Remove hardcoded API key, add encrypted storage with AES-256

app/build.gradle

@@ -40,8 +40,14 @@ dependencies {
     implementation 'androidx.recyclerview:recyclerview:1.3.2'
     implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.7.0'
     implementation 'androidx.lifecycle:lifecycle-livedata-ktx:2.7.0'
+    implementation 'androidx.security:security-crypto:1.1.0-alpha06'
     
     implementation 'com.squareup.okhttp3:okhttp:4.12.0'
     implementation 'com.google.code.gson:gson:2.10.1'
     implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.7.3'
+    
+    implementation 'io.noties.markwon:core:4.6.2'
+    implementation 'io.noties.markwon:ext-strikethrough:4.6.2'
+    implementation 'io.noties.markwon:ext-tables:4.6.2'
+    implementation 'io.noties.markwon:ext-tasklist:4.6.2'
 }

app/src/main/java/com/mistral/chat/ui/MainActivity.kt

@@ -12,6 +12,7 @@ import android.widget.ImageButton
 import android.widget.ImageView
 import android.widget.PopupMenu
 import android.widget.TextView
+import android.widget.Toast
 import androidx.appcompat.app.AlertDialog
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.app.AppCompatDelegate
@@ -19,6 +20,8 @@ import androidx.core.view.isVisible
 import androidx.lifecycle.lifecycleScope
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
+import androidx.security.crypto.EncryptedSharedPreferences
+import androidx.security.crypto.MasterKey
 import com.google.android.material.color.DynamicColors
 import com.google.android.material.progressindicator.LinearProgressIndicator
 import com.google.android.material.textfield.TextInputEditText
@@ -48,6 +51,7 @@ class MainActivity : AppCompatActivity() {
     private var availableModels: List<Pair<String, String>> = emptyList()
     private var selectedModelName: String = "mistral-small-latest"
     private lateinit var prefs: SharedPreferences
+    private lateinit var encryptedPrefs: SharedPreferences
 
     companion object {
         private const val PREFS_NAME = "mistral_chat_prefs"
@@ -57,7 +61,6 @@ class MainActivity : AppCompatActivity() {
         private const val KEY_MESSAGES = "chat_messages"
         private const val KEY_PROFILE_HASH = "profile_hash"
         private const val KEY_API_KEY = "api_key"
-        private const val DEFAULT_API_KEY = "YW0IjDBRLuyEBcgNjVeVUFlMI6fcZYLA"
     }
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -70,6 +73,22 @@ class MainActivity : AppCompatActivity() {
 
         gson = Gson()
         prefs = getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
+        
+        val masterKey = MasterKey.Builder(this)
+            .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
+            .build()
+        encryptedPrefs = EncryptedSharedPreferences.create(
+            this,
+            PREFS_NAME + "_secure",
+            masterKey,
+            EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
+            EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
+        )
+        
+        if (!hasApiKey()) {
+            showApiKeyDialog()
+        }
+        
         client = MistralClient(getApiKey())
 
         loadMessages()
@@ -231,22 +250,27 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun getApiKey(): String {
-        return prefs.getString(KEY_API_KEY, DEFAULT_API_KEY) ?: DEFAULT_API_KEY
+        return encryptedPrefs.getString(KEY_API_KEY, null) ?: ""
+    }
+
+    private fun hasApiKey(): Boolean {
+        return encryptedPrefs.contains(KEY_API_KEY)
     }
 
     private fun saveApiKey(apiKey: String) {
-        prefs.edit().putString(KEY_API_KEY, apiKey).apply()
+        encryptedPrefs.edit().putString(KEY_API_KEY, apiKey).apply()
         client = MistralClient(apiKey)
     }
 
     private fun deleteApiKey() {
-        prefs.edit().remove(KEY_API_KEY).apply()
+        encryptedPrefs.edit().remove(KEY_API_KEY).apply()
-        client = MistralClient(DEFAULT_API_KEY)
+        Toast.makeText(this, getString(R.string.api_key_deleted), Toast.LENGTH_SHORT).show()
+        showApiKeyDialog()
     }
 
     private fun showApiKeyDialog() {
         val currentKey = getApiKey()
-        val hasCustomKey = currentKey != DEFAULT_API_KEY && prefs.contains(KEY_API_KEY)
+        val hasCustomKey = currentKey.isNotEmpty()
         val displayKey = if (hasCustomKey && currentKey.length > 8) {
             currentKey.take(4) + "*".repeat(currentKey.length - 8) + currentKey.takeLast(4)
         } else if (hasCustomKey) {
@@ -270,25 +294,23 @@ class MainActivity : AppCompatActivity() {
                 val newKey = inputField.text?.toString()?.trim()
                 if (!newKey.isNullOrEmpty()) {
                     saveApiKey(newKey)
-                    showToast(getString(R.string.api_key_saved))
+                    Toast.makeText(this, getString(R.string.api_key_saved), Toast.LENGTH_SHORT).show()
+                } else {
+                    Toast.makeText(this, getString(R.string.enter_api_key), Toast.LENGTH_SHORT).show()
                 }
             }
-            .setNegativeButton(R.string.cancel, null)
             .apply {
                 if (hasCustomKey) {
+                    setNegativeButton(R.string.cancel, null)
                     setNeutralButton(R.string.delete) { _, _ ->
                         deleteApiKey()
-                        showToast(getString(R.string.api_key_deleted))
                     }
                 }
             }
+            .setCancelable(false)
             .show()
     }
 
-    private fun showToast(message: String) {
-        android.widget.Toast.makeText(this, message, android.widget.Toast.LENGTH_SHORT).show()
-    }
-
     private fun sendMessage(userInput: String) {
         val selectedModel = selectedModelName
         

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

@@ -32,4 +32,6 @@
     <string name="api_key_deleted">API ключ удалён</string>
     <string name="no_api_key">API ключ не установлен</string>
     <string name="api_key_current">Текущий ключ: %s</string>
+    <string name="enter_api_key">Введите API ключ</string>
+    <string name="api_key_required">Требуется API ключ Mistral</string>
 </resources>