Use truncate mode to replace the contents of existing files

`ContentResolver.openOutputStream(Uri)` does not truncate existing files. If the amount of data written is smaller than the file size, you end up with new data at the beginning of the file followed by old data at the end of the file.
This commit is contained in:
cketti 2022-03-29 16:12:12 +02:00
parent 539d198f8f
commit b9b5cab772
7 changed files with 13 additions and 12 deletions

1
changelog.d/5663.bugfix Normal file
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@ -0,0 +1 @@
Fixed key export when overwriting existing files

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@ -34,7 +34,7 @@ class KeysExporter @Inject constructor(
suspend fun export(password: String, uri: Uri) {
withContext(dispatchers.io) {
val data = session.cryptoService().exportRoomKeys(password)
context.contentResolver.openOutputStream(uri)
context.contentResolver.openOutputStream(uri, "wt")
?.use { it.write(data) }
?: throw IllegalStateException("Unable to open file for writing")
verifyExportedKeysOutputFileSize(uri, expectedSize = data.size.toLong())

View file

@ -165,7 +165,7 @@ class KeysBackupSetupStep3Fragment @Inject constructor() : VectorBaseFragment<Fr
lifecycleScope.launch(Dispatchers.Main) {
Try {
withContext(Dispatchers.IO) {
requireContext().contentResolver.openOutputStream(uri)
requireContext().contentResolver.openOutputStream(uri, "wt")
?.use { os ->
os.write(data.toByteArray())
os.flush()

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@ -81,7 +81,7 @@ class BootstrapSaveRecoveryKeyFragment @Inject constructor(
val uri = activityResult.data?.data ?: return@registerStartForActivityResult
lifecycleScope.launch(Dispatchers.IO) {
try {
sharedViewModel.handle(BootstrapActions.SaveKeyToUri(requireContext().contentResolver!!.openOutputStream(uri)!!))
sharedViewModel.handle(BootstrapActions.SaveKeyToUri(requireContext().contentResolver!!.openOutputStream(uri, "wt")!!))
} catch (failure: Throwable) {
sharedViewModel.handle(BootstrapActions.SaveReqFailed)
}

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@ -106,7 +106,7 @@ class KeyRequestsFragment @Inject constructor() : VectorBaseFragment<FragmentDev
when (it) {
is KeyRequestEvents.SaveAudit -> {
tryOrNull {
requireContext().contentResolver?.openOutputStream(it.uri)
requireContext().contentResolver?.openOutputStream(it.uri, "wt")
?.use { os -> os.write(it.raw.toByteArray()) }
}
}

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@ -53,7 +53,7 @@ class KeysExporterTest {
@Test
fun `when exporting then writes exported keys to context output stream`() {
givenFileDescriptorWithSize(size = A_ROOM_KEYS_EXPORT.size.toLong())
val outputStream = context.givenOutputStreamFor(A_URI)
val outputStream = context.givenOutputStreamFor(A_URI, mode = "wt")
runTest { keysExporter.export(A_PASSWORD, A_URI) }
@ -63,7 +63,7 @@ class KeysExporterTest {
@Test
fun `given different file size returned for export when exporting then throws UnexpectedExportKeysFileSizeException`() {
givenFileDescriptorWithSize(size = 110)
context.givenOutputStreamFor(A_URI)
context.givenOutputStreamFor(A_URI, mode = "wt")
assertFailsWith<UnexpectedExportKeysFileSizeException> {
runTest { keysExporter.export(A_PASSWORD, A_URI) }
@ -72,7 +72,7 @@ class KeysExporterTest {
@Test
fun `given output stream is unavailable for exporting to when exporting then throws IllegalStateException`() {
context.givenMissingOutputStreamFor(A_URI)
context.givenMissingOutputStreamFor(A_URI, mode = "wt")
assertFailsWith<IllegalStateException>(message = "Unable to open file for writing") {
runTest { keysExporter.export(A_PASSWORD, A_URI) }
@ -82,7 +82,7 @@ class KeysExporterTest {
@Test
fun `given exported file is missing after export when exporting then throws IllegalStateException`() {
context.givenFileDescriptor(A_URI, mode = "r") { null }
context.givenOutputStreamFor(A_URI)
context.givenOutputStreamFor(A_URI, mode = "wt")
assertFailsWith<IllegalStateException>(message = "Exported file not found") {
runTest { keysExporter.export(A_PASSWORD, A_URI) }

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@ -39,13 +39,13 @@ class FakeContext(
every { contentResolver.openFileDescriptor(uri, mode, null) } returns fileDescriptor
}
fun givenOutputStreamFor(uri: Uri): OutputStream {
fun givenOutputStreamFor(uri: Uri, mode: String): OutputStream {
val outputStream = mockk<OutputStream>(relaxed = true)
every { contentResolver.openOutputStream(uri) } returns outputStream
every { contentResolver.openOutputStream(uri, mode) } returns outputStream
return outputStream
}
fun givenMissingOutputStreamFor(uri: Uri) {
every { contentResolver.openOutputStream(uri) } returns null
fun givenMissingOutputStreamFor(uri: Uri, mode: String) {
every { contentResolver.openOutputStream(uri, mode) } returns null
}
}