Config: make parsing stricter

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

4 files changed, 19 insertions, 6 deletions

diff --git a/app/src/main/java/com/wireguard/android/backends/VpnService.java b/app/src/main/java/com/wireguard/android/backends/VpnService.java
index 084a2407..95736de5 100644
--- a/app/src/main/java/com/wireguard/android/backends/VpnService.java
+++ b/app/src/main/java/com/wireguard/android/backends/VpnService.java
@@ -369,6 +369,11 @@ public class VpnService extends Service
                     config.setName(configName);
                     configs.add(config);
                 } catch (IllegalArgumentException | IOException e) {
+                    try {
+                        file.delete();
+                    } catch (Exception e2) {
+                        Log.w(TAG, "Could not remove " + fileName, e2);
+                    }
                     Log.w(TAG, "Failed to load config from " + fileName, e);
                 }
             }
diff --git a/app/src/main/java/com/wireguard/config/Attribute.java b/app/src/main/java/com/wireguard/config/Attribute.java
index 4ee4e9f5..b2aa0d53 100644
--- a/app/src/main/java/com/wireguard/config/Attribute.java
+++ b/app/src/main/java/com/wireguard/config/Attribute.java
@@ -17,7 +17,7 @@ enum Attribute {
     LISTEN_PORT("ListenPort"),
     MTU("MTU"),
     PERSISTENT_KEEPALIVE("PersistentKeepalive"),
-    PRE_SHARED_KEY("PresharedKey"),
+    PRESHARED_KEY("PresharedKey"),
     PRIVATE_KEY("PrivateKey"),
     PUBLIC_KEY("PublicKey");
 
diff --git a/app/src/main/java/com/wireguard/config/Config.java b/app/src/main/java/com/wireguard/config/Config.java
index 2a282d09..d5f0c6e5 100644
--- a/app/src/main/java/com/wireguard/config/Config.java
+++ b/app/src/main/java/com/wireguard/config/Config.java
@@ -139,19 +139,27 @@ public class Config extends BaseObservable
                 new InputStreamReader(stream, StandardCharsets.UTF_8))) {
             Peer currentPeer = null;
             String line;
+            boolean inInterfaceSection = false;
             while ((line = reader.readLine()) != null) {
-                if (line.isEmpty())
+                if (line.isEmpty() || line.startsWith("#"))
                     continue;
                 if ("[Interface]".equals(line)) {
                     currentPeer = null;
+                    inInterfaceSection = true;
                 } else if ("[Peer]".equals(line)) {
                     currentPeer = addPeer();
-                } else if (currentPeer == null) {
+                    inInterfaceSection = false;
+                } else if (inInterfaceSection) {
                     iface.parse(line);
-                } else {
+                } else if (currentPeer != null) {
                     currentPeer.parse(line);
+                } else {
+                    throw new IllegalArgumentException("Invalid configuration line: " + line);
                 }
             }
+            if (!inInterfaceSection && currentPeer == null) {
+                throw new IllegalArgumentException("Did not find any config information");
+            }
         }
     }
 
diff --git a/app/src/main/java/com/wireguard/config/Peer.java b/app/src/main/java/com/wireguard/config/Peer.java
index 718a5c3c..ea73155f 100644
--- a/app/src/main/java/com/wireguard/config/Peer.java
+++ b/app/src/main/java/com/wireguard/config/Peer.java
@@ -104,7 +104,7 @@ public class Peer extends BaseObservable implements Copyable<Peer>, Observable,
             setEndpoint(key.parseFrom(line));
         else if (key == Attribute.PERSISTENT_KEEPALIVE)
             setPersistentKeepalive(key.parseFrom(line));
-        else if (key == Attribute.PRE_SHARED_KEY)
+        else if (key == Attribute.PRESHARED_KEY)
             setPreSharedKey(key.parseFrom(line));
         else if (key == Attribute.PUBLIC_KEY)
             setPublicKey(key.parseFrom(line));
@@ -161,7 +161,7 @@ public class Peer extends BaseObservable implements Copyable<Peer>, Observable,
         if (persistentKeepalive != null)
             sb.append(Attribute.PERSISTENT_KEEPALIVE.composeWith(persistentKeepalive));
         if (preSharedKey != null)
-            sb.append(Attribute.PRE_SHARED_KEY.composeWith(preSharedKey));
+            sb.append(Attribute.PRESHARED_KEY.composeWith(preSharedKey));
         if (publicKey != null)
             sb.append(Attribute.PUBLIC_KEY.composeWith(publicKey));
         return sb.toString();