Refactor openpgp-ktx to leverage coroutines (#1398)

* openpgp-ktx: leverage coroutines for async IPC

* Unwind nested dispatchers

* Fix name shadowing warning

Signed-off-by: Harsh Shandilya <me@msfjarvis.dev>

8 files changed, 163 insertions, 182 deletions

diff --git a/app/src/main/java/dev/msfjarvis/aps/ui/crypto/DecryptActivity.kt b/app/src/main/java/dev/msfjarvis/aps/ui/crypto/DecryptActivity.kt
index 8edd8f0b..24859852 100644
--- a/app/src/main/java/dev/msfjarvis/aps/ui/crypto/DecryptActivity.kt
+++ b/app/src/main/java/dev/msfjarvis/aps/ui/crypto/DecryptActivity.kt
@@ -165,55 +165,51 @@ class DecryptActivity : BasePgpActivity(), OpenPgpServiceConnection.OnBound {
     val inputStream = File(fullPath).inputStream()
     val outputStream = ByteArrayOutputStream()
 
-    lifecycleScope.launch(Dispatchers.IO) {
-      api?.executeApiAsync(data, inputStream, outputStream) { result ->
-        when (result?.getIntExtra(OpenPgpApi.RESULT_CODE, OpenPgpApi.RESULT_CODE_ERROR)) {
-          OpenPgpApi.RESULT_CODE_SUCCESS -> {
-            startAutoDismissTimer()
-            runCatching {
-              val showPassword = settings.getBoolean(PreferenceKeys.SHOW_PASSWORD, true)
-              val entry = passwordEntryFactory.create(lifecycleScope, outputStream.toByteArray())
-              val items = arrayListOf<FieldItem>()
-              val adapter = FieldItemAdapter(emptyList(), showPassword) { text -> copyTextToClipboard(text) }
-
-              if (settings.getBoolean(PreferenceKeys.COPY_ON_DECRYPT, false)) {
-                copyPasswordToClipboard(entry.password)
-              }
+    lifecycleScope.launch(Dispatchers.Main) {
+      val result = withContext(Dispatchers.IO) { checkNotNull(api).executeApi(data, inputStream, outputStream) }
+      when (result.getIntExtra(OpenPgpApi.RESULT_CODE, OpenPgpApi.RESULT_CODE_ERROR)) {
+        OpenPgpApi.RESULT_CODE_SUCCESS -> {
+          startAutoDismissTimer()
+          runCatching {
+            val showPassword = settings.getBoolean(PreferenceKeys.SHOW_PASSWORD, true)
+            val entry = passwordEntryFactory.create(lifecycleScope, outputStream.toByteArray())
+            val items = arrayListOf<FieldItem>()
+            val adapter = FieldItemAdapter(emptyList(), showPassword) { text -> copyTextToClipboard(text) }
+
+            if (settings.getBoolean(PreferenceKeys.COPY_ON_DECRYPT, false)) {
+              copyPasswordToClipboard(entry.password)
+            }
 
-              passwordEntry = entry
-              invalidateOptionsMenu()
+            passwordEntry = entry
+            invalidateOptionsMenu()
 
-              if (!entry.password.isNullOrBlank()) {
-                items.add(FieldItem.createPasswordField(entry.password!!))
-              }
+            if (!entry.password.isNullOrBlank()) {
+              items.add(FieldItem.createPasswordField(entry.password!!))
+            }
 
-              if (entry.hasTotp()) {
-                launch(Dispatchers.IO) {
-                  withContext(Dispatchers.Main) {
-                    val code = entry.totp.value
-                    items.add(FieldItem.createOtpField(code))
-                  }
-                  entry.totp.collect { code -> withContext(Dispatchers.Main) { adapter.updateOTPCode(code) } }
-                }
+            if (entry.hasTotp()) {
+              launch {
+                items.add(FieldItem.createOtpField(entry.totp.value))
+                entry.totp.collect { code -> withContext(Dispatchers.Main) { adapter.updateOTPCode(code) } }
               }
+            }
 
