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rikardwissingrikardwissing
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Add Android encryption code
1 parent 0ab293f commit 33f39e0

10 files changed

+294
-103
lines changed

‎android/TTFirebaseMessagingService.java

-94
This file was deleted.

‎android/TTFirebaseMessagingService.kt

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package com.teamtailor.app
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import com.google.firebase.messaging.RemoteMessage
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import expo.modules.notifications.service.ExpoFirebaseMessagingService
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import android.util.Log
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import org.json.JSONObject
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import com.teamtailor.modules.encryption.CryptoUtils
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class TTFirebaseMessagingService : ExpoFirebaseMessagingService() {
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companion object {
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private const val TAG = "TTFirebaseMessagingService"
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}
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override fun onMessageReceived(remoteMessage: RemoteMessage) {
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val originalData = remoteMessage.getData()
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Log.d(TAG, "Received message with data: ${originalData}")
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if (originalData["encrypted_data"]?.let { encryptedDataString ->
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try {
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val encryptedData = parseJsonToMap(encryptedDataString)
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val decryptedDataString = CryptoUtils.hybridDecrypt(
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encryptedData["encrypted_key"]!!,
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encryptedData["cipher_text"]!!,
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encryptedData["nonce"]!!,
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encryptedData["tag"]!!
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)
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val decryptedData = parseJsonToMap(decryptedDataString)
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val modifiedData = originalData.toMutableMap().apply {
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remove("encrypted_data")
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putAll(decryptedData)
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}
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val newMessage = RemoteMessage.Builder("/topics/default").apply {
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remoteMessage.getMessageId()?.let { setMessageId(it) }
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setData(modifiedData)
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setTtl(remoteMessage.getTtl())
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setCollapseKey(remoteMessage.getCollapseKey())
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}.build()
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super.onMessageReceived(newMessage)
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true
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} catch (e: Exception) {
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Log.e(TAG, "Failed to decrypt or parse encrypted data", e)
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false
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}
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} == true) {
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Log.d(TAG, "Successfully handled encrypted data")
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} else {
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Log.d(TAG, "No encrypted data found or decryption failed, passing original message")
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super.onMessageReceived(remoteMessage)
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}
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}
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private fun parseJsonToMap(jsonString: String): Map<String, String> =
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JSONObject(jsonString).let { json ->
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json.keys().asSequence().associateWith { key ->
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json.getString(key)
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}
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}
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}

‎android/build.gradle

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apply plugin: 'com.android.library'
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apply plugin: 'kotlin-android'
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apply plugin: 'maven-publish'
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group = 'com.teamtailor.modules.encryption'
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version = '0.5.0'
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buildscript {
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def expoModulesCorePlugin = new File(project(":expo-modules-core").projectDir.absolutePath, "ExpoModulesCorePlugin.gradle")
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if (expoModulesCorePlugin.exists()) {
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apply from: expoModulesCorePlugin
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applyKotlinExpoModulesCorePlugin()
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}
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// Simple helper that allows the root project to override versions declared by this library.
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ext.safeExtGet = { prop, fallback ->
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rootProject.ext.has(prop) ? rootProject.ext.get(prop) : fallback
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}
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// Ensures backward compatibility
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ext.getKotlinVersion = {
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if (ext.has("kotlinVersion")) {
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ext.kotlinVersion()
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} else {
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ext.safeExtGet("kotlinVersion", "1.8.10")
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}
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}
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repositories {
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mavenCentral()
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}
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dependencies {
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classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:${getKotlinVersion()}")
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}
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}
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afterEvaluate {
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publishing {
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publications {
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release(MavenPublication) {
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from components.release
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}
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}
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repositories {
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maven {
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url = mavenLocal().url
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}
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}
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}
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}
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android {
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compileSdkVersion safeExtGet("compileSdkVersion", 33)
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def agpVersion = com.android.Version.ANDROID_GRADLE_PLUGIN_VERSION
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if (agpVersion.tokenize('.')[0].toInteger() < 8) {
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compileOptions {
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sourceCompatibility JavaVersion.VERSION_11
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targetCompatibility JavaVersion.VERSION_11
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}
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kotlinOptions {
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jvmTarget = JavaVersion.VERSION_11.majorVersion
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}
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}
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namespace "com.teamtailor.modules.encryption"
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defaultConfig {
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minSdkVersion safeExtGet("minSdkVersion", 21)
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targetSdkVersion safeExtGet("targetSdkVersion", 34)
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versionCode 1
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versionName "0.5.0"
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}
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lintOptions {
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abortOnError false
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}
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publishing {
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singleVariant("release") {
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withSourcesJar()
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}
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}
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}
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repositories {
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mavenCentral()
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}
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dependencies {
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implementation project(':expo-modules-core')
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implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:${getKotlinVersion()}"
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}

‎android/src/main/AndroidManifest.xml

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<manifest>
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</manifest>

