Optional PSEC padding

app/src/main/java/sushi/hardcore/aira/AIRADatabase.kt

@@ -19,6 +19,8 @@ object AIRADatabase {
     external fun clearTemporaryFiles(): Int
     external fun getIdentityPublicKey(): ByteArray
     external fun getIdentityFingerprint(): String
+    external fun getUsePadding(): Boolean
+    external fun setUsePadding(usePadding: Boolean): Boolean
     external fun changeName(newName: String): Boolean
     external fun changePassword(databaseFolder: String, oldPassword: ByteArray?, newPassword: ByteArray?): Boolean
 }

app/src/main/java/sushi/hardcore/aira/ChatActivity.kt

@@ -126,8 +126,6 @@ class ChatActivity : ServiceBoundActivity() {
                                 if (this@ChatActivity.sessionId == sessionId) {
                                     runOnUiThread {
                                         findViewById<ConstraintLayout>(R.id.bottom_panel).visibility = View.GONE
-                                        binding.buttonSend.setOnClickListener(null)
-                                        binding.buttonAttach.setOnClickListener(null)
                                     }
                                 }
                             }

app/src/main/java/sushi/hardcore/aira/SettingsActivity.kt

@@ -12,8 +12,8 @@ import androidx.appcompat.app.AppCompatActivity
 import androidx.preference.EditTextPreference
 import androidx.preference.Preference
 import androidx.preference.PreferenceFragmentCompat
+import androidx.preference.SwitchPreferenceCompat
 import sushi.hardcore.aira.background_service.AIRAService
-import sushi.hardcore.aira.databinding.ActivityMainBinding
 import sushi.hardcore.aira.databinding.ActivitySettingsBinding
 import sushi.hardcore.aira.utils.StringUtils
 
@@ -22,20 +22,24 @@ class SettingsActivity: AppCompatActivity() {
         private lateinit var airaService: AIRAService
         override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
             setPreferencesFromResource(R.xml.preferences, rootKey)
-            val identityName = findPreference<EditTextPreference>("identityName")
+            val identityNamePreference = findPreference<EditTextPreference>("identityName")
+            val paddingPreference = findPreference<SwitchPreferenceCompat>("psecPadding")
+            identityNamePreference?.isPersistent = false
+            paddingPreference?.isPersistent = false
             Intent(activity, AIRAService::class.java).also { serviceIntent ->
                 activity?.bindService(serviceIntent, object : ServiceConnection {
                     override fun onServiceConnected(name: ComponentName?, service: IBinder) {
                         val binder = service as AIRAService.AIRABinder
                         airaService = binder.getService()
-                        identityName?.text = airaService.identityName
+                        identityNamePreference?.text = airaService.identityName
+                        paddingPreference?.isChecked = airaService.usePadding
                     }
                     override fun onServiceDisconnected(name: ComponentName?) {}
                 }, Context.BIND_AUTO_CREATE)
             }
-            identityName?.setOnPreferenceChangeListener { _, newValue ->
+            identityNamePreference?.setOnPreferenceChangeListener { _, newValue ->
                 if (airaService.changeName(newValue as String)) {
-                    identityName.text = newValue
+                    identityNamePreference.text = newValue
                 }
                 false
             }
@@ -107,6 +111,11 @@ class SettingsActivity: AppCompatActivity() {
                     false
                 }
             }
+            paddingPreference?.setOnPreferenceChangeListener { _, checked ->
+                airaService.usePadding = checked as Boolean
+                AIRADatabase.setUsePadding(checked)
+                true
+            }
         }
 
         private fun changePassword(context: Context, isIdentityProtected: Boolean, oldPasswordEditText: EditText, newPassword: ByteArray?) {

app/src/main/java/sushi/hardcore/aira/background_service/AIRAService.kt

@@ -48,6 +48,7 @@ class AIRAService : Service() {
     private val sendFileTransfers = mutableMapOf<Int, FilesSender>()
     val receiveFileTransfers = mutableMapOf<Int, FilesReceiver>()
     lateinit var contacts: HashMap<Int, Contact>
+    var usePadding = true
     private lateinit var serviceHandler: Handler
     private lateinit var notificationManager: NotificationManagerCompat
     private lateinit var nsdManager: NsdManager
@@ -308,7 +309,7 @@ class AIRAService : Service() {
                             sessionIdByKey[key] = sessionId
                             uiCallbacks?.onNewSession(sessionId, session.ip)
                             if (!isContact(sessionId)) {
-                                session.encryptAndSend(Protocol.askName())
+                                session.encryptAndSend(Protocol.askName(), usePadding)
                             }
                         } else {
                             session.close()
@@ -412,7 +413,7 @@ class AIRAService : Service() {
     }
 