-              if (!entry.username.isNullOrBlank()) {
-                items.add(FieldItem.createUsernameField(entry.username!!))
-              }
+            if (!entry.username.isNullOrBlank()) {
+              items.add(FieldItem.createUsernameField(entry.username!!))
+            }
 
-              entry.extraContent.forEach { (key, value) -> items.add(FieldItem(key, value, FieldItem.ActionType.COPY)) }
+            entry.extraContent.forEach { (key, value) -> items.add(FieldItem(key, value, FieldItem.ActionType.COPY)) }
 
-              binding.recyclerView.adapter = adapter
-              adapter.updateItems(items)
-            }
-              .onFailure { e -> e(e) }
+            binding.recyclerView.adapter = adapter
+            adapter.updateItems(items)
           }
-          OpenPgpApi.RESULT_CODE_USER_INTERACTION_REQUIRED -> {
-            val sender = getUserInteractionRequestIntent(result)
-            userInteractionRequiredResult.launch(IntentSenderRequest.Builder(sender).build())
-          }
-          OpenPgpApi.RESULT_CODE_ERROR -> handleError(result)
+            .onFailure { e -> e(e) }
+        }
+        OpenPgpApi.RESULT_CODE_USER_INTERACTION_REQUIRED -> {
+          val sender = getUserInteractionRequestIntent(result)
+          userInteractionRequiredResult.launch(IntentSenderRequest.Builder(sender).build())
         }
+        OpenPgpApi.RESULT_CODE_ERROR -> handleError(result)
       }
     }
   }
diff --git a/app/src/main/java/dev/msfjarvis/aps/ui/crypto/GetKeyIdsActivity.kt b/app/src/main/java/dev/msfjarvis/aps/ui/crypto/GetKeyIdsActivity.kt
index 9da4044a..120ccaab 100644
--- a/app/src/main/java/dev/msfjarvis/aps/ui/crypto/GetKeyIdsActivity.kt
+++ b/app/src/main/java/dev/msfjarvis/aps/ui/crypto/GetKeyIdsActivity.kt
@@ -15,6 +15,7 @@ import com.github.michaelbull.result.onFailure
 import com.github.michaelbull.result.runCatching
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import me.msfjarvis.openpgpktx.util.OpenPgpApi
 import me.msfjarvis.openpgpktx.util.OpenPgpUtils
 import org.openintents.openpgp.IOpenPgpService2
@@ -48,26 +49,25 @@ class GetKeyIdsActivity : BasePgpActivity() {
   /** Get the Key ids from OpenKeychain */
   private fun getKeyIds(data: Intent = Intent()) {
     data.action = OpenPgpApi.ACTION_GET_KEY_IDS
-    lifecycleScope.launch(Dispatchers.IO) {
-      api?.executeApiAsync(data, null, null) { result ->
-        when (result?.getIntExtra(OpenPgpApi.RESULT_CODE, OpenPgpApi.RESULT_CODE_ERROR)) {
-          OpenPgpApi.RESULT_CODE_SUCCESS -> {
-            runCatching {
-              val ids =
-                result.getLongArrayExtra(OpenPgpApi.RESULT_KEY_IDS)?.map { OpenPgpUtils.convertKeyIdToHex(it) }
-                  ?: emptyList()
-              val keyResult = Intent().putExtra(OpenPgpApi.EXTRA_KEY_IDS, ids.toTypedArray())
-              setResult(RESULT_OK, keyResult)
-              finish()
-            }
-              .onFailure { e -> e(e) }
+    lifecycleScope.launch(Dispatchers.Main) {
+      val result = withContext(Dispatchers.IO) { checkNotNull(api).executeApi(data, null, null) }
+      when (result.getIntExtra(OpenPgpApi.RESULT_CODE, OpenPgpApi.RESULT_CODE_ERROR)) {
+        OpenPgpApi.RESULT_CODE_SUCCESS -> {
+          runCatching {
+            val ids =
+              result.getLongArrayExtra(OpenPgpApi.RESULT_KEY_IDS)?.map { OpenPgpUtils.convertKeyIdToHex(it) }
+                ?: emptyList()
+            val keyResult = Intent().putExtra(OpenPgpApi.EXTRA_KEY_IDS, ids.toTypedArray())
+            setResult(RESULT_OK, keyResult)
+            finish()
           }
-          OpenPgpApi.RESULT_CODE_USER_INTERACTION_REQUIRED -> {
-            val sender = getUserInteractionRequestIntent(result)
-            userInteractionRequiredResult.launch(IntentSenderRequest.Builder(sender).build())
-          }
-          OpenPgpApi.RESULT_CODE_ERROR -> handleError(result)
+            .onFailure { e -> e(e) }
+        }
+        OpenPgpApi.RESULT_CODE_USER_INTERACTION_REQUIRED -> {
+          val sender = getUserInteractionRequestIntent(result)
+          userInteractionRequiredResult.launch(IntentSenderRequest.Builder(sender).build())
         }
+        OpenPgpApi.RESULT_CODE_ERROR -> handleError(result)
       }
     }
   }
diff --git a/app/src/main/java/dev/msfjarvis/aps/ui/crypto/PasswordCreationActivity.kt b/app/src/main/java/dev/msfjarvis/aps/ui/crypto/PasswordCreationActivity.kt
index 23409460..b72b3b86 100644
--- a/app/src/main/java/dev/msfjarvis/aps/ui/crypto/PasswordCreationActivity.kt
+++ b/app/src/main/java/dev/msfjarvis/aps/ui/crypto/PasswordCreationActivity.kt
@@ -394,97 +394,97 @@ class PasswordCreationActivity : BasePgpActivity(), OpenPgpServiceConnection.OnB
           else -> "$fullPath/$editName.gpg"
         }
 
