package edu.jiangxin.apktoolbox.file.password.recovery.checker;
   
   import edu.jiangxin.apktoolbox.file.password.recovery.exception.UnknownException;
   import org.apache.commons.io.IOUtils;
   import org.apache.pdfbox.Loader;
   import org.apache.pdfbox.io.RandomAccessReadBufferedFile;
   import org.apache.pdfbox.pdmodel.PDDocument;
   import org.apache.pdfbox.pdmodel.encryption.InvalidPasswordException;
   
  import java.io.IOException;
  
  /**
   * Brief introduction to PDF password
   * The standard security provided by PDF has two different passwords: user passwords and owner passwords.
   * A PDF document may be protected by a password for opening (user password)
   * and the document may also specify operations that should be restricted even when the document is decrypted:
   * printing; copying text and graphics out of the document; modifying the document;
   * and adding or modifying text notes (using owner password).
   */
  public class PdfChecker extends FileChecker {
  
      public PdfChecker() {
          super();
      }
  
      @Override
      public String[] getFileExtensions() {
          return new String[]{"pdf"};
      }
  
      @Override
      public String getFileDescription() {
          return "*.pdf";
      }
  
      @Override
      public String getDescription() {
          return "PDF Checker";
      }
  
      @Override
      public boolean prepareChecker() {
          return true;
      }
  
      @Override
      public boolean checkPassword(String password) {
          boolean result = false;
          PDDocument pdDocument = null;
          try {
              pdDocument = Loader.loadPDF(new RandomAccessReadBufferedFile(file), password);
              result = true;
          } catch (InvalidPasswordException e) {
              logger.debug("[InvalidPasswordException]password is incorrect: {}", password);
          } catch (IOException e) {
              throw new UnknownException(e);
          } finally {
              if (pdDocument != null) {
                  IOUtils.closeQuietly(pdDocument);
              }
          }
          return result;
      }
  }