Dart Requires Chilkat v11.0.0+

Create a Hash Signature for Value Added Tax Audit SOAP Message for Angola

See more OpenSSL Examples

Demonstrates how to create a hash signature that is required in Value Added Tax Audit Files in Angola, Africa.

It is the following two instructions that should be used to create a hash value to be put into a <hash></hash> field in SOAP XML file containing the tax data for the VAT authorities:

openssl dgst -shal -sign private.pem -outRegisto1.shal Registo1.txt

then

openssl enc -base64 - in Registo1.shal -out Registo1.b64 -A

Dart

import 'package:chilkat/chilkat.dart';

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

  final pkey = CkPrivateKey();

  // Load the private key from an PEM file.
  // Provide the password in the 2nd argument.
  // If no password is needed, just pass an empty string.
  try {
    pkey.loadAnyFormatFile('qa_data/rsa/rsaPrivKey_secret.pem', 'secret');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Assuming this is an RSA private key..
  final rsa = CkRsa();

  // Import the private key into the RSA object:
  try {
    rsa.usePrivateKey(pkey);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // OpenSSL uses big-endian.
  rsa.littleEndian = false;

  // SHA1 hash and sign, and return base64.
  rsa.encodingMode = 'base64';
  final b64sig = rsa.signStringENC('2018-05-18,2018-05-18T11:22:19;FAC 001/18;53.00;', 'sha1');
  print(b64sig);

  // The signature is equal in size to your private key.  For example, if you have a 1024-bit RSA key,
  // then 1024 bits = 128 bytes.   When 128 bytes is base64 encoded, the result is a string approximately
  // 4/3rds the size of the original.  128 * 4 / 3 = (approximately) 172 bytes.

  // If your RSA key is 2048-bits, then your signature will be twice as long.
}