// Copyright (C) 2017-2018 Baidu, Inc. All Rights Reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
//  * Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//  * Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in
//    the documentation and/or other materials provided with the
//    distribution.
//  * Neither the name of Baidu, Inc., nor the names of its
//    contributors may be used to endorse or promote products derived
//    from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#![crate_name = "secretsharingenclave"]
#![crate_type = "staticlib"]

#![cfg_attr(not(target_env = "sgx"), no_std)]
#![cfg_attr(target_env = "sgx", feature(rustc_private))]

extern crate sgx_types;
#[cfg(not(target_env = "sgx"))]
#[macro_use]
extern crate sgx_tstd as std;

use sgx_types::*;
use std::vec::Vec;
use std::slice;
use std::io::{self, Write};

extern crate threshold_secret_sharing as tss;

/// A function simply invokes ocall print to print the incoming string
///
/// # Parameters
///
/// **some_string**
///
/// A pointer to the string to be printed
///
/// **len**
///
/// An unsigned int indicates the length of str
///
/// # Return value
///
/// Always returns SGX_SUCCESS
#[no_mangle]
pub extern "C" fn say_something(some_string: *const u8, some_len: usize) -> sgx_status_t {
    let str_slice = unsafe { slice::from_raw_parts(some_string, some_len) };
    let _ = io::stdout().write(str_slice);

    const PRIME: i64 = 1300477;

    let ref tss = tss::shamir::ShamirSecretSharing {
        threshold: 9,
        share_count: 20,
        prime: PRIME,  // any large enough prime will do
    };

    let secret: i64 = 23242;
    println!("Secret generated is {}", secret);
    let all_shares = tss.share(secret);

    let reconstruct_share_count = 10;
    assert!(reconstruct_share_count >= tss.reconstruct_limit());

    let indices: Vec<usize> = (0..reconstruct_share_count).collect();
    let shares: &[i64] = &all_shares[0..reconstruct_share_count];
    let recovered_secret = tss.reconstruct(&indices, shares);

    println!("The recovered secret is {}", recovered_secret);
    assert_eq!(recovered_secret, secret);


    sgx_status_t::SGX_SUCCESS
}
