Add support for properly dealing with incorrect passwords (#1672)

app/src/main/java/dev/msfjarvis/aps/data/crypto/CryptoRepository.kt

@@ -42,7 +42,7 @@ constructor(
   ) {
     val keys = pgpKeyManager.getAllKeys().unwrap()
     // Iterates through the keys until the first successful decryption, then returns.
-    keys.first { key ->
+    keys.firstOrNull { key ->
       runCatching { pgpCryptoHandler.decrypt(key, password, message, out) }.isOk()
     }
   }

app/src/main/java/dev/msfjarvis/aps/ui/crypto/DecryptActivityV2.kt

@@ -10,6 +10,7 @@ import android.os.Bundle
 import android.view.Menu
 import android.view.MenuItem
 import androidx.lifecycle.lifecycleScope
+import com.github.michaelbull.result.runCatching
 import dagger.hilt.android.AndroidEntryPoint
 import dev.msfjarvis.aps.R
 import dev.msfjarvis.aps.data.crypto.CryptoRepository
@@ -17,6 +18,7 @@ import dev.msfjarvis.aps.data.passfile.PasswordEntry
 import dev.msfjarvis.aps.data.password.FieldItem
 import dev.msfjarvis.aps.databinding.DecryptLayoutBinding
 import dev.msfjarvis.aps.ui.adapters.FieldItemAdapter
+import dev.msfjarvis.aps.util.extensions.isErr
 import dev.msfjarvis.aps.util.extensions.unsafeLazy
 import dev.msfjarvis.aps.util.extensions.viewBinding
 import dev.msfjarvis.aps.util.settings.PreferenceKeys
@@ -42,6 +44,7 @@ class DecryptActivityV2 : BasePgpActivity() {
   private val relativeParentPath by unsafeLazy { getParentPath(fullPath, repoPath) }
 
   private var passwordEntry: PasswordEntry? = null
+  private var retries = 0
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
@@ -56,7 +59,7 @@ class DecryptActivityV2 : BasePgpActivity() {
         true
       }
     }
-    decrypt()
+    decrypt(isError = false)
   }
 
   override fun onCreateOptionsMenu(menu: Menu): Boolean {
@@ -126,36 +129,51 @@ class DecryptActivityV2 : BasePgpActivity() {
     )
   }
 
-  private fun decrypt() {
+  private fun decrypt(isError: Boolean) {
+    if (retries < MAX_RETRIES) {
+      retries += 1
+    } else {
+      finish()
+    }
     val dialog = PasswordDialog()
+    if (isError) {
+      dialog.setError()
+    }
     lifecycleScope.launch(Dispatchers.Main) {
       dialog.password.collectLatest { value ->
         if (value != null) {
-          decrypt(value)
+          if (runCatching { decrypt(value) }.isErr()) {
+            decrypt(isError = true)
+          }
         }
       }
     }
     dialog.show(supportFragmentManager, "PASSWORD_DIALOG")
   }
 
-  private fun decrypt(password: String) {
-    lifecycleScope.launch {
-      val message = withContext(Dispatchers.IO) { File(fullPath).readBytes().inputStream() }
-      val result =
-        withContext(Dispatchers.IO) {
-          val outputStream = ByteArrayOutputStream()
-          repository.decrypt(
-            password,
-            message,
-            outputStream,
-          )
-          outputStream
-        }
-      startAutoDismissTimer()
+  private suspend fun decrypt(password: String) {
+    val message = withContext(Dispatchers.IO) { File(fullPath).readBytes().inputStream() }
+    val result =
+      withContext(Dispatchers.IO) {
+        val outputStream = ByteArrayOutputStream()
+        repository.decrypt(
+          password,
+          message,
+          outputStream,
+        )
+        outputStream
+      }
+    require(result.size() != 0) { "Incorrect password" }
+    startAutoDismissTimer()
 
+    val entry = passwordEntryFactory.create(lifecycleScope, result.toByteArray())
+    passwordEntry = entry
+    createPasswordUi(entry)
+  }
+
+  private suspend fun createPasswordUi(entry: PasswordEntry) =
+    withContext(Dispatchers.Main) {
       val showPassword = settings.getBoolean(PreferenceKeys.SHOW_PASSWORD, true)
-      val entry = passwordEntryFactory.create(lifecycleScope, result.toByteArray())
-      passwordEntry = entry
       invalidateOptionsMenu()
 
       val items = arrayListOf<FieldItem>()
@@ -187,5 +205,8 @@ class DecryptActivityV2 : BasePgpActivity() {
         }
       }
     }
+
+  private companion object {
+    private const val MAX_RETRIES = 3
   }
 }

app/src/main/java/dev/msfjarvis/aps/ui/crypto/PasswordDialog.kt

@@ -8,6 +8,9 @@ package dev.msfjarvis.aps.ui.crypto
 import android.app.Dialog
 import android.content.DialogInterface
 import android.os.Bundle
+import android.view.KeyEvent
+import android.view.WindowManager
+import androidx.core.widget.doOnTextChanged
 import androidx.fragment.app.DialogFragment
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
 import dev.msfjarvis.aps.R
@@ -21,6 +24,7 @@ import kotlinx.coroutines.flow.asStateFlow
 class PasswordDialog : DialogFragment() {
 
   private val binding by unsafeLazy { DialogPasswordEntryBinding.inflate(layoutInflater) }
+  private var isError: Boolean = false
   private val _password = MutableStateFlow<String?>(null)
   val password = _password.asStateFlow()
 
@@ -28,15 +32,37 @@ class PasswordDialog : DialogFragment() {
     val builder = MaterialAlertDialogBuilder(requireContext())
     builder.setView(binding.root)
     builder.setTitle(R.string.password)
-    builder.setPositiveButton(android.R.string.ok) { _, _ ->
-      do {} while (!_password.tryEmit(binding.passwordEditText.text.toString()))
-      dismiss()
+    builder.setPositiveButton(android.R.string.ok) { _, _ -> tryEmitPassword() }
+    val dialog = builder.create()
+    dialog.window?.setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_VISIBLE)
+    dialog.setOnShowListener {
+      if (isError) {
+        binding.passwordField.error = getString(R.string.git_operation_wrong_password)
+      }
+      binding.passwordEditText.doOnTextChanged { _, _, _, _ -> binding.passwordField.error = null }
+      binding.passwordEditText.setOnKeyListener { _, keyCode, _ ->
+        if (keyCode == KeyEvent.KEYCODE_ENTER) {
+          tryEmitPassword()
+          return@setOnKeyListener true
+        }
+        false
+      }
     }
-    return builder.create()
+    return dialog
+  }
+
+  fun setError() {
+    isError = true
   }
 
   override fun onCancel(dialog: DialogInterface) {
     super.onCancel(dialog)
     finish()
   }
+
+  @Suppress("ControlFlowWithEmptyBody")
+  private fun tryEmitPassword() {
+    do {} while (!_password.tryEmit(binding.passwordEditText.text.toString()))
+    dismissAllowingStateLoss()
+  }
 }

app/src/main/res/layout/dialog_password_entry.xml

@@ -24,6 +24,7 @@
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:inputType="textPassword" />
+    <requestFocus />
   </com.google.android.material.textfield.TextInputLayout>
 
 </LinearLayout>