From aca1c1133279825c8f4396490a075b98d690a9a6 Mon Sep 17 00:00:00 2001 From: Emmm Monster <58943012+emmmx@users.noreply.github.com> Date: Mon, 24 May 2021 05:57:04 +0800 Subject: [PATCH] refactor(decrypt/qmc): typescript qmc mask --- src/decrypt/qmc.js | 6 +- src/decrypt/{qmcMask.js => qmcMask.ts} | 199 ++++++++----------------- 2 files changed, 69 insertions(+), 136 deletions(-) rename src/decrypt/{qmcMask.js => qmcMask.ts} (55%) diff --git a/src/decrypt/qmc.js b/src/decrypt/qmc.js index 5aebc6f..c36e6dd 100644 --- a/src/decrypt/qmc.js +++ b/src/decrypt/qmc.js @@ -1,4 +1,4 @@ -import {QmcMaskCreate58, QmcMaskDetectMflac, QmcMaskDetectMgg, QmcMaskGetDefault} from "./qmcMask"; +import {QmcMask, QmcMaskDetectMflac, QmcMaskDetectMgg, QmcMaskGetDefault} from "./qmcMask"; import {fromByteArray as Base64Encode, toByteArray as Base64Decode} from 'base64-js' import { AudioMimeType, @@ -68,7 +68,7 @@ export async function Decrypt(file, raw_filename, raw_ext) { } const info = GetMetaFromFile(raw_filename, musicMeta.common.title, musicMeta.common.artist) - if (handler.detect) reportKeyUsage(keyData, seed.Matrix128, + if (handler.detect) reportKeyUsage(keyData, seed.getMatrix128(), info.artist, info.title, musicMeta.common.album, raw_filename, raw_ext); let imgUrl = GetCoverFromFile(musicMeta); @@ -126,7 +126,7 @@ async function queryKeyInfo(keyData, filename, format) { body: JSON.stringify({Format: format, Key: Base64Encode(keyData), Filename: filename, Type: 44}), }); let data = await resp.json(); - return QmcMaskCreate58(Base64Decode(data.Matrix44)); + return new QmcMask(Base64Decode(data.Matrix44)); } catch (e) { console.log(e); } diff --git a/src/decrypt/qmcMask.js b/src/decrypt/qmcMask.ts similarity index 55% rename from src/decrypt/qmcMask.js rename to src/decrypt/qmcMask.ts index 16cd14b..ea356e8 100644 --- a/src/decrypt/qmcMask.js +++ b/src/decrypt/qmcMask.ts @@ -1,4 +1,4 @@ -import {BytesEquals, BytesHasPrefix, FLAC_HEADER, OGG_HEADER} from "@/decrypt/utils.ts"; +import {BytesHasPrefix, FLAC_HEADER, OGG_HEADER} from "@/decrypt/utils.ts"; const QMOggPublicHeader1 = [ 0x4f, 0x67, 0x67, 0x53, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xff, 0xff, @@ -35,96 +35,65 @@ const QMCDefaultMaskMatrix = [ 0xf9, 0xbc, 0x00, 0x11]; -class QmcMask { - constructor(matrix, superA, superB) { - if (superA === undefined || superB === undefined) { - if (matrix.length === 44) { - this.Matrix44 = matrix - this.generateMask128from44() - } else { - this.Matrix128 = matrix - this.generateMask44from128() - } - this.generateMask58from128() +const AllMapping: number[][] = []; +const Mask128to44: number[] = []; + +(function () { + for (let i = 0; i < 128; i++) { + let realIdx = (i * i + 27) % 256 + if (realIdx in AllMapping) { + AllMapping[realIdx].push(i) } else { - this.Matrix58 = matrix; - this.Super58A = superA; - this.Super58B = superB; - this.generateMask128from58(); - this.generateMask44from128() + AllMapping[realIdx] = [i] } } - generateMask128from58() { - if (this.Matrix58.length !