def test_prefix_aes_ecb_decryption(self):
"""Challenge 14"""
prefix = Crypto.gen_random_key(18)
target = "This is the target"
quote = lambda text: text
oracle, _, _ = Crypto.generate_aes_oracle(prefix, target, AES.MODE_ECB,
quote)
self.assertEqual(target, Crypto.decrypts_aes_ecb_byte_wise(oracle))
target = "A" * 16
oracle, _, _ = Crypto.generate_aes_oracle(prefix, target, AES.MODE_ECB,
quote)
self.assertEqual(target, Crypto.decrypts_aes_ecb_byte_wise(oracle))
def test_aes_ecb_decryption(self):
"""Challenge 12"""
data = Crypto.get_lines('data/12.txt')[0]
target = base64.b64decode(data)
quote = lambda text: text
oracle, _, _ = Crypto.generate_aes_oracle('', target, AES.MODE_ECB,
quote)
text = Crypto.decrypts_aes_ecb_byte_wise(oracle)
self.assertEqual(target, text)
def test_break_aes_ctr_fixed_nonce2(self):
"""Challenge 20"""
block_size = 16
quote = lambda t: t
counter = lambda: chr(25)*block_size
aes_ctr, _ = Crypto.generate_aes_oracle(
'', '', AES.MODE_CTR, quote, block_size, counter)
texts = [base64.b64decode(l) for l in open('data/20.txt').readlines()]
ciphers = [aes_ctr(text) for text in texts]
expected = FrequencyAnalyzer.get_repeating_xor(
ciphers[0], texts[0])[:block_size]
actual = Crypto.break_aes_ctr_with_fixed_nonce(ciphers, block_size)
self.assertEquals(expected, actual)
def test_cbc_bit_flipping(self):
"""Challenge 16"""
prefix = "comment1=cooking%20MCs;userdata="
suffix = ";comment2=%20like%20a%20pound%20of%20bacon"
oracle, key, _ = Crypto.generate_aes_oracle(prefix, suffix,
AES.MODE_CBC, urllib.quote)
def has_admin(cipher):
"""Checks if cipher has admin."""
text = Crypto.decrypt_aes(cipher, key, AES.MODE_CBC)
return text.find(';admin=true;') != -1
self.assertTrue(Crypto.flip_cipher_to_add_admin(oracle, has_admin))
def test_break_aes_ctr_fixed_nonce2(self):
"""Challenge 20"""
block_size = 16
quote = lambda t: t
counter = lambda: chr(25) * block_size
aes_ctr, _ = Crypto.generate_aes_oracle('', '', AES.MODE_CTR, quote,
block_size, counter)
texts = [base64.b64decode(l) for l in open('data/20.txt').readlines()]
ciphers = [aes_ctr(text) for text in texts]
expected = FrequencyAnalyzer.get_repeating_xor(ciphers[0],
texts[0])[:block_size]
actual = Crypto.break_aes_ctr_with_fixed_nonce(ciphers, block_size)
self.assertEquals(expected, actual)
def test_ctr_bit_flipping(self):
"""Challenge 26"""
prefix = "comment1=cooking%20MCs;userdata="
suffix = ";comment2=%20like%20a%20pound%20of%20bacon"
counter = Crypto.gen_aes_stream_counter_mt19973(3453243);
oracle, key = Crypto.generate_aes_oracle(
prefix, suffix, AES.MODE_CTR, urllib.quote, 16, counter=counter)
def has_admin(cipher):
"""Checks if cipher has admin."""
counter = Crypto.gen_aes_stream_counter_mt19973(3453243);
text = Crypto.decrypt_aes(cipher, key, AES.MODE_CTR, counter=counter)
return text.find(';admin=true;') != -1
self.assertTrue(Crypto.flip_cipher_to_add_admin_ctr(oracle, has_admin))
def test_break_aes_padding_leak(self):
"""Challenge 17"""
quote = lambda text: text
_, key, init_vector = Crypto.generate_aes_oracle(
'', '', AES.MODE_CBC, quote)
def has_valid_padding(cipher, init_vector):
"""Checks if cipher has valid padding."""
try:
Crypto.decrypt_aes(cipher, key, AES.MODE_CBC, init_vector)
except ValueError:
return False
return True
lines = [base64.b64decode(l) for l in open('data/17.txt').readlines()]
for line in lines:
cipher = Crypto.encrypt_aes(line, key, AES.MODE_CBC, init_vector)
self.assertEqual(line, Crypto.break_aes_using_padding_leak(
cipher, init_vector, has_valid_padding))
def test_break_aes_padding_leak(self):
"""Challenge 17"""
quote = lambda text: text
_, key, init_vector = Crypto.generate_aes_oracle(
'', '', AES.MODE_CBC, quote)
def has_valid_padding(cipher, init_vector):
"""Checks if cipher has valid padding."""
try:
Crypto.decrypt_aes(cipher, key, AES.MODE_CBC, init_vector)
except ValueError:
return False
return True
lines = [base64.b64decode(l) for l in open('data/17.txt').readlines()]
for line in lines:
cipher = Crypto.encrypt_aes(line, key, AES.MODE_CBC, init_vector)
self.assertEqual(
line,
Crypto.break_aes_using_padding_leak(cipher, init_vector,
has_valid_padding))
def test_ctr_bit_flipping(self):
"""Challenge 26"""
prefix = "comment1=cooking%20MCs;userdata="
suffix = ";comment2=%20like%20a%20pound%20of%20bacon"
counter = Crypto.gen_aes_stream_counter_mt19973(3453243)
oracle, key = Crypto.generate_aes_oracle(prefix,
suffix,
AES.MODE_CTR,
urllib.quote,
16,
counter=counter)
def has_admin(cipher):
"""Checks if cipher has admin."""
counter = Crypto.gen_aes_stream_counter_mt19973(3453243)
text = Crypto.decrypt_aes(cipher,
key,
AES.MODE_CTR,
counter=counter)
return text.find(';admin=true;') != -1
self.assertTrue(Crypto.flip_cipher_to_add_admin_ctr(oracle, has_admin))
