Update Qlyra application

android/app/src/main/kotlin/ru/qlyra/app/MainActivity.kt

@@ -49,6 +49,7 @@ import java.net.NetworkInterface
 import java.util.Collections
 import java.util.Random
 import java.util.concurrent.atomic.AtomicBoolean
+import java.security.MessageDigest
 
 class MainActivity : FlutterActivity() {
 
@@ -124,6 +125,23 @@ class MainActivity : FlutterActivity() {
 
         nfcAdapter = NfcAdapter.getDefaultAdapter(this)
 
+        MethodChannel(
+            flutterEngine.dartExecutor.binaryMessenger,
+            "ru.qlyra.app/update_integrity",
+        ).setMethodCallHandler { call, result ->
+            when (call.method) {
+                "verifyApkSigner" -> {
+                    val path = call.argument<String>("path")
+                    if (path == null) {
+                        result.error("INVALID_PATH", "APK path is required", null)
+                    } else {
+                        result.success(apkSignerMatchesInstalled(path))
+                    }
+                }
+                else -> result.notImplemented()
+            }
+        }
+
         MethodChannel(
             flutterEngine.dartExecutor.binaryMessenger,
             "ru.qlyra.app/nfc",
@@ -515,6 +533,38 @@ class MainActivity : FlutterActivity() {
         FkmChannel.attach(flutterEngine, this)
     }
 
+    @Suppress("DEPRECATION")
+    private fun apkSignerMatchesInstalled(path: String): Boolean {
+        return try {
+            val flags = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+                PackageManager.GET_SIGNING_CERTIFICATES
+            } else {
+                PackageManager.GET_SIGNATURES
+            }
+            val archive = packageManager.getPackageArchiveInfo(path, flags) ?: return false
+            if (archive.packageName != packageName) return false
+            val installed = packageManager.getPackageInfo(packageName, flags)
+            val archiveSigners = signerDigests(archive)
+            archiveSigners.isNotEmpty() && archiveSigners == signerDigests(installed)
+        } catch (_: Exception) {
+            false
+        }
+    }
+
+    @Suppress("DEPRECATION")
+    private fun signerDigests(info: android.content.pm.PackageInfo): Set<String> {
+        val signatures = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+            info.signingInfo?.apkContentsSigners.orEmpty()
+        } else {
+            info.signatures.orEmpty()
+        }
+        return signatures.map { signature ->
+            MessageDigest.getInstance("SHA-256")
+                .digest(signature.toByteArray())
+                .joinToString("") { byte -> "%02x".format(byte) }
+        }.toSet()
+    }
+
     override fun onCreate(savedInstanceState: Bundle?) {
         if (intent?.hasExtra(CallConst.EXTRA_CALL) == true) applyCallWindowFlags()
         super.onCreate(savedInstanceState)