scripting-docs/SCRIPTING.md

Script header

// ==SE_module==
// name: Your module name
// description: Your module description
// version: 1.0
// author: You
// ==/SE_module==

Global scope

• logInfo (messages: ObjectArray)

logInfo("hello", 14, false)

• type (className: String) gives an interface for static method calls, static fields and instantiation

var logObject = type("android.util.Log").newInstance()
logInfo(logObject) // prints "android.util.Log@000000"
type("java.lang.System").out.println("Hello!") // prints "Hello!"

• findClass (className: String) returns a java.lang.Class for a given class name

logInfo(findClass("java.lang.System")) // prints "class java.lang.System"

Execution sides

module.onManagerLoad = () => {
  // run code when manager context is started
}

module.onSnapActivity = () => {
  // run code when the main snapchat activity is created
}

IPC

Pass event through any execution side

module.onManagerLoad = () => {
  // declare event in manager side
  ipc.on("hello", args => {
    logInfo("Got event from snapchat app! arguments: ", args)
  })
}

module.onSnapActivity = () => {
  // send event to the manager from the snapchat app
  ipc.emit("hello", 1337)
}

Pass events between other installed scripts

• script1.js

module.onManagerLoad = () => {
  ipc.onBroadcast("mychannel", "eventA", (args) => {
    logInfo("eventA called from script1.js => " + args)
  })  
}

• script2.js

module.onManagerLoad = () => {
  ipc.onBroadcast("mychannel", "eventA", (args) => {
    logInfo("eventA called from script2.js => " + args)
    ipc.broadcast("mychannel", "eventC", "hello")
  })
}

• script3.js

module.onSnapActivity = () => {
  ipc.onBroadcast("mychannel", "eventC", (args) => {
    logInfo("eventC called from script3.js => " + args)
  })
  // channel, eventName, data
  ipc.broadcast("mychannel", "eventA", "hi")
}

result (android logcat)

eventA called from script1.js => hi
eventA called from script2.js => hi
eventC called from script3.js => hello

Hooks

types

• enum HookStage is a string value of "before" or "after"

• class HookCallback :

  • properties
    • getter/setter result: Object
    • getter thisObject: Object
    • getter method: JavaMember
    • getter args: ObjectArray
  • functions
    • cancel()
    • arg(index: Integer)
    • setArg(index: Integer, value: Object)
    • invokeOriginal()
    • invokeOriginal(args: ObjectArray)

• function HookUnhook unhooks hooked members

public interface

• Find members

  • findMethod (class: JavaClass, methodName: String) => Member
  • findMethod (className: String, methodName: String) => Member
  • findMethodWithParameters (class: JavaClass, methodName: String, types: StringArray) => Member
  • findMethodWithParameters (className: String, methodName: String, types: StringArray) => Member
  • findConstructor (class: JavaClass, types: StringArray) => Member
  • findConstructor (className: String, types: StringArray) => Member

• Hook members

  • hook (member: JavaMember, stage: HookStage, callback: HookCallback) => HookUnhook
  • hookAllMethods (class: JavaClass, methodName: String, stage: HookStage, callback: HookCallback) => HookUnhook
  • hookAllMethods (className: String, methodName: String, stage: HookStage, callback: HookCallback) => HookUnhook
  • hookAllConstructors (class: JavaClass, stage: HookStage, callback: HookCallback) => HookUnhook
  • hookAllConstructors (className: String, stage: HookStage, callback: HookCallback) => HookUnhook

Example

module.onSnapActivity = () => {
  hooker.hookAllConstructors("com.snapchat.client.messaging.Message", "before", callback => {
    logInfo("Message constructor " + callback.thisObject)
  })

  val hookerUnhook = hooker.hook(
    hooker.findMethod("com.snapchat.client.network_api.NetworkApi$CppProxy", "submit"), 
    "before", 
    (callback) => {
      logInfo("NetworkApi submit " + callback.arg(0))
    }
  )

  // unhook when needed using this call
  hookerUnhook();
}