#![allow(clippy::many_single_char_names)]
pub const fn sha1(data: &ConstBuffer) -> Digest {
let state: [u32; 5] = [0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476, 0xc3d2e1f0];
let len: u64 = 0;
let blocks = Blocks { len: 0, data: [0; 64] };
let (blocks, len, state) = process_blocks(blocks, data, len, state);
digest(state, len, blocks)
}
const BUFFER_SIZE: usize = 1024;
pub struct ConstBuffer {
data: [u8; BUFFER_SIZE],
head: usize,
}
impl ConstBuffer {
pub const fn from_slice(slice: &[u8]) -> Self {
let s = Self::new();
s.push_slice(slice)
}
pub const fn new() -> Self {
Self { data: [0; BUFFER_SIZE], head: 0 }
}
pub const fn push_slice(self, slice: &[u8]) -> Self {
self.push_amount(slice, slice.len())
}
const fn get(&self, index: usize) -> u8 {
self.data[index]
}
const fn len(&self) -> usize {
self.head
}
const fn as_slice(&self) -> &[u8] {
&self.data
}
pub const fn push_other(self, other: Self) -> Self {
self.push_amount(other.as_slice(), other.len())
}
const fn push_amount(mut self, slice: &[u8], amount: usize) -> Self {
let mut i = 0;
while i < amount {
self.data[self.head + i] = slice[i];
i += 1;
}
self.head += i;
self
}
}
struct Blocks {
len: u32,
data: [u8; 64],
}
const fn process_blocks(mut blocks: Blocks, data: &ConstBuffer, mut len: u64, mut state: [u32; 5]) -> (Blocks, u64, [u32; 5]) {
const fn as_block(input: &ConstBuffer, offset: usize) -> [u32; 16] {
let mut result = [0u32; 16];
let mut i = 0;
while i != 16 {
let off = offset + (i * 4);
result[i] = (input.get(off + 3) as u32) | ((input.get(off + 2) as u32) << 8) | ((input.get(off + 1) as u32) << 16) | ((input.get(off) as u32) << 24);
i += 1;
}
result
}
const fn clone_from_slice_64(mut data: [u8; 64], slice: &[u8], offset: usize, num_elems: usize) -> [u8; 64] {
let mut i = 0;
while i < num_elems {
data[i] = slice[offset + i];
i += 1;
}
data
}
let mut i = 0;
while i < data.len() {
if data.len() - i >= 64 {
let chunk_block = as_block(data, i);
len += 64;
state = process_state(state, chunk_block);
i += 64;
} else {
let num_elems = data.len() - i;
blocks.data = clone_from_slice_64(blocks.data, data.as_slice(), i, num_elems);
blocks.len = num_elems as u32;
break;
}
}
(blocks, len, state)
}
const fn process_state(mut state: [u32; 5], block: [u32; 16]) -> [u32; 5] {
let a = state[0];
let b = state[1];
let c = state[2];
let d = state[3];
let e = state[4];
let (block, b, e) = r0(block, a, b, c, d, e, 0);
let (block, a, d) = r0(block, e, a, b, c, d, 1);
let (block, e, c) = r0(block, d, e, a, b, c, 2);
let (block, d, b) = r0(block, c, d, e, a, b, 3);
let (block, c, a) = r0(block, b, c, d, e, a, 4);
let (block, b, e) = r0(block, a, b, c, d, e, 5);
let (block, a, d) = r0(block, e, a, b, c, d, 6);
let (block, e, c) = r0(block, d, e, a, b, c, 7);
let (block, d, b) = r0(block, c, d, e, a, b, 8);
let (block, c, a) = r0(block, b, c, d, e, a, 9);
let (block, b, e) = r0(block, a, b, c, d, e, 10);
let (block, a, d) = r0(block, e, a, b, c, d, 11);
let (block, e, c) = r0(block, d, e, a, b, c, 12);
let (block, d, b) = r0(block, c, d, e, a, b, 13);
let (block, c, a) = r0(block, b, c, d, e, a, 14);
let (block, b, e) = r0(block, a, b, c, d, e, 15);
let (block, a, d) = r1(block, e, a, b, c, d, 0);
let (block, e, c) = r1(block, d, e, a, b, c, 1);
let (block, d, b) = r1(block, c, d, e, a, b, 2);
let (block, c, a) = r1(block, b, c, d, e, a, 3);
let (block, b, e) = r2(block, a, b, c, d, e, 4);
let (block, a, d) = r2(block, e, a, b, c, d, 5);
