(Node.js) Create Enveloping XML Digital Signature

This example creates an enveloping digital signature.
An enveloping signature is where the signed data is contained within the Signature within an Object element.
This example signs non-XML text data where the XML signature constitutes the entire output.

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.

    // Let's use the ECDSA private key at https://www.chilkatsoft.com/exampleData/secp256r1-key.zip
    // for signing.
    var http = new chilkat.Http();
    var zipFile = new chilkat.BinData();
    var keyUrl = "https://www.chilkatsoft.com/exampleData/secp256r1-key.zip";

    var success = http.QuickGetBd(keyUrl,zipFile);
    if (success !== true) {
        console.log(http.LastErrorText);
        return;
    }

    var zip = new chilkat.Zip();
    success = zip.OpenBd(zipFile);
    // zipEntry: ZipEntry
    var zipEntry = zip.FirstMatchingEntry("*.pem");
    var ecKey = new chilkat.PrivateKey();
    success = ecKey.LoadPem(zipEntry.UnzipToString(0,"utf-8"));
    if (success !== true) {
        console.log(ecKey.LastErrorText);

        return;
    }

    // ----------------------------------------------------------------------------
    var gen = new chilkat.XmlDSigGen();

    // Provide the ECDSA key to the XML Digital Signature generator
    gen.SetPrivateKey(ecKey);

    // Add an enveloped reference to the content to be signed.
    var sbContent = new chilkat.StringBuilder();
    sbContent.Append("This is the content that is signed.");
    gen.AddEnvelopedRef("abc123",sbContent,"sha256","C14N","");

    // Generate the XML digital signature.
    // Notice that in other examples, the sbXml passed to CreateXmlDSigSb
    // already contains XML, and the XML signature is inserted at the location
    // specified by the SigLocation property.  In this case, both SigLocation
    // and sbXml are empty.  The result is that sbXml will contain just the Signature.
    var sbXml = new chilkat.StringBuilder();
    success = gen.CreateXmlDSigSb(sbXml);
    if (success !== true) {
        console.log(gen.LastErrorText);
        return;
    }

    // Examine the enveloped signature, where the data is contained within the XML Signature
    console.log(sbXml.GetAsString());

    // The Signature returned is compact and in a single line, like this:
    // <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#"><ds:SignedInfo><ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/><ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha256"/><ds:Reference URI="#abc123"><ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/><ds:DigestValue>tEVrbXXjeTXjF3tIojul4/sgeEGN49E1dxr/GMs8GNE=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>/pILUshwrzgdGc4bPgp85TDfbUiM9pn8EIPNRVWKuoVEtPsv4XRthUrv9aDDvajmyl2okLwTakANgtaxO1ULMw==</ds:SignatureValue><ds:KeyInfo><ds:KeyValue><ds:ECKeyValue xmlns="http://www.w3.org/2009/xmldsig11#"><ds:NamedCurve URI="urn:oid:1.2.840.10045.3.1.7" /><ds:PublicKey>BOVKaiLPKEDChhkA64UEBOXTv/VFHnhrUPN+bXqCvEl7rroAYpH5tKzbiGTtMSlp4JO9Pxg44zeX7EoWDvOrpD0=</ds:PublicKey></ds:ECKeyValue></ds:KeyValue></ds:KeyInfo><ds:Object Id="abc123">This is the content that is signed.</ds:Object></ds:Signature>

    // XML pretty-printed, the signature is as follows, but pretty-printing introductes whitespace that breaks the signature..

    // <?xml version="1.0" encoding="utf-8" ?>
    // <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
    //     <ds:SignedInfo>
    //         <ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" />
    //         <ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#ecdsa-sha256" />
    //         <ds:Reference URI="#abc123">
    //             <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256" />
    //             <ds:DigestValue>tEVrbXXjeTXjF3tIojul4/sgeEGN49E1dxr/GMs8GNE=</ds:DigestValue>
    //         </ds:Reference>
    //     </ds:SignedInfo>
    //     <ds:SignatureValue>/pILUshwrzgdGc4bPgp85TDfbUiM9pn8EIPNRVWKuoVEtPsv4XRthUrv9aDDvajmyl2okLwTakANgtaxO1ULMw==</ds:SignatureValue>
    //     <ds:KeyInfo>
    //         <ds:KeyValue>
    //             <ds:ECKeyValue xmlns="http://www.w3.org/2009/xmldsig11#">
    //                 <ds:NamedCurve URI="urn:oid:1.2.840.10045.3.1.7" />
    //                 <ds:PublicKey>BOVKaiLPKEDChhkA64UEBOXTv/VFHnhrUPN+bXqCvEl7rroAYpH5tKzbiGTtMSlp4JO9Pxg44zeX7EoWDvOrpD0=</ds:PublicKey>
    //             </ds:ECKeyValue>
    //         </ds:KeyValue>
    //     </ds:KeyInfo>
    //     <ds:Object Id="abc123">This is the content that is signed.</ds:Object>
    // </ds:Signature>
    // 

}

chilkatExample();