#![allow(dead_code)]
static SBOX: [[u8; 16]; 16] = [
[ 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, ],
[ 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, ],
[ 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, ],
[ 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, ],
[ 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, ],
[ 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, ],
[ 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, ],
[ 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, ],
[ 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, ],
[ 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, ],
[ 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, ],
[ 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, ],
[ 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, ],
[ 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, ],
[ 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, ],
[ 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16, ],
];
static INV_SBOX: [[u8; 16]; 16] = [
[ 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb, ],
[ 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb, ],
[ 0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e, ],
[ 0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25, ],
[ 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92, ],
[ 0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84, ],
[ 0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06, ],
[ 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b, ],
[ 0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73, ],
[ 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e, ],
[ 0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b, ],
[ 0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4, ],
[ 0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f, ],
[ 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef, ],
[ 0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61, ],
[ 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d, ],
];
#[repr(usize)]
#[derive(Debug, Clone, Copy)]
pub enum Blocksize {
B128 = 128,
B192 = 192,
B256 = 256,
}
impl Blocksize {
pub fn new (u: usize) -> Option<Blocksize> {
Some(match u {
128 => Blocksize::B128,
192 => Blocksize::B192,
256 => Blocksize::B256,
_ => return None
})
}
}
#[allow(clippy::upper_case_acronyms)]
pub struct AES {
blocksize: Blocksize,
expanded_key: [[u8; 4]; 60],
state: [u8; 16],
}
impl AES {
pub fn init(key: &[u8], blocksize: Blocksize) -> AES {
AES {
blocksize,
state: [0; 16],
expanded_key: AES::get_expanded_key(key, blocksize),
}
}
pub fn encrypt(&mut self, input: [u8; 16]) -> [u8; 16] {
self.state = input;
let rounds = self.blocksize as usize / 32 + 6;
self.add_round_key(0);
for round in 1..=rounds {
self.sub_bytes();
self.shift_rows();
if round < rounds {
self.mix_columns(false);
}
self.add_round_key(round);
}
let out = self.state;
self.state = [0; 16];
out
}
pub fn decrypt(&mut self, input: [u8; 16]) -> [u8; 16] {
self.state = input;
let rounds = self.blocksize as usize / 32 + 6;
self.add_round_key(rounds);
for round in (0..rounds).rev() {
self.inv_shift_rows();
self.inv_sub_bytes();
self.add_round_key(round);
if round >= 1 {
self.mix_columns(true);
}
}
let out = self.state;
self.state = [0; 16];
out
}
fn get_expanded_key(key: &[u8], blocksize: Blocksize) -> [[u8; 4]; 60] {
let mut temp: [u8; 4];
let nk = blocksize as usize / 32; let nr = blocksize as usize / 32 + 6;
let rcon: [u8; 10] = [0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36];
let mut expanded_key: [[u8; 4]; 60] = [[0; 4]; 60];
for i in 0..nk {
for j in 0..4 {
expanded_key[i][j] = key[(i*4) + j].to_owned();
}
}
for i in nk..(4 * (nr + 1)) {
temp = expanded_key[i - 1];
if i % nk == 0 {
AES::rot_word(&mut temp);
AES::sub_word(&mut temp);
temp[0] ^= rcon[i / nk - 1];
} else if nk > 6 && (i % nk) == 4 {
AES::sub_word(&mut temp);
}
for (j, tmp) in temp.iter().enumerate() {
