def get_ciphertexts(plaintexts):
rand_key = challenge11.get_rand_bytes(16)
ciphertexts = []
for plaintext in plaintexts:
aes_128_ctr = challenge18.AES128CTR(key=rand_key, nonce=0, counter=0)
ciphertext = aes_128_ctr.crypt(base64.b64decode(plaintext))
ciphertexts.append(ciphertext)
return ciphertexts
def get_ciphertexts():
plaintexts = [
'SSBoYXZlIG1ldCB0aGVtIGF0IGNsb3NlIG9mIGRheQ==',
'Q29taW5nIHdpdGggdml2aWQgZmFjZXM=',
'RnJvbSBjb3VudGVyIG9yIGRlc2sgYW1vbmcgZ3JleQ==',
'RWlnaHRlZW50aC1jZW50dXJ5IGhvdXNlcy4=',
'SSBoYXZlIHBhc3NlZCB3aXRoIGEgbm9kIG9mIHRoZSBoZWFk',
'T3IgcG9saXRlIG1lYW5pbmdsZXNzIHdvcmRzLA==',
'T3IgaGF2ZSBsaW5nZXJlZCBhd2hpbGUgYW5kIHNhaWQ=',
'UG9saXRlIG1lYW5pbmdsZXNzIHdvcmRzLA==',
'QW5kIHRob3VnaHQgYmVmb3JlIEkgaGFkIGRvbmU=',
'T2YgYSBtb2NraW5nIHRhbGUgb3IgYSBnaWJl',
'VG8gcGxlYXNlIGEgY29tcGFuaW9u',
'QXJvdW5kIHRoZSBmaXJlIGF0IHRoZSBjbHViLA==',
'QmVpbmcgY2VydGFpbiB0aGF0IHRoZXkgYW5kIEk=',
'QnV0IGxpdmVkIHdoZXJlIG1vdGxleSBpcyB3b3JuOg==',
'QWxsIGNoYW5nZWQsIGNoYW5nZWQgdXR0ZXJseTo=',
'QSB0ZXJyaWJsZSBiZWF1dHkgaXMgYm9ybi4=',
'VGhhdCB3b21hbidzIGRheXMgd2VyZSBzcGVudA==',
'SW4gaWdub3JhbnQgZ29vZCB3aWxsLA==',
'SGVyIG5pZ2h0cyBpbiBhcmd1bWVudA==',
'VW50aWwgaGVyIHZvaWNlIGdyZXcgc2hyaWxsLg==',
'V2hhdCB2b2ljZSBtb3JlIHN3ZWV0IHRoYW4gaGVycw==',
'V2hlbiB5b3VuZyBhbmQgYmVhdXRpZnVsLA==',
'U2hlIHJvZGUgdG8gaGFycmllcnM/',
'VGhpcyBtYW4gaGFkIGtlcHQgYSBzY2hvb2w=',
'QW5kIHJvZGUgb3VyIHdpbmdlZCBob3JzZS4=',
'VGhpcyBvdGhlciBoaXMgaGVscGVyIGFuZCBmcmllbmQ=',
'V2FzIGNvbWluZyBpbnRvIGhpcyBmb3JjZTs=',
'SGUgbWlnaHQgaGF2ZSB3b24gZmFtZSBpbiB0aGUgZW5kLA==',
'U28gc2Vuc2l0aXZlIGhpcyBuYXR1cmUgc2VlbWVkLA==',
'U28gZGFyaW5nIGFuZCBzd2VldCBoaXMgdGhvdWdodC4=',
'VGhpcyBvdGhlciBtYW4gSSBoYWQgZHJlYW1lZA==',
'QSBkcnVua2VuLCB2YWluLWdsb3Jpb3VzIGxvdXQu',
'SGUgaGFkIGRvbmUgbW9zdCBiaXR0ZXIgd3Jvbmc=',
'VG8gc29tZSB3aG8gYXJlIG5lYXIgbXkgaGVhcnQs',
'WWV0IEkgbnVtYmVyIGhpbSBpbiB0aGUgc29uZzs=',
'SGUsIHRvbywgaGFzIHJlc2lnbmVkIGhpcyBwYXJ0',
'SW4gdGhlIGNhc3VhbCBjb21lZHk7',
'SGUsIHRvbywgaGFzIGJlZW4gY2hhbmdlZCBpbiBoaXMgdHVybiw=',
'VHJhbnNmb3JtZWQgdXR0ZXJseTo=',
'QSB0ZXJyaWJsZSBiZWF1dHkgaXMgYm9ybi4=',
]
rand_key = challenge11.get_rand_bytes(16)
ciphertexts = []
check_plaintexts = []
for plaintext in plaintexts:
aes_128_ctr = challenge18.AES128CTR(key=rand_key, nonce=0, counter=0)
ciphertext = aes_128_ctr.crypt(base64.b64decode(plaintext))
ciphertexts.append(ciphertext)
check_plaintexts.append(base64.b64decode(plaintext))
