chore: refactor the internal storage layer (#40)

Reviewed-on: #40

composeApp/src/androidMain/kotlin/su/reya/coop/AppStorage.kt

@@ -1,8 +1,13 @@
-package su.reya.coop.coop.storage
+package su.reya.coop
 
+import android.content.Context
 import android.security.keystore.KeyGenParameterSpec
 import android.security.keystore.KeyProperties
 import android.util.Base64
+import androidx.datastore.preferences.core.edit
+import androidx.datastore.preferences.core.stringPreferencesKey
+import androidx.datastore.preferences.preferencesDataStore
+import kotlinx.coroutines.flow.first
 import java.nio.charset.StandardCharsets
 import java.security.KeyStore
 import javax.crypto.Cipher
@@ -10,10 +15,9 @@ import javax.crypto.KeyGenerator
 import javax.crypto.SecretKey
 import javax.crypto.spec.GCMParameterSpec
 
-data class SecretEntry(
-    val encrypted: String,
-    val iv: String
-)
+private val Context.dataStore by preferencesDataStore("secret_store")
+
+data class SecretEntry(val encrypted: String, val iv: String)
 
 class SecretCrypto {
     private val keyAlias = "coop"
@@ -21,11 +25,9 @@ class SecretCrypto {
     private val transformation = "AES/GCM/NoPadding"
 
     fun encrypt(content: String): SecretEntry {
-        // Initialize cipher
         val cipher = Cipher.getInstance(transformation)
         cipher.init(Cipher.ENCRYPT_MODE, getOrCreateKey())
 
-        // Encrypt content
         val encrypted = cipher.doFinal(content.toByteArray())
         val iv = cipher.iv
 
@@ -39,12 +41,10 @@ class SecretCrypto {
         val encrypted = Base64.decode(entry.encrypted, Base64.NO_WRAP)
         val iv = Base64.decode(entry.iv, Base64.NO_WRAP)
 
-        // Initialize cipher
         val cipher = Cipher.getInstance(transformation)
         val spec = GCMParameterSpec(128, iv)
         cipher.init(Cipher.DECRYPT_MODE, getOrCreateKey(), spec)
 
-        // Decrypt content
         val plaintext = cipher.doFinal(encrypted)
 
         return String(plaintext, StandardCharsets.UTF_8)
@@ -54,13 +54,9 @@ class SecretCrypto {
         val keyStore = KeyStore.getInstance(keyStoreType).apply { load(null) }
         val existingKey = keyStore.getKey(keyAlias, null)
 
-        // Return existing key if available
         if (existingKey is SecretKey) return existingKey
 
-        // Construct a new key generator
         val keyGenerator = KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, keyStoreType)
-
-        // Initialize key generation parameters
         val spec = KeyGenParameterSpec.Builder(
             keyAlias,
             KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT
@@ -70,9 +66,49 @@ class SecretCrypto {
             .setKeySize(256)
             .build()
 
-        // Generate a new key
         keyGenerator.init(spec)
-
         return keyGenerator.generateKey()
     }
-}
+}
+
+class AppStore(private val context: Context) : AppStorage {
+    private val crypto = SecretCrypto()
+
+    override suspend fun get(key: String): String? {
+        return context.dataStore.data.first()[stringPreferencesKey(key)]
+    }
+
+    override suspend fun set(key: String, value: String) {
+        context.dataStore.edit { it[stringPreferencesKey(key)] = value }
+    }
+
+    override suspend fun getSecret(key: String): String? {
+        val prefs = context.dataStore.data.first()
+        val encrypted = prefs[stringPreferencesKey("${key}_encrypted")] ?: return null
+        val iv = prefs[stringPreferencesKey("${key}_iv")] ?: return null
+
+        return crypto.decrypt(SecretEntry(encrypted, iv))
+    }
+
+    override suspend fun setSecret(key: String, value: String) {
+        val entry = crypto.encrypt(value)
+        context.dataStore.edit { prefs ->
+            prefs[stringPreferencesKey("${key}_encrypted")] = entry.encrypted
+            prefs[stringPreferencesKey("${key}_iv")] = entry.iv
+        }
+    }
+
+    override suspend fun clear(key: String) {
+        context.dataStore.edit { prefs ->
+            prefs.remove(stringPreferencesKey(key))
+            prefs.remove(stringPreferencesKey("${key}_encrypted"))
+            prefs.remove(stringPreferencesKey("${key}_iv"))
+        }
+    }
+
+    override suspend fun has(key: String): Boolean {
+        val prefs = context.dataStore.data.first()
+        return prefs.contains(stringPreferencesKey(key)) ||
+                prefs.contains(stringPreferencesKey("${key}_encrypted"))
+    }
+}

