Function EverCrypt_HKDF_expand 

pub unsafe extern "C" fn EverCrypt_HKDF_expand(
    a: Spec_Hash_Definitions_hash_alg,
    okm: *mut u8,
    prk: *mut u8,
    prklen: u32,
    info: *mut u8,
    infolen: u32,
    len: u32,
)