forked from um/web
Better Way to Detect Mflac Mask
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9aab7a7713
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27b74ea5dd
@ -29,7 +29,7 @@ async function Decrypt(file, raw_filename, raw_ext) {
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// 读取Meta
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let tag = await musicMetadata.parseBlob(musicData);
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const info = util.GetFileInfo(tag.common.artist, tag.common.title, raw_filename);
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reportKeyInfo(new Uint8Array(fileBuffer.slice(-0x170)), seed.mask,
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reportKeyInfo(new Uint8Array(fileBuffer.slice(-0x170)), seed.mask128,
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info.artist, info.title, tag.common.album, raw_filename);
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// 返回
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@ -51,38 +51,56 @@ class Mask {
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constructor() {
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this.index = -1;
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this.mask_index = -1;
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this.mask = new Uint8Array(128);
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this.mask128 = new Uint8Array(128);
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this.mask58_martix = new Uint8Array(56);
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this.mask58_super1 = 0x00;
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this.mask58_super2 = 0x00;
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}
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DetectMask(data) {
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let search_len = data.length - 256, mask;
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let search_len = Math.min(0x8000, data.length), mask;
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for (let block_idx = 0; block_idx < search_len; block_idx += 128) {
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let flag = true;
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mask = data.slice(block_idx, block_idx + 128);
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let next_mask = data.slice(block_idx + 128, block_idx + 256);
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for (let idx = 0; idx < 128; idx++) {
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if (mask[idx] !== next_mask[idx]) {
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flag = false;
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break;
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}
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}
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if (!flag) continue;
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const mask58 = this.Convert128to58(mask);
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if (mask58 === undefined) continue;
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for (let test_idx = 0; test_idx < FLAC_HEADER.length; test_idx++) {
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let p = data[test_idx] ^ mask[test_idx];
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if (p !== FLAC_HEADER[test_idx]) {
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flag = false;
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//todo: Check this
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break;
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}
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}
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if (!flag) continue;
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this.mask = mask;
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if (!FLAC_HEADER.every((val, idx) => {
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return val === mask[idx] ^ data[idx];
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})) continue;
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this.mask128 = mask;
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this.mask58_martix = mask58.matrix;
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this.mask58_super1 = mask58.super_8_1;
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this.mask58_super2 = mask58.super_8_2;
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return true;
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}
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return false;
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}
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Convert128to58(mask128) {
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const super_8_1 = mask128[0], super_8_2 = mask128[8];
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let matrix = [];
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for (let row_idx = 0; row_idx < 8; row_idx++) {
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const len_start = 16 * row_idx;
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const len_right_start = 120 - len_start;//16*(8-row_idx-1)+8
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if (mask128[len_start] !== super_8_1 || mask128[len_start + 8] !== super_8_2) {
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return
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}
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const row_left = mask128.slice(len_start + 1, len_start + 8);
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const row_right = mask128.slice(len_right_start + 1, len_right_start + 8).reverse();
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if (row_left.every((val, idx) => {
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return row_right[idx] === val
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})) {
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matrix.push(row_left);
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} else {
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return
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}
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}
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return {matrix, super_8_1, super_8_2}
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}
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NextMask() {
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this.index++;
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this.mask_index++;
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@ -93,7 +111,7 @@ class Mask {
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if (this.mask_index >= 128) {
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this.mask_index -= 128;
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}
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return this.mask[this.mask_index]
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return this.mask128[this.mask_index]
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}
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}
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