snapshot of https://github.com/tauri-apps/tauri.git (dev, 2026-09-23; blobs > 131072B omitted)

crates/tauri-codegen/src/vendor/blake3_reference.rs

@@ -0,0 +1,378 @@
+// Copyright 2019-2024 Tauri Programme within The Commons Conservancy
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-License-Identifier: MIT
+
+//! This is a lightly modified version of the BLAKE3 reference implementation.
+//!
+//! The changes applied are to remove unused item warnings due to using it
+//! vendored along with some minor clippy suggestions. No logic changes. I
+//! suggest diffing against the original to find all the changes.
+//!
+//! ## Original Header
+//! This is the reference implementation of BLAKE3. It is used for testing and
+//! as a readable example of the algorithms involved. Section 5.1 of [the BLAKE3
+//! spec](https://github.com/BLAKE3-team/BLAKE3-specs/blob/master/blake3.pdf)
+//! discusses this implementation. You can render docs for this implementation
+//! by running `cargo doc --open` in this directory.
+//!
+//! # Example
+//!
+//! ```
+//! let mut hasher = tauri_codegen::vendor::blake3_reference::Hasher::new();
+//! hasher.update(b"abc");
+//! hasher.update(b"def");
+//! let mut hash = [0; 32];
+//! hasher.finalize(&mut hash);
+//! let mut extended_hash = [0; 500];
+//! hasher.finalize(&mut extended_hash);
+//! assert_eq!(hash, extended_hash[..32]);
+//! ```
+//!
+//! CC0-1.0 OR Apache-2.0
+
+use core::cmp::min;
+use core::convert::TryInto;
+
+const OUT_LEN: usize = 32;
+const BLOCK_LEN: usize = 64;
+const CHUNK_LEN: usize = 1024;
+
+const CHUNK_START: u32 = 1 << 0;
+const CHUNK_END: u32 = 1 << 1;
+const PARENT: u32 = 1 << 2;
+const ROOT: u32 = 1 << 3;
+
+const IV: [u32; 8] = [
+  0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A, 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19,
+];
+
+const MSG_PERMUTATION: [usize; 16] = [2, 6, 3, 10, 7, 0, 4, 13, 1, 11, 12, 5, 9, 14, 15, 8];
+
+// The mixing function, G, which mixes either a column or a diagonal.
+fn g(state: &mut [u32; 16], a: usize, b: usize, c: usize, d: usize, mx: u32, my: u32) {
+  state[a] = state[a].wrapping_add(state[b]).wrapping_add(mx);
+  state[d] = (state[d] ^ state[a]).rotate_right(16);
+  state[c] = state[c].wrapping_add(state[d]);
+  state[b] = (state[b] ^ state[c]).rotate_right(12);
+  state[a] = state[a].wrapping_add(state[b]).wrapping_add(my);
+  state[d] = (state[d] ^ state[a]).rotate_right(8);
+  state[c] = state[c].wrapping_add(state[d]);
+  state[b] = (state[b] ^ state[c]).rotate_right(7);
+}
+
+fn round(state: &mut [u32; 16], m: &[u32; 16]) {
+  // Mix the columns.
+  g(state, 0, 4, 8, 12, m[0], m[1]);
+  g(state, 1, 5, 9, 13, m[2], m[3]);
+  g(state, 2, 6, 10, 14, m[4], m[5]);
+  g(state, 3, 7, 11, 15, m[6], m[7]);
+  // Mix the diagonals.
+  g(state, 0, 5, 10, 15, m[8], m[9]);
+  g(state, 1, 6, 11, 12, m[10], m[11]);
+  g(state, 2, 7, 8, 13, m[12], m[13]);
+  g(state, 3, 4, 9, 14, m[14], m[15]);
+}
+
+fn permute(m: &mut [u32; 16]) {
+  let mut permuted = [0; 16];
+  for i in 0..16 {
+    permuted[i] = m[MSG_PERMUTATION[i]];
+  }
+  *m = permuted;
+}
+
+fn compress(
+  chaining_value: &[u32; 8],
+  block_words: &[u32; 16],
+  counter: u64,
+  block_len: u32,
+  flags: u32,
+) -> [u32; 16] {
+  let mut state = [
+    chaining_value[0],
+    chaining_value[1],
+    chaining_value[2],
+    chaining_value[3],
+    chaining_value[4],
+    chaining_value[5],
+    chaining_value[6],
+    chaining_value[7],
+    IV[0],
+    IV[1],
+    IV[2],
+    IV[3],
+    counter as u32,
+    (counter >> 32) as u32,
+    block_len,
+    flags,
+  ];
+  let mut block = *block_words;
+
+  round(&mut state, &block); // round 1
+  permute(&mut block);
+  round(&mut state, &block); // round 2
+  permute(&mut block);
+  round(&mut state, &block); // round 3
+  permute(&mut block);
+  round(&mut state, &block); // round 4
+  permute(&mut block);
+  round(&mut state, &block); // round 5
+  permute(&mut block);
+  round(&mut state, &block); // round 6
+  permute(&mut block);
+  round(&mut state, &block); // round 7
+
+  for i in 0..8 {
+    state[i] ^= state[i + 8];
+    state[i + 8] ^= chaining_value[i];
+  }
+  state
+}
+
+fn first_8_words(compression_output: [u32; 16]) -> [u32; 8] {
+  compression_output[0..8].try_into().unwrap()
+}
+
+fn words_from_little_endian_bytes(bytes: &[u8], words: &mut [u32]) {
+  debug_assert_eq!(bytes.len(), 4 * words.len());
+  for (four_bytes, word) in bytes.as_chunks::<4>().0.iter().zip(words) {
+    *word = u32::from_le_bytes(*four_bytes);
+  }
+}
+
+// Each chunk or parent node can produce either an 8-word chaining value or, by
+// setting the ROOT flag, any number of final output bytes. The Output struct
+// captures the state just prior to choosing between those two possibilities.
