Function mbedtls_sys::ecdsa_sign

pub unsafe extern "C" fn ecdsa_sign(
    grp: *mut ecp_group, 
    r: *mut mpi, 
    s: *mut mpi, 
    d: *const mpi, 
    buf: *const c_uchar, 
    blen: size_t, 
    f_rng: Option<unsafe extern "C" fn(arg1: *mut c_void, arg2: *mut c_uchar, arg3: size_t) -> c_int>, 
    p_rng: *mut c_void
) -> c_int