libmceliece is a Classic McEliece microlibrary. libmceliece has a very simple stateless API based on the SUPERCOP API, with wire-format inputs and outputs, providing functions that directly match the KEM operations provided by Classic McEliece, such as functions

mceliece6960119_keypair
mceliece6960119_enc
mceliece6960119_dec

for the mceliece6960119 KEM.

Internally, libmceliece is based on the official Classic McEliece software, specifically the vec implementation (designed to work portably across CPUs) and the avx implementation (designed for higher performance on Intel/AMD CPUs with AVX2 instructions). libmceliece includes automatic run-time selection of implementations.

libmceliece is intended to be called by larger multi-function libraries (such as traditional cryptographic libraries), including libraries in other languages via FFI. The idea is that libmceliece takes responsibility for the details of Classic McEliece computation, including optimization, timing-attack protection, and (in ongoing work) verification, freeing up the calling libraries to concentrate on application-specific needs such as protocol integration. Applications can also call libmceliece directly.