     private fun sendAndSave(sessionId: Int, msg: ByteArray) {
-        sessions[sessionId]?.encryptAndSend(msg)
+        sessions[sessionId]?.encryptAndSend(msg, usePadding)
         if (msg[0] == Protocol.MESSAGE) {
             saveMsg(sessionId, msg)
         }
@@ -460,7 +461,7 @@ class AIRAService : Service() {
                                 identityName?.let {
                                     for (session in sessions.values) {
                                         try {
-                                            session.encryptAndSend(Protocol.tellName(it))
+                                            session.encryptAndSend(Protocol.tellName(it), usePadding)
                                         } catch (e: SocketException) {
                                             e.printStackTrace()
                                         }
@@ -498,6 +499,7 @@ class AIRAService : Service() {
                 sessionCounter++
             }
         }
+        usePadding = AIRADatabase.getUsePadding()
     }
 
     private fun encryptNextChunk(session: Session, filesSender: FilesSender) {
@@ -510,7 +512,7 @@ class AIRAService : Service() {
         }
         filesSender.nextChunk = if (read > 0) {
             filesSender.lastChunkSizes.add(nextChunk.size)
-            session.encrypt(nextChunk)
+            session.encrypt(nextChunk, usePadding)
         } else {
             null
         }
@@ -540,7 +542,7 @@ class AIRAService : Service() {
             receiveFileTransfers.remove(sessionId)!!.fileTransferNotification.onAborted()
         }
         if (outgoing) {
-            session.encryptAndSend(Protocol.abortFilesTransfer())
+            session.encryptAndSend(Protocol.abortFilesTransfer(), usePadding)
         }
     }
 
@@ -574,7 +576,7 @@ class AIRAService : Service() {
                                             when (buffer[0]) {
                                                 Protocol.ASK_NAME -> {
                                                     identityName?.let { name ->
-                                                        session.encryptAndSend(Protocol.tellName(name))
+                                                        session.encryptAndSend(Protocol.tellName(name), usePadding)
                                                     }
                                                 }
                                                 Protocol.TELL_NAME -> {
@@ -603,7 +605,7 @@ class AIRAService : Service() {
                                                             val chunk = buffer.sliceArray(1 until buffer.size)
                                                             try {
                                                                 outputStream.write(chunk)
-                                                                session.encryptAndSend(Protocol.ackChunk())
+                                                                session.encryptAndSend(Protocol.ackChunk(), usePadding)
                                                                 file.transferred += chunk.size
                                                                 if (file.transferred >= file.fileSize) {
                                                                     outputStream.close()

app/src/main/java/sushi/hardcore/aira/background_service/Session.kt

@@ -166,16 +166,20 @@ class Session(private val socket: SocketChannel, val outgoing: Boolean): Selecta
         return false
     }
 
-    private fun randomPad(input: ByteArray): ByteArray {
+    private fun pad(input: ByteArray, usePadding: Boolean): ByteArray {
         val encodedLen = ByteBuffer.allocate(MESSAGE_LEN_LEN).putInt(input.size).array()
-        val msgLen = input.size + MESSAGE_LEN_LEN
+        return if (usePadding) {
-        var len = 1000
+            val msgLen = input.size + MESSAGE_LEN_LEN
-        while (len < msgLen) {
+            var len = 1000
-            len *= 2
+            while (len < msgLen) {
+                len *= 2
+            }
+            val padding = ByteArray(len-msgLen)
+            prng.nextBytes(padding)
+            encodedLen + input + padding
+        } else {
+            encodedLen + input
         }
-        val padding = ByteArray(len-msgLen)
-        prng.nextBytes(padding)
-        return encodedLen + input + padding
     }
 
     private fun unpad(input: ByteArray): ByteArray {
@@ -190,8 +194,8 @@ class Session(private val socket: SocketChannel, val outgoing: Boolean): Selecta
         }
     }
 
