def test_pkcs7_pad_invalid_block_size():
with pytest.raises(ValueError):
set2.pkcs7_pad(b"YELLOW SUBMARINE", 0)
with pytest.raises(ValueError):
set2.pkcs7_pad(b"YELLOW SUBMARINE", -5)
with pytest.raises(ValueError):
set2.pkcs7_pad(b"YELLOW SUBMARINE", 14.3)
def encrypt_user_data(plaintext, key, iv):
return encrypt_aes_128_cbc(iv, pkcs7_pad(plaintext, block_size), key)
def test_pkcs7_pad():
assert set2.pkcs7_pad(b"YELLOW SUBMARINE", 20) == b"YELLOW SUBMARINE\x04\x04\x04\x04", \
"Should have four bytes of padding"
def test_pkcs7_pad_max_padding():
assert set2.pkcs7_pad(b"YELLOW SUBMARINES", 16) == \
b"YELLOW SUBMARINES\x0f\x0f\x0f\x0f\x0f\x0f\x0f\x0f\x0f\x0f\x0f\x0f\x0f\x0f\x0f", \
"Should have 15 bytes of padding"
def test_pkcs7_pad_no_padding():
assert set2.pkcs7_pad(b"YELLOW SUBMARINE", 16) == b"YELLOW SUBMARINE", \
"Should have no padding because input is same length as block"
def test_challenge9():
assert set2.pkcs7_pad(b"YELLOW SUBMARINE", 20) == b"YELLOW SUBMARINE\x04\x04\x04\x04"
for i in range(100):
bytestring = os.urandom(i)
assert bytestring == set2.pkcs7_unpad(set2.pkcs7_pad(bytestring, 16), 16)
def generate_payload_second_step():
payload = ""
payload += "A" * (block_size - len("email="))
payload += pkcs7_pad(b"admin", block_size).decode()
return payload
def encrypt_encoded_user_cookie(user):
return encrypt_aes_128_ecb(
pkcs7_pad(user.encode_as_cookie().encode(), block_size),
global_aes_128_key)