tinyaes is a few lines Cython wrapper for the tiny-AES-c library, a Small
portable AES128/192/256 in C.

The library offers a few modes, CTR mode is the only one currently wrapped.
Given the C API works modifying a buffer in-place, the wrapper offers:
- CTR_xcrypt_buffer(..) that works on all bytes convertible types, and
  encrypting a copy of the buffer,
- CTR_xcrypt_buffer_inplace(..) that works on bytearrays only, modifying the
  buffer in-place.