Function EVP_PKEY_encapsulate 

pub unsafe extern "C" fn EVP_PKEY_encapsulate(
    ctx: *mut EVP_PKEY_CTX,
    wrappedkey: *mut c_uchar,
    wrappedkeylen: *mut usize,
    genkey: *mut c_uchar,
    genkeylen: *mut usize,
) -> c_int