Plan M4a: gatewayd in 15 tasks, with skeletons and given tests

Each task's tests were run against a reference at its end state; the end states were replayed from master in order with the gate at each step (650 to 762 tests); each skeleton compiles against its tests and fails them. The reference is kept off this machine. Lessons T27 (every wait in a test has a limit) and T28 (mutate the reference before hand-over) come from this work. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
2026-09-23 19:05:44 -07:00
parent f38dc8d474
commit 0339dc13b2
69 changed files with 7790 additions and 3 deletions
@@ -0,0 +1,65 @@
+//! SHA-1 (FIPS 180-4), used only to check the `Sec-WebSocket-Accept` header of a WebSocket
+//! handshake (RFC 6455, section 4.2.2). Never use it for anything that needs to resist attack.
+
+/// The digest of `data`.
+pub fn sha1(data: &[u8]) -> [u8; 20] {
+    let mut h = Sha1::new();
+    h.update(data);
+    h.finish()
+}
+
+/// SHA-1 fed in pieces.
+#[derive(Debug, Clone)]
+pub struct Sha1 {
+    state: [u32; 5],
+    block: [u8; 64],
+    filled: usize,
+    length: u64,
+}
+
+impl Default for Sha1 {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Sha1 {
+    pub fn new() -> Sha1 {
+        Sha1 {
+            state: [
+                0x6745_2301,
+                0xEFCD_AB89,
+                0x98BA_DCFE,
+                0x1032_5476,
+                0xC3D2_E1F0,
+            ],
+            block: [0; 64],
+            filled: 0,
+            length: 0,
+        }
+    }
+
+    pub fn update(&mut self, mut data: &[u8]) {
+        // Add 8 * data.len() to `length` (wrapping; `u64::try_from`, never `as`). Copy bytes into
+        // `block` from `filled` on; each time it is full (64), `compress` it and set `filled` to 0.
+        // Use `split_at` and `get_mut(..)`, no indexing that can go out of bounds.
+        todo!()
+    }
+
+    pub fn finish(mut self) -> [u8; 20] {
+        // Save `length`. Feed 0x80 then zeros so that 56 bytes of the block are filled (56 -
+        // filled, or 120 - filled when filled >= 56), then the saved length as 8 big-endian bytes,
+        // through `update`. `update` adds to `length`: put the saved value back after. Then the
+        // five state words, big-endian.
+        todo!()
+    }
+
+    fn compress(&mut self, block: &[u8; 64]) {
+        // FIPS 180-4, section 6.1.2: w[0..16] are the block as big-endian u32s; w[i] = (w[i-3] ^
+        // w[i-8] ^ w[i-14] ^ w[i-16]).rotate_left(1) for 16..80. Eighty rounds with f and k by
+        // range: 0..=19 (b & c) | (!b & d), 0x5A827999; 20..=39 b ^ c ^ d, 0x6ED9EBA1; 40..=59 (b &
+        // c) | (b & d) | (c & d), 0x8F1BBCDC; 60..=79 b ^ c ^ d, 0xCA62C1D6. All additions
+        // wrapping. Add a..e into state.
+        todo!()
+    }
+}