Develop Reference

Zip Password functionality works wrong

I have a paradoxon, that I just cannot explain.
In short: I built a python script that is supposed to crack a zipped file, which is password protected.
This is what I've done:
(1) zip the text file:
zip --password bla zip3.zip myZip So the passphrase is "bla".
(2) Then I use the following Python Script:
import zipfile
import itertools
from itertools import *
import string
import time
That's the basic function, that is supposed to check, if a given password works or not:
def crack(File, pwd):
try:
File.extractall(pwd=str.encode(pwd))
print("\n---- SUCCESS! {0} ----".format(pwd))
except:
print("{0} did not work.".format(pwd))
pass
Here I specify, which characters I want to use for trying:
myLetters = string.ascii_letters
Here I specify, which zip-file I want to crack:
File = zipfile.ZipFile("PATH/TO/MY/zip3.zip", 'r')
Here I specify, how long the password-phrase is:
pwd_len = 3
here I specify, how many possible combinations of the charactes exist:
all_poss = (len(myLetters)**pwd_len)
Here is the procedure for concrete password cracking:
count = 0
start_time = time.time()
for i in range(0,pwd_len+1):
for j in map(''.join, itertools.product(myLetters, repeat=i)):
crack(File, j)
count += 1
print(round((count/all_poss)*100, 1), end='\r')
res_time = time.time() - start_time
print("\n--- {} ---".format(round(res_time,2)))
I use a nested loop, to try every password. If it works, I should get the Success-message. Else I should only see the "doesn't work message".
However...
If I type in my terminal: python3 pwdCracker.py >> out I get a long text file, which contains many many "does not work messages", BUT I also get a whole bunch of "Success-messages", although only ONE ("bla") should be correct.
Here is a little extract:
wN did not work.
---- SUCCESS! wO ----
wO did not work.
wP did not work.`
So apparently "wO" is working.. But why?? I set the password to "bla"! I really can open the file with "wO"... why can that happen??
Hope you can help!

The default zip encryption is known to be weak, and I think you are seeing hash collisions 1,2.
Most encryption methods (including those used in zip files) need a fixed length key, and so the password is hashed to give that key. The hash function used in zip is crc32 (specified here, although it details a different attack) which was designed for error checking rather than cryptographic hashing. Therefore it will be vulnerable to this type of attack.

The old zip format contains a check byte to quickly verify if your password is right or wrong. This check byte is verified against the last byte of the decrypted 'decryption header'.
Since the check byte is, well, only one byte, false positives happen quite frequently (1/256). What bruteforce crackers usually do in these cases is to check against multiple files from the same archive (hence using multiple check bytes).
From PkWare's APPNOTE.TXT:
After the header is decrypted, the last 1 or 2 bytes in Buffer SHOULD
be the high-order word/byte of the CRC for the file being decrypted,
stored in Intel low-byte/high-byte order. Versions of PKZIP prior to
2.0 used a 2 byte CRC check; a 1 byte CRC check is used on versions after 2.0.
This can be used to test if the password supplied is correct or not.
So what you are seeing is just that, false positives.

Dumbo(Python)/Hadoop unexpected output

I'm trying to execute the following code with dumbo(Python) / haddop
https://github.com/klbostee/dumbo/wiki/Short-tutorial#jobs-and-runners
I followed the tutorial correctly, I have done every step but when I run code in hadoop environment I obtain as output as follows:
SEQ/org.apache.hadoop.typedbytes.TypedBytesWritable/org.apache.hadoop.typedbytes.TypedBytesWritable�������ޭǡ�q���%�O��������������172.16.1.10������������������172.16.1.12������������������172.16.1.30������
It should return a list of IP addresses with connections counter.
Why those characters appear? Is it an encoding problem? How do I fix it? Thanks
Also if I try other programs in the tutorial, I have the same problem.

