Browse Source

delete js implementations

20230724
xhacker-zzz 2 years ago
parent
commit
ea0dec6f0b
  1. 24
      src/decrypt/kgm.ts
  2. 29
      src/decrypt/qmc.test.ts
  3. 103
      src/decrypt/qmc.ts
  4. 117
      src/decrypt/qmc_cipher.test.ts
  5. 199
      src/decrypt/qmc_cipher.ts
  6. 26
      src/decrypt/qmc_key.test.ts
  7. 127
      src/decrypt/qmc_key.ts
  8. 13
      src/decrypt/qmccache.ts
  9. 73
      src/utils/tea.test.ts
  10. 80
      src/utils/tea.ts

24
src/decrypt/kgm.ts

@ -9,7 +9,6 @@ import {
import { parseBlob as metaParseBlob } from 'music-metadata-browser';
import { DecryptResult } from '@/decrypt/entity';
import { DecryptKgmWasm } from '@/decrypt/kgm_wasm';
import { decryptKgmByteAtOffsetV2, decryptVprByteAtOffset } from '@jixun/kugou-crypto/dist/utils/decryptionHelper';
//prettier-ignore
const VprHeader = [
@ -29,33 +28,14 @@ export async function Decrypt(file: File, raw_filename: string, raw_ext: string)
} else {
if (!BytesHasPrefix(new Uint8Array(oriData), KgmHeader)) throw Error('Not a valid kgm(a) file!');
}
let musicDecoded: Uint8Array | undefined;
let musicDecoded = new Uint8Array();
if (globalThis.WebAssembly) {
console.log('kgm: using wasm decoder');
const kgmDecrypted = await DecryptKgmWasm(oriData, raw_ext);
if (kgmDecrypted.success) {
musicDecoded = kgmDecrypted.data;
console.log('kgm wasm decoder suceeded');
} else {
console.warn('KgmWasm failed with error %s', kgmDecrypted.error || '(unknown error)');
}
}
if (!musicDecoded) {
musicDecoded = new Uint8Array(oriData);
let bHeaderLen = new DataView(musicDecoded.slice(0x10, 0x14).buffer);
let headerLen = bHeaderLen.getUint32(0, true);
let key1 = Array.from(musicDecoded.slice(0x1c, 0x2c));
key1.push(0);
musicDecoded = musicDecoded.slice(headerLen);
let dataLen = musicDecoded.length;
const decryptByte = raw_ext === 'vpr' ? decryptVprByteAtOffset : decryptKgmByteAtOffsetV2;
for (let i = 0; i < dataLen; i++) {
musicDecoded[i] = decryptByte(musicDecoded[i], key1, i);
throw new Error(kgmDecrypted.error || '(unknown error)');
}
}

29
src/decrypt/qmc.test.ts

@ -1,29 +0,0 @@
import fs from 'fs';
import { QmcDecoder } from '@/decrypt/qmc';
import { BytesEqual } from '@/decrypt/utils';
function loadTestDataDecoder(name: string): {
cipherText: Uint8Array;
clearText: Uint8Array;
} {
const cipherBody = fs.readFileSync(`./testdata/${name}_raw.bin`);
const cipherSuffix = fs.readFileSync(`./testdata/${name}_suffix.bin`);
const cipherText = new Uint8Array(cipherBody.length + cipherSuffix.length);
cipherText.set(cipherBody);
cipherText.set(cipherSuffix, cipherBody.length);
return {
cipherText,
clearText: fs.readFileSync(`testdata/${name}_target.bin`),
};
}
test('qmc: real file', async () => {
const cases = ['mflac0_rc4', 'mflac_rc4', 'mflac_map', 'mgg_map', 'qmc0_static'];
for (const name of cases) {
const { clearText, cipherText } = loadTestDataDecoder(name);
const c = new QmcDecoder(cipherText);
const buf = c.decrypt();
expect(BytesEqual(buf, clearText)).toBeTruthy();
}
});

