As of pike-rc-1 release, glance uses cryptography instead of pycrypto.
so in may or so when queens comes out I'll deprecate ocata, and with it glance's pycrypto usage.
If someone wants to test glance with pycryptodome and has it passing upstream gate I'll use the patch, but it's not worth the effort.
Hey, I'm finding this cryptodome patching a good exercise and a decent amount of fun, so I'll take a look at it. Do you want to point me to a particular version that I should be focusing on? And yes, I see queens is the next openstack release due end of Feb 2018.