-    fun encrypt(plainText: ByteArray): ByteArray {
+    fun encrypt(plainText: ByteArray, usePadding: Boolean): ByteArray {
-        val padded = randomPad(plainText)
+        val padded = pad(plainText, usePadding)
         val rawMsgLen = ByteBuffer.allocate(MESSAGE_LEN_LEN).putInt(padded.size).array()
         val nonce = ivToNonce(applicationKeys.localIv, localCounter)
         localCounter++
@@ -200,8 +204,8 @@ class Session(private val socket: SocketChannel, val outgoing: Boolean): Selecta
         return rawMsgLen+localCipher.doFinal(padded)
     }
 
-    fun encryptAndSend(plainText: ByteArray) {
+    fun encryptAndSend(plainText: ByteArray, usePadding: Boolean) {
-        writeAll(encrypt(plainText))
+        writeAll(encrypt(plainText, usePadding))
     }
 
     fun ByteArray.toHexString() = joinToString("") { "%02x".format(it) }

app/src/main/native/src/identity.rs

@@ -20,6 +20,7 @@ impl<'a> DBKeys {
     pub const KEYPAIR: &'a str = "keypair";
     pub const SALT: &'a str = "salt";
     pub const MASTER_KEY: &'a str = "master_key";
+    pub const USE_PADDING: &'a str = "use_padding";
 }
 
 fn bool_to_byte(b: bool) -> u8 {
@@ -44,7 +45,8 @@ struct EncryptedIdentity {
     name: String,
     encrypted_keypair: Vec<u8>,
     salt: Vec<u8>,
-    encrypted_master_key: Vec<u8>
+    encrypted_master_key: Vec<u8>,
+    encrypted_use_padding: Vec<u8>,
 }
 
 pub struct Contact {
@@ -59,6 +61,7 @@ pub struct Identity {
     pub name: String,
     keypair: Keypair,
     pub master_key: [u8; crypto::MASTER_KEY_LEN],
+    pub use_padding: bool,
     database_folder: String,
 }
 
@@ -334,6 +337,13 @@ impl Identity {
         result
     }
 
+    pub fn set_use_padding(&mut self, use_padding: bool) -> Result<usize, rusqlite::Error> {
+        self.use_padding = use_padding;
+        let db = KeyValueTable::new(&self.get_database_path(), MAIN_TABLE)?;
+        let encrypted_use_padding = crypto::encrypt_data(&[bool_to_byte(use_padding)], &self.master_key).unwrap();
+        db.update(DBKeys::USE_PADDING, &encrypted_use_padding)
+    }
+
     pub fn zeroize(&mut self){
         self.master_key.zeroize();
         self.keypair.secret.zeroize();
@@ -345,11 +355,13 @@ impl Identity {
         let encrypted_keypair = db.get(DBKeys::KEYPAIR)?;
         let salt = db.get(DBKeys::SALT)?;
         let encrypted_master_key = db.get(DBKeys::MASTER_KEY)?;
+        let encrypted_use_padding = db.get(DBKeys::USE_PADDING)?;
         Ok(EncryptedIdentity {
             name: std::str::from_utf8(&name).unwrap().to_owned(),
             encrypted_keypair,
             salt,
             encrypted_master_key,
+            encrypted_use_padding,
         })
     }
 
@@ -375,12 +387,21 @@ impl Identity {
                 };
                 match crypto::decrypt_data(&encrypted_identity.encrypted_keypair, &master_key) {
                     Ok(keypair) => {
-                        Ok(Identity{
+                        match crypto::decrypt_data(&encrypted_identity.encrypted_use_padding, &master_key) {
-                            name: encrypted_identity.name,
+                            Ok(use_padding) => {
-                            keypair: Keypair::from_bytes(&keypair[..]).unwrap(),
+                                Ok(Identity{
-                            master_key: master_key,
+                                    name: encrypted_identity.name,
-                            database_folder: database_folder,
+                                    keypair: Keypair::from_bytes(&keypair[..]).unwrap(),
-                        })
+                                    master_key,
+                                    use_padding: byte_to_bool(use_padding[0]).unwrap(),
+                                    database_folder: database_folder,
+                                })
+                            }
+                            Err(e) => {
+                                print_error!(e);
+                                Err(String::from(DATABASE_CORRUPED_ERROR))
+                            }
+                        }
                     }
                     Err(e) => {
                         print_error!(e);
@@ -418,11 +439,13 @@ impl Identity {
             salt
         };
         db.set(DBKeys::SALT, &salt)?;
-
+        let encrypted_use_padding = crypto::encrypt_data(&[bool_to_byte(true)], &master_key).unwrap();
+        db.set(DBKeys::USE_PADDING, &encrypted_use_padding)?;
         Ok(Identity {
             name: name.to_owned(),
             keypair,
             master_key,
+            use_padding: true,
             database_folder
         })
     }

