extern crate byteorder;
extern crate natrium;

use natrium::chacha;

#[test]
fn quarter_round_test_vector() {
  let a = 0x11111111;
  let b = 0x01020304;
  let c = 0x9b8d6f43;
  let d = 0x01234567;

  let (a, b, c, d) = chacha::quarter_round(a, b, c, d);

  assert_eq!(a, 0xea2a92f4);
  assert_eq!(b, 0xcb1cf8ce);
  assert_eq!(c, 0x4581472e);
  assert_eq!(d, 0x5881c4bb);
}

#[test]
fn qround_test_vector() {
  let mut state = vec![
    0x879531e0, 0xc5ecf37d, 0x516461b1, 0xc9a62f8a, 0x44c20ef3, 0x3390af7f,
    0xd9fc690b, 0x2a5f714c, 0x53372767, 0xb00a5631, 0x974c541a, 0x359e9963,
    0x5c971061, 0x3d631689, 0x2098d9d6, 0x91dbd320,
  ];

  chacha::qround(&mut state, 2, 7, 8, 13);

  let expected = [
    0x879531e0, 0xc5ecf37d, 0xbdb886dc, 0xc9a62f8a, 0x44c20ef3, 0x3390af7f,
    0xd9fc690b, 0xcfacafd2, 0xe46bea80, 0xb00a5631, 0x974c541a, 0x359e9963,
    0x5c971061, 0xccc07c79, 0x2098d9d6, 0x91dbd320,
  ];

  assert_eq!(state, expected);
}

// Follows the IETF spec test data.
#[test]
fn chacha20_block_test_vector() {
  let key = chacha::Key::from_bytes(vec![
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b,
    0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
    0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
  ]).unwrap();

  let nonce = to_u32(vec![
    0x00, 0x00, 0x00, 0x09, 0x00, 0x00, 0x00, 0x4a, 0x00, 0x00, 0x00, 0x00,
  ]);

  let block_count = 1u32;

  let state = chacha::setup_state(&key, &nonce, block_count);
  let expected = vec![
    0x61707865, 0x3320646e, 0x79622d32, 0x6b206574, 0x03020100, 0x07060504,
    0x0b0a0908, 0x0f0e0d0c, 0x13121110, 0x17161514, 0x1b1a1918, 0x1f1e1d1c,
    0x00000001, 0x09000000, 0x4a000000, 0x00000000,
  ];
  assert_eq!(state, expected, "setup state");

  let working_state = chacha::rot20(&state);
  let expected = vec![
    0x837778ab, 0xe238d763, 0xa67ae21e, 0x5950bb2f, 0xc4f2d0c7, 0xfc62bb2f,
    0x8fa018fc, 0x3f5ec7b7, 0x335271c2, 0xf29489f3, 0xeabda8fc, 0x82e46ebd,
    0xd19c12b4, 0xb04e16de, 0x9e83d0cb, 0x4e3c50a2,
  ];
  assert_eq!(working_state, expected, "20 rotations");

  let res = chacha::chacha20_block(&key, &nonce, block_count);
  let expected = vec![
    0xe4e7f110, 0x15593bd1, 0x1fdd0f50, 0xc47120a3, 0xc7f4d1c7, 0x0368c033,
    0x9aaa2204, 0x4e6cd4c3, 0x466482d2, 0x09aa9f07, 0x05d7c214, 0xa2028bd9,
    0xd19c12b5, 0xb94e16de, 0xe883d0cb, 0x4e3c50a2,
  ];
  assert_eq!(res, expected, "block");

  fn to_u32(from: Vec<u8>) -> Vec<u32> {
    use self::byteorder::{ReadBytesExt, LE};
    use std::io::Cursor;

    let max = from.len() / 4;

    let mut state = Vec::with_capacity(max);
    let mut reader = Cursor::new(from);
    for _ in 0..max {
      let byte = reader.read_u32::<LE>().unwrap();
      state.push(byte);
    }

    state
  }
}