(Node.js) Sign a Byte Array to Create an Opaque Signature in a Byte Array

Signs data contained in a byte array to produce an opaque signature (also in a byte array). An opaque signature is a PKCS7 signature (also known as CAdES) that embeds the signed data. Also shows how to verify the signature and extract the original data.

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 cert = new chilkat.Cert();
    var success = cert.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123");
    if (success == false) {
        console.log(cert.LastErrorText);
        return;
    }

    var fac = new chilkat.FileAccess();

    fileBytes = fac.ReadEntireFile("qa_data/pdf/sample.pdf");
    if (fac.LastMethodSuccess !== true) {
        console.log(fac.LastErrorText);
        return;
    }

    var crypt = new chilkat.Crypt2();

    success = crypt.SetSigningCert(cert);

    // We can sign any type of file.

    sigBytes = crypt.OpaqueSignBytes(fileBytes);
    if (crypt.LastMethodSuccess !== true) {
        console.log(crypt.LastErrorText);
        return;
    }

    success = fac.WriteEntireFile("qa_output/sample.pdf.p7m",sigBytes);
    if (fac.LastMethodSuccess !== true) {
        console.log(fac.LastErrorText);
        return;
    }

    // We can verify the opaque signature and extract the original data like this

    originalData = crypt.OpaqueVerifyBytes(sigBytes);
    if (crypt.LastMethodSuccess !== true) {
        console.log(crypt.LastErrorText);
        return;
    }

    success = fac.WriteEntireFile("qa_output/sample.pdf",originalData);
    if (fac.LastMethodSuccess !== true) {
        console.log(fac.LastErrorText);
        return;
    }

    console.log("Signature is verified and the original data was extracted.");

}

chilkatExample();