bugfix for wrong buffer size for preDec

.gitignore

@@ -360,4 +360,12 @@ MigrationBackup/
 .ionide/
 
 # Fody - auto-generated XML schema
-FodyWeavers.xsd
+FodyWeavers.xsd
+
+# content from build
+npm/LICENSE.txt
+npm/QmcWasm.wasm
+npm/QmcLegacy.js
+npm/QmcWasm.js
+npm/QmcWasmBundle.js
+build/

README.md

@@ -26,6 +26,8 @@ const decrypted= (await DecryptQmcWasm(cipherText, extension)).data;
 
 ### 自行构建
 
+#### 依赖
+要自行构建此项目，请确保已经安装[Git]与[CMake]且其路径已经添加到 `PATH`
 #### Linux
 在此项目根目录中执行 `./build-wasm` 即可构建。构建结果将位于此项目根目录的npm子目录中。
 #### Windows
@@ -38,3 +40,5 @@ const decrypted= (await DecryptQmcWasm(cipherText, extension)).data;
 [授权协议]: https://github.com/nullptr-0/QmcWasm/blob/master/LICENSE.txt
 [qmc_wasm.ts]: https://github.com/nullptr-0/QmcWasm/blob/master/qmc_wasm.ts
 [GitHub Actions]: https://github.com/nullptr-0/QmcWasm/actions
+[Git]: https://git-scm.com/book/en/v2/Getting-Started-Installing-Git
+[CMake]: https://cmake.org/download/

build-wasm.cmd

@@ -11,6 +11,18 @@ if not exist build\emsdk (
   git clone https://github.com/emscripten-core/emsdk.git build\emsdk
 )
 
+rem Check for Ninja binary
+pushd build\wasm
+if not exist "ninja.exe" (
+  rem Install Ninja
+  curl -L https://github.com/ninja-build/ninja/releases/download/v1.11.1/ninja-win.zip -o ninja.zip
+  tar -xzvf ninja.zip
+  del ninja.zip
+)
+rem must setup PATH for ninja first to avoid conflict with emsdk_env.bat
+set PATH="%PATH%;%cd%"
+popd
+
 pushd build\emsdk
 rem git pull
 call emsdk.bat install 3.0.0
@@ -21,13 +33,6 @@ popd
 pushd build\wasm
 
 call emcmake cmake -DCMAKE_BUILD_TYPE=%BUILD_TYPE% ..\..
-rem Check if Ninja binary exists
-if not exist "ninja.exe" (
-  rem Install Ninja
-  curl -L https://github.com/ninja-build/ninja/releases/download/v1.11.1/ninja-win.zip -o ninja.zip
-  unzip ninja.zip
-  del ninja.zip
-)
 ninja.exe -f build.ninja -j 3
 
 set "TARGET_FILES=QmcLegacy.js QmcWasm.js QmcWasm.wasm QmcWasmBundle.js %CURR_DIR%\LICENSE.txt"

npm/package.json

@@ -8,7 +8,7 @@
   },
   "repository": {
     "type": "git",
-    "url": "git+https://github.com/xhacker-zzz/QmcWasm.git"
+    "url": "git+https://github.com/nullptr-0/QmcWasm.git"
   },
   "keywords": [
     "unlock-music",
@@ -18,7 +18,7 @@
   "author": "xhacker-zzz",
   "license": "Apache-2.0",
   "bugs": {
-    "url": "https://github.com/xhacker-zzz/QmcWasm/issues"
+    "url": "https://github.com/nullptr-0/QmcWasm/issues"
   },
-  "homepage": "https://github.com/xhacker-zzz/QmcWasm#readme"
+  "homepage": "https://github.com/nullptr-0/QmcWasm#readme"
 }

qmc_key.hpp

@@ -1,4 +1,4 @@
-#include"TencentTea.hpp"
+#include "TencentTea.hpp"
 #include "base64.hpp"
 
 void simpleMakeKey(uint8_t salt, int length, std::vector<uint8_t> &key_buf) {

qmc_wasm.ts

@@ -2,7 +2,7 @@ import { QmcCrypto } from '@xhacker/qmcwasm/QmcWasmBundle';
 import QmcCryptoModule from '@xhacker/qmcwasm/QmcWasmBundle';
 import { MergeUint8Array } from '@/utils/MergeUint8Array';
 
-// 每次处理 2M 的数据
+// 每次可以处理 2M 的数据
 const DECRYPTION_BUF_SIZE = 2 *1024 * 1024;
 
 export interface QMCDecryptionResult {
@@ -38,11 +38,12 @@ export async function DecryptQmcWasm(qmcBlob: ArrayBuffer, ext: string): Promise
   // 申请内存块，并文件末端数据到 WASM 的内存堆
   const qmcBuf = new Uint8Array(qmcBlob);
   const pQmcBuf = QmcCryptoObj._malloc(DECRYPTION_BUF_SIZE);
-  QmcCryptoObj.writeArrayToMemory(qmcBuf.slice(-DECRYPTION_BUF_SIZE), pQmcBuf);
+  const preDecDataSize = Math.min(DECRYPTION_BUF_SIZE, qmcBlob.byteLength); // 初始化缓冲区大小
+  QmcCryptoObj.writeArrayToMemory(qmcBuf.slice(-preDecDataSize), pQmcBuf);
 
   // 进行解密初始化
   ext = '.' + ext;
-  const tailSize = QmcCryptoObj.preDec(pQmcBuf, DECRYPTION_BUF_SIZE, ext);
+  const tailSize = QmcCryptoObj.preDec(pQmcBuf, preDecDataSize, ext);
   if (tailSize == -1) {
     result.error = QmcCryptoObj.getErr();
     return result;