app/src/main/native/src/key_value_table.rs

@@ -28,4 +28,7 @@ impl<'a> KeyValueTable<'a> {
     pub fn update(&self, key: &str, value: &[u8]) -> Result<usize, Error> {
         self.db.execute(&format!("UPDATE {} SET value=? WHERE key=\"{}\"", self.table_name, key), params![value])
     }
-}
+    /*pub fn upsert(&self, key: &str, value: &[u8]) -> Result<usize, Error> {
+        self.db.execute(&format!("INSERT INTO {} (key, value) VALUES(?1, ?2) ON CONFLICT(key) DO UPDATE SET value=?3", self.table_name), params![key, value, value])
+    }*/
+}

app/src/main/native/src/lib.rs

@@ -344,6 +344,24 @@ pub fn Java_sushi_hardcore_aira_AIRADatabase_changeName(env: JNIEnv, _: JClass,
     }
 }
 
+#[allow(non_snake_case)]
+#[no_mangle]
+pub fn Java_sushi_hardcore_aira_AIRADatabase_getUsePadding(_: JNIEnv, _: JClass) -> jboolean {
+    bool_to_jboolean(loaded_identity.lock().unwrap().as_mut().unwrap().use_padding)
+}
+
+#[allow(non_snake_case)]
+#[no_mangle]
+pub fn Java_sushi_hardcore_aira_AIRADatabase_setUsePadding(_: JNIEnv, _: JClass, use_padding: jboolean) -> jboolean {
+    match loaded_identity.lock().unwrap().as_mut().unwrap().set_use_padding(jboolean_to_bool(use_padding)) {
+        Ok(_) => 1,
+        Err(e) => {
+            log_error(e);
+            0
+        }
+    }
+}
+
 #[allow(non_snake_case)]
 #[no_mangle]
 pub fn Java_sushi_hardcore_aira_AIRADatabase_getIdentityFingerprint(env: JNIEnv, _: JClass) -> jobject {

