Develop Reference

java.lang.ClassNotFoundException on frida

I am trying to hook function of android messaging application.
I run frida hook script. then I get a following error:
Error: java.lang.ClassNotFoundException: Didn't find class "i0.a.a.a.e3.z" on path: DexPathList[[/data/app/xxxxx==/base.apk]]
In Jadx-Gui, base.apk is decompiled as follows
package i0.a.a.a.e3;
/* loaded from: classes5.dex */
public final class z {
}
script is as follows
let z = Java.use("i0.a.a.a.e3.z");
How can I solve this error?

Try running your hook inside the Java.perform() method of Frida.
Java.perform(function() {
let z = Java.use("i0.a.a.a.e3.z");
z["somefunction"].implementation = function (str) {
console.log('somefunctionis called' + ', ' + 'str: ' + str);
let ret = this.somefunction(str);
console.log('somefunctionret value is ' + ret);
return ret;
};
})
It solved my problem that was similar to yours.

How to get an argument from command line using Gradle task?

I'm trying to get an argument from the command line using a Gradle task:
class myApk extends DefaultTask {
#Option(option="apkName", description="apkName for your file")
String apkName
#TaskAction
void uploadApk() {
def arg = "curl -F \"demo${apkName}.apk=" +
"#${project.projectDir}\\app\\build\\outputs\\apk\\debug\\app-debug.apk\" " +
"https://URL"
project.exec {
commandLine("cmd", "/c", arg)
}
}
}
task uploadApk(type: myApk) { }
But after typing gradle uploadApk --apkName=foo in the terminal I get this kind of exception:
Problem configuring task :app:uploadApk from command line.
> Unknown command-line option '--apkName'.
P.S. I've read this topic(How to pass arguments from command line to gradle), but it doesn't seem helpful for this problem;(

Thanks to the comment above, I used -P to work it out

How to generate java files from swig?Is this done by gradle or do it with command line?

This is my Build.gradle file:-
project.ext {
// * SWIG options *
// This and the SWIG "task" at the bottom are loosely based on:
//
// http://androiddeveloper.co.il/using-swig/
swigModuleFiles = ['yourfy.i']
swigIncludeDirs = ['src/main/cpp/yourfy/src', 'src/main/cpp/yourfy/src/nxcommon/src/libnxcommon']
swigJavaOutputDir = file("src/main/java/com/yourfy/yourfy/swig").absolutePath
swigCxxOutputDir = file("src/main/cpp/swig").absolutePath
swigModuleFilesAbs = []
swigIncludeDirOpts = []
swigCxxModuleFilesAbs = []
swigModuleFiles.each { moduleFile ->
swigModuleFilesAbs.add(file("src/main/cpp/yourfy/src/yourfy/" + moduleFile).absolutePath)
swigCxxModuleFilesAbs.add(swigCxxOutputDir + "/" + moduleFile + ".cxx")
}
swigIncludeDirs.each { incDir ->
swigIncludeDirOpts.add("-I" + file(incDir).absolutePath)
}
}
// * Generate SWIG wrappers *
// Generate .java and .cxx files for the SWIG bindings.
//
// It has to be done in Gradle (as opposed to the native library's CMakeLists.txt), because
// Gradle calls the Java implementationr BEFORE running the native build, so the .java SWIG files will
// not have been generated yet when the implementationr runs. We have to ensure that they are generated
// before the Java implementationr runs.
//
// Thanks, Gradle!
//
// I would love to do this as a task, but unfortunately, it does not work. For some reason,
// when building from Android Studio (NOT when running Gradle from command line), CMake is
// actually invoked first, before any other tasks, which means that the Gradle-generated SWIG
// CXX source files might still be missing, which CMake then complains about and aborts. For
// now, we will have to run SWIG at the top level all the time to get it working. Right now,
// it's reasonably fast to do so, let's see how long this holds.
// More info:
def swigExec = '/usr/local/bin/swig'
// TODO: Add some auto-detection
if (project.hasProperty('swig.executable')) {
swigExec = project.property('swig.executable')
}
if (swigExec != null && file(swigExec).isFile()) {
file(project.swigJavaOutputDir).mkdirs()
file(project.swigCxxOutputDir).mkdirs()
// Delete previous output files (.cxx, .h and *.java in respective directories)
(file(project.swigJavaOutputDir).listFiles() + file(project.swigCxxOutputDir).listFiles()).each { file ->
if (file.name.toLowerCase().endsWith(".cxx")
|| file.name.toLowerCase().endsWith(".h")
|| file.name.toLowerCase().endsWith(".java")
) {
file.delete()
}
}
[project.swigModuleFilesAbs, project.swigCxxModuleFilesAbs].transpose().each { moduleFile, cxxFile ->
exec {
commandLine(
swigExec,
'-java',
'-c++',
'-package', 'com.yourfy.yourfy.swig',
*project.swigIncludeDirOpts,
'-outdir', project.swigJavaOutputDir,
'-o', cxxFile,
moduleFile
)
}
}
} else {
logger.error('Property swig.executable not set or invalid! You should set it in ' +
'the gradle.properties file of your gradle user home directory, pointing to ' +
'a SWIG > 3.0 executable')
}
How to generate swig wrapper files in android?There are some links added to here but still its not figure out.
Also tried following links also mentioned in the comment:-
Stackoverflow question link
Github link
I was trying both the links but didn't understand but still seems it difficult.

