def c5():
PLAINTEXT = ("Burning 'em, if you ain't quick and nimble\n" +
"I go crazy when I hear a cymbal")
KEY = "ICE"
EXPECTED = ('0b3637272a2b2e63622c2e69692a23693a2a3c6324202d623d63343c' +
'2a26226324272765272a282b2f20430a652e2c652a3124333a653e2b' +
'2027630c692b20283165286326302e27282f')
result = crypto.bytes_to_hex(
crypto.crypt_xor(crypto.str_to_bytes(PLAINTEXT),
crypto.str_to_bytes(KEY)))
print(result)
expect(result, EXPECTED)
def c5():
PLAINTEXT = ("Burning 'em, if you ain't quick and nimble\n" +
"I go crazy when I hear a cymbal")
KEY = "ICE"
EXPECTED = ('0b3637272a2b2e63622c2e69692a23693a2a3c6324202d623d63343c' +
'2a26226324272765272a282b2f20430a652e2c652a3124333a653e2b' +
'2027630c692b20283165286326302e27282f')
result = crypto.bytes_to_hex(crypto.crypt_xor(
crypto.str_to_bytes(PLAINTEXT),
crypto.str_to_bytes(KEY)))
print(result)
expect(result, EXPECTED)
def c12():
# Find block size
length = crypto.detect_cipher_block_size(crypto.encrypt_append_secret_ECB)
print('Determined block size to be {0}.'.format(length))
# Check the cipher uses ECB mode
ecb = crypto.detect_ECB(crypto.encrypt_append_secret_ECB)
if ecb:
print('The cipher uses ECB mode')
else:
raise ValueError('The cipher does not use ECB mode')
# Find number of blocks to crack for the secret
num_blocks = int(len(crypto.encrypt_append_secret_ECB(b'')) / length)
print ('There are {0} blocks to crack'.format(num_blocks))
print('Finding the secret...')
print()
secret = bytes(0)
for j in range(num_blocks):
for i in range(length):
block = {}
for b in range(0, 255):
plain = crypto.str_to_bytes('A' * (length - (i + 1))) + secret + b.to_bytes(1, byteorder='big')
block[b] = crypto.encrypt_append_secret_ECB(plain)[j*length:(j+1)*length]
match = crypto.encrypt_append_secret_ECB(b'A' * (length - (i + 1)))[j*length:(j+1)*length]
byte = [k for k,v in block.items() if v == match]
if not byte:
# Done - or failed to find a match (i.e padding)
break
secret += byte[0].to_bytes(1, byteorder='big')
print(secret.decode())
def c10():
INPUT_KEY = 'YELLOW SUBMARINE'
with open('inputs/10.txt') as f:
cipher = f.read()
cipher = crypto.base64_to_bytes(cipher)
key = crypto.str_to_bytes(INPUT_KEY)
plain = crypto.decrypt_AES_CBC(cipher, key)
print(plain)
def c7():
KEY = 'YELLOW SUBMARINE'
with open('inputs/7.txt') as f:
cipher = f.read()
cipher = crypto.base64_to_bytes(cipher)
key = crypto.str_to_bytes(KEY)
plain = crypto.decrypt_AES_ECB(cipher, key)
print('Plain: {0}'.format(plain.decode('utf-8')))
def encrypt(encoded):
'''
Encrypt a k=v encoded string using AES ECB mode.
Returns the ciphertext.
'''
global PROFILE_SECRET_KEY
if not PROFILE_SECRET_KEY:
PROFILE_SECRET_KEY = crypto.random_AES_key()
plain = crypto.str_to_bytes(encoded)
plain = crypto.plaintext_pad_PKCS7(plain)
return crypto.encrypt_AES_ECB(plain, PROFILE_SECRET_KEY)
def c6():
HAMMING_INPUTS = ('this is a test','wokka wokka!!!')
distance = textutils.hamming_distance(*map(crypto.str_to_bytes, HAMMING_INPUTS))
expect(distance, 37)
with open('inputs/6.txt') as f:
cipher = f.read()
cipher = crypto.base64_to_bytes(cipher)
keysize = crypto.brute_xor_keysize(cipher)
print('Guessing the key size is {0}'.format(keysize))
key = crypto.brute_xor_key(cipher, keysize)
print('Key: {0}'.format(key))
plain = crypto.fixed_xor(cipher, crypto.str_to_bytes(key))
print ('Plain: {0}'.format(plain.decode('utf-8')))
def c10():
# My own test data
message = 'The crow flies from the chicken coop at dawn.'
key = b'YeLlOw SuBmArInE'
blocksize = len(key)
iv = bytes([randrange(0, 256) for i in range(0, blocksize)])
cryptbytes = crypto.encrypt_aes_cbc(crypto.str_to_bytes(message), iv, key)
print('Encrypted: %r' % cryptbytes)
plainbytes = crypto.decrypt_aes_cbc(cryptbytes, iv, key)
print('Decrypted: %r' % plainbytes.decode())
expect(plainbytes.decode(), message)
# Decrypt the example from Cryptopals
key = b'YELLOW SUBMARINE'
blocksize = len(key)
iv = bytes([0] * blocksize)
cryptbytes = crypto.base64_to_bytes(open('inputs/10.txt').read())
decrypted = crypto.decrypt_aes_cbc(cryptbytes, iv, key)
print(decrypted.decode())
def c10():
# My own test data
message = 'The crow flies from the chicken coop at dawn.'
key = b'YeLlOw SuBmArInE'
blocksize = len(key)
iv = bytes([randrange(0, 256) for i in range(0, blocksize)])
cryptbytes = crypto.encrypt_aes_cbc(crypto.str_to_bytes(message), iv, key)
print('Encrypted: %r' % cryptbytes)
plainbytes = crypto.decrypt_aes_cbc(cryptbytes, iv, key)
print('Decrypted: %r' % plainbytes.decode())
expect(plainbytes.decode(), message)
# Decrypt the example from Cryptopals
key = b'YELLOW SUBMARINE'
blocksize = len(key)
iv = bytes([0]*blocksize)
cryptbytes = crypto.base64_to_bytes(open('inputs/10.txt').read())
decrypted = crypto.decrypt_aes_cbc(cryptbytes, iv, key)
print(decrypted.decode())
def encrypted_profile_for(email):
return crypto.encrypt_aes_ecb(
crypto.pkcs7_pad(
crypto.str_to_bytes(encode_profile(profile_for(email))),
len(PROFILE_KEY)), PROFILE_KEY)
def encrypted_profile_for(email):
return crypto.encrypt_aes_ecb(
crypto.pkcs7_pad(
crypto.str_to_bytes(encode_profile(profile_for(email))),
len(PROFILE_KEY)),
PROFILE_KEY)
def c9():
INPUT_BLOCK = 'YELLOW SUBMARINE'
OUTPUT_BLOCK = b'YELLOW SUBMARINE\x04\x04\x04\x04'
result = crypto.pad_PKCS7(crypto.str_to_bytes(INPUT_BLOCK), block_length=20)
print(result)
expect(result, OUTPUT_BLOCK)
def c9():
INPUT = 'YELLOW SUBMARINE'
EXPECT = b'YELLOW SUBMARINE\x04\x04\x04\x04'
result = crypto.pkcs7_pad(crypto.str_to_bytes(INPUT), 20)
print(result)
expect(result, EXPECT)
def c9():
INPUT = 'YELLOW SUBMARINE'
EXPECT = b'YELLOW SUBMARINE\x04\x04\x04\x04'
result = crypto.pkcs7_pad(crypto.str_to_bytes(INPUT), 20)
print(result)
expect(result, EXPECT)