expanded_key[i][j] = expanded_key[i - nk][j] ^ tmp;
}
}
expanded_key
}
fn gmult(mut a: u8, mut b: u8) -> u8 {
let mut p: u8 = 0;
let mut hbs: u8;
for _ in 0..8 {
if b & 1 != 0 {
p ^= a;
}
hbs = a & 0x80;
a <<= 1;
if hbs != 0 {
a ^= 0x1b; }
b >>= 1;
}
p
}
fn sub_word(word: &mut [u8; 4]) {
for i in 0..4 {
word[i] = SBOX[((word[i] >> 4) & 0xf) as usize][((word[i]) & 0xf) as usize];
}
}
fn rot_word(word: &mut [u8; 4]) {
let tmp: u8 = word[0];
word[0] = word[1];
word[1] = word[2];
word[2] = word[3];
word[3] = tmp;
}
fn sub_bytes(&mut self) {
for i in 0..16 {
self.state[i] =
SBOX[((self.state[i] >> 4) & 0xf) as usize][((self.state[i]) & 0xf) as usize];
}
}
fn inv_sub_bytes(&mut self) {
for i in 0..16 {
self.state[i] =
INV_SBOX[((self.state[i] >> 4) & 0xf) as usize][((self.state[i]) & 0xf) as usize];
}
}
fn shift_rows(&mut self) {
let mut tmp = self.state[1];
self.state[1] = self.state[5];
self.state[5] = self.state[9];
self.state[9] = self.state[13];
self.state[13] = tmp;
tmp = self.state[2];
self.state[2] = self.state[10];
self.state[10] = tmp;
tmp = self.state[6];
self.state[6] = self.state[14];
self.state[14] = tmp;
tmp = self.state[11];
self.state[11] = self.state[7];
self.state[7] = self.state[3];
self.state[3] = self.state[15];
self.state[15] = tmp;
}
fn inv_shift_rows(&mut self) {
let mut tmp = self.state[9];
self.state[9] = self.state[5];
self.state[5] = self.state[1];
self.state[1] = self.state[13];
self.state[13] = tmp;
tmp = self.state[2];
self.state[2] = self.state[10];
self.state[10] = tmp;
tmp = self.state[6];
self.state[6] = self.state[14];
self.state[14] = tmp;
tmp = self.state[3];
self.state[3] = self.state[7];
self.state[7] = self.state[11];
self.state[11] = self.state[15];
self.state[15] = tmp;
}
fn mix_columns(&mut self, inverse: bool) {
let matrix: [u8; 16] = if inverse {
[ 0xE, 0xB, 0xD, 0x9, 0x9, 0xE, 0xB, 0xD, 0xD, 0x9, 0xE, 0xB, 0xB, 0xD, 0x9, 0xE, ]
} else {
[ 0x2, 0x3, 0x1, 0x1, 0x1, 0x2, 0x3, 0x1, 0x1, 0x1, 0x2, 0x3, 0x3, 0x1, 0x1, 0x2, ]
};
let mut tmp_matrix: [u8; 16] = [0; 16];
for column in 0..4 {
for row in 0..4 {
for matrix_column in 0..4 {
tmp_matrix[row + (4 * column)] ^= AES::gmult(
matrix[(row * 4) + matrix_column],
self.state[matrix_column + (4 * column)],
);
}
}
}
self.state = tmp_matrix;
}
fn add_round_key(&mut self, round: usize) {
for x in 0..4 {
for y in 0..4 {
self.state[(x * 4) + y] ^= self.expanded_key[(round * 4) + x][y];
}
}
}
}
#[cfg(test)]
mod tests {
use super::{Blocksize, AES};
fn test_aes(blocksize: Blocksize, input: [u8; 16], key: &[u8], expected: [u8; 16]) {
let mut aes = AES::init(key, blocksize);
let out_encrypted = aes.encrypt(input);
if out_encrypted != expected {
println!("out_encrypted={out_encrypted:?}");
println!("expected={expected:?}");
panic!("encrypted data is wrong (blocksize={})!", blocksize as usize);
}
let out_decrypted = aes.decrypt(out_encrypted);
if out_decrypted != input {
println!("out_decrypted={out_decrypted:?}");
println!("input={input:?}");
panic!("decrypted data is wrong (blocksize={})!", blocksize as usize);
}
}
#[test]
fn test_aes_128() {
let plaintext: [u8; 16] = [0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff];
let key128: [u8; 16] = [0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f];
let cypher128: [u8; 16] = [0x69, 0xc4, 0xe0, 0xd8, 0x6a, 0x7b, 0x04, 0x30, 0xd8, 0xcd, 0xb7, 0x80, 0x70, 0xb4, 0xc5, 0x5a];
test_aes(Blocksize::B128, plaintext, &key128, cypher128);
let key192: [u8; 24] = [0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17];
let cypher192: [u8; 16]= [0xdd, 0xa9, 0x7c, 0xa4, 0x86, 0x4c, 0xdf, 0xe0, 0x6e, 0xaf, 0x70, 0xa0, 0xec, 0x0d, 0x71, 0x91];
test_aes(Blocksize::B192, plaintext, &key192, cypher192);
let key256: [u8; 32] = [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];
let cypher256: [u8; 16] = [0x8e, 0xa2, 0xb7, 0xca, 0x51, 0x67, 0x45, 0xbf, 0xea, 0xfc, 0x49, 0x90, 0x4b, 0x49, 0x60, 0x89];
test_aes(Blocksize::B256, plaintext, &key256, cypher256);
}
}