add android versoin

app/build.gradle

@@ -0,0 +1,17 @@
+apply plugin: 'com.android.library'
+
+android {
+    compileSdkVersion 23
+    buildToolsVersion "23.0.1"
+
+    defaultConfig {
+        minSdkVersion 16
+        targetSdkVersion 22
+        versionCode 1
+        versionName "1.0"
+    }
+}
+
+dependencies {
+    compile 'com.facebook.react:react-native:0.13.+'
+}

app/src/main/AndroidManifest.xml

@@ -0,0 +1,3 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.bitgo.randombytes">
+</manifest>

app/src/main/java/com/bitgo/randombytes/RandomBytesModule.java

@@ -0,0 +1,31 @@
+package com.bitgo.randombytes;
+
+import com.facebook.react.bridge.ReactMethod;
+import com.facebook.react.bridge.ReactApplicationContext;
+import com.facebook.react.bridge.Callback;
+
+import com.facebook.react.bridge.ReactContextBaseJavaModule;
+
+import java.security.SecureRandom;
+
+import android.util.Base64;
+
+class RandomBytesModule extends ReactContextBaseJavaModule {
+
+  public RandomBytesModule(ReactApplicationContext reactContext) {
+    super(reactContext);
+  }
+
+  @Override
+  public String getName() {
+    return "RNRandomBytes";
+  }
+  @ReactMethod
+  public void randomBytes(int size, Callback success) {
+    SecureRandom sr = new SecureRandom();
+    byte[] output = new byte[size];
+    sr.nextBytes(output);
+    String string = Base64.encodeToString(output, Base64.DEFAULT);
+    success.invoke(null, string);
+  }
+}

app/src/main/java/com/bitgo/randombytes/RandomBytesPackage.java

@@ -0,0 +1,34 @@
+package com.bitgo.randombytes;
+
+import com.facebook.react.ReactPackage;
+import com.facebook.react.bridge.JavaScriptModule;
+import com.facebook.react.bridge.NativeModule;
+import com.facebook.react.bridge.ReactApplicationContext;
+import com.facebook.react.uimanager.ViewManager;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public class RandomBytesPackage implements ReactPackage {
+
+  @Override
+  public List<NativeModule> createNativeModules(
+                              ReactApplicationContext reactContext) {
+    List<NativeModule> modules = new ArrayList<>();
+
+    modules.add(new RandomBytesModule(reactContext));
+
+    return modules;
+  }
+
+  @Override
+  public List<ViewManager> createViewManagers(ReactApplicationContext reactContext) {
+    return Collections.emptyList();
+  }
+
+  @Override
+  public List<Class<? extends JavaScriptModule>> createJSModules() {
+    return Collections.emptyList();
+  }
+}

build.gradle

@@ -0,0 +1,18 @@
+buildscript {
+    repositories {
+        jcenter()
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:1.3.0'
+
+        // NOTE: Do not place your application dependencies here; they belong
+        // in the individual module build.gradle files
+    }
+}
+
+allprojects {
+    repositories {
+        mavenLocal()
+        jcenter()
+    }
+}

settings.gradle

@@ -0,0 +1,2 @@
+rootProject.name = 'randombytes'
+include ':app'