I answer by myself. That output is the serialized form of Dumbo. There is no error.
To convert it into a readable text, it's sufficient the follow command (the answer was in the tutorial ! I don't saw it)
dumbo cat ipcounts/part* -hadoop /usr/local/hadoop | sort -k2,2nr | head -n 5

No results with python twitter search

I'm using python twitter to do a simple search but I'm not getting any results, even though I get results when performing the results manually. For example, I wrote a simple test script like this:
#! /usr/bin/env python
# coding=utf-8
import twitter
api=twitter.Api()
tweets=api.GetSearch(u'東京大学',per_page=10,page=1)
for t in tweets:
print t.text
If I search for 東京 (English: Tokyo), then it works, but if I increase this by 2 more characters like 東京大学 (English: Tokyo University) then nothing comes back.
Can someone tell me why? I have no ideas (T_T)
Thanks!

It turns out that by adding lang="ja" within the GetSearch command, I can return more results. I suppose that the default is US English users tweeting in Japanese, which gives far fewer results than Japanese users tweeting in Japanese.

MX Record lookup and check

I need to create a tool that will check a domains live mx records against what should be expected (we have had issues with some of our staff fiddling with them and causing all incoming mail to redirected into the void)
Now I won't lie, I'm not a competent programmer in the slightest! I'm about 40 pages into "dive into python" and can read and understand the most basic code. But I'm willing to learn rather than just being given an answer.
So would anyone be able to suggest which language I should be using?
I was thinking of using python and starting with something along the lines of using 0s.system() to do a (dig +nocmd domain.com mx +noall +answer) to pull up the records, I then get a bit confused about how to compare this to a existing set of records.
Sorry if that all sounds like nonsense!
Thanks
Chris

With dnspython module (not built-in, you must pip install it):
>>> import dns.resolver
>>> domain = 'hotmail.com'
>>> for x in dns.resolver.resolve(domain, 'MX'):
... print(x.to_text())
...
5 mx3.hotmail.com.
5 mx4.hotmail.com.
5 mx1.hotmail.com.
5 mx2.hotmail.com.

Take a look at dnspython, a module that should do the lookups for you just fine without needing to resort to system calls.

the above solutions are correct. some things I would like to add and update.
the dnspython has been updated to be used with python3 and it has superseeded the dnspython3 library so use of dnspython is recommended
the domain will strictly take in the domain and nothing else.
for example: dnspython.org is valid domain, not www.dnspython.org
here's a function if you want to get the mail servers for a domain.
def get_mx_server(domain: str = "dnspython.org") -> str:
mail_servers = resolver.resolve(domain, 'MX')
mail_servers = list(set([data.exchange.to_text()
for data in mail_servers]))
return ",".join(mail_servers)

How can I use Microsoft Word's spelling/grammar checker programmatically?

I want to process a medium to large number of text snippets using a spelling/grammar checker to get a rough approximation and ranking of their "quality." Speed is not really of concern either, so I think the easiest way is to write a script that passes off the snippets to Microsoft Word (2007) and runs its spelling and grammar checker on them.
Is there a way to do this from a script (specifically, Python)? What is a good resource for learning about controlling Word programmatically?
If not, I suppose I can try something from Open Source Grammar Checker (SO).
Update
In response to Chris' answer, is there at least a way to a) open a file (containing the snippet(s)), b) run a VBA script from inside Word that calls the spelling and grammar checker, and c) return some indication of the "score" of the snippet(s)?
Update 2
I've added an answer which seems to work, but if anyone has other suggestions I'll keep this question open for some time.

It took some digging, but I think I found a useful solution. Following the advice at http://www.nabble.com/Edit-a-Word-document-programmatically-td19974320.html I'm using the win32com module (if the SourceForge link doesn't work, according to this Stack Overflow answer you can use pip to get the module), which allows access to Word's COM objects. The following code demonstrates this nicely:
import win32com.client, os
wdDoNotSaveChanges = 0
path = os.path.abspath('snippet.txt')
snippet = 'Jon Skeet lieks ponies. I can haz reputashunz? '
snippet += 'This is a correct sentence.'
file = open(path, 'w')
file.write(snippet)
file.close()
app = win32com.client.gencache.EnsureDispatch('Word.Application')
doc = app.Documents.Open(path)
print "Grammar: %d" % (doc.GrammaticalErrors.Count,)
print "Spelling: %d" % (doc.SpellingErrors.Count,)
app.Quit(wdDoNotSaveChanges)
which produces
Grammar: 2
Spelling: 3
which match the results when invoking the check manually from Word.