package console;

import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;

import org.springframework.util.Base64Utils;
import org.springframework.util.StreamUtils;

import iaik.asn1.ASN1;
import iaik.asn1.CodingException;

public class PdfSigDecoder {

  /**
   * Decode a CAdES signature that is located in a PDF document.
   * 
   * @param args not supported yes
   * @throws CodingException In case of an ASN.1 decoding error
   * @throws IOException  In case of a general error 
   * @throws UnsupportedEncodingException In case of a general error
   */
  public static void main(String[] args) throws CodingException, UnsupportedEncodingException, IOException {
    InputStream is = PdfSigDecoder.class.getResourceAsStream("/pdf_cades_4.hex");
    String test = new String(StreamUtils.copyToByteArray(is), "UTF-8");
    test = test.replaceAll("\\n", "");
    final byte[] bytes = new byte[test.length() / 2];
    for (int i = 0; i < test.length() / 2; i++) {
      bytes[i] = (byte) Integer.parseInt(test.substring(i * 2, i * 2 + 2), 16);
    }
    Base64Utils.encodeToString(bytes);

    final ASN1 asn1 = new ASN1(bytes);

    System.out.println(asn1.toString());
    System.out.println(Base64Utils.encodeToString(bytes));

  }

}