python from hex to shellcode format - python

I try to convert a hex string to shellcode format
For example: I have a file in hex string like aabbccddeeff11223344
and I want to convert that through python to show this exact format:
"\xaa\xbb\xcc\xdd\xee\xff\x11\x22\x33\x44" including the quotes "".
My code is:
with open("file","r") as f:
a = f.read()
b = "\\x".join(a[i:i+2] for i in range(0, len(a), 2))
print b
so my output is aa\xbb\xcc\xdd\xee\xff\x11\x22\x33\x44\x.
I understand I can do it via sed command but I wonder how I may accomplish this through python.

The binascii standard module will help here:
import binascii
print repr(binascii.unhexlify("aabbccddeeff11223344"))
Output:
>>> print repr(binascii.unhexlify("aabbccddeeff11223344"))
'\xaa\xbb\xcc\xdd\xee\xff\x11"3D'

Related

Is there a better way to unpack a binary string in Python

At the moment I have a byte stream of a string that is received by my Python code and must be converted into a string. For now I managed to extract each character, convert them and append them to a string individually. The code looks something like this:
import struct
# The byte stream is received and stored in byte_stream
text = ''
i = 0
while i < len(byte_stream):
text = text + struct.unpack('c', byte_stream[i])[0]
i += 1
print(text)
But that surely cannot be the most efficient way... Is there a more elegant way to do achieve the same result?
From Convert bytes to a Python string:
byte_stream = [112, 52, 52]
''.join(map(chr, bytes))
>> p44

How to convert a word in string to binary

I was working on a module(the import module stuff) which would help to convert words in string to hex and binary(And octal if possible).I finished the hex part.But now I am struggling in case of the binary.I don't know where to start from or what to do.What I want to do is simple.It would take an input string such as 'test'.The function inside the module would convert it to binary.
What I have done till now is given below:
def string_hex(string): # Converts a word to hex
keyword = string.encode()
import binascii
hexadecimal=str(binascii.hexlify(keyword), 'ascii')
formatted_hex=':'.join(hexadecimal[i:i+2] for i in range(0, len(hexadecimal), 2))
return formatted_hex
def hex_string(hexa):
# hexa(Given this name because there is a built-in function hex()) should be written as string.For accuracy on words avoid symbols(, . !)
string = bytes.fromhex(hexa)
formatted_string = string.decode()
return formatted_string
I saved in the directory where I have installed my python in the name experiment.py.This is the way I call it.
>>> from experiment import string_hex
>>> string_hex('test')
'74:65:73:74'
Just like that I am able to convert it back also like this:
>>> from experiment import hex_string
>>> hex_string('74657374')
'test'
Just like this wanted to convert words in strings to binary.And one more thing I am using python 3.4.2.Please help me.
You can do it as follows. You don't even have to import binascii.
def string_hex(string):
return ':'.join(format(ord(c), 'x') for c in string)
def hex_string(hexa):
hexgen = (hexa[i:i+2] for i in range(0, len(hexa), 2))
return ''.join(chr(eval('0x'+n)) for n in hexgen)
def string_bin(string):
return ':'.join(format(ord(c), 'b') for c in string)
def bin_string(binary):
bingen = (binary[i:i+7] for i in range(0, len(binary), 7))
return ''.join(chr(eval('0b'+n)) for n in bingen)
And here is the output:
>>> string_hex('test')
'74:65:73:74'
>>> hex_string('74657374')
'test'
>>> string_bin('test')
'1110100:1100101:1110011:1110100'
>>> bin_string('1110100110010111100111110100')
'test'

Write bitarray to file in python?

I am trying to write a pit array to a file in python as in this example: python bitarray to and from file
however, I get garbage in my actual test file:
test_1 = ^#^#
test_2 = ^#^#
code:
from bitarray import bitarray
def test_function(myBitArray):
test_bitarray=bitarray(10)
test_bitarray.setall(0)
with open('test_file.inp','w') as output_file:
output_file.write('test_1 = ')
myBitArray.tofile(output_file)
output_file.write('\ntest_2 = ')
test_bitarray.tofile(output_file)
Any help with what's going wrong would be appreciated.
That's not garbage. The tofile function writes binary data to a binary file. A 10-bit-long bitarray with all 0's will be output as two bytes of 0. (The docs explain that when the length is not a multiple of 8, it's padded with 0 bits.) When you read that as text, two 0 bytes will look like ^#^#, because ^# is the way (many) programs represent a 0 byte as text.
If you want a human-readable text-friendly representation, use the to01 method, which returns a human-readable strings. For example:
with open('test_file.inp','w') as output_file:
output_file.write('test_1 = ')
output_file.write(myBitArray.to01())
output_file.write('\ntest_2 = ')
output_file(test_bitarray.to01())
Or maybe you want this instead:
output_file(str(test_bitarray))
… which will give you something like:
bitarray('0000000000')

Python 3.3: Hex and Dec converting

I'm able to convert Hex data to Decimal with:
file = open("my_text.txt", "r+")
data = input("Type Hex: ")
hex = int(data, 16)
str(hex)
print(str(hex))
file.write(str(hex))
file.close()
input("close: ")
But how can I convert Decimal data, like a number or a sentence, to Hex? Also, is it possible to write data to a hexadecimal offset?
How about something like this?
>>> print(hex(257))
0x101
>>> for ch in b'abc':
... print(hex(ch))
...
0x61
0x62
0x63
BTW, assigning to a variable called "hex" occludes the built-in function - it's best to avoid that.
HTH

Writing variables to a hex file in Python

So, I have got a float value: -1.0f, or something. And how could I write it into a file in hexadecimal format in Python? I mean that we open the file in notepad, we won't see the hexadecimal values, just the ASCII code.
In Python 3:
>>> import struct
>>> "".join("{0:02X}".format(b) for b in struct.pack(">f", -1.0))
'BF800000'
In Python 2:
>>> import struct
>>> "".join("{0:02X}".format(ord(b)) for b in struct.pack(">f", -1.0))
'BF800000'

Categories

Resources