-      lifecycleScope.launch(Dispatchers.IO) {
-        api?.executeApiAsync(encryptionIntent, inputStream, outputStream) { result ->
-          when (result?.getIntExtra(OpenPgpApi.RESULT_CODE, OpenPgpApi.RESULT_CODE_ERROR)) {
-            OpenPgpApi.RESULT_CODE_SUCCESS -> {
-              runCatching {
-                val file = File(path)
-                // If we're not editing, this file should not already exist!
-                // Additionally, if we were editing and the incoming and outgoing
-                // filenames differ, it means we renamed. Ensure that the target
-                // doesn't already exist to prevent an accidental overwrite.
-                if ((!editing || (editing && suggestedName != file.nameWithoutExtension)) && file.exists()) {
-                  snackbar(message = getString(R.string.password_creation_duplicate_error))
-                  return@executeApiAsync
-                }
-
-                if (!file.isInsideRepository()) {
-                  snackbar(message = getString(R.string.message_error_destination_outside_repo))
-                  return@executeApiAsync
-                }
+      lifecycleScope.launch(Dispatchers.Main) {
+        val result =
+          withContext(Dispatchers.IO) { checkNotNull(api).executeApi(encryptionIntent, inputStream, outputStream) }
+        when (result.getIntExtra(OpenPgpApi.RESULT_CODE, OpenPgpApi.RESULT_CODE_ERROR)) {
+          OpenPgpApi.RESULT_CODE_SUCCESS -> {
+            runCatching {
+              val file = File(path)
+              // If we're not editing, this file should not already exist!
+              // Additionally, if we were editing and the incoming and outgoing
+              // filenames differ, it means we renamed. Ensure that the target
+              // doesn't already exist to prevent an accidental overwrite.
+              if ((!editing || (editing && suggestedName != file.nameWithoutExtension)) && file.exists()) {
+                snackbar(message = getString(R.string.password_creation_duplicate_error))
+                return@runCatching
+              }
 
