VP 300: Password Hashes (85 pts)

Purpose

Practice calculating hashes and cracking them.

Getting Test Hashes

In the previous class, we harvested real password hashes from Windows machines with Cain.

Here's a simple test case. A password of 

password
has this hash on Windows machines: 
8846f7eaee8fb117ad06bdd830b7586c
Windows does not use any salt, so every user with the same password has the same password hash.

Calculating Windows NT Password Hashes with Python

Make a script with this code: 
import hashlib
h = hashlib.new('md4', 'password'.encode())
print(h)
The output is an address, not a hash value, as shown below.
To see the normal result in hexadecimal, add the hexdigest() method like this: 
import hashlib
h = hashlib.new('md4', 'password'.encode())
print(h.hexdigest())
Run the program again. This time you should get a hash value, as shown below:
This is a hexadecimal hash, but it's incorrect for Windows passwords. As shown above, the correct NT hash starts with 8846.

That's because the Windows algorithm uses Unicode, not ASCII, to encode the characters. Specifically, it uses a very old version of Unicode that uses only lengths of 16 and 32 bits to encode characters. Microsoft is now moving to UTF-8, but that process is only beginning.

Modify your program to use Unicode, as shown below. (NOTE: the code for Unicode is "UTF-16LE" with the letters in lowercase, NOT "utf-161e".) 

import hashlib
h = hashlib.new('md4', 'password'.encode("utf-16le"))
print(h.hexdigest())
Run the program again. This time you get the correct hash, as shown below:

Flag VP 300.1: Hash Dictionary (10 pts)

Create a program that calculates the NTLM hashes for all two-digit passwords from 00 to 99, as shown below.
Find the hash containing baad. That complete hash value is the flag.

Flags VP 300.2-4: Windows Hashes (15 pts)

The following Windows passwords are constructed according to this system:
CCSF-username-PIN
Where "username" is the username in lowercase and PIN is a two-digit number.

For example, a user named "Sam" might have a password like this:

CCSF-sam-01
Crack these passwords, which were collected from a Windows 7 machine with Cain.
Ming:"":"":AAD3B435B51404EEAAD3B435B51404EE:52C4859C0617E4A8FEC24BA890C5FC57
Mohammed:"":"":AAD3B435B51404EEAAD3B435B51404EE:39057EF3A9FE57D98E7A9BAB7CD2F4F9
sam:"":"":AAD3B435B51404EEAAD3B435B51404EE:19A641D2520B983ABB7C931CEFF933FA
Note that the NTLM hash is the rightmost part of each line, after the last colon.

The passwords are the flags, as shown below:

  • VP 300.2: Ming's password
  • VP 300.3: Mohammed's password
  • VP 300.4: Sam's password

Flags VP 300.5-7: MD5 Hashes with Several Rounds (15 pts)

The company using the Windows passwords in the previous challenge sets up an online system, with passwords formed the same way.

Somewhere in the Terms of Service, it strongly warns users not to re-use the same password as their Windows password.

In addition, it is now much more secure, because it uses MD5 instead of MD4, and not only that, it uses many rounds of MD5. The number of rounds is less than 100.

It doesn't use Unicode encoding.

Crack these hashes.

Ming: 7621eca98fe6a1885d4f5f56a0525915
Mohammed: b2173861e8787a326fb4476aa9585e1c
sam: 42e646b706acfab0cf8079351d176121

The passwords are the flags, as shown below:

  • VP 300.5: Ming's password
  • VP 300.6: Mohammed's password
  • VP 300.7: Sam's password

Flags VP 300.8-10: Many Rounds of MD5 and SHA-1 (15 pts)

Somehow, evil hackers broke into the previous Web application.

So the new, super-enhanced system uses a much larger number of MD5 rounds, followed by an even larger number of SHA1 hash rounds. Of course, the total number of hashing rounds is less than 500, because management is sure that's enough.

