Sync: Improve encryption and preferences API

pull/699/head
Alinson S. Xavier 5 years ago
parent 67ef3bb90c
commit ce0cbb6ee2

@ -100,6 +100,7 @@ dependencies {
implementation "io.ktor:ktor-client-android:$KTOR_VERSION" implementation "io.ktor:ktor-client-android:$KTOR_VERSION"
implementation "io.ktor:ktor-client-json:$KTOR_VERSION" implementation "io.ktor:ktor-client-json:$KTOR_VERSION"
implementation "io.ktor:ktor-client-jackson:$KTOR_VERSION" implementation "io.ktor:ktor-client-jackson:$KTOR_VERSION"
implementation "com.google.guava:guava:30.0-android"
implementation 'androidx.constraintlayout:constraintlayout:1.1.3' implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
compileOnly "javax.annotation:jsr250-api:1.0" compileOnly "javax.annotation:jsr250-api:1.0"
@ -118,7 +119,6 @@ dependencies {
androidTestImplementation 'androidx.annotation:annotation:1.0.0' androidTestImplementation 'androidx.annotation:annotation:1.0.0'
androidTestImplementation 'androidx.test:rules:1.1.1' androidTestImplementation 'androidx.test:rules:1.1.1'
androidTestImplementation 'androidx.test.ext:junit:1.1.1' androidTestImplementation 'androidx.test.ext:junit:1.1.1'
androidTestImplementation "com.google.guava:guava:24.1-android"
androidTestImplementation "io.ktor:ktor-client-mock:$KTOR_VERSION" androidTestImplementation "io.ktor:ktor-client-mock:$KTOR_VERSION"
androidTestImplementation "io.ktor:ktor-jackson:$KTOR_VERSION" androidTestImplementation "io.ktor:ktor-jackson:$KTOR_VERSION"
androidTestImplementation project(":uhabits-core") androidTestImplementation project(":uhabits-core")

@ -23,15 +23,6 @@ import org.junit.*
import java.io.* import java.io.*
class EncryptionExtTest : BaseAndroidTest() { class EncryptionExtTest : BaseAndroidTest() {
@Test
fun test_encrypt_decrypt_string() {
val original = "Hello world!"
val key = generateEncryptionKey()
val encrypted = original.encrypt(key)
val decrypted = encrypted.decrypt(key)
assertEquals("Hello world!", decrypted)
}
@Test @Test
fun test_encrypt_decrypt_file() { fun test_encrypt_decrypt_file() {
val original = File.createTempFile("file", ".txt") val original = File.createTempFile("file", ".txt")
@ -40,7 +31,7 @@ class EncryptionExtTest : BaseAndroidTest() {
writer.println("encryption test") writer.println("encryption test")
writer.close() writer.close()
val key = generateEncryptionKey() val key = EncryptionKey.generate()
val encrypted = original.encryptToString(key) val encrypted = original.encryptToString(key)
val decrypted = File.createTempFile("file", ".txt") val decrypted = File.createTempFile("file", ".txt")

@ -128,6 +128,18 @@ public class SettingsFragment extends PreferenceFragmentCompat
startActivity(intent); startActivity(intent);
return true; return true;
} }
else if (key.equals("pref_sync_enabled_dummy"))
{
if (prefs.isSyncEnabled())
{
prefs.disableSync();
}
else
{
Context context = getActivity();
context.startActivity(new IntentFactory().startSyncActivity(context));
}
}
return super.onPreferenceTreeClick(preference); return super.onPreferenceTreeClick(preference);
} }
@ -159,6 +171,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
private void updateSyncPreferences() private void updateSyncPreferences()
{ {
findPreference("pref_sync_display").setVisible(prefs.isSyncEnabled()); findPreference("pref_sync_display").setVisible(prefs.isSyncEnabled());
((CheckBoxPreference) findPreference("pref_sync_enabled_dummy")).setChecked(prefs.isSyncEnabled());
} }
private void updateWeekdayPreference() private void updateWeekdayPreference()
@ -182,19 +195,7 @@ public class SettingsFragment extends PreferenceFragmentCompat
Log.d("SettingsFragment", "updating widgets"); Log.d("SettingsFragment", "updating widgets");
widgetUpdater.updateWidgets(); widgetUpdater.updateWidgets();
} }
if (key.equals("pref_sync_enabled"))
{
if (prefs.isSyncEnabled())
{
Context context = getActivity();
context.startActivity(new IntentFactory().startSyncActivity(context));
}
else
{
prefs.setEncryptionKey("");
prefs.setSyncKey("");
}
}
BackupManager.dataChanged("org.isoron.uhabits"); BackupManager.dataChanged("org.isoron.uhabits");
updateWeekdayPreference(); updateWeekdayPreference();
updateSyncPreferences(); updateSyncPreferences();

