專案目的

UCam（全能相機）是一款免費優秀的軟體（App），例如︰智能相機、全景相機、防抖動、軟體防手震等豐富功能。由於 Android 4.4（API 19）導入了「儲存空間存取架構」（Storage Access Framework，SAF），早期版本在新的裝置無法存取外部記憶卡（SD 卡）。

本專案使用逆向工程方法產生 Smali（dex2jar + jd-gui），新增儲存空間挑選器提示使用者選擇儲存位置；並引入 DocumentsProvider API 改寫儲存檔案機制，最後重新編譯 Smali 輸出 Apk，驗證逆向工程重編譯操作正確無誤。

專案成果

AppUtils.init(Landroid/content/Context;)V

new-instance v0, Landroid/content/Intent;

const-class v1, Lcom/example/test/StoragePermissionsActivity;

sget-object v2, Lcom/ucamera/ucam/utils/AppUtils;->mContext:Landroid/content/Context;

invoke-direct {v0, v2, v1}, Landroid/content/Intent;-><init>(Landroid/content/Context;Ljava/lang/Class;)V

invoke-virtual {v2, v0}, Landroid/content/Context;->startActivity(Landroid/content/Intent;)V

StoragePermissionsActivity.triggerStorageAccessFrameowrk()V

new-instance v1, Landroid/content/Intent;

const-string v0, "android.intent.action.OPEN_DOCUMENT_TREE"

invoke-direct {v1, v0}, Landroid/content/Intent;-><init>(Ljava/lang/String;)V

.local v1, "intent":Landroid/content/Intent;

const/16 v0, 0x2a

invoke-virtual {p0, v1, v0}, Lcom/example/test/StoragePermissionsActivity;->startActivityForResult(Landroid/content/Intent;I)V

StorageUtils.updateImage(Landroid/content/ContentResolver;Landroid/net/Uri;Ljava/lang/String;JLandroid/location/Location;I[BII)Z

invoke-static {p0, v0}, Landroid/support/v4/provider/DocumentFile;->fromTreeUri(Landroid/content/Context;Landroid/net/Uri;)Landroid/support/v4/provider/DocumentFile;

move-result-object v6

.local v6, "document":Landroid/support/v4/provider/DocumentFile;

const-string v0, "image"

invoke-virtual {v6, v0, v1}, Landroid/support/v4/provider/DocumentFile;->createFile(Ljava/lang/String;Ljava/lang/String;)Landroid/support/v4/provider/DocumentFile;

move-result-object v7

invoke-virtual {v7}, Landroid/support/v4/provider/DocumentFile;->getUri()Landroid/net/Uri;

move-result-object v0

const-string v1, "w"

invoke-virtual {v5, v0, v1}, Landroid/content/ContentResolver;->openOutputStream(Landroid/net/Uri;Ljava/lang/String;)Ljava/io/OutputStream;

move-result-object v8

.local v8, "out":Ljava/io/OutputStream;

invoke-virtual {v8, p2}, Ljava/io/OutputStream;->write([B)V

invoke-virtual {v8}, Ljava/io/OutputStream;->close()V

註：專案展示內容取自軟體片段，純粹用於示範逆向工程應用的例子。

更新日期：2019/10/24