use tc_zeroize::Zeroize;
const BYTE_BIT: [u8; 8] = [128, 64, 32, 16, 8, 4, 2, 1];
const BIG_BYTE: [u32; 24] = [
0x800000, 0x400000, 0x200000, 0x100000, 0x80000, 0x40000, 0x20000, 0x10000, 0x8000, 0x4000,
0x2000, 0x1000, 0x800, 0x400, 0x200, 0x100, 0x80, 0x40, 0x20, 0x10, 0x8, 0x4, 0x2, 0x1,
];
const PC1: [u8; 56] = [
56, 48, 40, 32, 24, 16, 8, 0, 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59,
51, 43, 35, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 60, 52, 44, 36, 28,
20, 12, 4, 27, 19, 11, 3,
];
const TOTAL_ROTATIONS: [u8; 16] = [1, 2, 4, 6, 8, 10, 12, 14, 15, 17, 19, 21, 23, 25, 27, 28];
const PC2: [u8; 48] = [
13, 16, 10, 23, 0, 4, 2, 27, 14, 5, 20, 9, 22, 18, 11, 3, 25, 7, 15, 6, 26, 19, 12, 1, 40, 51,
30, 36, 46, 54, 29, 39, 50, 44, 32, 47, 43, 48, 38, 55, 33, 52, 45, 41, 49, 35, 28, 31,
];
const SP1: [u32; 64] = [
0x01010400, 0x00000000, 0x00010000, 0x01010404, 0x01010004, 0x00010404, 0x00000004, 0x00010000,
0x00000400, 0x01010400, 0x01010404, 0x00000400, 0x01000404, 0x01010004, 0x01000000, 0x00000004,
0x00000404, 0x01000400, 0x01000400, 0x00010400, 0x00010400, 0x01010000, 0x01010000, 0x01000404,
0x00010004, 0x01000004, 0x01000004, 0x00010004, 0x00000000, 0x00000404, 0x00010404, 0x01000000,
0x00010000, 0x01010404, 0x00000004, 0x01010000, 0x01010400, 0x01000000, 0x01000000, 0x00000400,
0x01010004, 0x00010000, 0x00010400, 0x01000004, 0x00000400, 0x00000004, 0x01000404, 0x00010404,
0x01010404, 0x00010004, 0x01010000, 0x01000404, 0x01000004, 0x00000404, 0x00010404, 0x01010400,
0x00000404, 0x01000400, 0x01000400, 0x00000000, 0x00010004, 0x00010400, 0x00000000, 0x01010004,
];
const SP2: [u32; 64] = [
0x80108020, 0x80008000, 0x00008000, 0x00108020, 0x00100000, 0x00000020, 0x80100020, 0x80008020,
0x80000020, 0x80108020, 0x80108000, 0x80000000, 0x80008000, 0x00100000, 0x00000020, 0x80100020,
0x00108000, 0x00100020, 0x80008020, 0x00000000, 0x80000000, 0x00008000, 0x00108020, 0x80100000,
0x00100020, 0x80000020, 0x00000000, 0x00108000, 0x00008020, 0x80108000, 0x80100000, 0x00008020,
0x00000000, 0x00108020, 0x80100020, 0x00100000, 0x80008020, 0x80100000, 0x80108000, 0x00008000,
0x80100000, 0x80008000, 0x00000020, 0x80108020, 0x00108020, 0x00000020, 0x00008000, 0x80000000,
0x00008020, 0x80108000, 0x00100000, 0x80000020, 0x00100020, 0x80008020, 0x80000020, 0x00100020,
0x00108000, 0x00000000, 0x80008000, 0x00008020, 0x80000000, 0x80100020, 0x80108020, 0x00108000,
];
const SP3: [u32; 64] = [
0x00000208, 0x08020200, 0x00000000, 0x08020008, 0x08000200, 0x00000000, 0x00020208, 0x08000200,
0x00020008, 0x08000008, 0x08000008, 0x00020000, 0x08020208, 0x00020008, 0x08020000, 0x00000208,
0x08000000, 0x00000008, 0x08020200, 0x00000200, 0x00020200, 0x08020000, 0x08020008, 0x00020208,
0x08000208, 0x00020200, 0x00020000, 0x08000208, 0x00000008, 0x08020208, 0x00000200, 0x08000000,
0x08020200, 0x08000000, 0x00020008, 0x00000208, 0x00020000, 0x08020200, 0x08000200, 0x00000000,
0x00000200, 0x00020008, 0x08020208, 0x08000200, 0x08000008, 0x00000200, 0x00000000, 0x08020008,
0x08000208, 0x00020000, 0x08000000, 0x08020208, 0x00000008, 0x00020208, 0x00020200, 0x08000008,
0x08020000, 0x08000208, 0x00000208, 0x08020000, 0x00020208, 0x00000008, 0x08020008, 0x00020200,
];
const SP4: [u32; 64] = [
0x00802001, 0x00002081, 0x00002081, 0x00000080, 0x00802080, 0x00800081, 0x00800001, 0x00002001,
0x00000000, 0x00802000, 0x00802000, 0x00802081, 0x00000081, 0x00000000, 0x00800080, 0x00800001,