@ -93,7 +93,7 @@ class SyncActivity : BaseActivity() {
private fun register() { private fun register() {
displayLoading() displayLoading()
taskRunner.execute(object : Task { taskRunner.execute(object : Task {
private lateinit var encKey: String private lateinit var encKey: EncryptionKey
private lateinit var syncKey: String private lateinit var syncKey: String
private var error = false private var error = false
override fun doInBackground() { override fun doInBackground() {
@ -101,11 +101,8 @@ class SyncActivity : BaseActivity() {
val server = RemoteSyncServer(baseURL = preferences.syncBaseURL) val server = RemoteSyncServer(baseURL = preferences.syncBaseURL)
try { try {
syncKey = server.register() syncKey = server.register()
encKey = generateEncryptionKey() encKey = EncryptionKey.generate()
preferences.isSyncEnabled = true preferences.enableSync(syncKey, encKey.base64)
preferences.encryptionKey = encKey
preferences.syncKey = syncKey;
syncManager.sync()
} catch (e: ServiceUnavailable) { } catch (e: ServiceUnavailable) {
error = true error = true
} }

@ -46,6 +46,9 @@ class SyncManager @Inject constructor(
private var currVersion = 0L private var currVersion = 0L
private var dirty = true private var dirty = true
private lateinit var encryptionKey: EncryptionKey
private lateinit var syncKey: String
init { init {
preferences.addListener(this) preferences.addListener(this)
commandRunner.addListener(this) commandRunner.addListener(this)
@ -53,44 +56,48 @@ class SyncManager @Inject constructor(
suspend fun sync() { suspend fun sync() {
if (!preferences.isSyncEnabled) { if (!preferences.isSyncEnabled) {
Log.i("SyncManager", "Device sync is disabled. Skipping sync") Log.i("SyncManager", "Device sync is disabled. Skipping sync.")
return return
} }
encryptionKey = EncryptionKey.fromBase64(preferences.encryptionKey)
syncKey = preferences.syncKey
try { try {
Log.i("SyncManager", "Starting sync (key: ${preferences.syncKey})") Log.i("SyncManager", "Starting sync (key: ${encryptionKey.base64})")
fetchAndMerge() pull()
upload() push()
Log.i("SyncManager", "Sync finished") Log.i("SyncManager", "Sync finished")
} catch (e: Exception) { } catch (e: Exception) {
Log.e("SyncManager", "Unexpected sync exception. Disabling sync", e) Log.e("SyncManager", "Unexpected sync exception. Disabling sync", e)
preferences.isSyncEnabled = false preferences.disableSync()
preferences.syncKey = ""
preferences.encryptionKey = ""
} }
} }
suspend fun upload() { private suspend fun push() {
if (!dirty) { if (!dirty) {
Log.i("SyncManager", "Database not dirty. Skipping upload.") Log.i("SyncManager", "Database not dirty. Skipping upload.")
return return
} }
Log.i("SyncManager", "Encrypting database...") Log.i("SyncManager", "Encrypting database...")
val db = DatabaseUtils.getDatabaseFile(context) val db = DatabaseUtils.getDatabaseFile(context)
val encryptedDB = db.encryptToString(preferences.encryptionKey) val encryptedDB = db.encryptToString(encryptionKey)
Log.i("SyncManager", "Uploading database (version ${currVersion}, ${encryptedDB.length / 1024} KB)") Log.i("SyncManager", "Uploading database (version ${currVersion}, ${encryptedDB.length / 1024} KB)")
server.put(preferences.syncKey, SyncData(currVersion, encryptedDB)) server.put(preferences.syncKey, SyncData(currVersion, encryptedDB))
dirty = false dirty = false
} }
suspend fun fetchAndMerge() { private suspend fun pull() {
Log.i("SyncManager", "Fetching database from server...") Log.i("SyncManager", "Fetching database from server...")
val data = server.getData(preferences.syncKey) val data = server.getData(preferences.syncKey)
Log.i("SyncManager", "Fetched database (version ${data.version}, ${data.content.length / 1024} KB)") Log.i("SyncManager", "Fetched database (version ${data.version}, ${data.content.length / 1024} KB)")
if (data.version == 0L) {
Log.i("SyncManager", "Initial upload detected. Marking db as dirty.")
dirty = true
}
if (data.version <= currVersion) { if (data.version <= currVersion) {
Log.i("SyncManager", "Local version is up-to-date. Skipping merge.") Log.i("SyncManager", "Local version is up-to-date. Skipping merge.")
} else { } else {
Log.i("SyncManager", "Decrypting and merging with local changes...") Log.i("SyncManager", "Decrypting and merging with local changes...")
data.content.decryptToFile(preferences.encryptionKey, tmpFile) data.content.decryptToFile(encryptionKey, tmpFile)
taskRunner.execute(importDataTaskFactory.create(tmpFile) { tmpFile.delete() }) taskRunner.execute(importDataTaskFactory.create(tmpFile) { tmpFile.delete() })
} }
currVersion = data.version + 1 currVersion = data.version + 1

