code: private void readKeyStore() throws IOException, OfficeWriterException {
  		if ((this.howc.getCryptKeystoreFile()!=null) && (!"".equals(this.howc.getCryptKeystoreFile()))) {
  			LOG.info("Using keystore to obtain credentials instead of passwords");
  			FlinkKeyStoreManager fksm = new FlinkKeyStoreManager();
  			try {
  				fksm.openKeyStore(new Path(this.howc.getCryptKeystoreFile()), this.howc.getCryptKeystoreType(), this.howc.getCryptKeystorePassword());
  				String password="";
  				if ((this.howc.getCryptKeystoreAlias()!=null) && (!"".equals(this.howc.getCryptKeystoreAlias()))) {
  					password=fksm.getPassword(this.howc.getCryptKeystoreAlias(), this.howc.getCryptKeystorePassword());
  				} else {
  					password=fksm.getPassword(this.howc.getFileName(), this.howc.getCryptKeystorePassword());
  				}
  				this.howc.setPassword(password);
  			} catch (NoSuchAlgorithmException | CertificateException | KeyStoreException | IllegalArgumentException | UnrecoverableEntryException | InvalidKeySpecException e) {
  				LOG.error("Cannopt read keystore. Exception: ",e);
  				throw new OfficeWriterException("Cannot read keystore to obtain credentials used to encrypt office documents "+e);
  			}
  			
  		}
  	}
docs: Reads the keystore to obtain credentials
  
  @throws IOException
  @throws OfficeWriterException