示例#1
0
def hamming_distance(payload_1, payload_2, type=None):
    if type != None:
        return hamming_distance(_string.conv(payload_1, type),
                                _string.conv(payload_2, type))
    hamming_distance = 0
    for x, y in zip(payload_1, payload_2):
        z = ord(x) ^ ord(y)
        while z:
            hamming_distance += 1
            z -= z & (-z)
    return hamming_distance
示例#2
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def frequency_matchness(payload, type=None):
    if type != None:
        return frequency_matchness(_string.conv(payload, type))
    # estimated_freq is obtained from https://ocw.mit.edu/ans7870/6/6.006/s08/lecturenotes/files/t8.shakespeare.txt
    estimated_freq = [
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.02280148136802659,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.2370624883890251,
        0.0016203149830768323, 8.610900520648024e-05, 1.8321064937548985e-07,
        0.0, 1.8321064937548985e-07, 3.847423636885287e-06,
        0.005692171665447094, 0.00011505628780780763, 0.00011523949845718312,
        1.1542270910655861e-05, 0.0, 0.015238362551156993,
        0.001479242783057705, 0.014295010917522596, 9.160532468774493e-07,
        5.4779984163271466e-05, 0.0001700194826204546, 6.70550976714293e-05,
        6.0459514293911655e-05, 1.7038590391920558e-05, 1.5023273248790168e-05,
        1.1542270910655861e-05, 7.511636624395084e-06, 7.328425975019594e-06,
        0.00017368369560796437, 0.00033472585640902, 0.0031510399586090502,
        8.574258390772925e-05, 1.8321064937548985e-07, 8.079589637459102e-05,
        0.0019193147628576318, 1.4656851950039188e-06, 0.008150308948118043,
        0.002823825738824425, 0.0039384793296249054, 0.0028732926141558073,
        0.007801659082356484, 0.002145946336135113, 0.0020453636896279686,
        0.003382435008770294, 0.010224253499048586, 0.00037869641225913756,
        0.0011351731835305351, 0.004371039672800437, 0.0029079194268877753,
        0.005008612732627142, 0.006084242455110643, 0.0021873519428939735,
        0.00021582214496432706, 0.005307612512407941, 0.006231177395909786,
        0.0072917838451444965, 0.0025885832650262963, 0.0006558941247642537,
        0.003022242872098081, 0.00011102565352154686, 0.0016670336986675822,
        9.74680654677606e-05, 0.00038199420394789636, 0.0,
        0.00038052851875289246, 0.0, 1.300795610565978e-05,
        1.8321064937548985e-07, 0.04482505031880485, 0.008527173253883424,
        0.012217951785552668, 0.024509737462803657, 0.07413087616096008,
        0.01260544230898183, 0.010449419387131065, 0.04001430508750324,
        0.03630941933583208, 0.0004968672811063285, 0.00535194948955681,
        0.026778251723370974, 0.017511273867309322, 0.03955957625575327,
        0.05155382783841847, 0.008523875462194666, 0.00044043840109867763,
        0.03827160539064358, 0.03938625898144406, 0.05312650805265767,
        0.021035880339994994, 0.006227146761623525, 0.013354957075576959,
        0.0008588915242722964, 0.015622555282897396, 0.00020134850366366336,
        0.0, 6.045951429391165e-06, 3.664212987509797e-07,
        1.8321064937548985e-07, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0
    ]
    actual_freq = [0] * 256
    MAX_SCORE = 0
    MIN_SCORE = -(reduce((lambda x, y: x + y**2), estimated_freq) + 1)
    score = 0
    for char in payload:
        actual_freq[ord(char)] += 1
    for pos in range(256):
        actual_freq[pos] /= float(len(payload))
        score -= pow(actual_freq[pos] - estimated_freq[pos], 2)
    return (score - MIN_SCORE) / (MAX_SCORE - MIN_SCORE)
示例#3
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import os
import _string
import _cipher

