def test_challenge2(self):
hex_input1 = '1c0111001f010100061a024b53535009181c'
hex_input2 = '686974207468652062756c6c277320657965'
xor_result = xor(hex_to_bytes(hex_input1), hex_to_bytes(hex_input2))
self.assertEquals(
'746865206b696420646f6e277420706c6179',
bytes_to_hex(xor_result)
)
def test_challenge1(self):
hex_input = '49276d206b696c6c696e6720796f757220627261696e206c696b65206120706f69736f6e6f7573206d757368726f6f6d'
rawbytes = hex_to_bytes(hex_input)
b64 = bytes_to_base64(rawbytes)
self.assertEqual(
'SSdtIGtpbGxpbmcgeW91ciBicmFpbiBsaWtlIGEgcG9pc29ub3VzIG11c2hyb29t',
b64
)
def test_challenge3(self):
hex_input1 = '1b37373331363f78151b7f2b783431333d78397828372d363c78373e783a393b3736'
rawbytes = hex_to_bytes(hex_input1)
score, translation, _ = find_best_single_byte_key(rawbytes)
self.assertEquals(
'Cooking MC\'s like a pound of bacon',
translation
)
def test_challenge8(self):
ecb_line_number = -1
for line_number, line in enumerate(readlines('8.txt')):
ciphertext = hex_to_bytes(line)
blocks = [ciphertext[s:s+16] for s in range(0, len(ciphertext), 16)]
counts = Counter(blocks)
histogram = [c for _, c in counts.most_common()]
if any(c > 2 for c in histogram):
ecb_line_number = line_number
# print counts
# print ciphertext
break
self.assertEqual(132, ecb_line_number)
def GET(self):
qs = web.input()
with open(qs.file, 'r') as f:
contents = f.read()
expected = crypto.hmac(key, contents)
# print 'expected: {}'.format(convert.bytes_to_hex(expected))
actual = convert.hex_to_bytes(qs.signature)
is_mac_valid = self._insecure_compare(expected, actual)
if not is_mac_valid:
raise web.InternalError('Invalid MAC')
return 'Valid MAC'
def test_challenge29(self):
secret_key = os.urandom(random.randint(1, 20))
# Server returns the message and mac to the attacker
message = 'comment1=cooking%20MCs;userdata=foo;comment2=%20like%20a%20pound%20of%20bacon'
mac = crypto.sha1_keyed_mac(secret_key, message)
raw = convert.hex_to_bytes(mac)
state = (
bitops.from_bytes_be(raw[0:4]),
bitops.from_bytes_be(raw[4:8]),
bitops.from_bytes_be(raw[8:12]),
bitops.from_bytes_be(raw[12:16]),
bitops.from_bytes_be(raw[16:20]),
)
for guessed_key_length in xrange(1, 100):
orig_message_length = guessed_key_length + len(message)
padding = crack.sha1_padding(orig_message_length)
# Attacker sets up a sha1 hash that is in the same state after
# hashing secret_key + message + padding
hasher = sha1.Sha1Hash()
hasher._h = state
hasher._message_byte_length = orig_message_length + len(padding)
suffix = ';user=admin'
falsified_mac = hasher.update(suffix).hexdigest()
falsified_data = message + padding + suffix
try:
# Check to see if the server accepts the falsified data and MAC
validate_mac(secret_key, falsified_data, falsified_mac,
crypto.sha1_keyed_mac)
break
except ValueError:
# Guessed key length was wrong. Keep going...
pass
self.assertEqual(len(secret_key), guessed_key_length)
def test_challenge4(self):
best_score = -1.0
best_translation = None
best_encrypted = None
for encrypted in readlines('4.txt'):
rawbytes = hex_to_bytes(encrypted)
score, translation, _ = find_best_single_byte_key(rawbytes)
if score > best_score:
best_score = score
best_encrypted = encrypted
best_translation = translation
# print 'Best score is: {}. Original cipher text: {}'.format(
# best_score,
# best_encrypted
# )
self.assertEquals(
'Now that the party is jumping\n',
best_translation
)
def test_challenge30(self):
secret_key = os.urandom(random.randint(1, 20))
# Server returns the message and mac to the attacker
message = 'comment1=cooking%20MCs;userdata=foo;comment2=%20like%20a%20pound%20of%20bacon'
mac = crypto.md4_keyed_mac(secret_key, message)
raw = convert.hex_to_bytes(mac)
state = [
bitops.from_bytes_le(raw[0:4]),
bitops.from_bytes_le(raw[4:8]),
bitops.from_bytes_le(raw[8:12]),
bitops.from_bytes_le(raw[12:16]),
]
for guessed_key_length in xrange(1, 100):
orig_message_length = guessed_key_length + len(message)
padding = crack.md4_padding(orig_message_length)
# Attacker sets up a md4 hash that is in the same state after
# hashing secret_key + message + padding
hasher = md4.MD4()
hasher.h = list(state)
hasher.count = (orig_message_length + len(padding)) / 64
suffix = ';user=admin'
falsified_mac = convert.bytes_to_hex(hasher.add(suffix).finish())
falsified_data = message + padding + suffix
try:
# Check to see if the server accepts the falsified data and MAC
validate_mac(secret_key, falsified_data, falsified_mac,
crypto.md4_keyed_mac)
break
except ValueError:
# Guessed key length was wrong. Keep going...
pass
self.assertEqual(len(secret_key), guessed_key_length)