Temporary usertokens via proof-of-work challenge (khanon/oai-reverse-proxy!68)

public/js/hash-worker.js

@@ -0,0 +1,121 @@
+importScripts(
+  "https://cdn.jsdelivr.net/npm/hash-wasm@4.11.0/dist/argon2.umd.min.js"
+);
+
+let active = false;
+let nonce = 0;
+let signature = "";
+let lastNotify = 0;
+let hashesSinceLastNotify = 0;
+let params = {
+  salt: null,
+  hashLength: 0,
+  iterations: 0,
+  memorySize: 0,
+  parallelism: 0,
+  targetValue: BigInt(0),
+  safariFix: false,
+};
+
+self.onmessage = async (event) => {
+  const { data } = event;
+  switch (data.type) {
+    case "stop":
+      active = false;
+      self.postMessage({ type: "paused", hashes: hashesSinceLastNotify });
+      return;
+    case "start":
+      active = true;
+      signature = data.signature;
+      nonce = data.nonce;
+
+      const c = data.challenge;
+      // decode salt to Uint8Array
+      const salt = new Uint8Array(c.s.length / 2);
+      for (let i = 0; i < c.s.length; i += 2) {
+        salt[i / 2] = parseInt(c.s.slice(i, i + 2), 16);
+      }
+
+      params = {
+        salt: salt,
+        hashLength: c.hl,
+        iterations: c.t,
+        memorySize: c.m,
+        parallelism: c.p,
+        targetValue: BigInt(c.d.slice(0, -1)),
+        safariFix: data.isMobileWebkit,
+      };
+
+      console.log("Started", params);
+      self.postMessage({ type: "started" });
+      setTimeout(solve, 0);
+      break;
+  }
+};
+
+const doHash = async (password) => {
+  const { salt, hashLength, iterations, memorySize, parallelism } = params;
+  return await self.hashwasm.argon2id({
+    password,
+    salt,
+    hashLength,
+    iterations,
+    memorySize,
+    parallelism,
+  });
+};
+
+const checkHash = (hash) => {
+  const { targetValue } = params;
+  const hashValue = BigInt(`0x${hash}`);
+  return hashValue <= targetValue;
+};
+
+const solve = async () => {
+  if (!active) {
+    console.log("Stopped solver", nonce);
+    return;
+  }
+
+  // Safari WASM doesn't like multiple calls in one worker
+  const batchSize = 1;
+  const batch = [];
+  for (let i = 0; i < batchSize; i++) {
+    batch.push(nonce++);
+  }
+
+  try {
+    const results = await Promise.all(
+      batch.map(async (nonce) => {
+        const hash = await doHash(String(nonce));
+        return { hash, nonce };
+      })
+    );
+    hashesSinceLastNotify += batchSize;
+
+    const solution = results.find(({ hash }) => checkHash(hash));
+    if (solution) {
+      console.log("Solution found", solution, params.salt);
+      self.postMessage({ type: "solved", nonce: solution.nonce });
+      active = false;
+    } else {
+      if (Date.now() - lastNotify > 1000) {
+        console.log("Last nonce", nonce, "Hashes", hashesSinceLastNotify);
+        self.postMessage({ type: "progress", hashes: hashesSinceLastNotify });
+        lastNotify = Date.now();
+        hashesSinceLastNotify = 0;
+      }
+      setTimeout(solve, 10);
+    }
+  } catch (error) {
+    console.error("Error", error);
+    const stack = error.stack;
+    const debug = {
+      stack,
+      lastNonce: nonce,
+      targetValue: params.targetValue,
+    };
+    self.postMessage({ type: "error", error: error.message, debug });
+    active = false;
+  }
+};