Function secp256k1_sys::secp256k1_ecdsa_sign

pub unsafe extern "C" fn secp256k1_ecdsa_sign(
    cx: *const Context, 
    sig: *mut Signature, 
    msg32: *const c_uchar, 
    sk: *const c_uchar, 
    noncefn: NonceFn, 
    noncedata: *const c_void
) -> c_int