103
src/decrypt/qmc.ts

@ -1,8 +1,6 @@
import { QmcMapCipher, QmcRC4Cipher, QmcStaticCipher, QmcStreamCipher } from './qmc_cipher';
import { AudioMimeType, GetArrayBuffer, SniffAudioExt } from '@/decrypt/utils';
import { DecryptResult } from '@/decrypt/entity';
import { QmcDeriveKey } from '@/decrypt/qmc_key';
import { DecryptQmcWasm } from '@/decrypt/qmc_wasm';
import { extractQQMusicMeta } from '@/utils/qm_meta';
@ -18,7 +16,7 @@ export const HandlerMap: { [key: string]: Handler } = {
mgg1: { ext: 'ogg', version: 2 },
mflac: { ext: 'flac', version: 2 },
mflac0: { ext: 'flac', version: 2 },
mmp4: { ext: 'mmp4', version: 2 },
mmp4: { ext: 'mp4', version: 2 },
// qmcflac / qmcogg:
// 有可能是 v2 加密但混用同一个后缀名。
@ -52,12 +50,10 @@ export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string)
let { version } = handler;
const fileBuffer = await GetArrayBuffer(file);
let musicDecoded: Uint8Array | undefined;
let musicDecoded = new Uint8Array();
let musicID: number | string | undefined;
if (version === 2 && globalThis.WebAssembly) {
console.log('qmc: using wasm decoder');
const v2Decrypted = await DecryptQmcWasm(fileBuffer, raw_ext);
// 若 v2 检测失败,降级到 v1 再尝试一次
if (v2Decrypted.success) {
@ -65,16 +61,8 @@ export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string)
musicID = v2Decrypted.songId;
console.log('qmc wasm decoder suceeded');
} else {
console.warn('QmcWasm failed with error %s', v2Decrypted.error || '(unknown error)');
}
throw new Error(v2Decrypted.error || '(unknown error)');
}
if (!musicDecoded) {
// may throw error
console.log('qmc: using js decoder');
const d = new QmcDecoder(new Uint8Array(fileBuffer));
musicDecoded = d.decrypt();
musicID = d.songID;
}
const ext = SniffAudioExt(musicDecoded, handler.ext);
@ -98,88 +86,3 @@ export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string)
mime: mime,
};
}
export class QmcDecoder {
private static readonly BYTE_COMMA = ','.charCodeAt(0);
private readonly file: Uint8Array;
private readonly size: number;
private decoded: boolean = false;
private audioSize?: number;
private cipher?: QmcStreamCipher;
public constructor(file: Uint8Array) {
this.file = file;
this.size = file.length;
this.searchKey();
}
private _songID?: number;
public get songID() {
return this._songID;
}
public decrypt(): Uint8Array {
if (!this.cipher) {
throw new Error('no cipher found');
}
if (!this.audioSize || this.audioSize <= 0) {
throw new Error('invalid audio size');
}
const audioBuf = this.file.subarray(0, this.audioSize);
if (!this.decoded) {
this.cipher.decrypt(audioBuf, 0);
this.decoded = true;
}
return audioBuf;
}
private searchKey() {
const last4Byte = this.file.slice(-4);
const textEnc = new TextDecoder();
if (textEnc.decode(last4Byte) === 'STag') {
throw new Error('文件中没有写入密钥,无法解锁,请降级App并重试');
} else if (textEnc.decode(last4Byte) === 'QTag') {
const sizeBuf = this.file.slice(-8, -4);
const sizeView = new DataView(sizeBuf.buffer, sizeBuf.byteOffset);
const keySize = sizeView.getUint32(0, false);
this.audioSize = this.size - keySize - 8;
const rawKey = this.file.subarray(this.audioSize, this.size - 8);
const keyEnd = rawKey.findIndex((v) => v == QmcDecoder.BYTE_COMMA);
if (keyEnd < 0) {
throw new Error('invalid key: search raw key failed');
}
this.setCipher(rawKey.subarray(0, keyEnd));
const idBuf = rawKey.subarray(keyEnd + 1);
const idEnd = idBuf.findIndex((v) => v == QmcDecoder.BYTE_COMMA);
if (keyEnd < 0) {
throw new Error('invalid key: search song id failed');
}
this._songID = parseInt(textEnc.decode(idBuf.subarray(0, idEnd)), 10);
} else {
const sizeView = new DataView(last4Byte.buffer, last4Byte.byteOffset);
const keySize = sizeView.getUint32(0, true);
if (keySize < 0x400) {
this.audioSize = this.size - keySize - 4;
const rawKey = this.file.subarray(this.audioSize, this.size - 4);
this.setCipher(rawKey);
} else {
this.audioSize = this.size;
this.cipher = new QmcStaticCipher();
}
}
}
private setCipher(keyRaw: Uint8Array) {
const keyDec = QmcDeriveKey(keyRaw);
if (keyDec.length > 300) {
this.cipher = new QmcRC4Cipher(keyDec);
} else {
this.cipher = new QmcMapCipher(keyDec);
}
}
}