b64_suffix = """
Um9sbGluJyBpbiBteSA1LjAKV2l0aCBteSByYWctdG9wIGRvd24gc28gbXkg
aGFpciBjYW4gYmxvdwpUaGUgZ2lybGllcyBvbiBzdGFuZGJ5IHdhdmluZyBq
dXN0IHRvIHNheSBoaQpEaWQgeW91IHN0b3A/IE5vLCBJIGp1c3QgZHJvdmUg
YnkK
""".strip().replace('\n', '')

suffix = _string.conv(b64_suffix, 'b64')
key = os.urandom(16)


def encryption_oracle(plaintext):
    padded_plaintext = _cipher.pad(plaintext + suffix)
    return _cipher.aes_encrypt(padded_plaintext, key)


def attack():
    # Cracks ECB mode: Obtain fixed_suffix given [payload + fixed_suffix]

    # Get block size and length of suffix
    expand_sizes = []
    plaintext_length = 0
    old_ciphertext = encryption_oracle('')
    while len(expand_sizes) < 2:
        plaintext_length += 1
        ciphertext = encryption_oracle('A' * plaintext_length)
        if len(ciphertext) > len(old_ciphertext):
示例#4
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import _string
import _cipher

f = open('source/7.txt')
b64_ciphertext = f.read()
f.close()

ciphertext = _string.conv(b64_ciphertext, 'b64')

print _cipher.aes_decrypt(ciphertext, 'YELLOW SUBMARINE')
示例#5
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import _string

hex_string = '49276d206b696c6c696e6720796f757220627261696e206c696b65206120706f69736f6e6f7573206d757368726f6f6d'
b64_string = 'SSdtIGtpbGxpbmcgeW91ciBicmFpbiBsaWtlIGEgcG9pc29ub3VzIG11c2hyb29t'
assert _string.conv(hex_string, 'hex', 'b64') == b64_string
示例#6
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import _string

hex_string_1 = '1c0111001f010100061a024b53535009181c'
hex_string_2 = '686974207468652062756c6c277320657965'
hex_string_3 = '746865206b696420646f6e277420706c6179'

string_1 = _string.conv(hex_string_1, 'hex')
string_2 = _string.conv(hex_string_2, 'hex')
string_3 = _string.conv(hex_string_3, 'hex')

assert _string.xor(string_1, string_2) == string_3
示例#7
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import _attack
import _string

hex_ciphertext = '1b37373331363f78151b7f2b783431333d78397828372d363c78373e783a393b3736'
ciphertext = _string.conv(hex_ciphertext, 'hex')

best_plaintext, best_matchness = _attack.xor_single_byte(ciphertext)

print '%s [Matchness: %f]' % (best_plaintext, best_matchness)
示例#8
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import _string
import _cipher
import _utils

plaintext = """
Burning 'em, if you ain't quick and nimble
I go crazy when I hear a cymbal
""".strip()
key = 'ICE'
hex_ciphertext = _string.conv(_cipher.xor_encrypt(plaintext, key), None, 'hex')

expected_hex_ciphertext = """
0b3637272a2b2e63622c2e69692a23693a2a3c6324202d623d63343c2a26226324272765272
a282b2f20430a652e2c652a3124333a653e2b2027630c692b20283165286326302e27282f
""".replace('\n', '')

assert hex_ciphertext == expected_hex_ciphertext
示例#9
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import _string
import _cipher

f = open('source/10.txt')
ciphertext = _string.conv(f.read(), 'b64')


def challenge_aes_decrypt(ciphertext, key, iv):
    # The decrypt method for this challenge.
    # Expected to have the same plaintext from AES-CBC mode.
    plaintext = ''
    last_ciphertext_block = iv
    for l in range(0, len(ciphertext), 16):
        ciphertext_block = ciphertext[l:l + 16]
        plaintext += _string.xor(
            _cipher.aes_decrypt(ciphertext_block, key, 'ECB'),
            last_ciphertext_block)
        last_ciphertext_block = ciphertext_block
    return plaintext


plaintext = _cipher.aes_decrypt(ciphertext, 'YELLOW SUBMARINE', 'CBC',
                                '\x00' * 16)
_plaintext = challenge_aes_decrypt(ciphertext, 'YELLOW SUBMARINE', '\x00' * 16)

assert plaintext == _plaintext
print _plaintext