def test_padding_bytes_will_be_size_of_padding_when_padding_one_byte(self):
pt = bytearray("YELLOW SUBMARIN")
blocksize = 16
padded = pkcs7_pad(pt, blocksize)
self.assertEquals(1, padded[-1])
def test_padding_should_work_with_one_byte_to_pad(self):
pt = bytearray("YELLOW SUBMARIN")
blocksize = 16
padded = pkcs7_pad(pt, blocksize)
self.assertEquals(16, len(padded))
def test_padding_multiple_of_blocksize_should_have_correct_padding_bytes(self):
pt = bytearray("XXXX----XXXX----YELLOW SUBMARIN")
blocksize = 16
padded = pkcs7_pad(pt, blocksize)
self.assertEquals(1, padded[-1])
def test_padding_bytes_will_be_size_of_padding_when_padding_one_byte(self):
pt = bytearray("YELLOW SUBMARIN")
blocksize = 16
padded = pkcs7_pad(pt, blocksize)
self.assertEquals(1, padded[-1])
def create_encrypted_response(self, headers, code, reason, body, aes):
response = 'HTTP/1.1 {0} {1}'.format(code, reason)
response += '\r\n' + str(headers) + '\r\n\r\n' + body
payload = aes.encrypt(utils.pkcs7_pad(response))
return payload
def test_padding_should_work_when_padding_a_block_of_right_length(self):
pt = bytearray("YELLOW SUBMARINE")
blocksize = 16
padded = pkcs7_pad(pt, blocksize)
self.assertEquals(32, len(padded))
def test_padding_should_work_with_one_byte_to_pad(self):
pt = bytearray("YELLOW SUBMARIN")
blocksize = 16
padded = pkcs7_pad(pt, blocksize)
self.assertEquals(16, len(padded))
def test_padding_should_work_when_padding_a_block_of_right_length(self):
pt = bytearray("YELLOW SUBMARINE")
blocksize = 16
padded = pkcs7_pad(pt, blocksize)
self.assertEquals(32, len(padded))
def create_encrypted_response(self, headers, code, reason, body, aes):
response = 'HTTP/1.1 {0} {1}'.format(code, reason)
response += '\r\n' + str(headers) + '\r\n\r\n' + body
payload = aes.encrypt(utils.pkcs7_pad(response))
return payload
def test_padding_multiple_of_blocksize_should_have_correct_padding_bytes(
self):
pt = bytearray("XXXX----XXXX----YELLOW SUBMARIN")
blocksize = 16
padded = pkcs7_pad(pt, blocksize)
self.assertEquals(1, padded[-1])
def test_when_padding_two_bytes_they_should_have_value_of_3(self):
pt = bytearray("YELLOW SUBMAR")
blocksize = 16
padded = pkcs7_pad(pt, blocksize)
self.assertEquals(3, padded[-1])
self.assertEquals(3, padded[-2])
self.assertEquals(3, padded[-3])
def test_when_padding_two_bytes_they_should_have_value_of_3(self):
pt = bytearray("YELLOW SUBMAR")
blocksize = 16
padded = pkcs7_pad(pt, blocksize)
self.assertEquals(3, padded[-1])
self.assertEquals(3, padded[-2])
self.assertEquals(3, padded[-3])
def oracle(plain):
random.seed(1337)
aes_key = ''.join(chr(random.randint(0, 255)) for _ in range(16))
prefix_nbr = random.randint(0, 50) # random count of bytes
prefix = ''.join(chr(random.randint(0, 255)) for _ in range(prefix_nbr))
p = prefix + plain + UNKNOWN
p_pad = pkcs7_pad(p, 16)
c = aes_encrypt_ecb(p_pad, aes_key)
return c
def create_payload(self, headers, method, uri, body, pubkey):
rng = Random.new()
key = rng.read(32)
iv = rng.read(16)
a = AES.new(key, AES.MODE_CBC, iv)
request = '{0} {1} HTTP/1.1'.format(method, uri)
request += '\r\n' + str(headers) + '\r\n\r\n' + body
payload = a.encrypt(utils.pkcs7_pad(request))
return payload, pubkey.encrypt(key + iv, os.urandom(256)), a
def create_payload(self, headers, method, uri, body, pubkey):
rng = Random.new()
key = rng.read(32)
iv = rng.read(16)
a = AES.new(key, AES.MODE_CBC, iv)
request = '{0} {1} HTTP/1.1'.format(method, uri)
request += '\r\n' + str(headers) + '\r\n\r\n' + body
payload = a.encrypt(utils.pkcs7_pad(request))
return payload, pubkey.encrypt(key + iv, os.urandom(256)), a
def aes_encrypt(m, k, mode, iv = None):
aes = AES.new(k, AES.MODE_ECB)
c = ""
# Add padding
if len(m) % BLOCK_SIZE() != 0:
m = m + pkcs7_pad(len(m), BLOCK_SIZE())
if mode == "CBC":
if iv is None:
raise ValueError("CBC mode requires an IV.")
else:
for i in range(0, len(m), BLOCK_SIZE()):
block = xor(m[i:i + BLOCK_SIZE()], iv)
iv = aes.encrypt(block)
c = c + iv
return c
elif mode == "ECB":
for i in range(0, len(m), BLOCK_SIZE()):
c = c + aes.encrypt(m[i:i + BLOCK_SIZE()])
return c
else:
raise ValueError("Incorrect mode used: " + mode)
import utils
print(b"YELLOW SUBMARINE\x04\x04\x04\x04" == utils.pkcs7_pad(
b"YELLOW SUBMARINE", 20))