@ -17,19 +17,61 @@
* with this program. If not, see <http://www.gnu.org/licenses/>. * with this program. If not, see <http://www.gnu.org/licenses/>.
*/ */
@file:Suppress("UnstableApiUsage")
package org.isoron.uhabits.utils package org.isoron.uhabits.utils
import android.util.* import android.util.*
import com.google.common.io.*
import java.io.* import java.io.*
import java.nio.* import java.nio.*
import java.nio.charset.StandardCharsets.* import java.util.zip.*
import javax.crypto.* import javax.crypto.*
import javax.crypto.spec.* import javax.crypto.spec.*
fun ByteArray.encrypt(key: String): ByteArray { /**
val keySpec = SecretKeySpec(Base64.decode(key, Base64.DEFAULT), "AES") * Encryption key which can be used with [File.encryptToString], [String.decryptToFile],
* [ByteArray.encrypt] and [ByteArray.decrypt].
*
* To randomly generate a new key, use [EncryptionKey.generate]. To load a key from a
* Base64-encoded string, use [EncryptionKey.fromBase64].
*/
class EncryptionKey private constructor(
val base64: String,
val secretKey: SecretKey,
) {
companion object {
fun fromBase64(base64: String): EncryptionKey {
val keySpec = SecretKeySpec(Base64.decode(base64, Base64.DEFAULT), "AES")
return EncryptionKey(base64, keySpec)
}
private fun fromSecretKey(spec: SecretKey): EncryptionKey {
val base64 = Base64.encodeToString(spec.encoded, Base64.DEFAULT).trim()
return EncryptionKey(base64, spec)
}
fun generate(): EncryptionKey {
try {
val generator = KeyGenerator.getInstance("AES").apply { init(256) }
return fromSecretKey(generator.generateKey())
} catch (e: Exception) {
throw RuntimeException(e)
}
}
}
}
/**
* Encrypts the byte stream using the provided symmetric encryption key.
*
* The initialization vector (16 bytes) is prepended to the cipher text. To decrypt the result, use
* [ByteArray.decrypt], providing the same key.
*/
fun ByteArray.encrypt(key: EncryptionKey): ByteArray {
val cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING") val cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING")
cipher.init(Cipher.ENCRYPT_MODE, keySpec) cipher.init(Cipher.ENCRYPT_MODE, key.secretKey)
val encrypted = cipher.doFinal(this) val encrypted = cipher.doFinal(this)
return ByteBuffer return ByteBuffer
.allocate(16 + encrypted.size) .allocate(16 + encrypted.size)
@ -38,48 +80,50 @@ fun ByteArray.encrypt(key: String): ByteArray {
.array() .array()
} }
fun ByteArray.decrypt(key: String): ByteArray { /**
* Decrypts a byte stream generated by [ByteArray.encrypt].
*/
fun ByteArray.decrypt(key: EncryptionKey): ByteArray {
val buffer = ByteBuffer.wrap(this) val buffer = ByteBuffer.wrap(this)
val iv = ByteArray(16) val iv = ByteArray(16)
buffer.get(iv) buffer.get(iv)
val encrypted = ByteArray(buffer.remaining()) val encrypted = ByteArray(buffer.remaining())
buffer.get(encrypted) buffer.get(encrypted)
val keySpec = SecretKeySpec(Base64.decode(key, Base64.DEFAULT), "AES")
val cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING") val cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING")
cipher.init(Cipher.DECRYPT_MODE, keySpec, IvParameterSpec(iv)) cipher.init(Cipher.DECRYPT_MODE, key.secretKey, IvParameterSpec(iv))
return cipher.doFinal(encrypted) return cipher.doFinal(encrypted)
} }
fun String.encrypt(key: String): String { /**
return Base64.encodeToString(this.toByteArray().encrypt(key), Base64.DEFAULT) * Takes a string produced by [File.encryptToString], decodes it with Base64, decompresses it with
} * gzip, decrypts it with the provided key, then writes the output to the specified file.
*/
fun String.decrypt(key: String): String { fun String.decryptToFile(key: EncryptionKey, output: File) {
return String(Base64.decode(this, Base64.DEFAULT).decrypt(key), UTF_8) val bytes = Base64.decode(this, Base64.DEFAULT).decrypt(key)
} ByteArrayInputStream(bytes).use { bytesInputStream ->
GZIPInputStream(bytesInputStream).use { gzipInputStream ->
fun String.decryptToFile(key: String, output: File) FileOutputStream(output).use { fileOutputStream ->
{ ByteStreams.copy(gzipInputStream, fileOutputStream)
val outputStream = FileOutputStream(output) }
output.writeBytes(Base64.decode(this, Base64.DEFAULT).decrypt(key)) }
outputStream.close() }
} }
fun File.encryptToString(key: String): String { /**
val bytes = ByteArray(this.length().toInt()) * Compresses the file with gzip, encrypts it using the the provided key, then returns a string
val inputStream = FileInputStream(this) * containing the Base64-encoded cipher bytes.
inputStream.read(bytes) *
inputStream.close() * To decrypt and decompress the cipher text back into a file, use [String.decryptToFile].
return Base64.encodeToString(bytes.encrypt(key), Base64.DEFAULT) */
fun File.encryptToString(key: EncryptionKey): String {
ByteArrayOutputStream().use { bytesOutputStream ->
FileInputStream(this).use { inputStream ->
GZIPOutputStream(bytesOutputStream).use { gzipOutputStream ->
ByteStreams.copy(inputStream, gzipOutputStream)
val bytes = bytesOutputStream.toByteArray()
return Base64.encodeToString(bytes.encrypt(key), Base64.DEFAULT)
}
}
}
} }
fun generateEncryptionKey(): String {
return try {
val keygen = KeyGenerator.getInstance("AES")
keygen.init(256)
val key = keygen.generateKey()
Base64.encodeToString(key.encoded, Base64.DEFAULT).trim()
} catch (e: Exception) {
throw RuntimeException(e)
}
}

