Gist for Security Android Medium

build.gradle

android {
  buildTypes {
    release {
       debuggable false
       minifyEnabled true
       shrinkResources true
       proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
       signingConfig signingConfigs.release
    }
  }
}

OkhttpBuilder.kt

val okHttpClient = OkHttpClient.Builder()
       .certificatePinner(CertificatePinner.Builder()
             .add(
                     "www.example.com",
                     "sha256/ZC3lTYTDBJQVf1P2V7+fibTqbIsWNR/X7CWNVW+CEEA="
             ).build()
        )
       .build()

RoomDatabaseBuilder.java

final SupportFactory factory = new SupportFactory(SQLiteDatabase.getBytes("userEnteredPassphrase"));
final SomeDatabase room = Room.databaseBuilder(activity, SomeDatabase.class, "YourDatabaseName")
  .openHelperFactory(factory)
  .build();

SampleClass.java

class a implements a1 {
    private final String as = "SomethingImportantTokenHere";
    
    public void e(String e) {
      if(as==e) {
        th();
      } else {
        eg();
      }  
    }
}

SampleClass.kt

class SampleClass : SomeInterface {
  private val someToken = "SomeImportantTokenHere"
  
  fun authenticate(token : String) {
    if(someToken==token){
      login()
    } else {
      forceLogout()
  }
}

sharedpref_after.xml

<?xml version='1.0' encoding='utf-8' standalone='yes' ?>
<map>
    <string name="ghleirukgheiuklhgujkwershgifsdjkleh" value="wegerujkfhgvnbidfjklsghuierghkjsdhbnv" />
    <string name="etglhj;riwkhgjkleurhgeruikljghetfge" value="equghkwrekhguisdjkghusjklrehbvkgjlifsrehguiorjkgbhljkert" />
</map>

sharedpref_before.xml

<?xml version='1.0' encoding='utf-8' standalone='yes' ?>
<map>
    <string name="username" value="something" />
    <string name="password" value="somethingImportant" />
</map>