117
src/decrypt/qmc_cipher.test.ts

@ -1,117 +0,0 @@
import { QmcMapCipher, QmcRC4Cipher, QmcStaticCipher } from '@/decrypt/qmc_cipher';
import fs from 'fs';
test('static cipher [0x7ff8,0x8000) ', () => {
//prettier-ignore
const expected = new Uint8Array([
0xD8, 0x52, 0xF7, 0x67, 0x90, 0xCA, 0xD6, 0x4A,
0x4A, 0xD6, 0xCA, 0x90, 0x67, 0xF7, 0x52, 0xD8,
])
const c = new QmcStaticCipher();
const buf = new Uint8Array(16);
c.decrypt(buf, 0x7ff8);
expect(buf).toStrictEqual(expected);
});
test('static cipher [0,0x10) ', () => {
//prettier-ignore
const expected = new Uint8Array([
0xC3, 0x4A, 0xD6, 0xCA, 0x90, 0x67, 0xF7, 0x52,
0xD8, 0xA1, 0x66, 0x62, 0x9F, 0x5B, 0x09, 0x00,
])
const c = new QmcStaticCipher();
const buf = new Uint8Array(16);
c.decrypt(buf, 0);
expect(buf).toStrictEqual(expected);
});
test('map cipher: get mask', () => {
//prettier-ignore
const expected = new Uint8Array([
0xBB, 0x7D, 0x80, 0xBE, 0xFF, 0x38, 0x81, 0xFB,
0xBB, 0xFF, 0x82, 0x3C, 0xFF, 0xBA, 0x83, 0x79,
])
const key = new Uint8Array(256);
for (let i = 0; i < 256; i++) key[i] = i;
const buf = new Uint8Array(16);
const c = new QmcMapCipher(key);
c.decrypt(buf, 0);
expect(buf).toStrictEqual(expected);
});
function loadTestDataCipher(name: string): {
key: Uint8Array;
cipherText: Uint8Array;
clearText: Uint8Array;
} {
return {
key: fs.readFileSync(`testdata/${name}_key.bin`),
cipherText: fs.readFileSync(`testdata/${name}_raw.bin`),
clearText: fs.readFileSync(`testdata/${name}_target.bin`),
};
}
test('map cipher: real file', async () => {
const cases = ['mflac_map', 'mgg_map'];
for (const name of cases) {
const { key, clearText, cipherText } = loadTestDataCipher(name);
const c = new QmcMapCipher(key);
c.decrypt(cipherText, 0);
expect(cipherText).toStrictEqual(clearText);
}
});
test('rc4 cipher: real file', async () => {
const cases = ['mflac0_rc4', 'mflac_rc4'];
for (const name of cases) {
const { key, clearText, cipherText } = loadTestDataCipher(name);
const c = new QmcRC4Cipher(key);
c.decrypt(cipherText, 0);
expect(cipherText).toStrictEqual(clearText);
}
});
test('rc4 cipher: first segment', async () => {
const cases = ['mflac0_rc4', 'mflac_rc4'];
for (const name of cases) {
const { key, clearText, cipherText } = loadTestDataCipher(name);
const c = new QmcRC4Cipher(key);
const buf = cipherText.slice(0, 128);
c.decrypt(buf, 0);
expect(buf).toStrictEqual(clearText.slice(0, 128));
}
});
test('rc4 cipher: align block (128~5120)', async () => {
const cases = ['mflac0_rc4', 'mflac_rc4'];
for (const name of cases) {
const { key, clearText, cipherText } = loadTestDataCipher(name);
const c = new QmcRC4Cipher(key);
const buf = cipherText.slice(128, 5120);
c.decrypt(buf, 128);
expect(buf).toStrictEqual(clearText.slice(128, 5120));
}
});
test('rc4 cipher: simple block (5120~10240)', async () => {
const cases = ['mflac0_rc4', 'mflac_rc4'];
for (const name of cases) {
const { key, clearText, cipherText } = loadTestDataCipher(name);
const c = new QmcRC4Cipher(key);
const buf = cipherText.slice(5120, 10240);
c.decrypt(buf, 5120);
expect(buf).toStrictEqual(clearText.slice(5120, 10240));
}
});

