Validate secret on manual entry

Closes #500

app/src/main/java/org/shadowice/flocke/andotp/Database/Entry.java

@@ -523,4 +523,14 @@ public class Entry {
     public int getColor() {
         return color;
     }
+
+    public static boolean validateSecret(String secret) {
+        try {
+            new Base32().decode(secret.toUpperCase());
+        } catch (Exception e) {
+            return false;
+        }
+
+        return true;
+    }
 }

app/src/main/java/org/shadowice/flocke/andotp/Dialogs/ManualEntryDialog.java

@@ -194,17 +194,34 @@ public class ManualEntryDialog {
         AlertDialog.Builder builder = new AlertDialog.Builder(callingActivity);
         builder.setTitle(R.string.dialog_title_manual_entry)
                 .setView(inputView)
-                .setPositiveButton(R.string.button_save, new DialogInterface.OnClickListener() {
+                .setPositiveButton(R.string.button_save, null)
+                .setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
                     @Override
-                    public void onClick(DialogInterface dialogInterface, int i) {
+                    public void onClick(DialogInterface dialogInterface, int i) {}
+                });
+
+        AlertDialog dialog = builder.create();
+        dialog.show();
+
+        final Button positiveButton = dialog.getButton(AlertDialog.BUTTON_POSITIVE);
+
+        positiveButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                //Replace spaces with empty characters
+                String secret = secretInput.getText().toString().replaceAll("\\s+","");
+
+                if (!Entry.validateSecret(secret)) {
+                    secretInput.setError(callingActivity.getString(R.string.error_invalid_secret));
+                    return;
+                }
+
                 Entry.OTPType type = (Entry.OTPType) typeInput.getSelectedItem();
                 TokenCalculator.HashAlgorithm algorithm = (TokenCalculator.HashAlgorithm) algorithmInput.getSelectedItem();
+                int digits = Integer.parseInt(digitsInput.getText().toString());
 
                 String issuer = issuerInput.getText().toString();
                 String label = labelInput.getText().toString();
-                        //Replace spaces with empty characters
-                        String secret = secretInput.getText().toString().replaceAll("\\s+","");
-                        int digits = Integer.parseInt(digitsInput.getText().toString());
 
                 if (type == Entry.OTPType.TOTP || type == Entry.OTPType.STEAM) {
                     int period = Integer.parseInt(periodInput.getText().toString());
@@ -241,17 +258,11 @@ public class ManualEntryDialog {
                         adapter.saveAndRefresh(settings.getAutoBackupEncryptedFullEnabled());
                     }
                 }
+
+                dialog.dismiss();
             }
-                })
-                .setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
-                    @Override
-                    public void onClick(DialogInterface dialogInterface, int i) {}
         });
 
-        AlertDialog dialog = builder.create();
-        dialog.show();
-
-        final Button positiveButton = dialog.getButton(AlertDialog.BUTTON_POSITIVE);
         positiveButton.setEnabled(false);
 
         TextWatcher watcher = new TextWatcher() {

app/src/main/res/values/strings_main.xml

@@ -73,6 +73,9 @@
     <string name="toast_qr_unsuported">QR Code not supported</string>
     <string name="toast_qr_failed_to_generate">Failed to generate QR Code</string>
 
+    <!-- Errors -->
+    <string name="error_invalid_secret">Invalid secret</string>
+
     <!-- Dialogs -->
     <string name="dialog_title_auth">Authenticate</string>
     <string name="dialog_title_manual_entry">Enter details</string>