feat(qmcv2): Experiment with qmc2-crypto

(cherry picked from commit c8eb1bc481347efb6d35e9122e17e624bde18772)
This commit is contained in:
Jixun Wu 2021-12-15 13:53:50 +00:00 committed by MengYX
parent ada078df19
commit 840d750716
No known key found for this signature in database
GPG Key ID: E63F9C7303E8F604
4 changed files with 129 additions and 19 deletions

11
package-lock.json generated
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@ -10,6 +10,7 @@
"license": "MIT",
"dependencies": {
"@babel/preset-typescript": "^7.16.5",
"@jixun/qmc2-crypto": "^0.0.5-R2",
"base64-js": "^1.5.1",
"browser-id3-writer": "^4.4.0",
"core-js": "^3.16.0",
@ -2980,6 +2981,11 @@
"regenerator-runtime": "^0.13.3"
}
},
"node_modules/@jixun/qmc2-crypto": {
"version": "0.0.5-R2",
"resolved": "https://registry.npmjs.org/@jixun/qmc2-crypto/-/qmc2-crypto-0.0.5-R2.tgz",
"integrity": "sha512-omrsnXSx7BpOCY8Yla+xwil0bYz/4sj3qEFy4hu4JL/ujeWMzASKq9WnW+UHfSnLUw6EGstub+CoSXrFeRDfqQ=="
},
"node_modules/@mrmlnc/readdir-enhanced": {
"version": "2.2.1",
"resolved": "https://registry.npmjs.org/@mrmlnc/readdir-enhanced/-/readdir-enhanced-2.2.1.tgz",
@ -23019,6 +23025,11 @@
"regenerator-runtime": "^0.13.3"
}
},
"@jixun/qmc2-crypto": {
"version": "0.0.5-R2",
"resolved": "https://registry.npmjs.org/@jixun/qmc2-crypto/-/qmc2-crypto-0.0.5-R2.tgz",
"integrity": "sha512-omrsnXSx7BpOCY8Yla+xwil0bYz/4sj3qEFy4hu4JL/ujeWMzASKq9WnW+UHfSnLUw6EGstub+CoSXrFeRDfqQ=="
},
"@mrmlnc/readdir-enhanced": {
"version": "2.2.1",
"resolved": "https://registry.npmjs.org/@mrmlnc/readdir-enhanced/-/readdir-enhanced-2.2.1.tgz",

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@ -18,6 +18,7 @@
},
"dependencies": {
"@babel/preset-typescript": "^7.16.5",
"@jixun/qmc2-crypto": "^0.0.5-R2",
"base64-js": "^1.5.1",
"browser-id3-writer": "^4.4.0",
"core-js": "^3.16.0",

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@ -9,6 +9,7 @@ import {
SniffAudioExt, WriteMetaToFlac, WriteMetaToMp3
} from "@/decrypt/utils";
import {parseBlob as metaParseBlob} from "music-metadata-browser";
import {decryptMGG} from "./qmcv2";
import iconv from "iconv-lite";
@ -42,31 +43,35 @@ export const HandlerMap: { [key: string]: Handler } = {
"776176": {handler: QmcMaskGetDefault, ext: "wav", detect: false}
};
function mergeUint8(array: Uint8Array[]): Uint8Array {
// Get the total length of all arrays.
let length = 0;
array.forEach(item => {
length += item.length;
});
// Create a new array with total length and merge all source arrays.
let mergedArray = new Uint8Array(length);
let offset = 0;
array.forEach(item => {
mergedArray.set(item, offset);
offset += item.length;
});
return mergedArray;
}
export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string): Promise<DecryptResult> {
if (!(raw_ext in HandlerMap)) throw `Qmc cannot handle type: ${raw_ext}`;
const handler = HandlerMap[raw_ext];
const fileData = new Uint8Array(await GetArrayBuffer(file));
let audioData, seed, keyData;
if (handler.detect) {
const keyLen = new DataView(fileData.slice(fileData.length - 4).buffer).getUint32(0, true)
const keyPos = fileData.length - 4 - keyLen;
audioData = fileData.slice(0, keyPos);
seed = handler.handler(audioData);
keyData = fileData.slice(keyPos, keyPos + keyLen);
if (!seed) seed = await queryKey(keyData, raw_filename, raw_ext);
if (!seed) throw raw_ext + "格式仅提供实验性支持";
} else {
audioData = fileData;
seed = handler.handler(audioData) as QmcMask;
if (!seed) throw raw_ext + "格式仅提供实验性支持";
}
let musicDecoded = seed.Decrypt(audioData);
const decodedParts = await decryptMGG(await file.arrayBuffer());
let musicDecoded = mergeUint8(decodedParts);
const ext = SniffAudioExt(musicDecoded, handler.ext);
const mime = AudioMimeType[ext];
let musicBlob = new Blob([musicDecoded], {type: mime});
let musicBlob = new Blob(decodedParts, {type: mime});
const musicMeta = await metaParseBlob(musicBlob);
for (let metaIdx in musicMeta.native) {
@ -80,8 +85,6 @@ export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string)
}
const info = GetMetaFromFile(raw_filename, musicMeta.common.title, musicMeta.common.artist)
if (keyData) reportKeyUsage(keyData, seed.getMatrix128(),
raw_filename, raw_ext, info.title, info.artist, musicMeta.common.album).then().catch();
let imgUrl = GetCoverFromFile(musicMeta);
if (!imgUrl) {