199
src/decrypt/qmc_cipher.ts

@ -1,199 +0,0 @@
export interface QmcStreamCipher {
decrypt(buf: Uint8Array, offset: number): void;
}
export class QmcStaticCipher implements QmcStreamCipher {
//prettier-ignore
private static readonly staticCipherBox: Uint8Array = new Uint8Array([
0x77, 0x48, 0x32, 0x73, 0xDE, 0xF2, 0xC0, 0xC8, //0x00
0x95, 0xEC, 0x30, 0xB2, 0x51, 0xC3, 0xE1, 0xA0, //0x08
0x9E, 0xE6, 0x9D, 0xCF, 0xFA, 0x7F, 0x14, 0xD1, //0x10
0xCE, 0xB8, 0xDC, 0xC3, 0x4A, 0x67, 0x93, 0xD6, //0x18
0x28, 0xC2, 0x91, 0x70, 0xCA, 0x8D, 0xA2, 0xA4, //0x20
0xF0, 0x08, 0x61, 0x90, 0x7E, 0x6F, 0xA2, 0xE0, //0x28
0xEB, 0xAE, 0x3E, 0xB6, 0x67, 0xC7, 0x92, 0xF4, //0x30
0x91, 0xB5, 0xF6, 0x6C, 0x5E, 0x84, 0x40, 0xF7, //0x38
0xF3, 0x1B, 0x02, 0x7F, 0xD5, 0xAB, 0x41, 0x89, //0x40
0x28, 0xF4, 0x25, 0xCC, 0x52, 0x11, 0xAD, 0x43, //0x48
0x68, 0xA6, 0x41, 0x8B, 0x84, 0xB5, 0xFF, 0x2C, //0x50
0x92, 0x4A, 0x26, 0xD8, 0x47, 0x6A, 0x7C, 0x95, //0x58
0x61, 0xCC, 0xE6, 0xCB, 0xBB, 0x3F, 0x47, 0x58, //0x60
0x89, 0x75, 0xC3, 0x75, 0xA1, 0xD9, 0xAF, 0xCC, //0x68
0x08, 0x73, 0x17, 0xDC, 0xAA, 0x9A, 0xA2, 0x16, //0x70
0x41, 0xD8, 0xA2, 0x06, 0xC6, 0x8B, 0xFC, 0x66, //0x78
0x34, 0x9F, 0xCF, 0x18, 0x23, 0xA0, 0x0A, 0x74, //0x80
0xE7, 0x2B, 0x27, 0x70, 0x92, 0xE9, 0xAF, 0x37, //0x88
0xE6, 0x8C, 0xA7, 0xBC, 0x62, 0x65, 0x9C, 0xC2, //0x90
0x08, 0xC9, 0x88, 0xB3, 0xF3, 0x43, 0xAC, 0x74, //0x98
0x2C, 0x0F, 0xD4, 0xAF, 0xA1, 0xC3, 0x01, 0x64, //0xA0
0x95, 0x4E, 0x48, 0x9F, 0xF4, 0x35, 0x78, 0x95, //0xA8
0x7A, 0x39, 0xD6, 0x6A, 0xA0, 0x6D, 0x40, 0xE8, //0xB0
0x4F, 0xA8, 0xEF, 0x11, 0x1D, 0xF3, 0x1B, 0x3F, //0xB8
0x3F, 0x07, 0xDD, 0x6F, 0x5B, 0x19, 0x30, 0x19, //0xC0
0xFB, 0xEF, 0x0E, 0x37, 0xF0, 0x0E, 0xCD, 0x16, //0xC8
0x49, 0xFE, 0x53, 0x47, 0x13, 0x1A, 0xBD, 0xA4, //0xD0
0xF1, 0x40, 0x19, 0x60, 0x0E, 0xED, 0x68, 0x09, //0xD8
0x06, 0x5F, 0x4D, 0xCF, 0x3D, 0x1A, 0xFE, 0x20, //0xE0
0x77, 0xE4, 0xD9, 0xDA, 0xF9, 0xA4, 0x2B, 0x76, //0xE8
0x1C, 0x71, 0xDB, 0x00, 0xBC, 0xFD, 0x0C, 0x6C, //0xF0
0xA5, 0x47, 0xF7, 0xF6, 0x00, 0x79, 0x4A, 0x11, //0xF8
])
public getMask(offset: number) {
if (offset > 0x7fff) offset %= 0x7fff;
return QmcStaticCipher.staticCipherBox[(offset * offset + 27) & 0xff];
}
public decrypt(buf: Uint8Array, offset: number) {
for (let i = 0; i < buf.length; i++) {
buf[i] ^= this.getMask(offset + i);
}
}
}
export class QmcMapCipher implements QmcStreamCipher {
key: Uint8Array;
n: number;
constructor(key: Uint8Array) {
if (key.length == 0) throw Error('qmc/cipher_map: invalid key size');
this.key = key;
this.n = key.length;
}
private static rotate(value: number, bits: number) {
let rotate = (bits + 4) % 8;
let left = value << rotate;
let right = value >> rotate;
return (left | right) & 0xff;
}
decrypt(buf: Uint8Array, offset: number): void {
for (let i = 0; i < buf.length; i++) {
buf[i] ^= this.getMask(offset + i);
}
}
private getMask(offset: number) {
if (offset > 0x7fff) offset %= 0x7fff;
