چالش PQC0¶

# REQUIRED: OpenSSL 3.5.0

import os
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad
from flag import flag

# generate private key
os.system("openssl genpkey -algorithm ML-KEM-768 -out priv-ml-kem-768.pem")
# generate public key
os.system("openssl pkey -in priv-ml-kem-768.pem -pubout -out pub-ml-kem-768.pem")
# generate shared secret
os.system("openssl pkeyutl -encap -inkey pub-ml-kem-768.pem -secret shared.dat -out ciphertext.dat")

with open("priv-ml-kem-768.pem", "rb") as f:
    private_key = f.read()

print("==== private_key ====")
print(private_key.decode())

with open("ciphertext.dat", "rb") as f:
    ciphertext = f.read()

print("==== ciphertext(hex) ====")
print(ciphertext.hex())

with open("shared.dat", "rb") as f:
    shared_secret = f.read()

encrypted_flag = AES.new(shared_secret, AES.MODE_ECB).encrypt(pad(flag, 16))

print("==== encrypted_flag(hex) ====")
print(encrypted_flag.hex())

import os
from Crypto.Cipher import AES
from Crypto.Util.Padding import pad, unpad
#from flag import flag

enc_flag='5f2b9c04a67523dac3e0b0d17f79aa2879f91ad60ba8d822869ece010a7f78f349ab75794ff4cb08819d79c9f44467bd'
ciphertext='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'

enc_flag=bytes.fromhex(enc_flag)
c=bytes.fromhex(ciphertext)

with open("ciphertext.dat", "wb") as f:
    f.write(c)

# genrate shared secret using private key and ciphertext
os.system("openssl pkeyutl -decap -inkey priv-ml-kem-768.pem -in ciphertext.dat -out shared_secret.dat")


with open("shared_secret.dat", "rb") as f:
    shared_secret = f.read()

flag = unpad(AES.new(shared_secret, AES.MODE_ECB).decrypt(enc_flag),16)
print(flag)