Reconstruct

src/decrypt/qmc.js

@@ -0,0 +1,91 @@
+const musicMetadata = require("music-metadata-browser");
+const util = require("./util");
+export {Decrypt}
+const SEED_MAP = [
+    [0x4a, 0xd6, 0xca, 0x90, 0x67, 0xf7, 0x52],
+    [0x5e, 0x95, 0x23, 0x9f, 0x13, 0x11, 0x7e],
+    [0x47, 0x74, 0x3d, 0x90, 0xaa, 0x3f, 0x51],
+    [0xc6, 0x09, 0xd5, 0x9f, 0xfa, 0x66, 0xf9],
+    [0xf3, 0xd6, 0xa1, 0x90, 0xa0, 0xf7, 0xf0],
+    [0x1d, 0x95, 0xde, 0x9f, 0x84, 0x11, 0xf4],
+    [0x0e, 0x74, 0xbb, 0x90, 0xbc, 0x3f, 0x92],
+    [0x00, 0x09, 0x5b, 0x9f, 0x62, 0x66, 0xa1]];
+
+
+async function Decrypt(file, raw_filename, raw_ext) {
+    // 获取扩展名
+    let new_ext;
+    switch (raw_ext) {
+        case "qmc0":
+        case "qmc3":
+            new_ext = "mp3";
+            break;
+        case "qmcogg":
+            new_ext = "ogg";
+            break;
+        case "qmcflac":
+            new_ext = "flac";
+            break;
+        default:
+            return {status: false, message: "File type is incorrect!"}
+    }
+    const mime = util.AudioMimeType[new_ext];
+    // 读取文件
+    const fileBuffer = await util.GetArrayBuffer(file);
+    const audioData = new Uint8Array(fileBuffer);
+    // 转换数据
+    const seed = new Mask();
+    for (let cur = 0; cur < audioData.length; ++cur) {
+        audioData[cur] ^= seed.NextMask();
+    }
+    // 导出
+    const musicData = new Blob([audioData], {type: mime});
+    const musicUrl = URL.createObjectURL(musicData);
+    // 读取Meta
+    let tag = await musicMetadata.parseBlob(musicData);
+    const info = util.GetFileInfo(tag.common.artist, tag.common.title, raw_filename, raw_ext);
+    let picUrl = util.GetCoverURL(tag);
+
+    // 返回
+    return {
+        status: true,
+        filename: info.filename,
+        title: info.title,
+        artist: info.artist,
+        album: tag.common.album,
+        picture: picUrl,
+        file: musicUrl,
+        mime: mime
+    }
+}
+
+class Mask {
+    constructor() {
+        this.x = -1;
+        this.y = 8;
+        this.dx = 1;
+        this.index = -1;
+    }
+
+    NextMask() {
+        let ret;
+        this.index++;
+        if (this.x < 0) {
+            this.dx = 1;
+            this.y = (8 - this.y) % 8;
+            ret = 0xc3
+        } else if (this.x > 6) {
+            this.dx = -1;
+            this.y = 7 - this.y;
+            ret = 0xd8
+        } else {
+            ret = SEED_MAP[this.y][this.x]
+        }
+        this.x += this.dx;
+        if (this.index === 0x8000 || (this.index > 0x8000 && (this.index + 1) % 0x8000 === 0)) {
+            return this.NextMask()
+        }
+        return ret
+    }
+
+}