-                file.outputStream().use { it.write(outputStream.toByteArray()) }
-
-                // associate the new password name with the last name's timestamp in
-                // history
-                val preference = getSharedPreferences("recent_password_history", Context.MODE_PRIVATE)
-                val oldFilePathHash = "$repoPath/${oldCategory?.trim('/')}/$oldFileName.gpg".base64()
-                val timestamp = preference.getString(oldFilePathHash)
-                if (timestamp != null) {
-                  preference.edit {
-                    remove(oldFilePathHash)
-                    putString(file.absolutePath.base64(), timestamp)
-                  }
-                }
+              if (!file.isInsideRepository()) {
+                snackbar(message = getString(R.string.message_error_destination_outside_repo))
+                return@runCatching
+              }
 
-                val returnIntent = Intent()
-                returnIntent.putExtra(RETURN_EXTRA_CREATED_FILE, path)
-                returnIntent.putExtra(RETURN_EXTRA_NAME, editName)
-                returnIntent.putExtra(RETURN_EXTRA_LONG_NAME, getLongName(fullPath, repoPath, editName))
-
-                if (shouldGeneratePassword) {
-                  val directoryStructure = AutofillPreferences.directoryStructure(applicationContext)
-                  val entry = passwordEntryFactory.create(lifecycleScope, content.encodeToByteArray())
-                  returnIntent.putExtra(RETURN_EXTRA_PASSWORD, entry.password)
-                  val username = entry.username ?: directoryStructure.getUsernameFor(file)
-                  returnIntent.putExtra(RETURN_EXTRA_USERNAME, username)
+              withContext(Dispatchers.IO) { file.outputStream().use { it.write(outputStream.toByteArray()) } }
+
+              // associate the new password name with the last name's timestamp in
+              // history
+              val preference = getSharedPreferences("recent_password_history", Context.MODE_PRIVATE)
+              val oldFilePathHash = "$repoPath/${oldCategory?.trim('/')}/$oldFileName.gpg".base64()
+              val timestamp = preference.getString(oldFilePathHash)
+              if (timestamp != null) {
+                preference.edit {
+                  remove(oldFilePathHash)
+                  putString(file.absolutePath.base64(), timestamp)
                 }
+              }
 
-                if (directoryInputLayout.isVisible && directoryInputLayout.isEnabled && oldFileName != null) {
-                  val oldFile = File("$repoPath/${oldCategory?.trim('/')}/$oldFileName.gpg")
-                  if (oldFile.path != file.path && !oldFile.delete()) {
-                    setResult(RESULT_CANCELED)
-                    MaterialAlertDialogBuilder(this@PasswordCreationActivity)
-                      .setTitle(R.string.password_creation_file_fail_title)
-                      .setMessage(getString(R.string.password_creation_file_delete_fail_message, oldFileName))
-                      .setCancelable(false)
-                      .setPositiveButton(android.R.string.ok) { _, _ -> finish() }
-                      .show()
-                    return@executeApiAsync
-                  }
-                }
+              val returnIntent = Intent()
+              returnIntent.putExtra(RETURN_EXTRA_CREATED_FILE, path)
+              returnIntent.putExtra(RETURN_EXTRA_NAME, editName)
+              returnIntent.putExtra(RETURN_EXTRA_LONG_NAME, getLongName(fullPath, repoPath, editName))
+
+              if (shouldGeneratePassword) {
+                val directoryStructure = AutofillPreferences.directoryStructure(applicationContext)
+                val entry = passwordEntryFactory.create(lifecycleScope, content.encodeToByteArray())
+                returnIntent.putExtra(RETURN_EXTRA_PASSWORD, entry.password)
+                val username = entry.username ?: directoryStructure.getUsernameFor(file)
+                returnIntent.putExtra(RETURN_EXTRA_USERNAME, username)
+              }
 