const idx = (offset * offset + 71214) % this.n;
return QmcMapCipher.rotate(this.key[idx], idx & 0x7);
}
}
export class QmcRC4Cipher implements QmcStreamCipher {
private static readonly FIRST_SEGMENT_SIZE = 0x80;
private static readonly SEGMENT_SIZE = 5120;
S: Uint8Array;
N: number;
key: Uint8Array;
hash: number;
constructor(key: Uint8Array) {
if (key.length == 0) {
throw Error('invalid key size');
}
this.key = key;
this.N = key.length;
// init seed box
this.S = new Uint8Array(this.N);
for (let i = 0; i < this.N; ++i) {
this.S[i] = i & 0xff;
}
let j = 0;
for (let i = 0; i < this.N; ++i) {
j = (this.S[i] + j + this.key[i % this.N]) % this.N;
[this.S[i], this.S[j]] = [this.S[j], this.S[i]];
}
// init hash base
this.hash = 1;
for (let i = 0; i < this.N; i++) {
let value = this.key[i];
// ignore if key char is '\x00'
if (!value) continue;
const next_hash = (this.hash * value) >>> 0;
if (next_hash == 0 || next_hash <= this.hash) break;
this.hash = next_hash;
}
}
decrypt(buf: Uint8Array, offset: number): void {
let toProcess = buf.length;
let processed = 0;
const postProcess = (len: number): boolean => {
toProcess -= len;
processed += len;
offset += len;
return toProcess == 0;
};
// Initial segment
if (offset < QmcRC4Cipher.FIRST_SEGMENT_SIZE) {
const len_segment = Math.min(buf.length, QmcRC4Cipher.FIRST_SEGMENT_SIZE - offset);
this.encFirstSegment(buf.subarray(0, len_segment), offset);
if (postProcess(len_segment)) return;
}
// align segment
if (offset % QmcRC4Cipher.SEGMENT_SIZE != 0) {
const len_segment = Math.min(QmcRC4Cipher.SEGMENT_SIZE - (offset % QmcRC4Cipher.SEGMENT_SIZE), toProcess);
this.encASegment(buf.subarray(processed, processed + len_segment), offset);
if (postProcess(len_segment)) return;
}
// Batch process segments
while (toProcess > QmcRC4Cipher.SEGMENT_SIZE) {
this.encASegment(buf.subarray(processed, processed + QmcRC4Cipher.SEGMENT_SIZE), offset);
postProcess(QmcRC4Cipher.SEGMENT_SIZE);
}
// Last segment (incomplete segment)
if (toProcess > 0) {
this.encASegment(buf.subarray(processed), offset);
}
}
private encFirstSegment(buf: Uint8Array, offset: number) {
for (let i = 0; i < buf.length; i++) {
buf[i] ^= this.key[this.getSegmentKey(offset + i)];
}
}
private encASegment(buf: Uint8Array, offset: number) {
// Initialise a new seed box
const S = this.S.slice(0);
// Calculate the number of bytes to skip.
// The initial "key" derived from segment id, plus the current offset.
const skipLen =
(offset % QmcRC4Cipher.SEGMENT_SIZE) + this.getSegmentKey(Math.floor(offset / QmcRC4Cipher.SEGMENT_SIZE));
// decrypt the block
let j = 0;
let k = 0;
for (let i = -skipLen; i < buf.length; i++) {
j = (j + 1) % this.N;
k = (S[j] + k) % this.N;
[S[k], S[j]] = [S[j], S[k]];
if (i >= 0) {
buf[i] ^= S[(S[j] + S[k]) % this.N];
}
}
}
private getSegmentKey(id: number): number {
const seed = this.key[id % this.N];
const idx = Math.floor((this.hash / ((id + 1) * seed)) * 100.0);
return idx % this.N;
}
}