@ -123,7 +123,7 @@
<CheckBoxPreference <CheckBoxPreference
android:defaultValue="false" android:defaultValue="false"
android:key="pref_sync_enabled" android:key="pref_sync_enabled_dummy"
android:summary="@string/pref_sync_summary" android:summary="@string/pref_sync_summary"
android:title="@string/pref_sync_title" android:title="@string/pref_sync_title"
app:iconSpaceReserved="false" /> app:iconSpaceReserved="false" />

@ -319,30 +319,29 @@ public class Preferences
return storage.getString("pref_sync_key", ""); return storage.getString("pref_sync_key", "");
} }
public void setSyncKey(String key)
{
storage.putString("pref_sync_key", key);
}
public String getEncryptionKey() public String getEncryptionKey()
{ {
return storage.getString("pref_encryption_key", ""); return storage.getString("pref_encryption_key", "");
} }
public void setEncryptionKey(String key) public boolean isSyncEnabled()
{ {
storage.putString("pref_encryption_key", key); return storage.getBoolean("pref_sync_enabled", false);
} }
public boolean isSyncEnabled() public void enableSync(String syncKey, String encKey)
{ {
return storage.getBoolean("pref_sync_enabled", false); storage.putBoolean("pref_sync_enabled", true);
storage.putString("pref_sync_key", syncKey);
storage.putString("pref_encryption_key", encKey);
for (Listener l : listeners) l.onSyncEnabled();
} }
public void setSyncEnabled(boolean enabled) public void disableSync()
{ {
storage.putBoolean("pref_sync_enabled", enabled); storage.putBoolean("pref_sync_enabled", false);
if(enabled) for (Listener l : listeners) l.onSyncEnabled(); storage.putString("pref_sync_key", "");
storage.putString("pref_encryption_key", "");
} }
public boolean areQuestionMarksEnabled() public boolean areQuestionMarksEnabled()

@ -165,9 +165,7 @@ public class ListHabitsBehavior
return; return;
} }
screen.showConfirmInstallSyncKey(() -> { screen.showConfirmInstallSyncKey(() -> {
prefs.setSyncKey(syncKey); prefs.enableSync(syncKey, encryptionKey);
prefs.setEncryptionKey(encryptionKey);
prefs.setSyncEnabled(true);
screen.showMessage(Message.SYNC_ENABLED); screen.showMessage(Message.SYNC_ENABLED);
}); });
} }

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