(Node.js) Create a Hash Signature for Value Added Tax Audit SOAP Message for Angola

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

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

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

    var pkey = new chilkat.PrivateKey();

    // 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.
    var success = pkey.LoadAnyFormatFile("qa_data/rsa/rsaPrivKey_secret.pem","secret");
    if (success !== true) {
        console.log(pkey.LastErrorText);
        return;
    }

    // Assuming this is an RSA private key..
    var rsa = new chilkat.Rsa();

    // Import the private key into the RSA object:
    success = rsa.ImportPrivateKeyObj(pkey);
    if (success !== true) {
        console.log(rsa.LastErrorText);
        return;
    }

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

    // SHA1 hash and sign, and return base64.
    rsa.EncodingMode = "base64";
    var b64sig = rsa.SignStringENC("2018-05-18,2018-05-18T11:22:19;FAC 001/18;53.00;","sha1");
    console.log(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.

}

chilkatExample();