def valid_padding(plaintext):
unpad = set2_ch10.unpad(plaintext)
padded = set2_ch9.padding(unpad, 16)
if plaintext == padded:
return unpad
else:
raise ValueError('Bad padding')
def encryption_oracle(message):
key = random_16_bytes()
message = random_append() + message + random_append()
# random choose either cbc or ebc
if randint(0,1):
message = set2_ch9.padding(message, 16)
return set1_ch7.encrypt(key, message) #ebc
else:
iv = random_16_bytes()
return set2_ch10.cbc_encrypt(key, message, iv) # cbc
def cbc_encrypt(key, plaintext, iv):
plaintext = set2_ch9.padding(plaintext, 16)
blocks = list(set1_ch6.chunks(plaintext, 16))
prev_encrypt = iv
ciphertext = []
for b in blocks:
xored = set1_ch2.xor(b, prev_encrypt)
prev_encrypt = set1_ch7.encrypt(key, xored)
ciphertext.append(prev_encrypt)
return b"".join(ciphertext)
def encrypt_profile(key, profile):
prof_padded = set2_ch9.padding(profile, 16)
encrypted = set1_ch7.encrypt(key, prof_padded)
return encrypted
def byte_ecb_encrypt(message, key):
unknown_string = b'Um9sbGluJyBpbiBteSA1LjAKV2l0aCBteSByYWctdG9wIGRvd24gc28gbXkgaGFpciBjYW4gYmxvdwpUaGUgZ2lybGllcyBvbiBzdGFuZGJ5IHdhdmluZyBqdXN0IHRvIHNheSBoaQpEaWQgeW91IHN0b3A/IE5vLCBJIGp1c3QgZHJvdmUgYnkK'
message += codecs.decode(unknown_string, 'base64')
message = set2_ch9.padding(message, 16)
return set1_ch7.encrypt(key, message)