This article contains instructions to build PyCrypto 2.6 for Windows XP (32 bits).

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The PyCrypto library provides Python with implementation for a lot of algorithms for cryptography. It’s very useful.

Ubuntu has it by default but if you want to have it for Python 3.2 on Windows, you must use Active Python, as there is no other binary release for Python 3.2 on the web.

In case you want to use the official Python distribution or if ActiveState did not (yet) released a PyCrypto for the version of Python you are using, this article might help you by putting together the steps to build it from source.

Also attached : a binary .exe for the impatients : pycrypto-2.6.win32-py3.2_0.exe.

Building on Windows XP 32bits

First install Python if not already done : www.python.org/download.

PyCrypto is an open source project so just get the package as well and unzip it : www.dlitz.net/software/pycrypto.

In order to fix a bug with distutils and the latest version of the compiler, edit <Python32_root>/Lib/distutils/cygwinccompiler.py by removing all occurrences of -mno-cygwin (this option has been removed in the latest versions).

Building PyCrypto requires a native compiler. By default it asks for Visual Studio but we will use MinGW :

  1. Install MinGw32 from sourceforge.net/projects/mingw
  2. Make sure to install “C++ compiler”, “C compiler” (not sure if it’s required) and “MSYS Basic System”
  3. Open a console with <MinGW_root>/msys/1.0/msys.bat (will give you an already set up PATH)

In this console type the following distutils command from the unzipped directory of PyCrypto :

python setup.py build --compiler=mingw32 install

And you’re done : PyCrypto installed !

If you are just looking for the binary release, I’ve attached the installer for Win 32. This is probably not an optimized binary as the compilation produced the following message : warning: GMP or MPIR library not found; Not building Crypto.PublicKey._fastmath…

Errors you might encounter

TypeError: unorderable types: NoneType() >= str()

gcc.exe is not in the PATH (bugs.python.org/issue8384). Use msys.bat or put all necessary tools in your PATH.

RuntimeError: chmod error

chmod.exe is not in the PATH (or MSYS is not installed)

IOError: Unable to find vcvarsall.bat

Visual Studio is not installed (bugs.python.org/issue2698). Use --compiler=mingw32.

References