04900000 complete. master key candidates : 0
[*] Search for keys in range 0x7fef04900000-0x7fef04a00000 complete. master key candidates : 6

[*] master key candidate: 78006A6CC504140E077D62D39F30DBBAFC5BDF5995039974
[*] master key candidate: 26C80BE3346E720DAA10620F2C9C8AD726CFCE2B818942F9
[*] master key candidate: 2DD97A4ED361F492C01FFF84962307D7B82343B94595726E
[*] master key candidate: 21BB87A2EB24FD663A0AC95E16BEEBF7728036994C0EEC19
[*] master key candidate: 05556393141766259F62053793F62098D21176BAAA540927
[*] master key candidate: 903C49F0FE0700C0133749F0FE0700404158544D00000000
$ python chainbreaker.py -h
usage: chainbreaker.py [-h] -f FILE (-k KEY | -p PASSWORD)

Tool for OS X Keychain Analysis by @n0fate

optional arguments:
  -h, --help            show this help message and exit
  -f FILE, --file FILE  Keychain file(*.keychain)
  -k KEY, --key KEY     Masterkey candidate
  -p PASSWORD, --password PASSWORD
                        User Password 
$ python chainbreaker.py -f ~/Desktop/show/login.keychain -k 26C80BE3346E720DAA10620F2C9C8AD726CFCE2B818942F9
 [-] DB Key
00000000:  05 55 63 93 14 17 66 25  9F 62 05 37 93 F6 20 98  .Uc...f%.b.7.. .
00000010:  D2 11 76 BA AA 54 09 27                                                   ..v..T.'
[+] Symmetric Key Table: 0x00006488
[+] Generic Password: 0x0000dea4
[+] Generic Password Record
 [-] RecordSize : 0x000000fc
 [-] Record Number : 0x00000000
 [-] SECURE_STORAGE_GROUP(SSGP) Area : 0x0000004c
 [-] Create DateTime: 20130318062355Z
 [-] Last Modified DateTime: 20130318062355Z
 [-] Description : 
 [-] Creator : 
 [-] Type : 
 [-] PrintName : ***********@gmail.com
 [-] Alias : 
 [-] Account : 1688945386
 [-] Service : iCloud
 [-] Password
00000000:  ** ** ** ** ** ** ** **  ** ** ** ** ** ** ** **  ****************
00000010:  7A ** 69 ** 50 ** 51 36  ** ** ** 48 32 61 31 66  ****************
00000020:  ** 49 ** 73 ** 62 ** 79  79 41 6F 3D              **********=

<snip>

[+] Internet Record
 [-] RecordSize : 0x0000014c
 [-] Record Number : 0x00000005
 [-] SECURE_STORAGE_GROUP(SSGP) Area : 0x0000002c
 [-] Create DateTime: 20130318065146Z
 [-] Last Modified DateTime: 20130318065146Z
 [-] Description : Web form password
 [-] Comment : default
 [-] Creator : 
 [-] Type : 
 [-] PrintName : www.facebook.com (***********@gmail.com)
 [-] Alias : 
 [-] Protected : 
 [-] Account : ***********@gmail.com
 [-] SecurityDomain : 
 [-] Server : www.facebook.com
 [-] Protocol Type : kSecProtocolTypeHTTPS
 [-] Auth Type : kSecAuthenticationTypeHTMLForm
 [-] Port : 0
 [-] Path : 
 [-] Password
00000000:  ** ** ** ** ** ** ** **  ** ** ** **              ************

If you have memory image only, you can dump a keychain file on it and decrypt keychain contents as link

Contacts

chainbreaker was written by n0fate E-Mail address can be found from source code.

License

GNU GPL v2