Some work has been already published regarding the subject of cryptograhic keys security within DRAM. Basically, we need to find something that looks like a key (entropic and specific length) and then confirm its nature by analyzing the memory structure around it (C data types).
The idea is to dump live memory of a process and use those techniques in order to find probable keys since, memory mapping doesn’t change. Thanks-fully, tools exist for that purpose.
The script is not only capable of injecting into already running processes, but also wrapping new ones, by launching them separately and injecting shortly afterwards. This makes it capable of dumping keys from almost any process/binary on the system.
Of course, accessing a memory is limited by kernel, which means that you will still require privileges for a process.
Linux disk ecnryption (LUKS) uses anti-forensic technique in order to mitigate such issue, however, extracting keys from a whole memory is still possible. Firefox browser uses somehow similar memory management, thus seems not to be affected. Same goes for PGP/GPG.
- Application Independable
- Process Wrapping
- Process Injection
- Unix – should work on any Unix-based OS
- BASH – the whole script
- root privileges (optional)
- AES and RSA keys only
- Fails most of the time for Firefox browser
- Won’t work for disk encryption (LUKS) and PGP/GPG
- Needs proper user privileges and memory authorizations
sudo apt install gdb aeskeyfind rsakeyfind || echo 'have you heard about source compiling?'
An interactive example for OpenSSL AES keys:
openssl aes-128-ecb -nosalt -out testAES.enc
Enter a password twice, then some text and before terminating:
Finally, press Ctrl+D 3 times and check the result.
OpenSSL RSA keys:
openssl genrsa -des3 -out testRSA.pem 2048
When prompted for passphrase:
openssl rsa -noout -text -in testRSA.pem
Let’s extract keys from SSH:
echo 'Ciphers [email protected]openssh.com' >> /etc/ssh/sshd_config ssh [email protected] CryKeX.sh ssh
echo 'cipher AES-256-CBC' >> /etc/openvpn/server.conf openvpn yourConf.ovpn sudo CryKeX.sh openvpn
TrueCrypt/VeraCrypt is also affected: Select “veracrypt” file in VeraCrypt, mount with password “pass” and:
sudo CryKeX.sh veracrypt
Chromium-based browsers (thanks Google):
CryKeX.sh chromium CryKeX.sh google-chrome
Despite Firefox not being explicitly affected, Tor Browser Bundle is still susceptible due to tunneling:
As said, you can also wrap processes:
apt install libssl-dev gcc -lcrypto cipher.c -o cipher CryKeX.sh cipher wrap cipher