Add Partial Support For .mflac

src/App.vue

@@ -6,7 +6,7 @@
                         :auto-upload="false"
                         :on-change="handleFile"
                         :show-file-list="false"
-                        accept=".ncm,.qmc0,.qmc3,.qmcflac,.qmcogg"
+                        accept=".ncm,.qmc0,.qmc3,.qmcflac,.qmcogg,.mflac"
                         action=""
                         drag
                         multiple>
@@ -69,7 +69,7 @@
             <el-footer id="app-footer">
                 <el-row>
                     音乐解锁：移除已购音乐的加密保护。
-                    目前支持网易云音乐(ncm)和QQ音乐(qmc0, qmc3, qmcflac, qmcogg)。
+                    目前支持网易云音乐(ncm)和QQ音乐(qmc0, qmc3, qmcflac, qmcogg, mflac)。
                     <a href="https://github.com/ix64/unlock-music/wiki/使用提示" target="_blank">使用提示</a>
                 </el-row>
                 <el-row>
@@ -90,6 +90,7 @@
     const NcmDecrypt = require("./plugins/ncm");
     const QmcDecrypt = require("./plugins/qmc");
     const RawDecrypt = require("./plugins/raw");
+    const MFlacDecrypt = require("./plugins/mflac");
     export default {
         name: 'app',
         components: {},
@@ -135,7 +136,11 @@
                         case "qmcogg":
                             data = await QmcDecrypt.Decrypt(file.raw);
                             break;
+                        case "mflac":
+                            data = await MFlacDecrypt.Decrypt(file.raw);
+                            break;
                         default:
+                            console.log("Not Supported File!");
                             break;
                     }
                     if (null != data) {

src/plugins/mflac.js

@@ -0,0 +1,118 @@
+const musicMetadata = require("music-metadata-browser");
+export {Decrypt}
+
+async function Decrypt(file) {
+    // 获取扩展名
+    let filename_ext = file.name.substring(file.name.lastIndexOf(".") + 1, file.name.length).toLowerCase();
+    if (filename_ext !== "mflac") return;
+    // 读取文件
+    const fileBuffer = await new Promise(resolve => {
+        const reader = new FileReader();
+        reader.onload = (e) => {
+            resolve(e.target.result);
+        };
+        reader.readAsArrayBuffer(file);
+    });
+    const audioData = new Uint8Array(fileBuffer.slice(0, -0x170));
+    const audioDataLen = audioData.length;
+
+    // 转换数据
+    const seed = new Mask();
+    if (!seed.DetectMask(audioData)) return;
+    for (let cur = 0; cur < audioDataLen; ++cur) {
+        audioData[cur] ^= seed.NextMask();
+    }
+    // 导出
+    const musicData = new Blob([audioData], {type: "audio/flac"});
+    const musicUrl = URL.createObjectURL(musicData);
+    console.log(musicUrl);
+
+    // 读取Meta
+    let tag = await musicMetadata.parseBlob(musicData);
+
+    // 处理无标题歌手
+    let filename_array = file.name.substring(0, file.name.lastIndexOf(".")).split("-");
+    let title = tag.common.title;
+    let artist = tag.common.artist;
+    if (filename_array.length > 1) {
+        if (artist === undefined) artist = filename_array[0].trim();
+        if (title === undefined) title = filename_array[1].trim();
+    } else if (filename_array.length === 1) {
+        if (title === undefined) title = filename_array[0].trim();
+    }
+    const filename = artist + " - " + title + ".flac";
+    // 处理无封面
+    let pic_url = "";
+
+    if (tag.common.picture !== undefined && tag.common.picture.length >= 1) {
+        const picture = tag.common.picture[0];
+        const blobPic = new Blob([picture.data], {type: picture.format});
+        pic_url = URL.createObjectURL(blobPic);
+    }
+    // 返回*/
+    return {
+        filename: filename,
+        title: title,
+        artist: artist,
+        album: tag.common.album,
+        picture: pic_url,
+        file: musicUrl,
+        mime: "audio/flac"
+    }
+}
+
+class Mask {
+    FLAC_HEADER = [0x66, 0x4C, 0x61, 0x43, 0x00];
+
+    constructor() {
+        this.index = -1;
+        this.mask_index = -1;
+        this.mask = Array(128).fill(0x00);
+    }
+
+    DetectMask(data) {
+
+        let search_len = data.length - 256, mask;
+        for (let block_idx = 0; block_idx < search_len; block_idx += 128) {
+            let flag = true;
+            mask = data.slice(block_idx, block_idx + 128);
+            let next_mask = data.slice(block_idx + 128, block_idx + 256);
+            for (let idx = 0; idx < 128; idx++) {
+                if (mask[idx] !== next_mask[idx]) {
+                    flag = false;
+                    break;
+                }
+            }
+            if (!flag) continue;
+
+
+            for (let test_idx = 0; test_idx < this.FLAC_HEADER.length; test_idx++) {
+                let p = data[test_idx] ^ mask[test_idx];
+                if (p !== this.FLAC_HEADER[test_idx]) {
+                    flag = false;
+                    debugger;
+                    break;
+                }
+            }
+            if (!flag) continue;
+            this.mask = mask;
+            console.log(mask);
+            return true;
+        }
+        return false;
+    }
+
+    NextMask() {
+        this.index++;
+        this.mask_index++;
+        if (this.index === 0x8000 || (this.index > 0x8000 && (this.index + 1) % 0x8000 === 0)) {
+            this.index++;
+            this.mask_index++;
+        }
+        if (this.mask_index >= 128) {
+            this.mask_index -= 128;
+        }
+        return this.mask[this.mask_index]
+    }
+
+}