Android Studio Gradle sourceSets copy

Android Studio 2.0 Preview 2, Gradle Wrapper 2.8, Mac OS X
-MainProjectWorkspace
-|-build.gradle
-|-settings.gradle
-|-gradle.properties
-|-gradle
-|-MyLibraryDependencies
-|-MyMainModule
--|-build.gradle
--|-build
--|-src
---|-androidTest
---|-main
----|-assets
----|-jniLibs
----|-libs
----|-java
-----|-com
----|-res
----|-AndroidManifest.xml
MyMainModule/build.gradle
//Not a single SourceSets configurations.
productFlavors {
flavor1 {
}
flavor2 {
}
}
buildTypes {
release {
}
debug {
}
}
A genius developer left System.out.println statements, instead of Log statements in several hundreds of Java source-files in 'src/main/java'. Ideally, we do not want Sysout statements getting bundled with either of the applicationVariants, specially flavor1Release and flavor2Release.
Before we make amends to those hundreds of Java source-files and eventually switch the Sysout statements to Log statements, we would need to turn them off urgently.
Two possible solutions -
Execute a simple script that will remove all the Sysout statements in the Java source-files in 'src/main/java'. But about that, variants flavor1Debug and flavor2Debug need the Loggers displaying what's going on in the App.
Execute a simple Gradle task at build-time, copy Java source-files from 'src/main/java' to 'src/release/java', ensuring Sysout statements are omitted.
Solution 2 appears to be quickest, easiest, elegant. Particularly when the Gradle Custom-task is executed independently. Except for that, Gradle-sync in Android-Studio seems to be copying everything from 'src/main' to 'src/release' including assets, jniLibs, libs, res and even the AndroidManifest.xml. Fortunately, the Java source-files are ripped-off the Sysout statements in 'src/release', which is the expected result, and ideally, only 'src/release/java' should remain without any other folders.
task prepareRelease(type: Task) {
Pattern sysoutRegex = Pattern.compile(<Sysout-Pattern>)
try {
File releaseFolder = file("src/release")
File mainFolder = file("src/main")
ByteArrayOutputStream output = new ByteArrayOutputStream()
exec {
commandLine = "sh"
args = ["-c", "find ${mainFolder.canonicalPath} -name '*' -type f -print ",
"| xargs egrep -l '${sysoutRegex.pattern()}'"]
standardOutput = output
}
def fileList = output.toString().split(System.getProperty("line.separator"))
fileList.each { line ->
File srcFile = file(line)
File destFile = file(srcFile.canonicalPath.replace("main", "release"))
def content = srcFile.readLines()
if (!destFile.exists()) {
destFile.parentFile.mkdirs()
destFile.createNewFile()
destFile.writable = true
}
destFile.withWriter { out ->
content.eachWithIndex { contentLine, index ->
if (!sysoutRegex.matcher(contentLine).find()) {
out.println contentLine
}
}
}
} catch (Exception fail) {
throw fail
}
}
There is nothing in the custom Gradle-task that may cause this error of making "src/release" an exact copy of "src/main", which was not intended to be.
Any pointers to prevent this default copy of "src/main" to "src/release" will be greatly appreciated.

Based off RaGe's comment - "How about using *.java as your find pattern instead of * ?"
Kudos. I was not supposed to break the "find | xargs egrep " before the '|' into two separate args in the args[] in the exec task. Indeed, a Genius!!!

