ecrypt-config.h, ecrypt-portable.h, 
ecrypt-machine.h, ecrypt-sync.h, ecrypt-sync.c: these are common ECRYPT files. 
crypt-mt-ref.c:  ECRYPT_keysetup(), ECRYPT_ivsetup(), ECRYPT_encrypt_bytes(), 
                     ECRYPT_decrypt_bytes() and ECRYPT_keystream_bytes() 
                     are defined in this file.