jnitrace engine

motor de jnitrace

Motor utilizado por Jnitrace para interceptar las llamadas de la API JNI.

jnitrace-engine es el proyecto utilizado por Jnitrace para interceptar y rastrear las llamadas API JNI. Se ha expuesto como un proyecto separado para permitir que los desarrolladores de módulos Frida usen el mismo motor para interceptar y modificar las llamadas de API JNI realizadas por las aplicaciones Android.

Instalación:

La forma más fácil de correr con jnitrace-engine es usar NPM:

npm install jnitrace-engine

Uso simple:

jnitrace-engine intenta reflejar la mayor cantidad posible de la API de Frida. JNIInterceptor proporciona una API para adjuntar a las llamadas de la API JNI de manera muy similar al Interceptor de Frida. La idea es hacer que el uso de la biblioteca sea fácil de usar para aquellos que ya están familiarizados con Frida. Los ejemplos a continuación son JavaScript, pero el módulo también admite TypeScript.

 import { JNIInterceptor } from "jnitrace-engine" ;

// Attach to the JNI FindClass method
JNIInterceptor . attach ( "FindClass" , {
    onEnter ( args ) {
        // called whenever the FindClass is about to be called
        console . log ( "FindClass method called" ) ;
        this . className = Memory . readCString ( args [ 1 ] ) ;
    } ,
    onLeave ( retval ) {
        // called whenever the FindClass method has finished executing
        console . log ( "tLoading Class:" , this . className ) ;
        console . log ( "tClass ID:" , retval . get ( ) ) ;
    }
} ) ; 

Uso avanzado:

 import { JNIInterceptor } from "jnitrace-engine" ;
import { JNILibraryWatcher } from "jnitrace-engine" ;
import { JNINativeReturnValue } from "jnitrace-engine" ;
import { ConfigBuilder } from "jnitrace-engine" ;

// configure the jnitrace-engine to limit what libraries to traces
const builder : ConfigBuilder = new ConfigBuilder ( ) ;

builder . libraries = [ "libnative-lib.so" ] ; // set a list of libraries to track
builder . backtrace = "fuzzy" ; // choose the backtracer type to use [accurate/fuzzy/none]
builder . includeExports = [ "Java_com_nativetest_MainActivity_stringFromJNI" ] ; // provide a list of library exports to track
builder . excludeExports = [ ] ; // provide a list of library exports to ignore
builder . env = true ; // set whether to trace the JNIEnv struct or ignore all of it
builder . vm = false ; // set whether to trace the JavaVM struct or ignore all of it

const config = builder . build ( ) ; //initialise the config - this makes it available to the engine

// An additional callback that can be used for listening to new libraries being loaded by an application
// Note this callback will be called for all libraries, not just the ones in the config
// libraries list
JNILibraryWatcher . setCallback ( {
    onLoaded ( path : string ) {
        console . log ( "Library Loaded " + path ) ;
        console . log ( "Currently Traced Libraries" , JSON . stringify ( config . libraries ) ) ;
    }
} ) ;

const findClassIntercept = JNIInterceptor . attach ( "FindClass" , {
    onEnter ( args : NativeArgumentValue [ ] ) {
        console . log ( "Find Class called" ) ;
        args [ 1 ] = NULL ; // Change the arguments to the FindClass function
        console . log ( "ThreadId" , this . threadId ) ;
        console . log ( "Address of FindClass method" , this . jniAddress ) ;
        this . backtrace . forEach ( ( element : NativePointer ) => {
            console . log ( "backtrace" , element ) ;
        } ) ;
    } ,
    onLeave ( retval : JNINativeReturnValue ) {
        // Change the retval to be returned to the caller of FindClass
        retval . replace ( NULL ) ;
        // Detach all JNI intercepts
        JNIInterceptor . detatchAll ( ) ;
    }
} ) ;

JNIInterceptor . attach ( "CallDoubleMethodV" , {
    onLeave ( retval : JNINativeReturnValue ) {
        // Log the method params of the Java method the JNI API is calling.
        // this.javaMethod will only exist if a Java method has been called.
        console . log ( "Java Method Args" , JSON . stringify ( this . javaMethod . params ) ) ;
        // Detach from the FindClass intercept
        findClassIntercept . detach ( ) ;
    }
} ) ;