I know, I know, zero knowledge proofs are not crypto. But:
We live in the post-snowden era. Providers and centralized hosting services are becomming a larger threat than man-in-the-middle attacks. People (including me) are loosing their trust in cryptography that's only meant to protect sensitive data between the communicating nodes in transit, not on the nodes themselves.
OpenSSL's philosophy is to bring primitives for algorithms that provide software-level privacy and otherwise require expertise/academic knowledge. Zero-knowledge technologies will (and already started to) get reputation and currently is in the premature state that cryptography was before OpenSSL. No low-level primitives, no high level "standard" API-s.
I'm a researcher of zero-knowledge proofs and would be happy to contribute into openssl introducing this kind of privacy-protecting technology that in my opinion is not that far from cryptography or OpenSSL concept.