First release for the dummy app to hide secrets in Android.

Signed-off-by: Paulo Silva <paulos@criticalblue.com>

Author: Exadra37

.gitignore

@@ -0,0 +1,14 @@
+*.iml
+.gradle
+/local.properties
+/.idea/caches
+/.idea/libraries
+/.idea/modules.xml
+/.idea/workspace.xml
+/.idea/navEditor.xml
+/.idea/assetWizardSettings.xml
+.DS_Store
+/build
+/captures
+.externalNativeBuild
+.local/

.idea/codeStyles/Project.xml

@@ -5,4 +5,39 @@ A quick demo to show several ways of hiding secrets in a mobile app, like in:
 * source code
 * manifest file
 * gradle file
-* NDK
+* JNI/NDK
+
+
+## SETUP
+
+To set the API key for `GRADLE_ENV_API_KEY`:
+
+```bash
+$ export GRADLE_ENV_API_KEY=$(echo "api-key-for-gradle-file-from-env" | openssl dgst -binary -sha256 | openssl enc -base64)
+$ echo $GRADLE_ENV_API_KEY
+srqGFqMm23R6A7YJbAEmKRuSQ6TWnLq3YNtAWbEoSuE=
+```
+
+To set the API key for `JNI_API_KEY`:
+
+```bash
+$  cp -v app/src/main/cpp/api_key.h.example app/src/main/cpp/api_key.h
+'app/src/main/cpp/api_key.h.example' -> 'app/src/main/cpp/api_key.h'
+```
+
+Now edit the file `app/src/main/cpp/api_key.h` and look for the palce holder
+`ANDROID_HIDE_SECRETS_API_KEY_H` and replace its dummy value
+`place-the-api-key-here` with your desired API key, maybe like:
+
+```bash
+echo "api-key-for-the-jni-file" | openssl dgst -binary -sha256 | openssl enc -base64
+yDbx5R+a6zJ3H76iU9YB9U0GY6DjZ4FiWFb8vCMCdLg=
+```
+
+## RUN
+
+Just start your Android Studio and build and run this project as usual for any
+other mobile app.
+
+The app is a dummy one that only shows in the main screen all API keys hidden in
+the code, just to prove that we can retrieve them.

.idea/gradle.xml

@@ -0,0 +1 @@
+/build

.idea/misc.xml

@@ -0,0 +1,49 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion 28
+    defaultConfig {
+        applicationId "com.criticalblue.androidhidesecrets"
+        minSdkVersion 15
+        targetSdkVersion 28
+        versionCode 1
+        versionName "1.0"
+        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        resValue "string", "GRADLE_API_KEY", 'YXBpLWtleS1zdG9yZWQtaW4tZ3JhZGxlLWZpbGUK'
+        manifestPlaceholders = [GRADLE_API_KEY_PLACEHOLDER: "YXBpLWtleS1wbGFjZWhvbGRlci1pbi1ncmFkbGUtZmlsZQo="]
+        resValue "string", "GRADLE_ENV_API_KEY", "$System.env.GRADLE_ENV_API_KEY"
+        externalNativeBuild {
+            cmake {
+                cppFlags ""
+            }
+        }
+    }
+    buildTypes {
+        release {
+            debuggable false
+            minifyEnabled true
+            shrinkResources true
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+        debug {
+            debuggable true
+            minifyEnabled true
+            shrinkResources true
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+    externalNativeBuild {
+        cmake {
+            path "src/main/cpp/CMakeLists.txt"
+        }
+    }
+}
+
+dependencies {
+    implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation 'com.android.support:appcompat-v7:28.0.0'
+    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
+    testImplementation 'junit:junit:4.12'
+    androidTestImplementation 'com.android.support.test:runner:1.0.2'
+    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
+}

.idea/runConfigurations.xml

@@ -0,0 +1,21 @@
+# Add project specific ProGuard rules here.
+# You can control the set of applied configuration files using the
+# proguardFiles setting in build.gradle.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
+
+# Uncomment this to preserve the line number information for
+# debugging stack traces.
+#-keepattributes SourceFile,LineNumberTable
+
+# If you keep the line number information, uncomment this to
+# hide the original source file name.
+#-renamesourcefileattribute SourceFile