1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148
pub use cipher::{BlockCipher, NewBlockCipher}; use core::ops::{BitXor, Shl, Shr}; use byteorder::{BigEndian, ByteOrder}; use cipher::consts::{U16, U4, U8}; use cipher::generic_array::GenericArray; use crate::simd::{slice_block, unslice_block, WrapArithmetic}; const TEA_DELTA: u32 = 0x9E3779B9; pub type Block8 = GenericArray<u8, U8>; pub type Block8x4 = GenericArray<Block8, U4>; macro_rules! define_tea_impl { ( $name:ident, $rounds:expr, $shift:expr, $doc:expr ) => { #[doc=$doc] #[derive(Clone)] pub struct $name { key: [u32; 4], } impl $name { #[inline] fn encrypt_core<T>(&self, x: T, y: T) -> (T, T) where T: Copy + WrapArithmetic<T> + WrapArithmetic<u32> + BitXor<Output = T> + Shl<usize, Output = T> + Shr<usize, Output = T> { let mut sum: u32 = 0; let (mut x, mut y) = (x, y); let k0 = self.key[0]; let k1 = self.key[1]; let k2 = self.key[2]; let k3 = self.key[3]; for _ in 0..$rounds { sum = sum.wrapping_add(TEA_DELTA); x = WrapArithmetic::wrapping_add(x, WrapArithmetic::wrapping_add(y << 4, k0) ^ WrapArithmetic::wrapping_add(y, sum) ^ WrapArithmetic::wrapping_add(y >> 5, k1)); y = WrapArithmetic::wrapping_add(y, WrapArithmetic::wrapping_add(x << 4, k2) ^ WrapArithmetic::wrapping_add(x, sum) ^ WrapArithmetic::wrapping_add(x >> 5, k3)); } (x, y) } #[inline] fn decrypt_core<T>(&self, x: T, y: T) -> (T, T) where T: Copy + WrapArithmetic<T> + WrapArithmetic<u32> + BitXor<Output = T> + Shl<usize, Output = T> + Shr<usize, Output = T> { let mut sum: u32 = TEA_DELTA << $shift; let (mut x, mut y) = (x, y); let k0 = self.key[0]; let k1 = self.key[1]; let k2 = self.key[2]; let k3 = self.key[3]; for _ in 0..$rounds { y = WrapArithmetic::wrapping_sub(y, WrapArithmetic::wrapping_add(x << 4, k2) ^ WrapArithmetic::wrapping_add(x, sum) ^ WrapArithmetic::wrapping_add(x >> 5, k3)); x = WrapArithmetic::wrapping_sub(x, WrapArithmetic::wrapping_add(y << 4, k0) ^ WrapArithmetic::wrapping_add(y, sum) ^ WrapArithmetic::wrapping_add(y >> 5, k1)); sum = sum.wrapping_sub(TEA_DELTA); } (x, y) } } impl NewBlockCipher for $name { type KeySize = U16; #[inline] fn new(key: &GenericArray<u8, U16>) -> Self { Self { key: [ BigEndian::read_u32(&key[0..4]), BigEndian::read_u32(&key[4..8]), BigEndian::read_u32(&key[8..12]), BigEndian::read_u32(&key[12..16]), ] } } } impl BlockCipher for $name { type BlockSize = U8; type ParBlocks = U4; #[inline] fn encrypt_block(&self, block: &mut Block8) { let x = BigEndian::read_u32(&block[0..4]); let y = BigEndian::read_u32(&block[4..8]); let (x, y) = self.encrypt_core(x, y); BigEndian::write_u32(&mut block[0..4], x); BigEndian::write_u32(&mut block[4..8], y); } #[inline] fn decrypt_block(&self, block: &mut Block8) { let x = BigEndian::read_u32(&block[0..4]); let y = BigEndian::read_u32(&block[4..8]); let (x, y) = self.decrypt_core(x, y); BigEndian::write_u32(&mut block[0..4], x); BigEndian::write_u32(&mut block[4..8], y); } #[inline] fn encrypt_blocks(&self, blocks: &mut Block8x4) { let (xs, ys) = slice_block(blocks); let (xs, ys) = self.encrypt_core(xs, ys); unslice_block(xs, ys, blocks); } #[inline] fn decrypt_blocks(&self, blocks: &mut Block8x4) { let (xs, ys) = slice_block(blocks); let (xs, ys) = self.decrypt_core(xs, ys); unslice_block(xs, ys, blocks); } } } } define_tea_impl!(Tea16, 16, 4, "TEA block cipher instance of 16 rounds"); define_tea_impl!(Tea32, 32, 5, "TEA block cipher instance of 32 rounds"); define_tea_impl!(Tea64, 64, 6, "TEA block cipher instance of 64 rounds");