let (block, e, c) = r2(block, d, e, a, b, c, 6);
let (block, d, b) = r2(block, c, d, e, a, b, 7);
let (block, c, a) = r2(block, b, c, d, e, a, 8);
let (block, b, e) = r2(block, a, b, c, d, e, 9);
let (block, a, d) = r2(block, e, a, b, c, d, 10);
let (block, e, c) = r2(block, d, e, a, b, c, 11);
let (block, d, b) = r2(block, c, d, e, a, b, 12);
let (block, c, a) = r2(block, b, c, d, e, a, 13);
let (block, b, e) = r2(block, a, b, c, d, e, 14);
let (block, a, d) = r2(block, e, a, b, c, d, 15);
let (block, e, c) = r2(block, d, e, a, b, c, 0);
let (block, d, b) = r2(block, c, d, e, a, b, 1);
let (block, c, a) = r2(block, b, c, d, e, a, 2);
let (block, b, e) = r2(block, a, b, c, d, e, 3);
let (block, a, d) = r2(block, e, a, b, c, d, 4);
let (block, e, c) = r2(block, d, e, a, b, c, 5);
let (block, d, b) = r2(block, c, d, e, a, b, 6);
let (block, c, a) = r2(block, b, c, d, e, a, 7);
let (block, b, e) = r3(block, a, b, c, d, e, 8);
let (block, a, d) = r3(block, e, a, b, c, d, 9);
let (block, e, c) = r3(block, d, e, a, b, c, 10);
let (block, d, b) = r3(block, c, d, e, a, b, 11);
let (block, c, a) = r3(block, b, c, d, e, a, 12);
let (block, b, e) = r3(block, a, b, c, d, e, 13);
let (block, a, d) = r3(block, e, a, b, c, d, 14);
let (block, e, c) = r3(block, d, e, a, b, c, 15);
let (block, d, b) = r3(block, c, d, e, a, b, 0);
let (block, c, a) = r3(block, b, c, d, e, a, 1);
let (block, b, e) = r3(block, a, b, c, d, e, 2);
let (block, a, d) = r3(block, e, a, b, c, d, 3);
let (block, e, c) = r3(block, d, e, a, b, c, 4);
let (block, d, b) = r3(block, c, d, e, a, b, 5);
let (block, c, a) = r3(block, b, c, d, e, a, 6);
let (block, b, e) = r3(block, a, b, c, d, e, 7);
let (block, a, d) = r3(block, e, a, b, c, d, 8);
let (block, e, c) = r3(block, d, e, a, b, c, 9);
let (block, d, b) = r3(block, c, d, e, a, b, 10);
let (block, c, a) = r3(block, b, c, d, e, a, 11);
let (block, b, e) = r4(block, a, b, c, d, e, 12);
let (block, a, d) = r4(block, e, a, b, c, d, 13);
let (block, e, c) = r4(block, d, e, a, b, c, 14);
let (block, d, b) = r4(block, c, d, e, a, b, 15);
let (block, c, a) = r4(block, b, c, d, e, a, 0);
let (block, b, e) = r4(block, a, b, c, d, e, 1);
let (block, a, d) = r4(block, e, a, b, c, d, 2);
let (block, e, c) = r4(block, d, e, a, b, c, 3);
let (block, d, b) = r4(block, c, d, e, a, b, 4);
let (block, c, a) = r4(block, b, c, d, e, a, 5);
let (block, b, e) = r4(block, a, b, c, d, e, 6);
let (block, a, d) = r4(block, e, a, b, c, d, 7);
let (block, e, c) = r4(block, d, e, a, b, c, 8);
let (block, d, b) = r4(block, c, d, e, a, b, 9);
let (block, c, a) = r4(block, b, c, d, e, a, 10);
let (block, b, e) = r4(block, a, b, c, d, e, 11);
let (block, a, d) = r4(block, e, a, b, c, d, 12);
let (block, e, c) = r4(block, d, e, a, b, c, 13);
let (block, d, b) = r4(block, c, d, e, a, b, 14);
let (_, c, a) = r4(block, b, c, d, e, a, 15);
state[0] = state[0].wrapping_add(a);
state[1] = state[1].wrapping_add(b);
state[2] = state[2].wrapping_add(c);
state[3] = state[3].wrapping_add(d);
state[4] = state[4].wrapping_add(e);
state
}
const fn digest(mut state: [u32; 5], len: u64, blocks: Blocks) -> Digest {
const fn clone_from_slice_128(mut data: [u8; 128], slice: &[u8], offset: usize, num_elems: usize) -> [u8; 128] {
let mut i = 0;
while i < num_elems {
data[i] = slice[offset + i];
i += 1;
}
data
}
const fn clone_slice_128(mut data: [u8; 128], slice: &[u8], _offset: usize) -> [u8; 128] {
let mut i = 0;
while i < slice.len() {
data[_offset + i] = slice[i];