‎android/src/main/java/com/teamtailor/modules/encryption/CryptoUtils.kt

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package com.teamtailor.modules.encryption
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import android.security.keystore.KeyGenParameterSpec
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import android.security.keystore.KeyProperties
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import android.util.Base64
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import java.security.KeyPairGenerator
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import java.security.KeyStore
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import java.security.SecureRandom
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import javax.crypto.Cipher
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import javax.crypto.spec.GCMParameterSpec
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import javax.crypto.spec.SecretKeySpec
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object CryptoUtils {
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private const val KEY_ALIAS = "com.teamtailor.modules.encryption.cryptoutils2"
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private const val ANDROID_KEYSTORE = "AndroidKeyStore"
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private const val GCM_TAG_LENGTH = 128
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private fun getOrCreateKeyPair(): KeyStore.PrivateKeyEntry {
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val keyStore = KeyStore.getInstance(ANDROID_KEYSTORE)
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keyStore.load(null)
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if (!keyStore.containsAlias(KEY_ALIAS)) {
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val spec = KeyGenParameterSpec.Builder(
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KEY_ALIAS,
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KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT
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)
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.setDigests(KeyProperties.DIGEST_SHA1) // Changed to SHA1 to match Ruby/iOS
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.setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_RSA_OAEP)
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.setKeySize(2048) // Explicitly set key size to match other implementations
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.build()
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val generator = KeyPairGenerator.getInstance(
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KeyProperties.KEY_ALGORITHM_RSA,
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ANDROID_KEYSTORE
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)
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generator.initialize(spec)
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generator.generateKeyPair()
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}
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return keyStore.getEntry(KEY_ALIAS, null) as KeyStore.PrivateKeyEntry
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}
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fun getPublicKey(): String {
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val entry = getOrCreateKeyPair()
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return Base64.encodeToString(entry.certificate.publicKey.encoded, Base64.NO_WRAP)
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}
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fun hybridDecrypt(encryptedKey: String, cipherText: String, nonce: String, tag: String): String {
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val aesKey = rsaDecrypt(encryptedKey)
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val cipher = Cipher.getInstance("AES/GCM/NoPadding")
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val nonceBytes = Base64.decode(nonce, Base64.NO_WRAP)
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val cipherBytes = Base64.decode(cipherText, Base64.NO_WRAP)
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val tagBytes = Base64.decode(tag, Base64.NO_WRAP)
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val spec = GCMParameterSpec(GCM_TAG_LENGTH, nonceBytes)
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val secretKey = SecretKeySpec(aesKey, "AES") // AES-256 key from RSA decryption
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cipher.init(Cipher.DECRYPT_MODE, secretKey, spec)
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val decryptedBytes = cipher.doFinal(cipherBytes + tagBytes)
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return String(decryptedBytes, Charsets.UTF_8)
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}
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fun rsaDecrypt(encryptedBase64: String): ByteArray {
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val entry = getOrCreateKeyPair()
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// Use RSA/ECB/OAEPWithSHA-1AndMGF1Padding to match Ruby's OpenSSL::PKey::RSA::PKCS1_OAEP_PADDING
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val cipher = Cipher.getInstance("RSA/ECB/OAEPWithSHA-1AndMGF1Padding")
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cipher.init(Cipher.DECRYPT_MODE, entry.privateKey)
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val encryptedBytes = Base64.decode(encryptedBase64, Base64.NO_WRAP)
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return cipher.doFinal(encryptedBytes)
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}
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fun deleteKeyPair() {
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val keyStore = KeyStore.getInstance(ANDROID_KEYSTORE)
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keyStore.load(null)
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keyStore.deleteEntry(KEY_ALIAS)
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}
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fun testEncryption(message: String): Boolean {
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val entry = getOrCreateKeyPair()
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val cipher = Cipher.getInstance("RSA/ECB/OAEPWithSHA-1AndMGF1Padding")
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// Encrypt
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cipher.init(Cipher.ENCRYPT_MODE, entry.certificate.publicKey)
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val encrypted = cipher.doFinal(message.toByteArray())
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// Decrypt
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cipher.init(Cipher.DECRYPT_MODE, entry.privateKey)
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val decrypted = cipher.doFinal(encrypted)
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return message == String(decrypted)
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}
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}

‎android/src/main/java/com/teamtailor/modules/encryption/EncryptionModule.kt

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package com.teamtailor.modules.encryption
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import expo.modules.kotlin.modules.Module
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import expo.modules.kotlin.modules.ModuleDefinition
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class EncryptionModule : Module() {
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override fun definition() = ModuleDefinition {
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Name("EncryptionModule")
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Function("getPublicKey") {
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CryptoUtils.getPublicKey()
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}
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Function("hybridDecrypt") { encryptedKey: String, cipherText: String, nonce: String, tag: String ->
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CryptoUtils.hybridDecrypt(encryptedKey, cipherText, nonce, tag)
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}
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Function("deleteKeyPair") {
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CryptoUtils.deleteKeyPair()
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}
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Function("testEncryption") { message: String ->
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CryptoUtils.testEncryption(message)
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}
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Function("rsaDecrypt") { encryptedBase64: String ->
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CryptoUtils.rsaDecrypt(encryptedBase64)
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}
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}
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}

‎expo-module.config.json

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{
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"name": "ttmobile-notification-service",
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"platforms": ["ios"],
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"platforms": ["ios", "android"],
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"ios": {
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"modules": ["EncryptionModule"]
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},
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"android": {
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"modules": ["com.teamtailor.modules.encryption.EncryptionModule"]
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}
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}

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