authfs: Add FFI to libcrypto

The FFI is currently used for accessing SHA256 related functions, as
well as SHA256_CTX struct. The whole header is included for bindgen
since we wouldn't want to inline the internal struct definition of
SHA256_CTX.

Bug: 171310075
Test: atest authfs_host_test_src_lib

Change-Id: I0bdec7956d4d0ee407122395fe2b48a437214f3f
4 files changed
tree: 2870ab197077f8def7b7c96545b712ee2880a514
  1. authfs/
  2. docs/
  3. .clang-format
  4. PREUPLOAD.cfg