-                val commitMessageRes = if (editing) R.string.git_commit_edit_text else R.string.git_commit_add_text
-                lifecycleScope.launch {
-                  commitChange(resources.getString(commitMessageRes, getLongName(fullPath, repoPath, editName)))
-                    .onSuccess {
-                      setResult(RESULT_OK, returnIntent)
-                      finish()
-                    }
+              if (directoryInputLayout.isVisible && directoryInputLayout.isEnabled && oldFileName != null) {
+                val oldFile = File("$repoPath/${oldCategory?.trim('/')}/$oldFileName.gpg")
+                if (oldFile.path != file.path && !oldFile.delete()) {
+                  setResult(RESULT_CANCELED)
+                  MaterialAlertDialogBuilder(this@PasswordCreationActivity)
+                    .setTitle(R.string.password_creation_file_fail_title)
+                    .setMessage(getString(R.string.password_creation_file_delete_fail_message, oldFileName))
+                    .setCancelable(false)
+                    .setPositiveButton(android.R.string.ok) { _, _ -> finish() }
+                    .show()
+                  return@runCatching
                 }
               }
-                .onFailure { e ->
-                  if (e is IOException) {
-                    e(e) { "Failed to write password file" }
-                    setResult(RESULT_CANCELED)
-                    MaterialAlertDialogBuilder(this@PasswordCreationActivity)
-                      .setTitle(getString(R.string.password_creation_file_fail_title))
-                      .setMessage(getString(R.string.password_creation_file_write_fail_message))
-                      .setCancelable(false)
-                      .setPositiveButton(android.R.string.ok) { _, _ -> finish() }
-                      .show()
-                  } else {
-                    e(e)
+
+              val commitMessageRes = if (editing) R.string.git_commit_edit_text else R.string.git_commit_add_text
+              lifecycleScope.launch {
+                commitChange(resources.getString(commitMessageRes, getLongName(fullPath, repoPath, editName)))
+                  .onSuccess {
+                    setResult(RESULT_OK, returnIntent)
+                    finish()
                   }
-                }
-            }
-            OpenPgpApi.RESULT_CODE_USER_INTERACTION_REQUIRED -> {
-              val sender = getUserInteractionRequestIntent(result)
-              userInteractionRequiredResult.launch(IntentSenderRequest.Builder(sender).build())
+              }
             }
-            OpenPgpApi.RESULT_CODE_ERROR -> handleError(result)
+              .onFailure { e ->
+                if (e is IOException) {
+                  e(e) { "Failed to write password file" }
+                  setResult(RESULT_CANCELED)
+                  MaterialAlertDialogBuilder(this@PasswordCreationActivity)
+                    .setTitle(getString(R.string.password_creation_file_fail_title))
+                    .setMessage(getString(R.string.password_creation_file_write_fail_message))
+                    .setCancelable(false)
+                    .setPositiveButton(android.R.string.ok) { _, _ -> finish() }
+                    .show()
+                } else {
+                  e(e)
+                }
+              }
+          }
+          OpenPgpApi.RESULT_CODE_USER_INTERACTION_REQUIRED -> {
+            val sender = getUserInteractionRequestIntent(result)
+            userInteractionRequiredResult.launch(IntentSenderRequest.Builder(sender).build())
           }
+          OpenPgpApi.RESULT_CODE_ERROR -> handleError(result)
         }
       }
     }
diff --git a/autofill-parser/CHANGELOG.md b/autofill-parser/CHANGELOG.md
index 71d94cb5..f9a4fc2c 100644
--- a/autofill-parser/CHANGELOG.md
+++ b/autofill-parser/CHANGELOG.md
@@ -12,6 +12,8 @@ All notable changes to this project will be documented in this file.
 
 - The library now requires Kotlin 1.5.0 configured with `kotlinOptions.languageVersion = "1.5"`.
 
+- The synchronous and callback based APIs in `OpenPgpApi` have been removed in favor of a singular coroutines-based entrypoint.
+
 ### Fixed
 
 - Fix build warning from undeclared unsigned type use.
diff --git a/openpgp-ktx/api/openpgp-ktx.api b/openpgp-ktx/api/openpgp-ktx.api
index dad53f16..6fd1ef85 100644
--- a/openpgp-ktx/api/openpgp-ktx.api
+++ b/openpgp-ktx/api/openpgp-ktx.api
@@ -88,8 +88,7 @@ public final class me/msfjarvis/openpgpktx/util/OpenPgpApi {
 	public static final field RESULT_SIGNATURE_MICALG Ljava/lang/String;
 	public static final field SERVICE_INTENT_2 Ljava/lang/String;
 	public fun <init> (Landroid/content/Context;Lorg/openintents/openpgp/IOpenPgpService2;)V
-	public final fun executeApi (Landroid/content/Intent;Ljava/io/InputStream;Ljava/io/OutputStream;)Landroid/content/Intent;
-	public final fun executeApiAsync (Landroid/content/Intent;Ljava/io/InputStream;Ljava/io/OutputStream;Lkotlin/jvm/functions/Function1;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
+	public final fun executeApi (Landroid/content/Intent;Ljava/io/InputStream;Ljava/io/OutputStream;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 }
 
