Unlock Kuwo .kwm Files!

src/decrypt/common.js

@@ -1,4 +1,5 @@
 const NcmDecrypt = require("./ncm");
+const KwmDecrypt = require("./kwm");
 const QmcDecrypt = require("./qmc");
 const RawDecrypt = require("./raw");
 const TmDecrypt = require("./tm");
@@ -11,6 +12,9 @@ export async function CommonDecrypt(file) {
         case "ncm":// Netease Mp3/Flac
             rt_data = await NcmDecrypt.Decrypt(file.raw, raw_filename, raw_ext);
             break;
+        case "kwm"://Kuwo Mp3/Flac
+            rt_data = await KwmDecrypt.Decrypt(file.raw, raw_filename, raw_ext);
+            break
         case "mp3":// Raw Mp3
         case "flac"://Raw Flac
         case "m4a":// Raw M4a

src/decrypt/kwm.js

@@ -0,0 +1,89 @@
+import {
+    AudioMimeType,
+    DetectAudioExt, FLAC_HEADER,
+    GetArrayBuffer,
+    GetFileInfo,
+    GetMetaCoverURL,
+    IsBytesEqual,
+    RequestJsonp
+} from "./util";
+import {QmcMaskCreate58, QmcMaskDetectMflac, QmcMaskDetectMgg, QmcMaskGetDefault} from "./qmcMask";
+
+import {decode} from "iconv-lite"
+
+const musicMetadata = require("music-metadata-browser");
+const MagicHeader = [
+    0x79, 0x65, 0x65, 0x6C, 0x69, 0x6F, 0x6E, 0x2D,
+    0x6B, 0x75, 0x77, 0x6F, 0x2D, 0x74, 0x6D, 0x65,
+]
+const PreDefinedKey = "MoOtOiTvINGwd2E6n0E1i7L5t2IoOoNk"
+
+export async function Decrypt(file, raw_filename, raw_ext) {
+    const oriData = new Uint8Array(await GetArrayBuffer(file));
+    if (!IsBytesEqual(MagicHeader, oriData.slice(0, 0x10)))
+        return {status: false, message: "Not a valid kwm file!"}
+
+    let fileKey = oriData.slice(0x18, 0x20)
+    let mask = createMaskFromKey(fileKey)
+
+    function Uint8ArrayToString(fileData) {
+        var dataString = "";
+        for (var i = 0; i < fileData.length; i++) {
+            dataString += String.fromCharCode(fileData[i]);
+        }
+
+        return dataString
+    }
+
+    console.log(Uint8ArrayToString(oriData.slice(0x30, 0x38)))
+
+    let audioData = oriData.slice(0x400);
+    let lenAudioData = audioData.length;
+    for (let cur = 0; cur < lenAudioData; ++cur)
+        audioData[cur] ^= mask[cur % 0x20];
+
+
+    const ext = DetectAudioExt(audioData, "mp3");
+    const mime = AudioMimeType[ext];
+    let musicBlob = new Blob([audioData], {type: mime});
+
+    const musicMeta = await musicMetadata.parseBlob(musicBlob);
+    const info = GetFileInfo(musicMeta.common.artist, musicMeta.common.title, raw_filename);
+
+    const imgUrl = GetMetaCoverURL(musicMeta);
+
+    return {
+        status: true,
+        title: info.title,
+        artist: info.artist,
+        ext: ext,
+        album: musicMeta.common.album,
+        picture: imgUrl,
+        file: URL.createObjectURL(musicBlob),
+        mime: mime
+    }
+}
+
+
+function createMaskFromKey(keyBytes) {
+    let keyView = new DataView(keyBytes.buffer)
+    let keyStr = keyView.getBigUint64(0, true).toString()
+    let keyStrTrim = trimKey(keyStr)
+    let key = new Uint8Array(32)
+    for (let i = 0; i < 32; i++) {
+        key[i] = PreDefinedKey[i].charCodeAt() ^ keyStrTrim[i].charCodeAt()
+    }
+    return key
+}
+
+
+function trimKey(keyRaw) {
+    let lenRaw = keyRaw.length;
+    let out = keyRaw;
+    if (lenRaw > 32) {
+        out = keyRaw.slice(0, 32)
+    } else if (lenRaw < 32) {
+        out = keyRaw.padEnd(32, keyRaw)
+    }
+    return out
+}

src/decrypt/util.js

@@ -3,6 +3,10 @@ export const FLAC_HEADER = [0x66, 0x4C, 0x61, 0x43];
 export const MP3_HEADER = [0x49, 0x44, 0x33];
 export const OGG_HEADER = [0x4F, 0x67, 0x67, 0x53];
 export const M4A_HEADER = [0x66, 0x74, 0x79, 0x70];
+export const WMA_HEADER = [
+    0x30, 0x26, 0xB2, 0x75, 0x8E, 0x66, 0xCF, 0x11,
+    0xA6, 0xD9, 0x00, 0xAA, 0x00, 0x62, 0xCE, 0x6C,
+]
 export const AudioMimeType = {
     mp3: "audio/mpeg",
     flac: "audio/flac",
@@ -63,6 +67,7 @@ export function DetectAudioExt(data, fallbackExt) {
     if (IsBytesEqual(FLAC_HEADER, data.slice(0, FLAC_HEADER.length))) return "flac";
     if (IsBytesEqual(OGG_HEADER, data.slice(0, OGG_HEADER.length))) return "ogg";
     if (IsBytesEqual(M4A_HEADER, data.slice(4, 4 + M4A_HEADER.length))) return "m4a";
+    if (IsBytesEqual(WMA_HEADER, data.slice(0, WMA_HEADER.length))) return "wma";
     return fallbackExt;
 }