[anastasis] Improve I/O logic for file backups

3 files changed, 90 insertions, 50 deletions

diff --git a/anastasis/src/main/java/net/taler/anastasis/reducers/ReducerManager.kt b/anastasis/src/main/java/net/taler/anastasis/reducers/ReducerManager.kt
index 237a0a3..2b9eda6 100644
--- a/anastasis/src/main/java/net/taler/anastasis/reducers/ReducerManager.kt
+++ b/anastasis/src/main/java/net/taler/anastasis/reducers/ReducerManager.kt
@@ -34,11 +34,28 @@ import net.taler.anastasis.models.ContinentInfo
 import net.taler.anastasis.models.CoreSecret
 import net.taler.anastasis.models.CountryInfo
 import net.taler.anastasis.models.Policy
+import net.taler.anastasis.models.ReducerArgs.AddAuthentication
+import net.taler.anastasis.models.ReducerArgs.AddPolicy
+import net.taler.anastasis.models.ReducerArgs.AddProvider
+import net.taler.anastasis.models.ReducerArgs.DeleteAuthentication
+import net.taler.anastasis.models.ReducerArgs.DeletePolicy
+import net.taler.anastasis.models.ReducerArgs.DeleteProvider
+import net.taler.anastasis.models.ReducerArgs.EnterSecret
+import net.taler.anastasis.models.ReducerArgs.EnterSecretName
+import net.taler.anastasis.models.ReducerArgs.EnterUserAttributes
+import net.taler.anastasis.models.ReducerArgs.SelectChallenge
+import net.taler.anastasis.models.ReducerArgs.SelectContinent
+import net.taler.anastasis.models.ReducerArgs.SelectCountry
+import net.taler.anastasis.models.ReducerArgs.SolveChallengeRequest
+import net.taler.anastasis.models.ReducerArgs.UpdateExpiration
+import net.taler.anastasis.models.ReducerArgs.UpdatePolicy
 import net.taler.anastasis.models.ReducerState
+import net.taler.anastasis.shared.FileUtils.bufferedReadBytes
 import net.taler.anastasis.shared.Utils
+import net.taler.common.CryptoUtils
 import net.taler.common.Timestamp
+import java.io.InputStream
 import kotlin.time.Duration.Companion.seconds
-import net.taler.anastasis.models.ReducerArgs.*
 
 class ReducerManager(
     private val state: MutableStateFlow<ReducerState?>,
@@ -272,6 +289,25 @@ class ReducerManager(
         }
     }
 
+    fun enterFileSecret(
+        inputStream: InputStream?,
+        secret: CoreSecret,
+        expiration: Timestamp,
+    ) = scope.launch {
+        // TODO: better IO error handling
+        val bytes = inputStream?.bufferedReadBytes() ?: return@launch
+        val encodedBytes = CryptoUtils.encodeCrock(bytes)
+        state.value?.let { initialState ->
+            addTask(Tasks.Type.None)
+            api.reduceAction(initialState, "enter_secret", EnterSecret(
+                secret = secret.copy(value = encodedBytes),
+                expiration = expiration,
+            ))
+                .onSuccess { onSuccess(it) }
+                .onError { onError(it) }
+        }
+    }
+
     fun updateSecretExpiration(expiration: Timestamp) = scope.launch {
         state.value?.let { initialState ->
             addTask(Tasks.Type.None)
diff --git a/anastasis/src/main/java/net/taler/anastasis/shared/FileUtils.kt b/anastasis/src/main/java/net/taler/anastasis/shared/FileUtils.kt
index 2626aa0..df66e69 100644
--- a/anastasis/src/main/java/net/taler/anastasis/shared/FileUtils.kt
+++ b/anastasis/src/main/java/net/taler/anastasis/shared/FileUtils.kt
@@ -20,26 +20,12 @@ import android.content.Context
 import android.net.Uri
 import android.provider.DocumentsContract
 import android.provider.OpenableColumns
+import android.util.Log
+import java.io.ByteArrayOutputStream
+import java.io.IOException
+import java.io.InputStream
 