0x00000001, 0x00002000, 0x00800000, 0x00802001, 0x00000080, 0x00800000, 0x00002001, 0x00002080,
0x00800081, 0x00000001, 0x00002080, 0x00800080, 0x00002000, 0x00802080, 0x00802081, 0x00000081,
0x00800080, 0x00800001, 0x00802000, 0x00802081, 0x00000081, 0x00000000, 0x00000000, 0x00802000,
0x00002080, 0x00800080, 0x00800081, 0x00000001, 0x00802001, 0x00002081, 0x00002081, 0x00000080,
0x00802081, 0x00000081, 0x00000001, 0x00002000, 0x00800001, 0x00002001, 0x00802080, 0x00800081,
0x00002001, 0x00002080, 0x00800000, 0x00802001, 0x00000080, 0x00800000, 0x00002000, 0x00802080,
];
const SP5: [u32; 64] = [
0x00000100, 0x02080100, 0x02080000, 0x42000100, 0x00080000, 0x00000100, 0x40000000, 0x02080000,
0x40080100, 0x00080000, 0x02000100, 0x40080100, 0x42000100, 0x42080000, 0x00080100, 0x40000000,
0x02000000, 0x40080000, 0x40080000, 0x00000000, 0x40000100, 0x42080100, 0x42080100, 0x02000100,
0x42080000, 0x40000100, 0x00000000, 0x42000000, 0x02080100, 0x02000000, 0x42000000, 0x00080100,
0x00080000, 0x42000100, 0x00000100, 0x02000000, 0x40000000, 0x02080000, 0x42000100, 0x40080100,
0x02000100, 0x40000000, 0x42080000, 0x02080100, 0x40080100, 0x00000100, 0x02000000, 0x42080000,
0x42080100, 0x00080100, 0x42000000, 0x42080100, 0x02080000, 0x00000000, 0x40080000, 0x42000000,
0x00080100, 0x02000100, 0x40000100, 0x00080000, 0x00000000, 0x40080000, 0x02080100, 0x40000100,
];
const SP6: [u32; 64] = [
0x20000010, 0x20400000, 0x00004000, 0x20404010, 0x20400000, 0x00000010, 0x20404010, 0x00400000,
0x20004000, 0x00404010, 0x00400000, 0x20000010, 0x00400010, 0x20004000, 0x20000000, 0x00004010,
0x00000000, 0x00400010, 0x20004010, 0x00004000, 0x00404000, 0x20004010, 0x00000010, 0x20400010,
0x20400010, 0x00000000, 0x00404010, 0x20404000, 0x00004010, 0x00404000, 0x20404000, 0x20000000,
0x20004000, 0x00000010, 0x20400010, 0x00404000, 0x20404010, 0x00400000, 0x00004010, 0x20000010,
0x00400000, 0x20004000, 0x20000000, 0x00004010, 0x20000010, 0x20404010, 0x00404000, 0x20400000,
0x00404010, 0x20404000, 0x00000000, 0x20400010, 0x00000010, 0x00004000, 0x20400000, 0x00404010,
0x00004000, 0x00400010, 0x20004010, 0x00000000, 0x20404000, 0x20000000, 0x00400010, 0x20004010,
];
const SP7: [u32; 64] = [
0x00200000, 0x04200002, 0x04000802, 0x00000000, 0x00000800, 0x04000802, 0x00200802, 0x04200800,
0x04200802, 0x00200000, 0x00000000, 0x04000002, 0x00000002, 0x04000000, 0x04200002, 0x00000802,
0x04000800, 0x00200802, 0x00200002, 0x04000800, 0x04000002, 0x04200000, 0x04200800, 0x00200002,
0x04200000, 0x00000800, 0x00000802, 0x04200802, 0x00200800, 0x00000002, 0x04000000, 0x00200800,
0x04000000, 0x00200800, 0x00200000, 0x04000802, 0x04000802, 0x04200002, 0x04200002, 0x00000002,
0x00200002, 0x04000000, 0x04000800, 0x00200000, 0x04200800, 0x00000802, 0x00200802, 0x04200800,
0x00000802, 0x04000002, 0x04200802, 0x04200000, 0x00200800, 0x00000000, 0x00000002, 0x04200802,
0x00000000, 0x00200802, 0x04200000, 0x00000800, 0x04000002, 0x04000800, 0x00000800, 0x00200002,
];
const SP8: [u32; 64] = [
0x10001040, 0x00001000, 0x00040000, 0x10041040, 0x10000000, 0x10001040, 0x00000040, 0x10000000,
0x00040040, 0x10040000, 0x10041040, 0x00041000, 0x10041000, 0x00041040, 0x00001000, 0x00000040,
0x10040000, 0x10000040, 0x10001000, 0x00001040, 0x00041000, 0x00040040, 0x10040040, 0x10041000,
0x00001040, 0x00000000, 0x00000000, 0x10040040, 0x10000040, 0x10001000, 0x00041040, 0x00040000,
0x00041040, 0x00040000, 0x10041000, 0x00001000, 0x00000040, 0x10040040, 0x00001000, 0x00041040,
0x10001000, 0x00000040, 0x10000040, 0x10040000, 0x10040040, 0x10000000, 0x00040000, 0x10001040,