26
src/decrypt/qmc_key.test.ts

@ -1,26 +0,0 @@
import { QmcDeriveKey, simpleMakeKey } from '@/decrypt/qmc_key';
import fs from 'fs';
test('key dec: make simple key', () => {
expect(simpleMakeKey(106, 8)).toStrictEqual([0x69, 0x56, 0x46, 0x38, 0x2b, 0x20, 0x15, 0x0b]);
});
function loadTestDataKeyDecrypt(name: string): {
cipherText: Uint8Array;
clearText: Uint8Array;
} {
return {
cipherText: fs.readFileSync(`testdata/${name}_key_raw.bin`),
clearText: fs.readFileSync(`testdata/${name}_key.bin`),
};
}
test('key dec: real file', async () => {
const cases = ['mflac_map', 'mgg_map', 'mflac0_rc4', 'mflac_rc4'];
for (const name of cases) {
const { clearText, cipherText } = loadTestDataKeyDecrypt(name);
const buf = QmcDeriveKey(cipherText);
expect(buf).toStrictEqual(clearText);
}
});

127
src/decrypt/qmc_key.ts

@ -1,127 +0,0 @@
import { TeaCipher } from '@/utils/tea';
const SALT_LEN = 2;
const ZERO_LEN = 7;
export function QmcDeriveKey(raw: Uint8Array): Uint8Array {
const textDec = new TextDecoder();
let rawDec = Buffer.from(textDec.decode(raw), 'base64');
let n = rawDec.length;
if (n < 16) {
throw Error('key length is too short');
}
rawDec = decryptV2Key(rawDec);
const simpleKey = simpleMakeKey(106, 8);
let teaKey = new Uint8Array(16);
for (let i = 0; i < 8; i++) {
teaKey[i << 1] = simpleKey[i];
teaKey[(i << 1) + 1] = rawDec[i];
}
const sub = decryptTencentTea(rawDec.subarray(8), teaKey);
rawDec.set(sub, 8);
return rawDec.subarray(0, 8 + sub.length);
}
// simpleMakeKey exported only for unit test
export function simpleMakeKey(salt: number, length: number): number[] {
const keyBuf: number[] = [];
for (let i = 0; i < length; i++) {
const tmp = Math.tan(salt + i * 0.1);
keyBuf[i] = 0xff & (Math.abs(tmp) * 100.0);
}
return keyBuf;
}
const mixKey1: Uint8Array = new Uint8Array([ 0x33, 0x38, 0x36, 0x5A, 0x4A, 0x59, 0x21, 0x40, 0x23, 0x2A, 0x24, 0x25, 0x5E, 0x26, 0x29, 0x28 ])
const mixKey2: Uint8Array = new Uint8Array([ 0x2A, 0x2A, 0x23, 0x21, 0x28, 0x23, 0x24, 0x25, 0x26, 0x5E, 0x61, 0x31, 0x63, 0x5A, 0x2C, 0x54 ])
function decryptV2Key(key: Buffer): Buffer
{
const textEnc = new TextDecoder();
if (key.length < 18 || textEnc.decode(key.slice(0, 18)) !== 'QQMusic EncV2,Key:') {
return key;
}
let out = decryptTencentTea(key.slice(18), mixKey1);
out = decryptTencentTea(out, mixKey2);
const textDec = new TextDecoder();
const keyDec = Buffer.from(textDec.decode(out), 'base64');
let n = keyDec.length;
if (n < 16) {
throw Error('EncV2 key decode failed');
}
return keyDec;
}
function decryptTencentTea(inBuf: Uint8Array, key: Uint8Array): Uint8Array {
if (inBuf.length % 8 != 0) {
throw Error('inBuf size not a multiple of the block size');
}
if (inBuf.length < 16) {
throw Error('inBuf size too small');
}
const blk = new TeaCipher(key, 32);
const tmpBuf = new Uint8Array(8);
const tmpView = new DataView(tmpBuf.buffer);
blk.decrypt(tmpView, new DataView(inBuf.buffer, inBuf.byteOffset, 8));
const nPadLen = tmpBuf[0] & 0x7; //只要最低三位
/*密文格式:PadLen(1byte)+Padding(var,0-7byte)+Salt(2byte)+Body(var byte)+Zero(7byte)*/
const outLen = inBuf.length - 1 /*PadLen*/ - nPadLen - SALT_LEN - ZERO_LEN;
const outBuf = new Uint8Array(outLen);
let ivPrev = new Uint8Array(8);
let ivCur = inBuf.slice(0, 8); // init iv
let inBufPos = 8;
// 跳过 Padding Len 和 Padding
let tmpIdx = 1 + nPadLen;
// CBC IV 处理
const cryptBlock = () => {
ivPrev = ivCur;
ivCur = inBuf.slice(inBufPos, inBufPos + 8);
for (let j = 0; j < 8; j++) {
tmpBuf[j] ^= ivCur[j];
}
blk.decrypt(tmpView, tmpView);
inBufPos += 8;
tmpIdx = 0;
};
// 跳过 Salt
for (let i = 1; i <= SALT_LEN; ) {
if (tmpIdx < 8) {
tmpIdx++;
i++;
} else {
cryptBlock();
}
}
// 还原明文
let outBufPos = 0;
while (outBufPos < outLen) {
if (tmpIdx < 8) {
outBuf[outBufPos] = tmpBuf[tmpIdx] ^ ivPrev[tmpIdx];
outBufPos++;
tmpIdx++;
} else {
cryptBlock();
}
}
// 校验Zero
for (let i = 1; i <= ZERO_LEN; i++) {
if (tmpBuf[tmpIdx] != ivPrev[tmpIdx]) {
throw Error('zero check failed');
}
}
return outBuf;
}

