This series will first introduce the idea of the existing source code encryption scheme 、 Method 、 Advantages and disadvantages , Then it introduces how to customize Python Interpreter to achieve better encryption and decryption of the source .
because Python Dynamic and open source features , Lead to Python It's hard to encrypt the code well . Some voices in the community believe that such restrictions are true , The purpose of commercial protection should be achieved by legal means rather than by encrypting the source code ; And there are some voices that want a way to encrypt anyway . So , People come up with all kinds of encryption 、 Or a confused scheme , To protect the source code .
Common source protection methods are as follows ：
Let's talk about these plans briefly .
1 issue .pyc file
1.1 Ideas
Everybody knows ,Python The interpreter will first generate... During code execution .pyc file , Then explain the execution .pyc Contents of the file . Yes, of course ,Python The interpreter can also directly execute .pyc file . and .pyc Files are binary files , Can 't see the source content directly . If the code is released to the customer environment .pyc Instead of .py Word of the file , Can't that protect Python The purpose of the code ？
1.2 Method
hold .py The file is compiled as .pyc file , It's a very easy thing , You don't need to run all the code once , Then go and get the .pyc file .
in fact ,Python A standard library is provided with the name compileall The library of , It's easy to compile .
Execute the following command to traverse All under directory .py file , Compile it as .pyc file ：
python -m compileall Then delete All under directory .py The files can be packaged and released ：
$ find <src> -name '*.py' -type f -print -exec rm {} \;
1.3 advantage
1.4 Insufficient
Bad interpreter compatibility ,.pyc Can only run on a specific version of the interpreter
There are decompilators out there , The cost of cracking is low
python-uncompyle6 It's such a decompiler , Excellent results .
Execute the following command , Can be .pyc Decompile file to .py file ：
$ uncompyle6 *compiled-python-file-pyc-or-pyo*
2 Code obfuscation
If the code is confused to a certain extent , Even the author looked at all the words , Is it possible to protect the source code ？
2.1 Ideas
Since our aim is to confuse , Through a series of transformations , Let the code gradually not so easy to understand , Then we can do it like this ：- Remove comments and documents . There are no such instructions , It's not so easy to understand in some key logics .- Change indent . The perfect indent is comfortable to watch , If the indent changes from long to short , You must be upset when you look at it .- stay tokens Put some space in the middle . It's like changing indent .- Rename function 、 class 、 Variable . Naming directly affects readability , Messy names are a big obstacle to reading comprehension .- Insert invalid code in a blank line . That's the trick , Use irrelevant code to disrupt the reading rhythm .
2.2 Method
Method 1 ： Use oxyry Confusion
pyob.oxyry.com/ It's an online confusion Python Code site , Using it can easily confuse .
Suppose we have a paragraph like this Python Code , Class is involved 、 function 、 Parameters, etc ：
# coding: utf-8
class A(object):
"""
Description
"""
def __init__(self, x, y, default=None):
self.z = x + y
self.default = default
def name(self):
return 'No Name'
def always():
return True
num = 1
a = A(num, 999, 100)
a.name()
always()
after Oxyry The confusion , Get the following code ：
class A (object ):#line:4
""#line:7
def __init__ (O0O0O0OO00OO000O0 ,OO0O0OOOO0000O0OO ,OO0OO00O00OO00OOO ,OO000OOO0O000OOO0 =None ):#line:9
O0O0O0OO00OO000O0 .z =OO0O0OOOO0000O0OO +OO0OO00O00OO00OOO #line:10
O0O0O0OO00OO000O0 .default =OO000OOO0O000OOO0 #line:11
def name (O000O0O0O00O0O0OO ):#line:13
return 'No Name'#line:14
def always ():#line:17
return True #line:18
num =1 #line:21
a =A (num ,999 ,100 )#line:22
a .name ()#line:23
always ()
The code after confusion is mainly in comments 、 Some adjustments have been made to the parameter name and space , A little bit of a reading barrier .
Method 2 ： Use pyobfuscate Library to confuse
pyobfuscate It's a very old Python Code obfuscation Library , But it is “ Hale and hearty ” 了 .
For the same paragraph above Python Code , the pyobfuscate The effect of confusion is as follows ：
# coding: utf-8
if 64 - 64: i11iIiiIii
if 65 - 65: O0 / iIii1I11I1II1 % OoooooooOO - i1IIi
class o0OO00 ( object ) :
if 78 - 78: i11i . oOooOoO0Oo0O
if 10 - 10: IIiI1I11i11
if 54 - 54: i11iIi1 - oOo0O0Ooo
if 2 - 2: o0 * i1 * ii1IiI1i % OOooOOo / I11i / Ii1I
def __init__ ( self , x , y , default = None ) :
self . z = x + y
self . default = default
if 48 - 48: iII111i % IiII + I1Ii111 / ooOoO0o * Ii1I
def name ( self ) :
return 'No Name'
if 46 - 46: ooOoO0o * I11i - OoooooooOO
if 30 - 30: o0 - O0 % o0 - OoooooooOO * O0 * OoooooooOO
def Oo0o ( ) :
return True
if 60 - 60: i1 + I1Ii111 - I11i / i1IIi
if 40 - 40: oOooOoO0Oo0O / O0 % ooOoO0o + O0 * i1IIi
I1Ii11I1Ii1i = 1
Ooo = o0OO00 ( I1Ii11I1Ii1i , 999 , 100 )
Ooo . name ( )
Oo0o ( ) # dd678faae9ac167bc83abf78e5cb2f3f0688d3a3
Compared to method one , Method two looks better . Except for class and function renaming 、 Added some spaces , The most obvious is the insertion of a number of unrelated pieces of code , It's getting harder to read .
2.3 advantage
2.4 Insufficient
3 Use py2exe
3.1 Ideas
py2exe It's a will Python The script is converted to Windows Tools for executable files on the platform . The principle is to compile the source code as .pyc file , Plus the necessary dependencies , Package them together into an executable .
If the final issue is by py2exe Packaged binaries , That is not to achieve the purpose of protecting the source code ？
3.2 Method
Use py2exe It's easy to pack .
1） Write entry file . In this example, the name is hello.py：
print 'Hello World`
2） To write setup.py：
from distutils.core import setup
import py2exe
setup(console=['hello.py'])
3） Generate executable files
python setup.py py2exe
The generated executable is located at dist\hello.exe.
3.3 advantage
3.4 Insufficient
4 Use Cython
4.1 Ideas
although Cython The main purpose is to improve the performance , But based on its principles ： take .py/.pyx Compiled into .c file , then .c The file is compiled as .so(Unix) or .pyd(Windows), Another advantage is that it's hard to crack .
4.2 Method
Use Cython The steps of development are not complicated .
1） Write file hello.pyx or hello.py：
def hello():
print('hello')
2） To write setup.py：
from distutils.core import setup
from Cython.Build import cythonize
setup(name='Hello World app',
ext_modules=cythonize('hello.pyx'))
3） Compiled into .c, And then compile it to .so or .pyd：
python setup.py build_ext --inplace
perform python -c "from hello import hello;hello()" Can directly reference the generated binary file hello() function .
4.3 advantage
4.4 Insufficient
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