mirror of
https://github.com/Evil0ctal/WeChat-Channels-Video-File-Decryption.git
synced 2026-10-25 17:36:33 +08:00
Evil0ctal
8900a7c6fb
问题修复: - 修复解密超过 80MB 视频时页面崩溃的问题（issue #4 #6 #8） - 根因：旧实现将整段视频经 CDP 管道传入浏览器做 XOR，base64 膨胀后超过 Chromium DevTools 协议 100MB 单条消息上限，导致页面被关闭 - 将 XOR 解密从浏览器移至 Node.js 端，浏览器仅负责生成 128KB 密钥流， 视频数据不再进入浏览器，文件大小不再受此限制 新功能: - 新增 lib/decrypt.js 解密核心模块（decryptBuffer / assertMp4） - 新增 decode_key 密钥流 LRU 缓存，命中后跳过浏览器 WASM 调用， 可通过 KEYSTREAM_CACHE_MAX 环境变量配置上限（默认100） - 新增 test/decrypt.test.js 单元测试，覆盖 120MB 大文件边界场景 其他: - Dockerfile 补充拷贝 lib 目录，修复容器内模块缺失 - worker.html 的 decryptVideo 标注为已弃用（保留向后兼容） - 更新 README 架构说明，补充大文件故障排除与「如何获取 decode_key」说明 - 版本号升级至 2.1.0
98 lines
3.3 KiB
JavaScript
98 lines
3.3 KiB
JavaScript
/**
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* lib/decrypt 单元测试（零依赖，node test/decrypt.test.js 运行）
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*
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* 验证 decryptBuffer 与参考实现（Python CLI decrypt_video / 旧 worker.html
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* decryptVideo）的 XOR 逻辑字节级一致，覆盖大文件边界场景。
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*/
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const assert = require('assert');
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const { KEYSTREAM_SIZE, decryptBuffer, assertMp4 } = require('../lib/decrypt');
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let passed = 0;
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function test(name, fn) {
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fn();
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passed++;
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console.log(` ✅ ${name}`);
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}
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/**
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* 参考实现：等价于 Python CLI 的
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* decrypt_len = min(len(keystream), len(encrypted))
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* 前 decrypt_len 字节做 XOR，其余原样
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*/
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function referenceDecrypt(encrypted, keystream) {
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const out = Buffer.alloc(encrypted.length);
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const n = Math.min(keystream.length, encrypted.length);
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for (let i = 0; i < n; i++) out[i] = encrypted[i] ^ keystream[i];
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for (let i = n; i < encrypted.length; i++) out[i] = encrypted[i];
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return out;
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}
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// 用固定种子的伪随机生成可复现数据（避免依赖 Math.random）
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function pseudoBuffer(size, seed) {
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const buf = Buffer.alloc(size);
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let s = seed >>> 0;
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for (let i = 0; i < size; i++) {
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s = (s * 1664525 + 1013904223) >>> 0; // LCG
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buf[i] = s & 0xff;
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}
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return buf;
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}
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console.log('运行 lib/decrypt 测试...\n');
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const keystream = pseudoBuffer(KEYSTREAM_SIZE, 12345);
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test('小文件(<128KB)：仅前段加密，结果与参考实现一致', () => {
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const encrypted = pseudoBuffer(50 * 1024, 7);
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const got = decryptBuffer(encrypted, keystream);
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assert.deepStrictEqual(got, referenceDecrypt(encrypted, keystream));
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});
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test('恰好 128KB：全量加密，结果与参考实现一致', () => {
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const encrypted = pseudoBuffer(KEYSTREAM_SIZE, 99);
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const got = decryptBuffer(encrypted, keystream);
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assert.deepStrictEqual(got, referenceDecrypt(encrypted, keystream));
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});
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test('大文件(120MB > CDP 100MB 上限)：前 128KB 加密、其余明文保留', () => {
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const size = 120 * 1024 * 1024;
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const encrypted = pseudoBuffer(size, 2026);
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const got = decryptBuffer(encrypted, keystream);
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// 前 128KB 应被 XOR
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for (let i = 0; i < 1000; i++) {
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assert.strictEqual(got[i], encrypted[i] ^ keystream[i]);
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}
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// 128KB 之后应为明文（与原始一致）
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assert.strictEqual(got[KEYSTREAM_SIZE], encrypted[KEYSTREAM_SIZE]);
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assert.strictEqual(got[size - 1], encrypted[size - 1]);
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assert.strictEqual(got.length, size);
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});
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test('XOR 可逆：decrypt(encrypt(x)) === x', () => {
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const plain = pseudoBuffer(200 * 1024, 555);
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const encrypted = decryptBuffer(plain, keystream); // XOR 即加密
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const back = decryptBuffer(encrypted, keystream); // 再 XOR 即解密
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assert.deepStrictEqual(back, plain);
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});
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test('decryptBuffer 不修改入参 encrypted', () => {
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const encrypted = pseudoBuffer(10 * 1024, 1);
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const copy = Buffer.from(encrypted);
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decryptBuffer(encrypted, keystream);
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assert.deepStrictEqual(encrypted, copy);
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});
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test('assertMp4：合法 ftyp 通过', () => {
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const buf = Buffer.concat([Buffer.from([0, 0, 0, 0]), Buffer.from('ftypisom')]);
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assert.doesNotThrow(() => assertMp4(buf));
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});
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test('assertMp4：缺失签名抛错', () => {
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const buf = Buffer.from('not a valid mp4 header here');
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assert.throws(() => assertMp4(buf), /ftyp/);
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});
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console.log(`\n✅ 全部 ${passed} 项测试通过`);
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