13
src/decrypt/qmccache.ts

@ -17,7 +17,7 @@ import { parseBlob as metaParseBlob } from 'music-metadata-browser';
export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string): Promise<DecryptResult> {
const buffer = await GetArrayBuffer(file);
let musicDecoded: Uint8Array | undefined;
let musicDecoded = new Uint8Array();
if (globalThis.WebAssembly) {
console.log('qmc: using wasm decoder');
@ -27,19 +27,10 @@ export async function Decrypt(file: Blob, raw_filename: string, raw_ext: string)
musicDecoded = qmcDecrypted.data;
console.log('qmc wasm decoder suceeded');
} else {
console.warn('QmcWasm failed with error %s', qmcDecrypted.error || '(unknown error)');
throw new Error(qmcDecrypted.error || '(unknown error)');
}
}
if (!musicDecoded) {
musicDecoded = new Uint8Array(buffer);
let length = musicDecoded.length;
for (let i = 0; i < length; i++) {
let byte = musicDecoded[i] ^ 0xf4; // xor 0xf4
byte = ((byte & 0b0011_1111) << 2) | (byte >> 6); // rol 2
musicDecoded[i] = byte;
}
}
let ext = SniffAudioExt(musicDecoded, '');
const newName = SplitFilename(raw_filename);
let audioBlob: Blob;

