/*
* Copyright (C) 2014 Philippine Android Developers Community
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package ph.devcon.android.auth;
import android.content.Context;
import android.content.SharedPreferences;
import android.provider.Settings;
import android.util.Base64;
import java.util.Map;
import java.util.Set;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
/**
* Created by lope on 8/26/14.
*/
public class ObscuredSharedPreferences implements SharedPreferences {
protected static final String UTF8 = "utf-8";
private static final char[] SEKRIT = {'k', 'e', 'w', 'l'};
protected SharedPreferences delegate;
protected Context context;
public ObscuredSharedPreferences(Context context, SharedPreferences delegate) {
this.delegate = delegate;
this.context = context;
}
public class Editor implements SharedPreferences.Editor {
protected SharedPreferences.Editor delegate;
public Editor() {
this.delegate = ObscuredSharedPreferences.this.delegate.edit();
}
@Override
public Editor putBoolean(String key, boolean value) {
delegate.putString(key, encrypt(Boolean.toString(value)));
return this;
}
@Override
public Editor putFloat(String key, float value) {
delegate.putString(key, encrypt(Float.toString(value)));
return this;
}
@Override
public Editor putInt(String key, int value) {
delegate.putString(key, encrypt(Integer.toString(value)));
return this;
}
@Override
public Editor putLong(String key, long value) {
delegate.putString(key, encrypt(Long.toString(value)));
return this;
}
@Override
public Editor putString(String key, String value) {
delegate.putString(key, encrypt(value));
return this;
}
@Override
public SharedPreferences.Editor putStringSet(String key, Set<String> keySet) {
delegate.putStringSet(key, encrypt(keySet));
return this;
}
@Override
public void apply() {
delegate.apply();
}
@Override
public Editor clear() {
delegate.clear();
return this;
}
@Override
public boolean commit() {
return delegate.commit();
}
@Override
public Editor remove(String s) {
delegate.remove(s);
return this;
}
}
public Editor edit() {
return new Editor();
}
@Override
public Map<String, ?> getAll() {
throw new UnsupportedOperationException(); // left as an exercise to the reader
}
@Override
public boolean getBoolean(String key, boolean defValue) {
final String v = delegate.getString(key, null);
return v != null ? Boolean.parseBoolean(decrypt(v)) : defValue;
}
@Override
public float getFloat(String key, float defValue) {
final String v = delegate.getString(key, null);
return v != null ? Float.parseFloat(decrypt(v)) : defValue;
}
@Override
public int getInt(String key, int defValue) {
final String v = delegate.getString(key, null);
return v != null ? Integer.parseInt(decrypt(v)) : defValue;
}
@Override
public long getLong(String key, long defValue) {
final String v = delegate.getString(key, null);
return v != null ? Long.parseLong(decrypt(v)) : defValue;
}
@Override
public String getString(String key, String defValue) {
final String v = delegate.getString(key, null);
return v != null ? decrypt(v) : defValue;
}
@Override
public Set<String> getStringSet(String key, Set<String> defStringSet) {
final Set<String> stringSet = delegate.getStringSet(key, defStringSet);
return stringSet != null ? decrypt(stringSet) : defStringSet;
}
@Override
public boolean contains(String s) {
return delegate.contains(s);
}
@Override
public void registerOnSharedPreferenceChangeListener(OnSharedPreferenceChangeListener onSharedPreferenceChangeListener) {
delegate.registerOnSharedPreferenceChangeListener(onSharedPreferenceChangeListener);
}
@Override
public void unregisterOnSharedPreferenceChangeListener(OnSharedPreferenceChangeListener onSharedPreferenceChangeListener) {
delegate.unregisterOnSharedPreferenceChangeListener(onSharedPreferenceChangeListener);
}
protected String encrypt(String value) {
try {
final byte[] bytes = value != null ? value.getBytes(UTF8) : new byte[0];
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithMD5AndDES");
SecretKey key = keyFactory.generateSecret(new PBEKeySpec(SEKRIT));
Cipher pbeCipher = Cipher.getInstance("PBEWithMD5AndDES");
pbeCipher.init(Cipher.ENCRYPT_MODE, key, new PBEParameterSpec(Settings.Secure.getString(context.getContentResolver(), Settings.System.ANDROID_ID).getBytes(UTF8), 20));
return new String(Base64.encode(pbeCipher.doFinal(bytes), Base64.NO_WRAP), UTF8);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
protected Set<String> encrypt(Set<String> valueSet) {
for (String key : valueSet) {
valueSet.remove(key);
valueSet.add(encrypt(key));
}
return valueSet;
}
protected String decrypt(String value) {
try {
final byte[] bytes = value != null ? Base64.decode(value, Base64.DEFAULT) : new byte[0];
SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithMD5AndDES");
SecretKey key = keyFactory.generateSecret(new PBEKeySpec(SEKRIT));
Cipher pbeCipher = Cipher.getInstance("PBEWithMD5AndDES");
pbeCipher.init(Cipher.DECRYPT_MODE, key, new PBEParameterSpec(Settings.Secure.getString(context.getContentResolver(), Settings.System.ANDROID_ID).getBytes(UTF8), 20));
return new String(pbeCipher.doFinal(bytes), UTF8);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
protected Set<String> decrypt(Set<String> valueSet) {
for (String key : valueSet) {
valueSet.remove(key);
valueSet.add(decrypt(key));
}
return valueSet;
}
}