+struct Output {
+  input_chaining_value: [u32; 8],
+  block_words: [u32; 16],
+  counter: u64,
+  block_len: u32,
+  flags: u32,
+}
+
+impl Output {
+  fn chaining_value(&self) -> [u32; 8] {
+    first_8_words(compress(
+      &self.input_chaining_value,
+      &self.block_words,
+      self.counter,
+      self.block_len,
+      self.flags,
+    ))
+  }
+
+  fn root_output_bytes(&self, out_slice: &mut [u8]) {
+    for (output_block_counter, out_block) in (0u64..).zip(out_slice.chunks_mut(2 * OUT_LEN)) {
+      let words = compress(
+        &self.input_chaining_value,
+        &self.block_words,
+        output_block_counter,
+        self.block_len,
+        self.flags | ROOT,
+      );
+      // The output length might not be a multiple of 4.
+      for (word, out_word) in words.iter().zip(out_block.chunks_mut(4)) {
+        out_word.copy_from_slice(&word.to_le_bytes()[..out_word.len()]);
+      }
+    }
+  }
+}
+
+struct ChunkState {
+  chaining_value: [u32; 8],
+  chunk_counter: u64,
+  block: [u8; BLOCK_LEN],
+  block_len: u8,
+  blocks_compressed: u8,
+  flags: u32,
+}
+
+impl ChunkState {
+  fn new(key_words: [u32; 8], chunk_counter: u64, flags: u32) -> Self {
+    Self {
+      chaining_value: key_words,
+      chunk_counter,
+      block: [0; BLOCK_LEN],
+      block_len: 0,
+      blocks_compressed: 0,
+      flags,
+    }
+  }
+
+  fn len(&self) -> usize {
+    BLOCK_LEN * self.blocks_compressed as usize + self.block_len as usize
+  }
+
+  fn start_flag(&self) -> u32 {
+    if self.blocks_compressed == 0 {
+      CHUNK_START
+    } else {
+      0
+    }
+  }
+
+  fn update(&mut self, mut input: &[u8]) {
+    while !input.is_empty() {
+      // If the block buffer is full, compress it and clear it. More
+      // input is coming, so this compression is not CHUNK_END.
+      if self.block_len as usize == BLOCK_LEN {
+        let mut block_words = [0; 16];
+        words_from_little_endian_bytes(&self.block, &mut block_words);
+        self.chaining_value = first_8_words(compress(
+          &self.chaining_value,
+          &block_words,
+          self.chunk_counter,
+          BLOCK_LEN as u32,
+          self.flags | self.start_flag(),
+        ));
+        self.blocks_compressed += 1;
+        self.block = [0; BLOCK_LEN];
+        self.block_len = 0;
+      }
+
+      // Copy input bytes into the block buffer.
+      let want = BLOCK_LEN - self.block_len as usize;
+      let take = min(want, input.len());
+      self.block[self.block_len as usize..][..take].copy_from_slice(&input[..take]);
+      self.block_len += take as u8;
+      input = &input[take..];
+    }
+  }
+
+  fn output(&self) -> Output {
+    let mut block_words = [0; 16];
+    words_from_little_endian_bytes(&self.block, &mut block_words);
+    Output {
+      input_chaining_value: self.chaining_value,
+      block_words,
+      counter: self.chunk_counter,
+      block_len: self.block_len as u32,
+      flags: self.flags | self.start_flag() | CHUNK_END,
+    }
+  }
+}
+
+fn parent_output(
+  left_child_cv: [u32; 8],
+  right_child_cv: [u32; 8],
+  key_words: [u32; 8],
+  flags: u32,
+) -> Output {
+  let mut block_words = [0; 16];
+  block_words[..8].copy_from_slice(&left_child_cv);
+  block_words[8..].copy_from_slice(&right_child_cv);
+  Output {
+    input_chaining_value: key_words,
+    block_words,
+    counter: 0,                  // Always 0 for parent nodes.