 public final class me/msfjarvis/openpgpktx/util/OpenPgpApi$Companion {
diff --git a/openpgp-ktx/gradle.properties b/openpgp-ktx/gradle.properties
index b19a52c9..2b966a19 100644
--- a/openpgp-ktx/gradle.properties
+++ b/openpgp-ktx/gradle.properties
@@ -3,7 +3,7 @@
 # SPDX-License-Identifier: Apache-2.0
 #
 
-VERSION_NAME=3.0.0
+VERSION_NAME=4.0.0-SNAPSHOT
 POM_ARTIFACT_ID=openpgp-ktx
 POM_NAME=openpgp-ktx
 POM_DESCRIPTION=Reimplementation of OpenKeychain's integration library in Kotlin
diff --git a/openpgp-ktx/src/main/java/me/msfjarvis/openpgpktx/util/OpenPgpApi.kt b/openpgp-ktx/src/main/java/me/msfjarvis/openpgpktx/util/OpenPgpApi.kt
index 42ee94bb..c855f619 100644
--- a/openpgp-ktx/src/main/java/me/msfjarvis/openpgpktx/util/OpenPgpApi.kt
+++ b/openpgp-ktx/src/main/java/me/msfjarvis/openpgpktx/util/OpenPgpApi.kt
@@ -2,7 +2,7 @@
  * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
-@file:Suppress("Unused")
+@file:Suppress("BlockingMethodInNonBlockingContext", "Unused")
 
 package me.msfjarvis.openpgpktx.util
 
@@ -14,8 +14,6 @@ import java.io.IOException
 import java.io.InputStream
 import java.io.OutputStream
 import java.util.concurrent.atomic.AtomicInteger
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.withContext
 import org.openintents.openpgp.IOpenPgpService2
 import org.openintents.openpgp.OpenPgpError
 
@@ -23,17 +21,7 @@ public class OpenPgpApi(private val context: Context, private val service: IOpen
 
   private val pipeIdGen: AtomicInteger = AtomicInteger()
 
-  public suspend fun executeApiAsync(
-    data: Intent?,
-    inputStream: InputStream?,
-    outputStream: OutputStream?,
-    callback: (intent: Intent?) -> Unit
-  ) {
-    val result = executeApi(data, inputStream, outputStream)
-    withContext(Dispatchers.Main) { callback.invoke(result) }
-  }
-
-  public fun executeApi(data: Intent?, inputStream: InputStream?, outputStream: OutputStream?): Intent? {
+  public suspend fun executeApi(data: Intent, inputStream: InputStream?, outputStream: OutputStream?): Intent {
     var input: ParcelFileDescriptor? = null
     return try {
       if (inputStream != null) {
@@ -57,37 +45,38 @@ public class OpenPgpApi(private val context: Context, private val service: IOpen
     }
   }
 