== 56) throw "incorrect mask58 matrix length"; + let idx44 = 0 + AllMapping.forEach(all128 => { + all128.forEach(_i128 => { + Mask128to44[_i128] = idx44 + }) + idx44++ + }) +})(); - let matrix128 = []; - for (let rowIdx = 0; rowIdx < 8; rowIdx += 1) { - matrix128 = matrix128.concat( - [this.Super58A], - this.Matrix58.slice(7 * rowIdx, 7 * rowIdx + 7), - [this.Super58B], - this.Matrix58.slice(56 - 7 - 7 * rowIdx, 56 - 7 * rowIdx).reverse() - ); + +export class QmcMask { + private readonly Matrix128: number[]; + + constructor(matrix: number[] | Uint8Array) { + if (matrix instanceof Uint8Array) matrix = Array.from(matrix) + if (matrix.length === 44) { + this.Matrix128 = this._generate128(matrix) + } else if (matrix.length === 128) { + this.Matrix128 = matrix + } else { + throw Error("invalid mask length") } - this.Matrix128 = matrix128; } - generateMask58from128() { - if (this.Matrix128.length !== 128) throw "incorrect mask128 length"; - - const superA = this.Matrix128[0], superB = this.Matrix128[8]; - let matrix58 = []; - - for (let rowIdx = 0; rowIdx < 8; rowIdx += 1) { - let lenStart = 16 * rowIdx; - let lenRightStart = 120 - lenStart; - if (this.Matrix128[lenStart] !== superA || this.Matrix128[lenStart + 8] !== superB) { - throw "decode mask-128 to mask-58 failed" - } - let rowLeft = this.Matrix128.slice(lenStart + 1, lenStart + 8); - let rowRight = this.Matrix128.slice(lenRightStart + 1, lenRightStart + 8).reverse(); - if (BytesEquals(rowLeft, rowRight)) { - matrix58 = matrix58.concat(rowLeft); - } else { - throw "decode mask-128 to mask-58 failed" - } - } - this.Matrix58 = matrix58; - this.Super58A = superA; - this.Super58B = superB; + getMatrix128() { + return this.Matrix128 } - generateMask44from128() { - if (this.Matrix128.length !== 128) throw "incorrect mask128 matrix length"; - let mapping = GetConvertMapping() - this.Matrix44 = [] + getMatrix44(): number[] { + const matrix44: number[] = [] let idxI44 = 0 - mapping.forEach(it256 => { + AllMapping.forEach(it256 => { let it256Len = it256.length for (let i = 1; i < it256Len; i++) { if (this.Matrix128[it256[0]] !== this.Matrix128[it256[i]]) { throw "decode mask-128 to mask-44 failed" } } - this.Matrix44[idxI44] = this.Matrix128[it256[0]] + matrix44[idxI44] = this.Matrix128[it256[0]] idxI44++ }) + return matrix44 } - generateMask128from44() { - if (this.Matrix44.length !== 44) throw "incorrect mask length" - this.Matrix128 = [] - let idx44 = 0 - GetConvertMapping().forEach(it256 => { - it256.forEach(m => { - this.Matrix128[m] = this.Matrix44[idx44] - }) - idx44++ - }) - } - - Decrypt(data) { + Decrypt(data: Uint8Array) { + if (!this.Matrix128) throw Error("bad call sequence") let dst = data.slice(0); let index = -1; let maskIdx = -1; @@ -140,13 +109,25 @@ class QmcMask { } return dst; } + + private _generate128(matrix44: number[]): number[] { + const matrix128: number[] = [] + let idx44 = 0 + AllMapping.forEach(it256 => { + it256.forEach(m => { + matrix128[m] = matrix44[idx44] + }) + idx44++ + }) + return matrix128 + } } export function QmcMaskGetDefault() { return new QmcMask(QMCDefaultMaskMatrix) } -export function QmcMaskDetectMflac(data) { +export function QmcMaskDetectMflac(data: Uint8Array) { let search_len = Math.min(0x8000, data.length), mask; for (let block_idx = 0; block_idx < search_len; block_idx += 128) { try { @@ -160,9 +141,9 @@ export function QmcMaskDetectMflac(data) { return mask; } -export function QmcMaskDetectMgg(data) { +export function QmcMaskDetectMgg(data: Uint8Array) { if (data.length < 0x100) return - let matrixConfidence = {}; + let matrixConfidence: { [key: number]: { [key: number]: number } } = {}; for (let i = 0; i < 44; i++) matrixConfidence[i] = {}; const page2 = data[0x54] ^ data[0xC] ^ QMOggPublicHeader1[0xC]; @@ -171,7 +152,7 @@ export function QmcMaskDetectMgg(data) { for (let idx128 = 0; idx128 < spHeader.length; idx128++) { if (spConf[idx128] === 0) continue; - let idx44 = GetMask44Index(idx128); + let idx44 = Mask128to44[idx128 % 128]; let _m = data[idx128] ^ spHeader[idx128] let confidence = spConf[idx128]; if (_m in matrixConfidence[idx44]) { @@ -183,7 +164,7 @@ export function QmcMaskDetectMgg(data) { let matrix = []; try { for (let i = 0; i < 44; i++) - matrix[i] = getMaskConfidenceResult(matrixConfidence[i]); + matrix[i] = calcMaskFromConfidence(matrixConfidence[i]); } catch (e) { return; } @@ -191,82 +172,34 @@ export function QmcMaskDetectMgg(data) { if (!BytesHasPrefix(mask.Decrypt(data.slice(0, OGG_HEADER.length)), OGG_HEADER)) { return; } - return mask; } -export function QmcMaskCreate128(mask128) { - return new QmcMask(mask128) -} -export function QmcMaskCreate58(matrix, superA, superB) { - return new QmcMask(matrix, superA, superB) -} - -export function QmcMaskCreate44(mask44) { - return new QmcMask(mask44) -} - -/** - * @param confidence {{}} - * @returns {number} - */ -function getMaskConfidenceResult(confidence) { - if (confidence.length === 0) throw "can not match at least one key"; - if (confidence.length > 1) console.warn("There are 2 potential value for the mask!") - let result, conf = 0; +function calcMaskFromConfidence(confidence: { [key: number]: number }) { + console.log(confidence) + const count = Object.keys(confidence).length + if (count === 0) throw "can not match at least one key"; + if (count > 1) console.warn("There are 2 potential value for the mask!") + let result = "" + let conf = 0 for (let idx in confidence) { if (confidence[idx] > conf) { result = idx; conf = confidence[idx]; } } - return parseInt(result) + return Number(result) } -/** - * @return {number} - */ - - -const allMapping = []; -const mask128to44 = []; - -(function () { - for (let i = 0; i < 128; i++) { - let realIdx = (i * i + 27) % 256 - if (realIdx in allMapping) { - allMapping[realIdx].push(i) - } else { - allMapping[realIdx] = [i] - } - } - - let idx44 = 0 - allMapping.forEach(all128 => { - all128.forEach(_i128 => { - mask128to44[_i128] = idx44 - }) - idx44++ - }) -})(); - -function GetConvertMapping() { - return allMapping; -} - -function GetMask44Index(idx128) { - return mask128to44[idx128 % 128] -} - -function QmcGenerateOggHeader(page2) { +function QmcGenerateOggHeader(page2: number) { let spec = [page2, 0xFF] for (let i = 2; i < page2; i++) spec.push(0xFF) spec.push(0xFF) return QMOggPublicHeader1.concat(spec, QMOggPublicHeader2) } -function QmcGenerateOggConf(page2) { +function QmcGenerateOggConf(page2: number) { let specConf = [6, 0] for (let i = 2; i < page2; i++) specConf.push(4) specConf.push(0)