+    block_len: BLOCK_LEN as u32, // Always BLOCK_LEN (64) for parent nodes.
+    flags: PARENT | flags,
+  }
+}
+
+fn parent_cv(
+  left_child_cv: [u32; 8],
+  right_child_cv: [u32; 8],
+  key_words: [u32; 8],
+  flags: u32,
+) -> [u32; 8] {
+  parent_output(left_child_cv, right_child_cv, key_words, flags).chaining_value()
+}
+
+/// An incremental hasher that can accept any number of writes.
+pub struct Hasher {
+  chunk_state: ChunkState,
+  key_words: [u32; 8],
+  cv_stack: [[u32; 8]; 54], // Space for 54 subtree chaining values:
+  cv_stack_len: u8,         // 2^54 * CHUNK_LEN = 2^64
+  flags: u32,
+}
+
+impl Hasher {
+  fn new_internal(key_words: [u32; 8], flags: u32) -> Self {
+    Self {
+      chunk_state: ChunkState::new(key_words, 0, flags),
+      key_words,
+      cv_stack: [[0; 8]; 54],
+      cv_stack_len: 0,
+      flags,
+    }
+  }
+
+  /// Construct a new `Hasher` for the regular hash function.
+  pub fn new() -> Self {
+    Self::new_internal(IV, 0)
+  }
+
+  fn push_stack(&mut self, cv: [u32; 8]) {
+    self.cv_stack[self.cv_stack_len as usize] = cv;
+    self.cv_stack_len += 1;
+  }
+
+  fn pop_stack(&mut self) -> [u32; 8] {
+    self.cv_stack_len -= 1;
+    self.cv_stack[self.cv_stack_len as usize]
+  }
+
+  // Section 5.1.2 of the BLAKE3 spec explains this algorithm in more detail.
+  fn add_chunk_chaining_value(&mut self, mut new_cv: [u32; 8], mut total_chunks: u64) {
+    // This chunk might complete some subtrees. For each completed subtree,
+    // its left child will be the current top entry in the CV stack, and
+    // its right child will be the current value of `new_cv`. Pop each left
+    // child off the stack, merge it with `new_cv`, and overwrite `new_cv`
+    // with the result. After all these merges, push the final value of
+    // `new_cv` onto the stack. The number of completed subtrees is given
+    // by the number of trailing 0-bits in the new total number of chunks.
+    while total_chunks & 1 == 0 {
+      new_cv = parent_cv(self.pop_stack(), new_cv, self.key_words, self.flags);
+      total_chunks >>= 1;
+    }
+    self.push_stack(new_cv);
+  }
+
+  /// Add input to the hash state. This can be called any number of times.
+  pub fn update(&mut self, mut input: &[u8]) {
+    while !input.is_empty() {
+      // If the current chunk is complete, finalize it and reset the
+      // chunk state. More input is coming, so this chunk is not ROOT.
+      if self.chunk_state.len() == CHUNK_LEN {
+        let chunk_cv = self.chunk_state.output().chaining_value();
+        let total_chunks = self.chunk_state.chunk_counter + 1;
+        self.add_chunk_chaining_value(chunk_cv, total_chunks);
+        self.chunk_state = ChunkState::new(self.key_words, total_chunks, self.flags);
+      }
+
+      // Compress input bytes into the current chunk state.
+      let want = CHUNK_LEN - self.chunk_state.len();
+      let take = min(want, input.len());
+      self.chunk_state.update(&input[..take]);
+      input = &input[take..];
+    }
+  }
+
+  /// Finalize the hash and write any number of output bytes.
+  pub fn finalize(&self, out_slice: &mut [u8]) {
+    // Starting with the Output from the current chunk, compute all the
+    // parent chaining values along the right edge of the tree, until we
+    // have the root Output.
+    let mut output = self.chunk_state.output();
+    let mut parent_nodes_remaining = self.cv_stack_len as usize;
+    while parent_nodes_remaining > 0 {
+      parent_nodes_remaining -= 1;
+      output = parent_output(
+        self.cv_stack[parent_nodes_remaining],
+        output.chaining_value(),
+        self.key_words,
+        self.flags,
+      );
+    }
+    output.root_output_bytes(out_slice);
+  }
+}
+
+impl Default for Hasher {
+  fn default() -> Self {
+    Self::new()
+  }
+}