VP 330: Argon2 Hashes (47 pts)

Purpose

Theory If you just want to do the hands-on projects, skip this section. Background Read this article (you can skip sections 3.2 - 6.3): Argon2: the memory-hard function for password hashing and other applications Then answer the questions below. Flags VP 330.1: Hash System (2 pts) What hashing system uses SMix and ROMix? Flags VP 330.2: Hash Type (2 pts) What is the technical term for a hash function with this property: D(α) > 1/α as α → 0 Flags VP 330.3: Side-Channel (2 pts) Which flavor of Argon2 is vulnerable to side-channel attacks? Flags VP 330.4: Chains (2 pts) What parameter determines how many independent computational chains can be run? Flags VP 330.5: Cold Boot (2 pts) Which flavor of Argon2 resists cold-boot attacks?

Installing Argon2-cffi

argon2-cffi

python3 -m pip install argon2-cffi

Testing Argon2-cffi

python3

from argon2 import PasswordHasher
ph = PasswordHasher()
hash = ph.hash("s3kr3tp4ssw0rd")
hash
ph.verify(hash, "s3kr3tp4ssw0rd")
ph.verify(hash, "wrongpassword")

dir(ph)
ph.__class__

Flags VP 330.6: Salt Length (2 pts) How many bytes long is the salt used in the password hash you computed in the previous steps?

Flags VP 330.7: Password (10 pts) The password is passwordNN, where NN is a two digit number, like password11. Find the password matching the hash below. That password is the flag. $argon2id$v=19$m=102400,t=2,p=8$Mux7n699exB8C1AkxNhuRg$CX1V+Ge1I8vbrcY+8nbuCw

Flags VP 330.8: Hash (10 pts) Calculate a hash of password using these parameters: Time cost: 100 Memory cost: 102400 Parallelism: 8 Hash length: 8 bytes Salt length: 8 bytes Encoding: utf-8 Type: Argon2id The flag is covered by a green rectangle in the image below.

Flags VP 330.9: Password (10 pts) The password is passwordNN, where NN is a two digit number, like password11. Find the password matching the hash below. That password is the flag. Part of the hash has been redacted and replaced with underscores. $argon2id$v=19$m=10000,____,p=8$Wqly3ozrCqU$AxBO2QSKTG4

Flags VP 330.10: Salt (5 pts) Find the salt for this hash. That salt, as eight ASCII characters, is the flag. $argon2id$v=19$m=2000,t=1,p=8$eEhMUHNvN04$AYQTWoJXnJE

References