All of the CFFI code is copied from cryptography. Patches were contributed back to cryptography. PyPy vendors it's own copy of the cffi backend thus it renames the compiled shared object to _pypy_openssl.so (cryptography can ship their own cffi backend)
Currently this module is tested using CPython's standard library test suite.
Copy over all the sources into the folder lib_pypy/_cffi_ssl/*. Updating the cffi backend can be simply done by the following command:
$ cp -r <cloned cryptography folder>/src/_cffi_src/* .
Copied over release version 1.7.2