wavelet init

Wavelet/frontend/lib/cap-solver.ts

@@ -0,0 +1,183 @@
+/**
+ * Cap PoW (Proof-of-Work) 人机验证前端实现
+ * 与后端 internal/util/cap 算法完全对应
+ *
+ * 求解在 Web Worker 中执行，不阻塞主线程 UI。
+ */
+
+// ——— Challenge / Redeem API types ———
+
+export interface ChallengeResponse {
+  challenge: { c: number; s: number; d: number };
+  token: string;
+  expires: number;
+}
+
+export interface RedeemResponse {
+  success: boolean;
+  token?: string;
+  expires?: number;
+  error?: string;
+}
+
+// ——— Worker 代码（内联 Blob，避免独立文件的打包配置问题）———
+//
+// 算法与 Go 后端 internal/util/cap/cap.go + prng.go 完全对应：
+//   · FNV-1a 32-bit  (Math.imul 保证 32-bit 截断)
+//   · xorshift32 PRNG → hex 字符串
+//   · SubtleCrypto SHA-256 校验答案
+
+const WORKER_SOURCE = /* js */ `
+// FNV-1a 32-bit
+function fnv1a(str) {
+  let h = 2166136261 >>> 0;
+  for (let i = 0; i < str.length; i++) {
+    h ^= str.charCodeAt(i);
+    h = Math.imul(h, 16777619) >>> 0;
+  }
+  return h;
+}
+function fnv1aResume(state, str) {
+  let h = state >>> 0;
+  for (let i = 0; i < str.length; i++) {
+    h ^= str.charCodeAt(i);
+    h = Math.imul(h, 16777619) >>> 0;
+  }
+  return h;
+}
+
+// xorshift32 PRNG → hex string
+function prngFromHash(seed, len) {
+  let s = seed >>> 0, r = '';
+  while (r.length < len) {
+    s ^= (s << 13) >>> 0;
+    s ^= (s >>> 17) >>> 0;
+    s ^= (s << 5)  >>> 0;
+    s  = s >>> 0;
+    r += s.toString(16).padStart(8, '0');
+  }
+  return r.slice(0, len);
+}
+
+// SHA-256 via SubtleCrypto (available in workers)
+async function sha256Hex(input) {
+  const buf = await crypto.subtle.digest('SHA-256', new TextEncoder().encode(input));
+  return Array.from(new Uint8Array(buf)).map(b => b.toString(16).padStart(2, '0')).join('');
+}
+
+// Solve one puzzle
+async function solvePuzzle(token, index, size, difficulty) {
+  const tFnv    = fnv1a(token);
+  const saltSeed   = fnv1aResume(tFnv, String(index + 1));
+  const targetSeed = fnv1aResume(saltSeed, 'd');
+  const salt   = prngFromHash(saltSeed,   size);
+  const target = prngFromHash(targetSeed, difficulty);
+
+  for (let nonce = 0; nonce < 10_000_000; nonce++) {
+    if ((await sha256Hex(salt + nonce)).startsWith(target)) return nonce;
+  }
+  throw new Error('无法在合理范围内求解第 ' + (index + 1) + ' 个难题');
+}
+
+// Entry point — receive task from main thread
+self.onmessage = async ({ data }) => {
+  const { token, count, size, difficulty } = data;
+  try {
+    const t0 = performance.now();
+    const solutions = [];
+    for (let i = 0; i < count; i++) {
+      solutions.push(await solvePuzzle(token, i, size, difficulty));
+    }
+    const elapsed = ((performance.now() - t0) / 1000).toFixed(3);
+    self.postMessage({ type: 'done', solutions, elapsed });
+  } catch (err) {
+    self.postMessage({ type: 'error', message: err.message });
+  }
+};
+`;
+
+// ——— 在 Web Worker 中求解，返回 Promise<number[]> ———
+
+function solveInWorker(
+  token: string,
+  count: number,
+  size: number,
+  difficulty: number,
+): Promise<{ solutions: number[]; elapsed: string }> {
+  return new Promise((resolve, reject) => {
+    const blob = new Blob([WORKER_SOURCE], { type: 'application/javascript' });
+    const url = URL.createObjectURL(blob);
+    const worker = new Worker(url);
+
+    worker.onmessage = (e) => {
+      URL.revokeObjectURL(url);
+      worker.terminate();
+      if (e.data.type === 'done') {
+        resolve({ solutions: e.data.solutions, elapsed: e.data.elapsed });
+      } else {
+        reject(new Error(e.data.message));
+      }
+    };
+
+    worker.onerror = (err) => {
+      URL.revokeObjectURL(url);
+      worker.terminate();
+      reject(new Error(err.message || 'Worker 执行失败'));
+    };
+
+    worker.postMessage({ token, count, size, difficulty });
+  });
+}
+
+// ——— Full Cap flow: get challenge → solve (Worker) → redeem → return X-Cap-Token ———
+
+export async function getCapToken(scope = 'login'): Promise<string> {
+  // 1. 获取难题
+  const challengeRes = await fetch('/api/cap/challenge', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ scope }),
+  });
+  if (!challengeRes.ok) {
+    throw new Error('获取人机验证难题失败');
+  }
+  const challenge: ChallengeResponse = await challengeRes.json();
+  const { c: count, s: size, d: difficulty } = challenge.challenge;
+
+  console.groupCollapsed('[Cap] 人机验证 PoW 求解开始');
+  console.log(`  难题数量 (count)    : ${count}`);
+  console.log(`  验证难度 (difficulty): ${difficulty}`);
+  console.log(`  盐值长度 (size)     : ${size}`);
+  console.groupEnd();
+
+  // 2. 在 Worker 中求解（不阻塞主线程）
+  const t0 = performance.now();
+  const { solutions, elapsed } = await solveInWorker(
+    challenge.token,
+    count,
+    size,
+    difficulty,
+  );
+  const wallTime = ((performance.now() - t0) / 1000).toFixed(3);
+
+  console.groupCollapsed('[Cap] 人机验证 PoW 求解完成');
+  console.log(`  难题数量 (count)    : ${count}`);
+  console.log(`  验证难度 (difficulty): ${difficulty}`);
+  console.log(`  Worker 耗时         : ${elapsed}s`);
+  console.log(`  总耗时（含通信）     : ${wallTime}s`);
+  console.log(`  Solutions           :`, solutions);
+  console.groupEnd();
+
+  // 3. 提交答案兑换一次性凭证
+  const redeemRes = await fetch('/api/cap/redeem', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ token: challenge.token, solutions, scope }),
+  });
+  const redeemData: RedeemResponse = await redeemRes.json();
+  if (!redeemData.success || !redeemData.token) {
+    throw new Error(redeemData.error || '人机验证失败');
+  }
+
+  return redeemData.token;
+}