Function secp256k1_zkp_sys::secp256k1_ecdsa_sign

pub unsafe extern "C" fn secp256k1_ecdsa_sign(
    cx: *const Context, 
    sig: *mut Signature, 
    msg32: *const u8, 
    sk: *const u8, 
    noncefn: Option<unsafe extern "C" fn(*mut u8, *const u8, *const u8, *const u8, *mut c_void, u32) -> i32>, 
    noncedata: *const c_void
) -> i32