Improve comment parsing in key files.

Mifare Classic Tool/app/src/main/java/de/syss/MifareClassicTool/Common.java

@@ -362,10 +362,10 @@ public static byte[] readUriRaw(Uri uri, Context context) {
  }
 
  /**
- * Read a as BufferedReader line by line with the option to ignore
- * lines starting with #.
+ * Read a as BufferedReader line by line with some exceptions.
+ * Empty lines and leading/tailing whitespaces will be ignored.
  * @param reader The reader object initialized with a file (data).
- * @param readComments True if lines starting with # should be ignored.
+ * @param readComments True if comments (marked with #) should be read as well.
  * @param context The Context in which error Toasts will be shown.
  * @return The content with each line representing an array item
  * or Null in case of an read error.
@@ -377,19 +377,27 @@ private static String[] readLineByLine(BufferedReader reader,
  ArrayList<String> linesArray = new ArrayList<>();
  try {
  while ((line = reader.readLine()) != null) {
- // Ignore empty lines.
- // Ignore comments if readComments == false.
- if (!line.equals("")
- && (readComments || !line.startsWith("#"))) {
- try {
- linesArray.add(line);
- } catch (OutOfMemoryError e) {
- // Error. File is too big
- // (too many lines, out of memory).
- Toast.makeText(context, R.string.info_file_to_big,
- Toast.LENGTH_LONG).show();
- return null;
+ // Remove comments if readComments is false.
+ if (!readComments) {
+ if (line.matches("^#+$")) {
+ continue;
  }
+ line = line.split("#")[0];
+ }
+ // Ignore leading/tailing whitespaces.
+ line = line.trim();
+ // Ignore empty lines.
+ if (line.equals("")) {
+ continue;
+ }
+ try {
+ linesArray.add(line);
+ } catch (OutOfMemoryError e) {
+ // Error. File is too big
+ // (too many lines, out of memory).
+ Toast.makeText(context, R.string.info_file_to_big,
+ Toast.LENGTH_LONG).show();
+ return null;
  }
  }
  } catch (IOException ex) {
@@ -1459,6 +1467,8 @@ public static int isValidDump(String[] lines, boolean ignoreAsterisk) {
 
  /**
  * Check if the user input is a valid key file.
+ * Empty lines, leading/tailing whitespaces and comments (marked with #)
+ * will be ignored.
  * @param lines Lines of a key file.
  * @return <ul>
  * <li>0 - All O.K.</li>
@@ -1469,25 +1479,38 @@ public static int isValidDump(String[] lines, boolean ignoreAsterisk) {
  */
  public static int isValidKeyFile(String[] lines) {
  boolean keyFound = false;
- for (int i = 0; i < lines.length; i++) {
- if (!lines[i].startsWith("#") && !lines[i].equals("")
- && !lines[i].matches("[0-9A-Fa-f]+")) {
- // Not pure hex and not a comment.
+ if (lines == null || lines.length == 0) {
+ return 1;
+ }
+ for (String line : lines) {
+ // Remove comments.
+ if (line.matches("^#+$")) {
+ continue;
+ }
+ line = line.split("#")[0];
+
+ // Ignore leading/tailing whitespaces.
+ line = line.trim();
+
+ // Ignore empty lines.
+ if (line.equals("")) {
+ continue;
+ }
+
+ // Is hex?
+ if (!line.matches("[0-9A-Fa-f]+")) {
  return 2;
  }
 
- if (!lines[i].startsWith("#") && !lines[i].equals("")
- && lines[i].length() != 12) {
- // Not 12 chars per line.
+ // Is 6 byte long (12 chars)?
+ if (line.length() != 12) {
  return 3;
  }
 
- if (!lines[i].startsWith("#") && !lines[i].equals("")) {
- // At least one key found.
- lines[i] = lines[i].toUpperCase(Locale.getDefault());
- keyFound = true;
- }
+ // At least one key found.
+ keyFound = true;
  }
+
  if (!keyFound) {
  // No key found.
  return 1;