0x00000000, 0x10041040, 0x00040040, 0x10000040, 0x10040000, 0x10001000, 0x10001040, 0x00000000,
0x10041040, 0x00041000, 0x00041000, 0x00001040, 0x00001040, 0x00040040, 0x10000000, 0x10041000,
];
pub(crate) fn generate_working_key(encrypting: bool, key: &[u8; 8]) -> [u32; 32] {
let mut new_key = [0_u32; 32];
let mut pc1m = [false; 56];
let mut pcr = [false; 56];
for (j, &permuted_bit) in PC1.iter().enumerate() {
let bit = usize::from(permuted_bit);
pc1m[j] = key[bit >> 3] & BYTE_BIT[bit & 7] != 0;
}
for (round, &rotation) in TOTAL_ROTATIONS.iter().enumerate() {
let first = if encrypting {
round << 1
} else {
(15 - round) << 1
};
let second = first + 1;
for (j, bit) in pcr[..28].iter_mut().enumerate() {
let rotated = j + usize::from(rotation);
*bit = pc1m[if rotated < 28 { rotated } else { rotated - 28 }];
}
for (offset, bit) in pcr[28..].iter_mut().enumerate() {
let j = offset + 28;
let rotated = j + usize::from(rotation);
*bit = pc1m[if rotated < 56 { rotated } else { rotated - 28 }];
}
for j in 0..24 {
if pcr[usize::from(PC2[j])] {
new_key[first] |= BIG_BYTE[j];
}
if pcr[usize::from(PC2[j + 24])] {
new_key[second] |= BIG_BYTE[j];
}
}
}
for i in (0..32).step_by(2) {
let first = new_key[i];
let second = new_key[i + 1];
new_key[i] = ((first & 0x00fc0000) << 6)
| ((first & 0x00000fc0) << 10)
| ((second & 0x00fc0000) >> 10)
| ((second & 0x00000fc0) >> 6);
new_key[i + 1] = ((first & 0x0003f000) << 12)
| ((first & 0x0000003f) << 16)
| ((second & 0x0003f000) >> 4)
| (second & 0x0000003f);
}
pc1m.zeroize();
pcr.zeroize();
new_key
}
pub(crate) fn des_func(working_key: &[u32; 32], high: &mut u32, low: &mut u32) {
let mut left = *high;
let mut right = *low;
let mut work = ((left >> 4) ^ right) & 0x0f0f0f0f;
right ^= work;
left ^= work << 4;
work = ((left >> 16) ^ right) & 0x0000ffff;
right ^= work;
left ^= work << 16;
work = ((right >> 2) ^ left) & 0x33333333;
left ^= work;
right ^= work << 2;
work = ((right >> 8) ^ left) & 0x00ff00ff;
left ^= work;
right ^= work << 8;
right = right.rotate_left(1);
work = (left ^ right) & 0xaaaaaaaa;
left ^= work;
right ^= work;
left = left.rotate_left(1);
for round in 0..8 {
work = right.rotate_right(4) ^ working_key[round * 4];
let mut fval = SP7[(work & 0x3f) as usize]
| SP5[((work >> 8) & 0x3f) as usize]
| SP3[((work >> 16) & 0x3f) as usize]
| SP1[((work >> 24) & 0x3f) as usize];
work = right ^ working_key[round * 4 + 1];
fval |= SP8[(work & 0x3f) as usize]
| SP6[((work >> 8) & 0x3f) as usize]
| SP4[((work >> 16) & 0x3f) as usize]
| SP2[((work >> 24) & 0x3f) as usize];
left ^= fval;
work = left.rotate_right(4) ^ working_key[round * 4 + 2];
fval = SP7[(work & 0x3f) as usize]
| SP5[((work >> 8) & 0x3f) as usize]
| SP3[((work >> 16) & 0x3f) as usize]
| SP1[((work >> 24) & 0x3f) as usize];
work = left ^ working_key[round * 4 + 3];
fval |= SP8[(work & 0x3f) as usize]
| SP6[((work >> 8) & 0x3f) as usize]
| SP4[((work >> 16) & 0x3f) as usize]
| SP2[((work >> 24) & 0x3f) as usize];
right ^= fval;
}
right = right.rotate_right(1);
work = (left ^ right) & 0xaaaaaaaa;
left ^= work;
right ^= work;
left = left.rotate_right(1);
work = ((left >> 8) ^ right) & 0x00ff00ff;
right ^= work;
left ^= work << 8;
work = ((left >> 2) ^ right) & 0x33333333;
right ^= work;
left ^= work << 2;
work = ((right >> 16) ^ left) & 0x0000ffff;
left ^= work;
right ^= work << 16;
work = ((right >> 4) ^ left) & 0x0f0f0f0f;
left ^= work;
right ^= work << 4;
*high = right;
*low = left;
}