def f(x):
if type(x) == str:
x = bytearray(x, 'utf-8')
unknown_str_b64 = "Um9sbGluJyBpbiBteSA1LjAKV2l0aCBteSByYWctdG9wIGRvd24gc28gbXkgaGFpciBjYW4gYmxvdwpUaGUgZ2lybGllcyBvbiBzdGFuZGJ5IHdhdmluZyBqdXN0IHRvIHNheSBoaQpEaWQgeW91IHN0b3A/IE5vLCBJIGp1c3QgZHJvdmUgYnkK"
unknown_str = b64_to_bytes(unknown_str_b64)
new_pt = pkcs7_pad(x + unknown_str, BLK_SZ)
return encrypt_aes_ecb(new_pt, KEY)
def aes_cbc_encrypt(pt, key, iv):
# pad if needed
pt_padded = pkcs7_pad(pt, BLK_SZ)
pt_chunks = chunk(pt_padded, BLK_SZ)
prev_blk = iv
ct_blks = []
for pt_blk in pt_chunks:
# xor with prev blk
pt_xored = xor(prev_blk, pt_blk)
# ECB encrypt
ct_blk = encrypt_aes_ecb(pt_xored, key)
ct_blks.append(ct_blk)
# store as prev blk
prev_blk = ct_blk
ct_s = functools.reduce(lambda a, b: a + b, ct_blks)
return ct_s
def encryption_oracle(x):
if type(x) == str:
x = bytearray(x, "utf-8")
bytes_append_len = 5 + secrets.randbelow(6)
bytes_prepend_len = 5 + secrets.randbelow(6)
bytes_appended = bytearray(secrets.token_bytes(bytes_append_len))
bytes_prepended = bytearray(secrets.token_bytes(bytes_prepend_len))
pt = pkcs7_pad(bytes_prepended + x + bytes_appended, 16)
encryption_scheme = secrets.randbelow(2)
if (encryption_scheme == ECB_MODE):
# do ECB
ct = encrypt_aes_ecb(pt, gen_aes_key())
elif (encryption_scheme == CBC_MODE):
# do CBC
ct = aes_cbc_encrypt(pt, gen_aes_key(), secrets.token_bytes(BLK_SZ))
return ct, encryption_scheme
def profile_for(x):
x = x.replace("&", "")
x = x.replace("=", "")
d = {'email': x, 'uid': 10, 'role': 'user'}
return encrypt_aes_ecb(pkcs7_pad(obj_to_qs(d), BLK_SZ), KEY)