The file include\pyport.h in Python installation directory does not have #include < stdint.h > anymore. This leaves intmax_t undefined.
A workaround for Microsoft VC compiler is to force include stdint.h via OS environment variable CL:
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC>vcvarsall
pip install pycrypto
C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC>pip install pycrypto Collecting pycrypto Using cached pycrypto-2.6.1.tar.gz Installing collected packages: pycrypto Running setup.py install for pycrypto ... done Successfully installed pycrypto-2.6.1