PV204 Security technologies
File and disk encryption – lab intro
Milan Brož xbroz@fi.muni.cz
Faculty of Informatics, Masaryk University
Laboratory – FDE attack examples
Basic understanding of some tools and hw
VeraCrypt, LUKS, chip-based encryption
I. HW key-logger attack (remote => video only)
II. Scanning memory image for encryption key
ColdBoot attack principle
III. Flawed algorithm and watermarking
Revealing TrueCrypt hidden disk existence (CBC)
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Environment setup
VirtualBox virtual machine (in IS)
• note: image is large >4GB (disk-encrypted Linux)
• slightly modified Debian Linux
• Login: pv204
• Password: pv204 (including root/sudo and disk unlock)
VM has all tools prepared.
You can use own distro, but some tools need to be installed locally:
• TrueCrypt 7.1a (last non-crippled version)
• VeraCrypt 1.2x
• Cryptsetup 2.x (distro provides it)
• Patched AesKeyfind – in Exercise2_aeskeyfind.zip
or https://github.com/mbroz/aeskeyfind
• Small utilities for Exercise 3 – in Exercise3_tc_cbc_hidden_attack.zip
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Demo
• Storage in Linux
• lsblk command
• device-mapper dm-crypt (disk encryption), dmsetup
• cryptsetup (LUKS: open, dump metadata)
• CBC benchmark (encryption/decryption speed)
• VeraCrypt intro
• basic concepts (RNG, key-derivation, encryption, chained ciphers)
• create AES encrypted container for key search
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Display storage stack (with some encryption devices)
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cryptsetup benchmark
Display volume key for active dm-crypt device
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cryptsetup metadata dump / VeraCrypt and LUKS1 device
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cryptsetup dump of volume key
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EXERCISE II
KEY FROM MEMORY IMAGE
How to dump VirtualBox memory image
For exercise II. you need to get content (dump) of memory from running VM.
In Exercise2_aeskeyfind.zip are scripts for Linux/Windows
• Vbox_save_memcore.bat or
• linux/vbox_save_memcore_linux
If you have different paths, it needs some tweaks – script contains only:
vboxmanage debugvm pv204_fde dumpvmcore --filename memcore.img
Then use memcore.img as parameter for aeskeyfind command.
You can try another images, or other FS; VMware VM paused images etc.
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AESkeyfind output example
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Image analysis on host
dm-crypt key (from VeraCrypt container)
Questions for you:
• What are other keys?
• Why some keys repeats?
• Why is VeraCrypt key
printed swapped?
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EXERCISE III
WRONGLY USED CBC MODE
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EXERCISE I
HW KEYLOGGER
Simple HW Keylogger Demo
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HW Keylogger – KeyDaemon module
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