73
src/utils/tea.test.ts

@ -1,73 +0,0 @@
// Copyright 2021 MengYX. All rights reserved.
//
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in https://go.dev/LICENSE.
import { TeaCipher } from '@/utils/tea';
test('key size', () => {
// prettier-ignore
const testKey = new Uint8Array([
0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff,
0x00,
])
expect(() => new TeaCipher(testKey.slice(0, 16))).not.toThrow();
expect(() => new TeaCipher(testKey)).toThrow();
expect(() => new TeaCipher(testKey.slice(0, 15))).toThrow();
});
// prettier-ignore
const teaTests = [
// These were sourced from https://github.com/froydnj/ironclad/blob/master/testing/test-vectors/tea.testvec
{
rounds: TeaCipher.numRounds,
key: new Uint8Array([
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
]),
plainText: new Uint8Array([0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]),
cipherText: new Uint8Array([0x41, 0xea, 0x3a, 0x0a, 0x94, 0xba, 0xa9, 0x40]),
},
{
rounds: TeaCipher.numRounds,
key: new Uint8Array([
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
]),
plainText: new Uint8Array([0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff]),
cipherText: new Uint8Array([0x31, 0x9b, 0xbe, 0xfb, 0x01, 0x6a, 0xbd, 0xb2]),
},
{
rounds: 16,
key: new Uint8Array([
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
]),
plainText: new Uint8Array([0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]),
cipherText: new Uint8Array([0xed, 0x28, 0x5d, 0xa1, 0x45, 0x5b, 0x33, 0xc1]),
},
];
test('rounds', () => {
const tt = teaTests[0];
expect(() => new TeaCipher(tt.key, tt.rounds - 1)).toThrow();
});
test('encrypt & decrypt', () => {
for (const tt of teaTests) {
const c = new TeaCipher(tt.key, tt.rounds);
const buf = new Uint8Array(8);
const bufView = new DataView(buf.buffer);
c.encrypt(bufView, new DataView(tt.plainText.buffer));
expect(buf).toStrictEqual(tt.cipherText);
c.decrypt(bufView, new DataView(tt.cipherText.buffer));
expect(buf).toStrictEqual(tt.plainText);
}
});

80
src/utils/tea.ts

@ -1,80 +0,0 @@
// Copyright 2021 MengYX. All rights reserved.
//
// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in https://go.dev/LICENSE.
// TeaCipher is a typescript port to golang.org/x/crypto/tea
// Package tea implements the TEA algorithm, as defined in Needham and
// Wheeler's 1994 technical report, “TEA, a Tiny Encryption Algorithm”. See
// http://www.cix.co.uk/~klockstone/tea.pdf for details.
//
// TEA is a legacy cipher and its short block size makes it vulnerable to
// birthday bound attacks (see https://sweet32.info). It should only be used
// where compatibility with legacy systems, not security, is the goal.
export class TeaCipher {
// BlockSize is the size of a TEA block, in bytes.
static readonly BlockSize = 8;
// KeySize is the size of a TEA key, in bytes.
static readonly KeySize = 16;
// delta is the TEA key schedule constant.
static readonly delta = 0x9e3779b9;
// numRounds 64 is the standard number of rounds in TEA.
static readonly numRounds = 64;
k0: number;
k1: number;
k2: number;
k3: number;
rounds: number;
constructor(key: Uint8Array, rounds: number = TeaCipher.numRounds) {
if (key.length != 16) {
throw Error('incorrect key size');
}
if ((rounds & 1) != 0) {
throw Error('odd number of rounds specified');
}
const k = new DataView(key.buffer);
this.k0 = k.getUint32(0, false);
this.k1 = k.getUint32(4, false);
this.k2 = k.getUint32(8, false);
this.k3 = k.getUint32(12, false);
this.rounds = rounds;
}
encrypt(dst: DataView, src: DataView) {
let v0 = src.getUint32(0, false);
let v1 = src.getUint32(4, false);
let sum = 0;
for (let i = 0; i < this.rounds / 2; i++) {
sum = sum + TeaCipher.delta;
v0 += ((v1 << 4) + this.k0) ^ (v1 + sum) ^ ((v1 >>> 5) + this.k1);
v1 += ((v0 << 4) + this.k2) ^ (v0 + sum) ^ ((v0 >>> 5) + this.k3);
}
dst.setUint32(0, v0, false);
dst.setUint32(4, v1, false);
}
decrypt(dst: DataView, src: DataView) {
let v0 = src.getUint32(0, false);
let v1 = src.getUint32(4, false);
let sum = (TeaCipher.delta * this.rounds) / 2;
for (let i = 0; i < this.rounds / 2; i++) {
v1 -= ((v0 << 4) + this.k2) ^ (v0 + sum) ^ ((v0 >>> 5) + this.k3);
v0 -= ((v1 << 4) + this.k0) ^ (v1 + sum) ^ ((v1 >>> 5) + this.k1);
sum -= TeaCipher.delta;
}
dst.setUint32(0, v0, false);
dst.setUint32(4, v1, false);
}
}
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