And now each user has to click "I Agree" to a pop-up box requiring them not to re-use passwords, so only a complete idiot would do that.

Crack these hashes if you can! Send in the correct passwords to collect credit.

Ming: ce788ed5f855e51e6fd78f923b43a6407467c5f2
Mohammed: 582d99006950cddeb2df9f40b3f65ebc283dc378
sam: da660655f4d4714fe605e9063d1ded4b749c50a9

The passwords are the flags, as shown below:

  • VP 300.8: Ming's password
  • VP 300.9: Mohammed's password
  • VP 300.10: Sam's password

Linux Password Hashes

Here's a password hash for the password "password" from a Debian 10 linux system:
user:$6$jeWFhYPiV3G.U2Kw$J8PgrCnOgw2n2wd2Ua2qM3R.09oc4q4JzbjsKSEbE5A xtLAlFvJUdyZKV0B5R0mJX0MI3yaV3QhWnS3flBSG41:18448:0:99999:7:::
On a Linux machine (not a Mac), execute this command, to open Python 3 interactively:
python3
Execute these commands to reproduce the password hash shown above: 
import crypt
crypt.crypt("password", "$6$jeWFhYPiV3G.U2Kw")
The password hash is correct, as shown below.

Flags VP 300.11-13: Linux Hashes (15 pts)

The following Linux passwords are constructed according to this system:
CCSF-username-PIN
Where "username" is the username in lowercase and PIN is a two-digit number.

For example, a user named "Sam" might have a password like this:

CCSF-sam-01
Crack these passwords, which were collected from a Debian 10 machine. 
ming:$6$blbkhFFelIX6BLYW$n95GODbW3vJwYdchQ/k5OX7rxq3NxGIcJdlLeh4npWNZFaTw/09Lf0TFtfwCEEFqjtSlIIWSFMMSa4pmCAvoN0:18448:0:99999:7:::
mohammed:$6$zVTWI579J7rOQRHd$0PHXw6LjOibKKLHQ9MYE0qbDdEyl8iS4XNclAhNj6UiYPcae6W0DYA3u95b3usGyJNBgf3XUkPIxbO7xDST73/:18448:0:99999:7:::
sam:$6$BCP8vBklvVHIpoNx$3wgjb1cbcmc7QxMFzkymS9jU1iPZghF94n0/ppA4QGBz94wM9T4dxEPsMMx5GBy/NJFoPXTfv0Z3ZTAro0UqY.:18448:0:99999:7:::
Note that the NTLM hash is the rightmost part of each line, after the last colon.

The passwords are the flags, as shown below:

  • VP 300.11: Ming's password
  • VP 300.12: Mohammed's password
  • VP 300.13: Sam's password

Flags VP 300.14-16: Lastpass-Type Hashes (15 pts)

Lastpass reportedly uses "a random salt and 100,000 rounds of server-side PBKDF2-SHA256" hashing.

Crack these passwords, in the same form as the previous challenges, using PBKDF2
with these parameters:

  • Salt: SIXTEEN_TONS_OF_
  • Interations: 100.000
  • Hash function: SHA256
  • Derived Key Length: 256 bits 
ming: 9aff907d8f56caca86df82c2de874398e41ed1dc3bb347c72a4609c920b485a9
mohammed: a7825b5000f71460a9523395010fbda36ad53c5ff699ebdfc552b52b24931e8d
sam: 6387a2fcd0facda4fc82075fd68ea1b613ac72f08c712fe81898c663d7ccbfe1
The passwords are the flags, as shown below:
  • VP 300.14: Ming's password
  • VP 300.15: Mohammed's password
  • VP 300.16: Sam's password

References

UTF-16 from Wikipedia
crypt function not hashing properly on Mac (uses a specific salt)
PBKDF2
Updated to Python 3 7-1-2020
Explanation of Unicode expanded 7-4-2020
Flag numbers fixed 7-4-2020