(Node.js) JWE using A256GCMKW

This example demonstrates creating a JCE with AES GCM key wrap.

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

    var success;
    var plaintext = "My text to enrypt";

    var jwe = new chilkat.Jwe();

    // First build the JWE Protected Header: 

    //         {
    //             "alg": "A256GCMKW",
    //             "kid": "18ec08e1-bfa9-4d95-b205-2b4dd1d4321d",
    //             "tag": "kfPduVQ3T3H6vnewt--ksw",
    //             "iv": "KkYT0GX_2jHlfqN_",
    //             "enc": "A128CBC-HS256"
    //         }

    var jweProtHdr = new chilkat.JsonObject();
    jweProtHdr.AppendString("alg","A256GCMKW");
    // kid is optional
    jweProtHdr.AppendString("kid","18ec08e1-bfa9-4d95-b205-2b4dd1d4321d");
    // tag is optional
    jweProtHdr.AppendString("tag","kfPduVQ3T3H6vnewt--ksw");
    jweProtHdr.AppendString("enc","A256GCM");
    // the iv should be 16 random chars.
    var prng = new chilkat.Prng();
    jweProtHdr.AppendString("iv",prng.RandomString(16,true,true,true));
    jwe.SetProtectedHeader(jweProtHdr);

    console.log("JWE Protected Header: " + jweProtHdr.Emit());
    console.log("--");

    // Given that we have 256-bit AES, our key should be 32 bytes.
    // The ascii string here is 32 bytes, therefore the 2nd arg is "ascii" to use these
    // ascii chars directly as the key.
    var aesWrappingKey = "2baf4f730f5e4542b428593ef9cceb0e";
    jwe.SetWrappingKey(0,aesWrappingKey,"ascii");

    // Encrypt and return the JWE:
    var strJwe = jwe.Encrypt(plaintext,"utf-8");
    if (jwe.LastMethodSuccess !== true) {
        console.log(jwe.LastErrorText);
        return;
    }

    // Show the JWE we just created:
    console.log(strJwe);

    // Decrypt the JWE that was just produced.
    // 1) Load the JWE.
    // 2) Set the AES wrapping key.
    // 3) Decrypt.
    var jwe2 = new chilkat.Jwe();
    success = jwe2.LoadJwe(strJwe);
    if (success !== true) {
        console.log(jwe2.LastErrorText);
        return;
    }

    // Set the AES wrap key.  Important to use "ascii"
    jwe2.SetWrappingKey(0,aesWrappingKey,"ascii");

    // Decrypt.
    var originalPlaintext = jwe2.Decrypt(0,"utf-8");
    if (jwe2.LastMethodSuccess !== true) {
        console.log(jwe2.LastErrorText);
        return;
    }

    console.log("original text: ");
    console.log(originalPlaintext);

}

chilkatExample();