composeApp/src/androidMain/kotlin/su/reya/coop/MainActivity.kt

@@ -12,7 +12,6 @@ import androidx.activity.viewModels
 import androidx.core.splashscreen.SplashScreen.Companion.installSplashScreen
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
-import su.reya.coop.coop.storage.SecretStore
 import su.reya.coop.nostr.NostrManager
 import su.reya.coop.viewmodel.AuthViewModel
 import su.reya.coop.viewmodel.ChatViewModel
@@ -26,15 +25,13 @@ class MainActivity : ComponentActivity() {
 
     private val factory by lazy {
         object : ViewModelProvider.Factory {
+            private val storage = AppStore(this@MainActivity)
+            private val nostrViewModel = NostrViewModel(NostrManager.instance)
+            private val chatViewModel = ChatViewModel(NostrManager.instance)
             private val androidSigner =
                 AndroidExternalSigner(this@MainActivity, externalSignerLauncher)
-            private val secretStore = SecretStore(this@MainActivity)
-            private val nostrViewModel =
-                NostrViewModel(NostrManager.instance)
-            private val chatViewModel =
-                ChatViewModel(NostrManager.instance)
             private val authViewModel =
-                AuthViewModel(NostrManager.instance, secretStore, androidSigner)
+                AuthViewModel(NostrManager.instance, storage, androidSigner)
 
             override fun <T : ViewModel> create(modelClass: Class<T>): T {
                 return when {

composeApp/src/androidMain/kotlin/su/reya/coop/storage/SecretStore.kt

@@ -1,43 +0,0 @@
-package su.reya.coop.coop.storage
-
-import android.content.Context
-import androidx.datastore.preferences.core.edit
-import androidx.datastore.preferences.core.stringPreferencesKey
-import androidx.datastore.preferences.preferencesDataStore
-import kotlinx.coroutines.flow.first
-import su.reya.coop.storage.SecretStorage
-
-private val Context.dataStore by preferencesDataStore("secret_store")
-
-class SecretStore(private val context: Context) : SecretStorage {
-    private val crypto = SecretCrypto()
-
-    override suspend fun set(key: String, value: String) {
-        val entry = crypto.encrypt(value)
-
-        context.dataStore.edit { prefs ->
-            prefs[stringPreferencesKey("${key}_encrypted")] = entry.encrypted
-            prefs[stringPreferencesKey("${key}_iv")] = entry.iv
-        }
-    }
-
-    override suspend fun get(key: String): String? {
-        val prefs = context.dataStore.data.first()
-        val encrypted = prefs[stringPreferencesKey("${key}_encrypted")] ?: return null
-        val iv = prefs[stringPreferencesKey("${key}_iv")] ?: return null
-
-        return crypto.decrypt(SecretEntry(encrypted, iv))
-    }
-
-    override suspend fun clear(key: String) {
-        context.dataStore.edit { prefs ->
-            prefs.remove(stringPreferencesKey("${key}_encrypted"))
-            prefs.remove(stringPreferencesKey("${key}_iv"))
-        }
-    }
-
-    override suspend fun has(key: String): Boolean {
-        val prefs = context.dataStore.data.first()
-        return prefs[stringPreferencesKey("${key}_encrypted")] != null
-    }
-}