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A toy rainbow table script
#!/usr/bin/env python3
import sys
from hashlib import md5
from base64 import b64encode
from binascii import hexlify, unhexlify
from time import time
def reduction_function(hash, max_password_length):
length = (hash[0] % (max_password_length - 1)) + 1
return b64encode(hash[1:])[:length]
def create_chain(starting_value, chain_length, max_password_length, show_each_step):
current_password = bytes(str(starting_value), "utf-8")
begin = current_password
for link in range(chain_length):
hash = md5(current_password).digest()
if show_each_step:
sys.stdout.write("{}={} => ".format(str(current_password, "utf-8"), str(hexlify(hash[0:6]), "utf-8")))
current_password = reduction_function(hash, max_password_length)
end = current_password
return begin, end
def create_table(num_chains, chain_length, max_password_length, show_each_step):
table = {}
for i in range(num_chains):
if show_each_step:
sys.stdout.write("Chain {}: ".format(i))
begin, end = create_chain(i, chain_length, max_password_length, show_each_step)
table[end] = begin
if show_each_step:
sys.stdout.write("{}\n".format(str(end, "utf-8")))
return table
def print_table(table, show_each_step):
if not show_each_step:
length = 0
for key in table:
length += len(key) + len(table[key])
print('Table size: {}KB / {} chains'.format(round(length/1024, 1), len(table)))
return
print("\nThe rainbow table contains:")
for key in table:
value = table[key]
print("{} => {}".format(str(key, "utf-8"), str(value, "utf-8")))
def find_in_table(hash, rainbow_table, chain_length, max_password_length, show_each_step):
password_reduced = reduction_function(hash, max_password_length)
print("\nLooking for hash '{}', reduced to '{}'.".format(str(hexlify(hash[0:6]), "utf-8"), str(password_reduced, "utf-8")))
current_password = password_reduced
previous_password = password_reduced
begin = None
for link in range(chain_length):
tmp_hash = md5(current_password).digest()
current_password = reduction_function(tmp_hash, max_password_length)
if show_each_step:
print("hashed=>reduced '{}' to '{}'".format(str(previous_password, 'utf-8'), str(current_password, "utf-8")))
if current_password in rainbow_table:
begin = rainbow_table[current_password]
if show_each_step:
print("Found a match, {} is in our rainbow table:".format(str(current_password, 'utf-8')))
print(" {} => {}".format(str(current_password, 'utf-8'), str(begin, 'utf-8')))
print("The table starts with '{}'. Let's walk that chain and look for the hash.".format(str(begin, "utf-8")))
break
previous_password = current_password
if begin is None:
print('Reduced hash not found in any of the chains.')
return
current_password = begin
for link in range(chain_length):
tmp_hash = md5(current_password).digest()
if show_each_step:
print("hashed '{}' to {}...".format(str(current_password, 'utf-8'), str(hexlify(tmp_hash[0:6]), "utf-8")))
if tmp_hash == hash:
print("That hash matches! Found the password: {}".format(str(current_password, "utf-8")))
return current_password
current_password = reduction_function(tmp_hash, max_password_length)
print("Password for hash '{}' not found.".format(str(hexlify(hash[0:6]), 'utf-8')))
num_chains = 5
chain_length = 15
max_password_length = 10
show_each_step = True
password_hashes = ['04b4284653cc01171b12655c6d35a60b'
, '23f52cae795a0e4df7ea66eb47252cc7'
, '5234beb92651a71318d2245698aa58a1'
, '7668b281026237d6e7f2b6e209624153'
]
print("Creating rainbow table with {} chains of length {}...".format(num_chains, chain_length))
starttime = time()
rainbow_table = create_table(num_chains, chain_length, max_password_length, show_each_step)
print('That took {0:.2g} seconds.'.format(time() - starttime))
print_table(rainbow_table, show_each_step)
starttime = time()
for hash in password_hashes:
find_in_table(unhexlify(hash), rainbow_table, chain_length, max_password_length, show_each_step)
print('That took {0:.2g} seconds.'.format(time() - starttime))
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