95
src/decrypt/qmcv2.ts Normal file
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@ -0,0 +1,95 @@
import QMCCryptoModule from '@jixun/qmc2-crypto';
// EOF Magic detection.
const DETECTION_SIZE = 40;
// Process in 2m buffer size
const DECRYPTION_BUF_SIZE = 2 * 1024 * 1024;
/**
* QMC2
*
* Uint8Array
* `null`
* @param {ArrayBuffer} mggBlob Blob
* @param {string} name
* @return {Promise<Uint8Array[]|null>}
*/
export async function decryptMGG(mggBlob: ArrayBuffer) {
// 初始化模组
const QMCCrypto = await QMCCryptoModule();
// 申请内存块,并文件末端数据到 WASM 的内存堆
const detectionBuf = new Uint8Array(mggBlob.slice(-DETECTION_SIZE));
const pDetectionBuf = QMCCrypto._malloc(detectionBuf.length);
QMCCrypto.writeArrayToMemory(detectionBuf, pDetectionBuf);
// 检测结果内存块
const pDetectionResult = QMCCrypto._malloc(QMCCrypto.sizeof_qmc_detection());
// 进行检测
const detectOK = QMCCrypto.detectKeyEndPosition(
pDetectionResult,
pDetectionBuf,
detectionBuf.length
);
// 提取结构体内容:
// (pos: i32; len: i32; error: char[??])
const position = QMCCrypto.getValue(pDetectionResult, "i32");
const len = QMCCrypto.getValue(pDetectionResult + 4, "i32");
const detectionError = QMCCrypto.UTF8ToString(pDetectionResult + 8);
// 释放内存
QMCCrypto._free(pDetectionBuf);
QMCCrypto._free(pDetectionResult);
if (detectOK) {
// 计算解密后文件的大小。
// 之前得到的 position 为相对当前检测数据起点的偏移。
const decryptedSize = mggBlob.byteLength - DETECTION_SIZE + position;
// $prog.max = decryptedSize;
// 提取嵌入到文件的 EKey
const ekey = new Uint8Array(
mggBlob.slice(decryptedSize, decryptedSize + len)
);
// 解码 UTF-8 数据到 string
const decoder = new TextDecoder();
const ekey_b64 = decoder.decode(ekey);
// 初始化加密与缓冲区
const hCrypto = QMCCrypto.createInstWidthEKey(ekey_b64);
const buf = QMCCrypto._malloc(DECRYPTION_BUF_SIZE);
const decryptedParts = [];
let offset = 0;
let bytesToDecrypt = decryptedSize;
while (bytesToDecrypt > 0) {
const blockSize = Math.min(bytesToDecrypt, DECRYPTION_BUF_SIZE);
// 解密一些片段
const blockData = new Uint8Array(
mggBlob.slice(offset, offset + blockSize)
);
QMCCrypto.writeArrayToMemory(blockData, buf);
QMCCrypto.decryptStream(hCrypto, buf, offset, blockSize);
decryptedParts.push(QMCCrypto.HEAPU8.slice(buf, buf + blockSize));
offset += blockSize;
bytesToDecrypt -= blockSize;
// $prog.value = offset;
// 避免网页卡死,让 event loop 处理一下其它事件。
// Worker 应该不需要等待也可以?
// await new Promise((resolve) => setTimeout(resolve));
}
QMCCrypto._free(buf);
hCrypto.delete();
return decryptedParts;
} else {
throw new Error("ERROR: could not decrypt\n " + detectionError);
}
}