-  /** InputStream and OutputStreams are always closed after operating on them! */
-  private fun executeApi(data: Intent?, input: ParcelFileDescriptor?, os: OutputStream?): Intent? {
+  private suspend fun executeApi(
+    data: Intent,
+    inputFd: ParcelFileDescriptor?,
+    outputStream: OutputStream?,
+  ): Intent {
     var output: ParcelFileDescriptor? = null
     return try {
       // always send version from client
-      data?.putExtra(EXTRA_API_VERSION, API_VERSION)
+      data.putExtra(EXTRA_API_VERSION, API_VERSION)
       val result: Intent
-      var pumpThread: Thread? = null
       var outputPipeId = 0
-      if (os != null) {
+      if (outputStream != null) {
         outputPipeId = pipeIdGen.incrementAndGet()
         output = service.createOutputPipe(outputPipeId)
-        pumpThread = ParcelFileDescriptorUtil.pipeTo(os, output)
       }
       // blocks until result is ready
-      result = service.execute(data, input, outputPipeId)
+      result = service.execute(data, inputFd, outputPipeId)
       // set class loader to current context to allow unparcelling
       // of OpenPgpError and OpenPgpSignatureResult
       // http://stackoverflow.com/a/3806769
       result.setExtrasClassLoader(context.classLoader)
-      // wait for ALL data being pumped from remote side
-      pumpThread?.join()
+      if (outputStream != null) {
+        ParcelFileDescriptorUtil.pipeTo(outputStream, output)
+      }
       result
-    } catch (e: Exception) {
+    } catch (e: Throwable) {
       Log.e(TAG, "Exception in executeApi call", e)
       val result = Intent()
       result.putExtra(RESULT_CODE, RESULT_CODE_ERROR)
       result.putExtra(RESULT_ERROR, OpenPgpError(OpenPgpError.CLIENT_SIDE_ERROR, e.message))
       result
     } finally {
-      // close() is required to halt the TransferThread
       if (output != null) {
         try {
           output.close()
diff --git a/openpgp-ktx/src/main/java/me/msfjarvis/openpgpktx/util/ParcelFileDescriptorUtil.kt b/openpgp-ktx/src/main/java/me/msfjarvis/openpgpktx/util/ParcelFileDescriptorUtil.kt
index dc3ef736..1229b95c 100644
--- a/openpgp-ktx/src/main/java/me/msfjarvis/openpgpktx/util/ParcelFileDescriptorUtil.kt
+++ b/openpgp-ktx/src/main/java/me/msfjarvis/openpgpktx/util/ParcelFileDescriptorUtil.kt
@@ -2,6 +2,8 @@
  * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
  * SPDX-License-Identifier: Apache-2.0
  */
+@file:Suppress("BlockingMethodInNonBlockingContext")
+
 package me.msfjarvis.openpgpktx.util
 
 import android.os.ParcelFileDescriptor
@@ -11,30 +13,27 @@ import android.util.Log
 import java.io.IOException
 import java.io.InputStream
 import java.io.OutputStream
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
 
 internal object ParcelFileDescriptorUtil {
 
   private const val TAG = "PFDUtils"
 
-  @Throws(IOException::class)
-  internal fun pipeFrom(inputStream: InputStream): ParcelFileDescriptor {
+  internal suspend fun pipeFrom(inputStream: InputStream): ParcelFileDescriptor {
     val pipe = ParcelFileDescriptor.createPipe()
     val readSide = pipe[0]
     val writeSide = pipe[1]
-    TransferThread(inputStream, AutoCloseOutputStream(writeSide)).start()
+    transferStreams(inputStream, AutoCloseOutputStream(writeSide))
     return readSide
   }
 
-  @Throws(IOException::class)
-  internal fun pipeTo(outputStream: OutputStream, output: ParcelFileDescriptor?): TransferThread {
-    val t = TransferThread(AutoCloseInputStream(output), outputStream)
-    t.start()
-    return t
+  internal suspend fun pipeTo(outputStream: OutputStream, output: ParcelFileDescriptor?) {
+    transferStreams(AutoCloseInputStream(output), outputStream)
   }
 
-  internal class TransferThread(val `in`: InputStream, private val out: OutputStream) : Thread("IPC Transfer Thread") {
-
-    override fun run() {
+  private suspend fun transferStreams(`in`: InputStream, `out`: OutputStream) {
+    withContext(Dispatchers.IO) {
       val buf = ByteArray(4096)
       var len: Int
       try {
@@ -52,9 +51,5 @@ internal object ParcelFileDescriptorUtil {
         } catch (ignored: IOException) {}
       }
     }
-
-    init {
-      isDaemon = true
-    }
   }
 }