From 7d91551126f3af7022eced2e3fc514b8353170ea Mon Sep 17 00:00:00 2001
From: Kamil Bobrowski <kamil.bobrowski@gmail.com>
Date: Mon, 3 Aug 2020 21:53:55 +0200
Subject: [PATCH] reading from the stream in a loop

this ensures that desired number of bytes will be read,
as stream.read(byte[] buffer) will just make effort to read
at least 1 byte
---
 .../ExposureNotificationServiceImpl.kt                 | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureNotificationServiceImpl.kt b/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureNotificationServiceImpl.kt
index b7610210..9bbda334 100644
--- a/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureNotificationServiceImpl.kt
+++ b/play-services-nearby-core/src/main/kotlin/org/microg/gms/nearby/exposurenotification/ExposureNotificationServiceImpl.kt
@@ -159,7 +159,15 @@ class ExposureNotificationServiceImpl(private val context: Context, private val
                             val entry = stream.nextEntry ?: break
                             if (entry.name == "export.bin") {
                                 val prefix = ByteArray(16)
-                                if (stream.read(prefix) == prefix.size && String(prefix).trim() == "EK Export v1") {
+                                var totalBytesRead = 0
+                                var bytesRead = 0
+                                while (bytesRead != -1 && totalBytesRead < prefix.size) {
+                                    bytesRead = stream.read(prefix, totalBytesRead, prefix.size - totalBytesRead)
+                                    if (bytesRead > 0) {
+                                        totalBytesRead += bytesRead
+                                    }
+                                }
+                                if (totalBytesRead == prefix.size && String(prefix).trim() == "EK Export v1") {
                                     val fileKeys = storeDiagnosisKeyExport(params.token, TemporaryExposureKeyExport.ADAPTER.decode(stream))
                                     keys + fileKeys
                                 } else {