New Relic in Android Studio - newrelic.properties - variants

I'm integrating New Relic in my project (with Android Studio & Gradle) which has 2 variants. Each variant has its own generated token, which I store in each variant's string.xml file.
In the New Relic documentation, it states the following:
In your project’s root directory (projectname/app), add a newrelic.properties file with the following line:
com.newrelic.application_token=generated_token
The problem is, if I do this, how can make the correct token appear for the correct variant? If this file must appear in the project root, I can't create one per variant, and so I'm forced to use the same token for both variants, which doesn't work for my requirements.
Any insight would be appreciated.

Okay, so after contacting the support team at New Relic, there is apparently no direct solution for this as of today, although they said they've opened a feature request, and so this problem might be solved soon.
From what I managed to understand, the reason this file is needed is so that the New Relic system can display an un-obfuscated error log when an exception occurs on a production version which has been obfuscated with ProGuard.
The New Relic system, with the help of this file, will upload the ProGuard mapping.txt file to the New Relic servers and associate it with your app according to the specified token. With this, New Relic can un-obfuscate stack traces and display a descriptive stack trace with actual class & method names, rather a, b, c, etc.
As a workaround, I was told that I can forego this file all together, if I upload the mapping file manually.
The mapping file can be found at:
build/outputs/proguard/release/mapping.txt
In order to manually upload the file, perform the following via command line:
curl -v -F proguard=#"<path_to_mapping.txt>" -H "X-APP-LICENSE-KEY:<APPLICATION_TOKEN>" https://mobile-symbol-upload.newrelic.com/symbol
This must be done for each variant which is being obfuscated with ProGuard (classically, release builds).
Source
Hope this helps someone else.

