(Java) IKOF Generation Code for Montenegro Fiscalization Service

Demonstrates computing the IKOF MD5 summary value as described in section 4.3 of this document: https://poreskauprava.gov.me/ResourceManager/FileDownload.aspx?rId=416042&rType=2

Chilkat Java Downloads Java Libs for Windows, MacOS, Linux, Alpine Linux, Solaris Java Libs for Android

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    String concatenatedParams = "12345678|2019-06-12T17:05:43+02:00|9952|bb123bb1231|cc123cc1231|ss123ss123|199.01";

    // Get the private key from a pfx file.
    CkPfx pfx = new CkPfx();
    boolean success = pfx.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123");
    if (success != true) {
        System.out.println(pfx.lastErrorText());
        return;
        }

    CkPrivateKey privKey = pfx.GetPrivateKey(0);
    if (pfx.get_LastMethodSuccess() == false) {
        System.out.println(pfx.lastErrorText());
        return;
        }

    // Create IIC signature according to RSASSA-PKCS-v1_5 using SHA256
    CkRsa rsa = new CkRsa();
    success = rsa.ImportPrivateKeyObj(privKey);
    if (success == false) {
        System.out.println(rsa.lastErrorText());
        return;
        }

    // PKCS-v1_5 is used by default.
    rsa.put_EncodingMode("hex");
    rsa.put_Charset("utf-8");
    String hexSig = rsa.signStringENC(concatenatedParams,"sha256");

    System.out.println("Signature value result is: " + hexSig);

    // Compute the MD5 hash of the bytes.
    CkCrypt2 crypt = new CkCrypt2();
    crypt.put_EncodingMode("hex");
    crypt.put_HashAlgorithm("md5");
    CkBinData bd = new CkBinData();
    bd.AppendEncoded(hexSig,"hex");
    String md5_summary = crypt.hashBdENC(bd);

    System.out.println("MD5 summary value is: " + md5_summary);
  }
}