app/src/main/res/drawable/ic_blur.xml

@@ -0,0 +1,5 @@
+<vector android:height="24dp" android:tint="#FFFFFF"
+    android:viewportHeight="24" android:viewportWidth="24"
+    android:width="24dp" xmlns:android="http://schemas.android.com/apk/res/android">
+    <path android:fillColor="@android:color/white" android:pathData="M6,13c-0.55,0 -1,0.45 -1,1s0.45,1 1,1 1,-0.45 1,-1 -0.45,-1 -1,-1zM6,17c-0.55,0 -1,0.45 -1,1s0.45,1 1,1 1,-0.45 1,-1 -0.45,-1 -1,-1zM6,9c-0.55,0 -1,0.45 -1,1s0.45,1 1,1 1,-0.45 1,-1 -0.45,-1 -1,-1zM3,9.5c-0.28,0 -0.5,0.22 -0.5,0.5s0.22,0.5 0.5,0.5 0.5,-0.22 0.5,-0.5 -0.22,-0.5 -0.5,-0.5zM6,5c-0.55,0 -1,0.45 -1,1s0.45,1 1,1 1,-0.45 1,-1 -0.45,-1 -1,-1zM21,10.5c0.28,0 0.5,-0.22 0.5,-0.5s-0.22,-0.5 -0.5,-0.5 -0.5,0.22 -0.5,0.5 0.22,0.5 0.5,0.5zM14,7c0.55,0 1,-0.45 1,-1s-0.45,-1 -1,-1 -1,0.45 -1,1 0.45,1 1,1zM14,3.5c0.28,0 0.5,-0.22 0.5,-0.5s-0.22,-0.5 -0.5,-0.5 -0.5,0.22 -0.5,0.5 0.22,0.5 0.5,0.5zM3,13.5c-0.28,0 -0.5,0.22 -0.5,0.5s0.22,0.5 0.5,0.5 0.5,-0.22 0.5,-0.5 -0.22,-0.5 -0.5,-0.5zM10,20.5c-0.28,0 -0.5,0.22 -0.5,0.5s0.22,0.5 0.5,0.5 0.5,-0.22 0.5,-0.5 -0.22,-0.5 -0.5,-0.5zM10,3.5c0.28,0 0.5,-0.22 0.5,-0.5s-0.22,-0.5 -0.5,-0.5 -0.5,0.22 -0.5,0.5 0.22,0.5 0.5,0.5zM10,7c0.55,0 1,-0.45 1,-1s-0.45,-1 -1,-1 -1,0.45 -1,1 0.45,1 1,1zM10,12.5c-0.83,0 -1.5,0.67 -1.5,1.5s0.67,1.5 1.5,1.5 1.5,-0.67 1.5,-1.5 -0.67,-1.5 -1.5,-1.5zM18,13c-0.55,0 -1,0.45 -1,1s0.45,1 1,1 1,-0.45 1,-1 -0.45,-1 -1,-1zM18,17c-0.55,0 -1,0.45 -1,1s0.45,1 1,1 1,-0.45 1,-1 -0.45,-1 -1,-1zM18,9c-0.55,0 -1,0.45 -1,1s0.45,1 1,1 1,-0.45 1,-1 -0.45,-1 -1,-1zM18,5c-0.55,0 -1,0.45 -1,1s0.45,1 1,1 1,-0.45 1,-1 -0.45,-1 -1,-1zM21,13.5c-0.28,0 -0.5,0.22 -0.5,0.5s0.22,0.5 0.5,0.5 0.5,-0.22 0.5,-0.5 -0.22,-0.5 -0.5,-0.5zM14,17c-0.55,0 -1,0.45 -1,1s0.45,1 1,1 1,-0.45 1,-1 -0.45,-1 -1,-1zM14,20.5c-0.28,0 -0.5,0.22 -0.5,0.5s0.22,0.5 0.5,0.5 0.5,-0.22 0.5,-0.5 -0.22,-0.5 -0.5,-0.5zM10,8.5c-0.83,0 -1.5,0.67 -1.5,1.5s0.67,1.5 1.5,1.5 1.5,-0.67 1.5,-1.5 -0.67,-1.5 -1.5,-1.5zM10,17c-0.55,0 -1,0.45 -1,1s0.45,1 1,1 1,-0.45 1,-1 -0.45,-1 -1,-1zM14,12.5c-0.83,0 -1.5,0.67 -1.5,1.5s0.67,1.5 1.5,1.5 1.5,-0.67 1.5,-1.5 -0.67,-1.5 -1.5,-1.5zM14,8.5c-0.83,0 -1.5,0.67 -1.5,1.5s0.67,1.5 1.5,1.5 1.5,-0.67 1.5,-1.5 -0.67,-1.5 -1.5,-1.5z"/>
+</vector>

app/src/main/res/values/strings.xml

@@ -81,4 +81,7 @@
     <string name="about">About</string>
     <string name="version">AIRA version</string>
     <string name="refresh_name">Refresh name</string>
+    <string name="security">Security</string>
+    <string name="use_psec_padding">Use PSEC padding</string>
+    <string name="psec_padding_summary">PSEC padding obfuscates the length of your messages but uses more network bandwidth.</string>
 </resources>

app/src/main/res/xml/preferences.xml

@@ -28,6 +28,16 @@
 
     </PreferenceCategory>
 
+    <PreferenceCategory android:title="@string/security">
+
+        <SwitchPreferenceCompat
+            android:key="psecPadding"
+            android:title="@string/use_psec_padding"
+            android:summary="@string/psec_padding_summary"
+            android:icon="@drawable/ic_blur"/>
+
+    </PreferenceCategory>
+
     <PreferenceCategory android:title="@string/about">
 
         <Preference