From 79051439c5fcd01f6724431682d2ee26d6e3aa3f Mon Sep 17 00:00:00 2001
From: akwizgran <michael@briarproject.org>
Date: Sat, 5 Mar 2022 13:54:48 +0000
Subject: [PATCH] Catch NPE thrown by NetworkInterface.getNetworkInterfaces().

---
 .../briarproject/bramble/util/NetworkUtils.java  |  2 +-
 .../system/AbstractSecureRandomProvider.java     | 16 ++++++----------
 2 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/bramble-api/src/main/java/org/briarproject/bramble/util/NetworkUtils.java b/bramble-api/src/main/java/org/briarproject/bramble/util/NetworkUtils.java
index d2ad5ef88..f6a4cdc83 100644
--- a/bramble-api/src/main/java/org/briarproject/bramble/util/NetworkUtils.java
+++ b/bramble-api/src/main/java/org/briarproject/bramble/util/NetworkUtils.java
@@ -26,7 +26,7 @@ public class NetworkUtils {
 			// Despite what the docs say, the return value can be null
 			//noinspection ConstantConditions
 			return ifaces == null ? emptyList() : list(ifaces);
-		} catch (SocketException e) {
+		} catch (SocketException | NullPointerException e) {
 			logException(LOG, WARNING, e);
 			return emptyList();
 		}
diff --git a/bramble-core/src/main/java/org/briarproject/bramble/system/AbstractSecureRandomProvider.java b/bramble-core/src/main/java/org/briarproject/bramble/system/AbstractSecureRandomProvider.java
index d7691ea73..66b7df159 100644
--- a/bramble-core/src/main/java/org/briarproject/bramble/system/AbstractSecureRandomProvider.java
+++ b/bramble-core/src/main/java/org/briarproject/bramble/system/AbstractSecureRandomProvider.java
@@ -7,14 +7,13 @@ import java.io.DataOutputStream;
 import java.io.IOException;
 import java.net.InetAddress;
 import java.net.NetworkInterface;
-import java.util.Enumeration;
 import java.util.Map.Entry;
 import java.util.Properties;
 
 import javax.annotation.concurrent.Immutable;
 
-import static java.net.NetworkInterface.getNetworkInterfaces;
 import static java.util.Collections.list;
+import static org.briarproject.bramble.util.NetworkUtils.getNetworkInterfaces;
 
 @Immutable
 @NotNullByDefault
@@ -25,14 +24,11 @@ abstract class AbstractSecureRandomProvider implements SecureRandomProvider {
 		out.writeLong(System.currentTimeMillis());
 		out.writeLong(System.nanoTime());
 		out.writeLong(Runtime.getRuntime().freeMemory());
-		Enumeration<NetworkInterface> ifaces = getNetworkInterfaces();
-		if (ifaces != null) {
-			for (NetworkInterface i : list(ifaces)) {
-				for (InetAddress a : list(i.getInetAddresses()))
-					out.write(a.getAddress());
-				byte[] hardware = i.getHardwareAddress();
-				if (hardware != null) out.write(hardware);
-			}
+		for (NetworkInterface i : getNetworkInterfaces()) {
+			for (InetAddress a : list(i.getInetAddresses()))
+				out.write(a.getAddress());
+			byte[] hardware = i.getHardwareAddress();
+			if (hardware != null) out.write(hardware);
 		}
 		for (Entry<String, String> e : System.getenv().entrySet()) {
 			out.writeUTF(e.getKey());