return ciphertexts, check_plaintexts
def func1(key):
strings = [
"MDAwMDAwTm93IHRoYXQgdGhlIHBhcnR5IGlzIGp1bXBpbmc=",
"MDAwMDAxV2l0aCB0aGUgYmFzcyBraWNrZWQgaW4gYW5kIHRoZSBWZWdhJ3MgYXJlIHB1bXBpbic=",
"MDAwMDAyUXVpY2sgdG8gdGhlIHBvaW50LCB0byB0aGUgcG9pbnQsIG5vIGZha2luZw==",
"MDAwMDAzQ29va2luZyBNQydzIGxpa2UgYSBwb3VuZCBvZiBiYWNvbg==",
"MDAwMDA0QnVybmluZyAnZW0sIGlmIHlvdSBhaW4ndCBxdWljayBhbmQgbmltYmxl",
"MDAwMDA1SSBnbyBjcmF6eSB3aGVuIEkgaGVhciBhIGN5bWJhbA==",
"MDAwMDA2QW5kIGEgaGlnaCBoYXQgd2l0aCBhIHNvdXBlZCB1cCB0ZW1wbw==",
"MDAwMDA3SSdtIG9uIGEgcm9sbCwgaXQncyB0aW1lIHRvIGdvIHNvbG8=",
"MDAwMDA4b2xsaW4nIGluIG15IGZpdmUgcG9pbnQgb2g=",
"MDAwMDA5aXRoIG15IHJhZy10b3AgZG93biBzbyBteSBoYWlyIGNhbiBibG93"
]
choice = base64.b64decode(random.choice(strings))
choice_padded = challenge9.pkcs7_pad(16, choice)
iv = challenge11.get_rand_bytes(16)
ciphertext = challenge10.encrypt_aes_128_cbc(key, iv, choice_padded)
return choice, ciphertext, iv
def func2(key, iv, ciphertext):
plaintext_padded = challenge10.decrypt_aes_128_cbc(key, iv, ciphertext)
try:
plaintext = challenge15.pkcs7_unpad(plaintext_padded)
return True
except Exception as err:
pass
return False
if __name__ == "__main__":
rand_key = challenge11.get_rand_bytes(16)
# choice only used to verify decrypt
choice, ciphertext, iv = func1(rand_key)
block_size = 16
blocks = []
blocks.append(iv)
blocks += challenge16.split_into_blocks(ciphertext)
plainblocks = []
for block_num in range(0, len(blocks) - 1):
plainblock = bytearray("\x00") * block_size
block1 = bytearray(blocks[block_num])
original_block1 = block1
block2 = blocks[block_num + 1]
import challenge7
import challenge9
import challenge11
def encryption_oracle(random_prefix, attacker_controlled, target_bytes, random_key):
plainbuf = random_prefix + attacker_controlled + target_bytes
padded_plainbuf = challenge9.pkcs7_pad(16, plainbuf)
encbuf = challenge7.encrypt_aes_128_ecb(random_key, padded_plainbuf)
return encbuf
if __name__ == "__main__":
random_key = challenge11.get_rand_bytes(16)
rand_size = random.randint(0, 64)
random_prefix = challenge11.get_rand_bytes(rand_size)
block_size = 16
num_padded_bytes = block_size - 1
base_block = chr(num_padded_bytes)*num_padded_bytes
# dictionary of "<byte><0xf padding>" encbufs
block_dict = {}
for i in range(256):
block = chr(i) + base_block
encbuf = challenge7.encrypt_aes_128_ecb(random_key, block)
block_dict[encbuf] = chr(i)