i += 1;
}
data
}
const fn as_block(input: &[u8], offset: usize) -> [u32; 16] {
let mut result = [0u32; 16];
let mut i = 0;
while i != 16 {
let off = offset + (i * 4);
result[i] = (input[off + 3] as u32) | ((input[off + 2] as u32) << 8) | ((input[off + 1] as u32) << 16) | ((input[off] as u32) << 24);
i += 1;
}
result
}
let bits = (len + (blocks.len as u64)) * 8;
let extra = [(bits >> 56) as u8, (bits >> 48) as u8, (bits >> 40) as u8, (bits >> 32) as u8, (bits >> 24) as u8, (bits >> 16) as u8, (bits >> 8) as u8, bits as u8];
let mut last = [0; 128];
let blocklen = blocks.len as usize;
last = clone_from_slice_128(last, &blocks.data, 0, blocklen);
last[blocklen] = 0x80;
if blocklen < 56 {
last = clone_slice_128(last, &extra, 56);
state = process_state(state, as_block(&last, 0));
} else {
last = clone_slice_128(last, &extra, 120);
state = process_state(state, as_block(&last, 0));
state = process_state(state, as_block(&last, 64));
}
Digest { data: state }
}
const fn rol(value: u32, bits: usize) -> u32 {
(value << bits) | (value >> (32 - bits))
}
const fn blk(block: &[u32], i: usize) -> u32 {
let value = block[(i + 13) & 15] ^ block[(i + 8) & 15] ^ block[(i + 2) & 15] ^ block[i];
rol(value, 1)
}
const fn r0(block: [u32; 16], v: u32, mut w: u32, x: u32, y: u32, mut z: u32, i: usize) -> ([u32; 16], u32, u32) {
let n = ((w & (x ^ y)) ^ y).wrapping_add(block[i]).wrapping_add(0x5a82_7999).wrapping_add(rol(v, 5));
z = z.wrapping_add(n);
w = rol(w, 30);
(block, w, z)
}
const fn r1(mut block: [u32; 16], v: u32, mut w: u32, x: u32, y: u32, mut z: u32, i: usize) -> ([u32; 16], u32, u32) {
block[i] = blk(&block, i);
let n = ((w & (x ^ y)) ^ y).wrapping_add(block[i]).wrapping_add(0x5a82_7999).wrapping_add(rol(v, 5));
z = z.wrapping_add(n);
w = rol(w, 30);
(block, w, z)
}
const fn r2(mut block: [u32; 16], v: u32, mut w: u32, x: u32, y: u32, mut z: u32, i: usize) -> ([u32; 16], u32, u32) {
block[i] = blk(&block, i);
let n = (w ^ x ^ y).wrapping_add(block[i]).wrapping_add(0x6ed9_eba1).wrapping_add(rol(v, 5));
z = z.wrapping_add(n);
w = rol(w, 30);
(block, w, z)
}
const fn r3(mut block: [u32; 16], v: u32, mut w: u32, x: u32, y: u32, mut z: u32, i: usize) -> ([u32; 16], u32, u32) {
block[i] = blk(&block, i);
let n = (((w | x) & y) | (w & x)).wrapping_add(block[i]).wrapping_add(0x8f1b_bcdc).wrapping_add(rol(v, 5));
z = z.wrapping_add(n);
w = rol(w, 30);
(block, w, z)
}
const fn r4(mut block: [u32; 16], v: u32, mut w: u32, x: u32, y: u32, mut z: u32, i: usize) -> ([u32; 16], u32, u32) {
block[i] = blk(&block, i);
let n = (w ^ x ^ y).wrapping_add(block[i]).wrapping_add(0xca62_c1d6).wrapping_add(rol(v, 5));
z = z.wrapping_add(n);
w = rol(w, 30);
(block, w, z)
}
pub struct Digest {
data: [u32; 5],
}
impl Digest {
pub const fn bytes(&self) -> [u8; 20] {
[
(self.data[0] >> 24) as u8,
(self.data[0] >> 16) as u8,
(self.data[0] >> 8) as u8,
self.data[0] as u8,
(self.data[1] >> 24) as u8,
(self.data[1] >> 16) as u8,
(self.data[1] >> 8) as u8,
self.data[1] as u8,
(self.data[2] >> 24) as u8,
(self.data[2] >> 16) as u8,
(self.data[2] >> 8) as u8,
self.data[2] as u8,
(self.data[3] >> 24) as u8,
(self.data[3] >> 16) as u8,
(self.data[3] >> 8) as u8,
self.data[3] as u8,
(self.data[4] >> 24) as u8,
(self.data[4] >> 16) as u8,
(self.data[4] >> 8) as u8,
self.data[4] as u8,
]
}
}
impl std::fmt::Display for Digest {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
for i in self.data.iter() {
write!(f, "{i:08x}")?;
}
Ok(())
}
}