 object FileUtils {
-//    fun Context.createTempFileForDoc(uri: Uri): File {
-//        val storageDir = createTempDirectory()
-//        val filename = resolveDocFilename(uri) ?: UUID.randomUUID().toString()
-//        val file = File(storageDir.pathString, filename)
-//        if (file.exists()) file.delete()
-//        file.createNewFile()
-//
-//        // Read file and copy to temp file
-//        val inputStream = contentResolver.openInputStream(uri)
-//        inputStream?.copyTo(file.outputStream())
-//        inputStream?.close()
-//
-//        // TODO: not the best solution!
-//        // Delete file on Java VM exit for security
-//        file.deleteOnExit()
-//        return file
-//    }
-
     fun Context.resolveDocFilename(uri: Uri): String? =
         contentResolver.query(uri, null, null, null, null)?.use { cursor ->
             val nameIndex = cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME)
@@ -53,4 +39,23 @@ object FileUtils {
             cursor.moveToFirst()
             cursor.getString(mimeIndex)
         }
+
+    // Source: https://stackoverflow.com/a/12223201
+    fun InputStream.bufferedReadBytes(): ByteArray? = use {
+        val buffer = ByteArrayOutputStream()
+        val data = ByteArray(16384)
+        var bytesRead: Int
+        try {
+            while (true) {
+                bytesRead = it.read(data, 0, data.size)
+                if (bytesRead == -1) break
+                buffer.write(data)
+            }
+            buffer.flush()
+            return buffer.toByteArray()
+        } catch (e: IOException) {
+            Log.d("FileUtils", e.stackTraceToString())
+            return null
+        }
+    }
 }
\ No newline at end of file
diff --git a/anastasis/src/main/java/net/taler/anastasis/ui/screens/backup/EditSecretScreen.kt b/anastasis/src/main/java/net/taler/anastasis/ui/screens/backup/EditSecretScreen.kt
index 937b5d3..70eb47d 100644
--- a/anastasis/src/main/java/net/taler/anastasis/ui/screens/backup/EditSecretScreen.kt
+++ b/anastasis/src/main/java/net/taler/anastasis/ui/screens/backup/EditSecretScreen.kt
@@ -107,38 +107,37 @@ fun EditSecretScreen(
                     onSecretEdited = { data ->
                         secretData = data
                         if (data !is SecretData.Empty) {
-                            viewModel.reducerManager?.enterSecret(
-                                secret = when (data) {
-                                    is SecretData.File -> {
-                                        val filename = context.resolveDocFilename(data.documentUri)
-                                        val mimeType = context.resolveDocMimeType(data.documentUri)
-                                        val inputStream = context.contentResolver.openInputStream(data.documentUri)
-                                        if (inputStream != null) {
-                                            val secret = CoreSecret(
-                                                // TODO: readBytes() has a 2GB limit
-                                                // TODO: make this SLOW readBytes() + encodeCrock operation async
-                                                value = CryptoUtils.encodeCrock(inputStream.readBytes()),
-                                                filename = filename,
-                                                mime = mimeType ?: "application/octet-stream",
-                                            )
-                                            inputStream.close()
-                                            secret
-                                        } else {
-                                            error("couldn't open file")
-                                        }
-                                    }
-                                    is SecretData.PlainText -> CoreSecret(
-                                        value = CryptoUtils.encodeCrock(data.value.toByteArray(Charsets.UTF_8)),
-                                        mime = "text/plain",
-                                    )
-                                    else -> error("impossible case")
-                                },
-                                expiration = Timestamp.fromMillis(
-                                    secretExpirationDate
-                                        .toInstant(tz)
-                                        .toEpochMilliseconds()
-                                )
+                            val expiration = Timestamp.fromMillis(
+                                secretExpirationDate
+                                    .toInstant(tz)
+                                    .toEpochMilliseconds()
                             )
+                            when (data) {
+                                is SecretData.File -> {
+                                    val filename = context.resolveDocFilename(data.documentUri)
+                                    val mimeType = context.resolveDocMimeType(data.documentUri)
+                                    val inputStream = context.contentResolver.openInputStream(data.documentUri)
+                                    viewModel.reducerManager?.enterFileSecret(
+                                        inputStream = inputStream,
+                                        secret = CoreSecret(
+                                            value = "", // Doesn't matter
+                                            filename = filename,
+                                            mime = mimeType,
+                                        ),
+                                        expiration = expiration,
+                                    )
+                                }
+                                is SecretData.PlainText -> {
+                                    viewModel.reducerManager?.enterSecret(
+                                        secret = CoreSecret(
+                                            value = CryptoUtils.encodeCrock(data.value.toByteArray(Charsets.UTF_8)),
+                                            mime = "text/plain",
+                                        ),
+                                        expiration = expiration,
+                                    )
+                                }
+                                else -> {} // Impossible case
+                            }
                         }
                     },
                     onExpirationEdited = { date ->