I solved creating some Gradle tasks. Please, take a look at https://discuss.newrelic.com/t/how-to-set-up-newrelic-properties-file-for-project-with-multiple-build-variants/46176/5
I following a code that worked pretty well for me.
Add the New Relic application token on a string resource file. i.e.: api.xml.
Create a new Gradle file. i.e: newrelic-util.gradle.
Add the following content on the newly created Gradle file:
apply plugin: 'com.android.application'
android.applicationVariants.all { variant ->
//<editor-fold desc="Setup New Relic property file">
def variantName = variant.name.capitalize()
def newRelicTasksGroup = "newrelic"
def projectDirPath = project.getProjectDir().absolutePath
def newRelicPropertyFileName = "newrelic.properties"
def newRelicPropertyFilePath = "${projectDirPath}/${newRelicPropertyFileName}"
// Cleanup task for New Relic property file creation process.
def deleteNewRelicPropertyFile = "deleteNewRelicPropertyFile"
def taskDeleteNewRelicPropertyFile = project.tasks.findByName(deleteNewRelicPropertyFile)
if (!taskDeleteNewRelicPropertyFile) {
taskDeleteNewRelicPropertyFile = tasks.create(name: deleteNewRelicPropertyFile) {
group = newRelicTasksGroup
description = "Delete the newrelic.properties file on project dir."
doLast {
new File("${newRelicPropertyFilePath}").with {
if (exists()) {
logger.lifecycle("Deleting file ${absolutePath}.")
delete()
} else {
logger.lifecycle("Nothing to do. File ${absolutePath} not found.")
}
}
}
}
}
/*
* Fix for warning message reported by task "newRelicMapUploadVariantName"
* Message:
* [newrelic] newrelic.properties was not found! Mapping file for variant [variantName] not uploaded.
* New Relic discussion:
* https://discuss.newrelic.com/t/how-to-set-up-newrelic-properties-file-for-project-with-multiple-build-variants/46176
*/
def requiredTaskName = "assemble${variantName}"
def taskAssembleByVariant = project.tasks.findByName(requiredTaskName)
def createNewRelicPropertyFileVariantName = "createNewRelicPropertyFile${variantName}"
// 0. Searching task candidate to be dependent.
if (taskAssembleByVariant) {
logger.debug("Candidate task to be dependent found: ${taskAssembleByVariant.name}")
// 1. Task creation
def taskCreateNewRelicPropertyFile = tasks.create(name: createNewRelicPropertyFileVariantName) {
group = newRelicTasksGroup
description = "Generate the newrelic.properties file on project dir.\nA key/value propety " +
"will be written in file to be consumed by newRelicMapUploadVariantName task."
logger.debug("Creating task: ${name}")
doLast {
def newRelicPropertyKey = "com.newrelic.application_token"
def newRelicStringResourceKey = "new_relic_key"
def targetResourceFileName = "api.xml"
def variantXmlResourceFilePath = "${projectDirPath}/src/${variant.name}/res/values/${targetResourceFileName}"
def mainXmlResourceFilePath = "${projectDirPath}/src/main/res/values/${targetResourceFileName}"
def xmlResourceFilesPaths = [variantXmlResourceFilePath, mainXmlResourceFilePath]
xmlResourceFilesPaths.any { xmlResourceFilePath ->
// 1.1. Searching xml resource file.
def xmlResourceFile = new File(xmlResourceFilePath)
if (xmlResourceFile.exists()) {
logger.lifecycle("Reading property from xml resource file: ${xmlResourceFilePath}.")
// 1.2. Searching for string name new_relic_key api.xml resource file.
def nodeResources = new XmlParser().parse(xmlResourceFile)
def nodeString = nodeResources.find {
Node nodeString -> nodeString.'#name'.toString() == newRelicStringResourceKey
}
// 1.3. Checking if string name new_relic_key was found.
if (nodeString != null) {
def newRelicApplicationToken = "${nodeString.value()[0]}"
logger.lifecycle("name:${nodeString.'#name'.toString()};" +
"value:${newRelicApplicationToken}")
// 1.4 Checking the content of newRelicApplicationToken
if (newRelicApplicationToken == 'null' || newRelicApplicationToken.allWhitespace) {
logger.warn("Invalid value for key ${newRelicStringResourceKey}. " +
"Please, consider configuring a value for key ${newRelicStringResourceKey}" +
" on ${xmlResourceFile.name} resource file for buildVariant: ${variantName}. " +
"The ${newRelicPropertyFileName} will be not created.")
return true // break the loop
}
// 1.5. File creation.
File fileProperties = new File(newRelicPropertyFilePath)
fileProperties.createNewFile()
logger.lifecycle("File ${fileProperties.absolutePath} created.")
// 1.6. Writing content on properties file.
def fileComments = "File generated dynamically by gradle task ${createNewRelicPropertyFileVariantName}.\n" +
"Don't change it manually.\n" +
"Don't track it on VCS."
new Properties().with {
load(fileProperties.newDataInputStream())
setProperty(newRelicPropertyKey, newRelicApplicationToken.toString())
store(fileProperties.newWriter(), fileComments)
}
logger.lifecycle("Properties saved on file ${fileProperties.absolutePath}.")
return true // break the loop
} else {
logger.warn("The key ${newRelicStringResourceKey} was not found on ${xmlResourceFile.absolutePath}.\n" +
"Please, consider configuring a key/value on ${xmlResourceFile.name} resource file for buildVariant: ${variantName}.")
return // continue to next xmlResourceFilePath
}
} else {
logger.error("Resource file not found: ${xmlResourceFile.absolutePath}")
return // continue next xmlResourceFilePath
}
}
}
}
// 2. Task dependency setup
// To check the task dependencies, use:
// logger.lifecycle("Task ${name} now depends on tasks:")
// dependsOn.forEach { dep -> logger.lifecycle("\tTask: ${dep}") }
tasks['clean'].dependsOn taskDeleteNewRelicPropertyFile
taskCreateNewRelicPropertyFile.dependsOn taskDeleteNewRelicPropertyFile
taskAssembleByVariant.dependsOn taskCreateNewRelicPropertyFile
} else {
logger.error("Required task ${requiredTaskName} was not found. " +
"The task ${createNewRelicPropertyFileVariantName} will be not created.")
}
//</editor-fold>
}
On app/build.gradle file, apply the Gradle file.
apply from: './newrelic-util.gradle'
That’s it. I created a file named newrelic-util.gradle on project app dir. If you execute the task assembleAnyVariantName, the task createNewRelicPropertyFileAnyVarianteName will be performed first. Tip: don’t track the generated file newrelic.properties file. Ignore it on your VCS.
Additionally, the task deleteNewRelicPropertyFile will be performed right before the tasks ‘clean’ and ‘createNewRelicPropertyFileAnyVarianteName’ in order to avoid a file with a wrong New Relic application token.