Show meaningful error message when no valid challenge was passed

pp3345 · Oct 4, 2018 · 5b7b52c · 5b7b52c
1 parent cd90092
commit 5b7b52c
Showing 3 changed files with 11 additions and 1 deletion.
diff --git a/app/src/main/java/net/pp3345/ykdroid/ChallengeResponseActivity.java b/app/src/main/java/net/pp3345/ykdroid/ChallengeResponseActivity.java
@@ -32,6 +32,7 @@ public class ChallengeResponseActivity extends Activity implements ConnectionMan
 	private SlotPreferenceManager slotPreferenceManager;
 	private Slot selectedSlot;
 	private String purpose;
+	private byte[] challenge;
 
 	@Override
 	protected void onCreate(final Bundle savedInstanceState) {
@@ -43,6 +44,13 @@ protected void onCreate(final Bundle savedInstanceState) {
 		this.requestWindowFeature(Window.FEATURE_NO_TITLE);
 		this.setContentView(R.layout.activity_challenge_response);
 
+		this.challenge = this.getIntent().getByteArrayExtra("challenge");
+		if (this.challenge == null || this.challenge.length == 0) {
+			this.showError();
+			((TextView) ChallengeResponseActivity.this.findViewById(R.id.info)).setText(R.string.invalid_challenge);
+			return;
+		}
+
 		switch (this.connectionManager.getSupportedConnectionMethods()) {
 			case ConnectionManager.CONNECTION_METHOD_USB | ConnectionManager.CONNECTION_METHOD_NFC:
 				((TextView) this.findViewById(R.id.info)).setText(R.string.attach_or_swipe_yubikey);
@@ -91,7 +99,7 @@ public void onYubiKeyConnected(final YubiKey yubiKey) {
 			@Override
 			protected byte[] doInBackground(final Void... nothing) {
 				try {
-					return yubiKey.challengeResponse(ChallengeResponseActivity.this.selectedSlot, ChallengeResponseActivity.this.getIntent().getByteArrayExtra("challenge"));
+					return yubiKey.challengeResponse(ChallengeResponseActivity.this.selectedSlot, ChallengeResponseActivity.this.challenge);
 				} catch (final Exception e) {
 					this.executionException = e;
 					return null;

diff --git a/app/src/main/res/values-de/strings.xml b/app/src/main/res/values-de/strings.xml
@@ -11,4 +11,5 @@
         <item>Slot 1</item>
         <item>Slot 2</item>
     </string-array>
+    <string name="invalid_challenge">Es wurde keine gültige Challenge übergeben. Sollte das Problem bestehen bleiben, kontaktiere bitte den Entwickler der App, mit der du ykDroid benutzen möchtest.</string>
 </resources>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
@@ -6,6 +6,7 @@
     <string name="no_supported_connection_method">Your device supports neither USB host mode nor NFC. YubiKeys can not be used.</string>
     <string name="press_button">Please press the button on your YubiKey.</string>
     <string name="unplug_yubikey">An error has occurred. Please unplug your YubiKey.</string>
+    <string name="invalid_challenge">An invalid challenge was passed. If this problem persists, please contact the vendor of the app you are trying to use ykDroid with.</string>
     <string-array name="slots">
         <item>Slot 1</item>
         <item>Slot 2</item>