def enumerateBlock(oneByteLess):
all = list()
for i in range(256):
all.append(oneByteLess + bytearray([i]))
return all
# Merge this with stuff from @Home
bs = 16
# Initialise known
known = bytearray(bs - 1)
howManyBlocks = len(encryptionOracle(bytearray([0x00]*bs)))//bs
for k in range(howManyBlocks):
for iBytes in range( bs):
# Generate iBytes Less input
iBytesLess = bytearray(bs-1-iBytes)
forgedInput = known[-1 *(bs-1):]
realBlock = encryptionOracle(iBytesLess)
for enum in enumerateBlock(forgedInput):
forgedBlock = encryptionOracle(enum)
if forgedBlock[0:bs] == realBlock[k*bs:k*bs+bs]:
print("Block {0} Byte {1} MUST be {2:x}".format(k, iBytes, enum[-1]))
known.append(enum[-1]) # Append cracked Byte
break
hexdump(known[bs-1:], title="Broke the encryption Oracle")
# it becomes
# key=bytearray(b"Terminator X: Bring\'the noiseTerminator X: Bring the
# noise")
#"5. Now that you probably know the KEYSIZE: break the ciphertext into blocks of KEYSIZE length."
blocks = partitionList(ciphertext, bestKeysize)
transposed = list()
#"6. Now transpose the blocks: make a block that is the first byte of every block, and a block that is the second byte of every block, and so on."
#(You basically transform the problem of repeatingKeyXOR to a single KeyXOR, which we can already break using libs.xor.breakSingleByteXOR)
for i in range(bestKeysize):
tmp = bytearray()
for block in blocks:
if i < len(block):
tmp.append(block[i])
transposed.append(tmp)
#"7. Solve each block as if it was single-character XOR. You already have code to do this."
key = bytearray()
for i in range(len(transposed)):
#"8. For each block, the single-byte XOR key that produces the best looking histogram
# is the repeating-key XOR key byte for that block. Put them together and
# you have the key."
p, k, s = breakSingleByteXOR(transposed[i])
key.append(k)
# Finally decrypt everything
print("Decrypt ciphertext with key={0}".format(key))
plaintext = repeatingKeyXOR(ciphertext, key)
hexdump(plaintext)
# https://cryptopals.com/sets/1/challenges/2
from libs.utils import hex2bytes, bytes2hex, hexdump
from libs.crypto.xor import fixedXOR
buffer1 = hex2bytes("1c0111001f010100061a024b53535009181c")
buffer2 = hex2bytes("686974207468652062756c6c277320657965")
result = fixedXOR(buffer1, buffer2)
hexdump(buffer1)
hexdump(buffer2)
print("== equals ==")
hexdump(result)
if result == hex2bytes("746865206b696420646f6e277420706c6179"):
print("Challenge 2 successful!")
else:
print("Challenge 2 failed miserably")
from libs.utils import hexdump, hex2bytes
from libs.analysis import detectECB
import base64
# Read File
file = open("Set1/Set1Challenge8.txt", "r")
i = 0
for line in file:
ciphertext = hex2bytes(line[:-1])
score = detectECB(ciphertext)
if score > 0:
hexdump(
ciphertext,
title="Detected ECB-Encrypted Ciphertext with score={0}".format(
score))
i += 1
key = bytearray("YELLOW SUBMARINE", "utf-8")
# https://cryptopals.com/sets/1/challenges/3
from libs.utils import hex2bytes, bytes2hex, hexdump
from libs.analysis import scoreEnglish
from libs.crypto.xor import breakSingleByteXOR
ciphertext = hex2bytes(
"1b37373331363f78151b7f2b783431333d78397828372d363c78373e783a393b3736")
p, k, s = breakSingleByteXOR(ciphertext)
hexdump(ciphertext)
print("Broke it with with k={1}:".format(ciphertext, k))
hexdump(p)
# https://cryptopals.com/sets/1/challenges/5
from libs.utils import hexdump, hex2bytes
from libs.crypto.xor import repeatingKeyXOR
plaintext = bytearray(
"Burning 'em, if you ain't quick and nimble\nI go crazy when I hear a cymbal", "utf-8")
key = bytearray("ICE", "utf-8")
solution = hex2bytes(
"0b3637272a2b2e63622c2e69692a23693a2a3c6324202d623d63343c2a26226324272765272a282b2f20430a652e2c652a3124333a653e2b2027630c692b20283165286326302e27282f")
ciphertext = repeatingKeyXOR(plaintext, key)
print("Plaintext:")
hexdump(plaintext)
print("Encrypted with k={0}".format(key))
hexdump(ciphertext)
if ciphertext == solution:
print("Challenge 5 successful!")
else:
print("Challenge 5 failed miserably")
# https://cryptopals.com/sets/1/challenges/4
from libs.utils import hex2bytes, bytes2hex, hexdump
from libs.analysis import scoreEnglish
from libs.crypto.xor import breakSingleByteXOR
file = open("Set1/Set1Challenge4.txt", "r")
bestScore = 0
bestKey = None
bestPlaintext = None
bestCiphertext = None
for line in file:
ciphertext = hex2bytes(line[:-1]) # ommit \n
plaintext, key, score = breakSingleByteXOR(ciphertext)
if bestScore < score:
bestScore = score
bestKey = key
bestPlaintext = plaintext
bestCiphertext = ciphertext
print("Ciphertext:")
hexdump(bestCiphertext)
print("Broke it with with k={0}:".format(bestKey))
hexdump(bestPlaintext)
from libs.utils import hexdump
from libs.crypto.blockciphermodes import AES128Decrypt_ECB
import base64
# Read File
with open("Set1/Set1Challenge7.txt", "rb") as file:
ciphertext = base64.b64decode(file.read())
key = bytearray("YELLOW SUBMARINE", "utf-8")
plaintext = AES128Decrypt_ECB(ciphertext, key)
hexdump(plaintext, title="Decrypted using AES128-ECB and k={0}".format(key))
from libs.crypto.blockciphermodes import AES128Decrypt_CBC
from libs.utils import hexdump
import base64
with open("Set2/Set2Challenge10.txt", "rb") as file:
ciphertext = base64.b64decode(file.read())
key = bytearray("YELLOW SUBMARINE", "utf-8")
iv = bytearray([0x0] * 16)
plaintext = AES128Decrypt_CBC(ciphertext, key, iv)
hexdump(plaintext,
title="Decrypted using AES128-CBC, k={0} and iv={1}:".format(key, iv))
