experiment: start implementing checks in wasm (client side only so far)

Signed-off-by: Xe Iaso <me@xeiaso.net>

wasm/pow/sha256/run.js

@@ -0,0 +1,105 @@
+// Load and instantiate the .wasm file
+const response = await fetch("sha256.wasm");
+
+const importObject = {
+  anubis: {
+    anubis_update_nonce: (nonce) => {
+      console.log(`Received nonce update: ${nonce}`);
+      // Your logic here
+    }
+  }
+};
+
+const module = await WebAssembly.compileStreaming(response);
+const instance = await WebAssembly.instantiate(module, importObject);
+
+// Get exports
+const {
+  anubis_work,
+  anubis_validate,
+  data_ptr,
+  result_hash_ptr,
+  result_hash_size,
+  verification_hash_ptr,
+  verification_hash_size,
+  set_data_length,
+  memory
+} = instance.exports;
+
+console.log(instance.exports);
+
+function uint8ArrayToHex(arr) {
+  return Array.from(arr)
+    .map((c) => c.toString(16).padStart(2, "0"))
+    .join("");
+}
+
+function hexToUint8Array(hexString) {
+  // Remove whitespace and optional '0x' prefix
+  hexString = hexString.replace(/\s+/g, '').replace(/^0x/, '');
+
+  // Check for valid length
+  if (hexString.length % 2 !== 0) {
+    throw new Error('Invalid hex string length');
+  }
+
+  // Check for valid characters
+  if (!/^[0-9a-fA-F]+$/.test(hexString)) {
+    throw new Error('Invalid hex characters');
+  }
+
+  // Convert to Uint8Array
+  const byteArray = new Uint8Array(hexString.length / 2);
+  for (let i = 0; i < byteArray.length; i++) {
+    const byteValue = parseInt(hexString.substr(i * 2, 2), 16);
+    byteArray[i] = byteValue;
+  }
+
+  return byteArray;
+}
+
+// Write data to buffer
+function writeToBuffer(data) {
+  if (data.length > 1024) throw new Error("Data exceeds buffer size");
+
+  // Get pointer and create view
+  const offset = data_ptr();
+  const buffer = new Uint8Array(memory.buffer, offset, data.length);
+
+  // Copy data
+  buffer.set(data);
+
+  // Set data length
+  set_data_length(data.length);
+}
+
+function readFromChallenge() {
+  const offset = result_hash_ptr();
+  const buffer = new Uint8Array(memory.buffer, offset, result_hash_size());
+
+  return buffer;
+}
+
+// Example usage:
+const data = hexToUint8Array("98ea6e4f216f2fb4b69fff9b3a44842c38686ca685f3f55dc48c5d3fb1107be4");
+writeToBuffer(data);
+
+// Call work function
+const t0 = Date.now();
+const nonce = anubis_work(16, 0, 1);
+const t1 = Date.now();
+
+console.log(`Done! Took ${t1 - t0}ms, ${nonce} iterations`);
+
+const challengeBuffer = readFromChallenge();
+
+{
+  const buffer = new Uint8Array(memory.buffer, verification_hash_ptr(), verification_hash_size());
+  buffer.set(challengeBuffer);
+}
+
+// Validate
+const isValid = anubis_validate(nonce, 10) === 1;
+console.log(isValid);
+
+console.log(uint8ArrayToHex(readFromChallenge()));