(Node.js) JWE using ECDH-ES+A256KW

See more JSON Web Encryption (JWE) Examples

{
    "kty": "EC",
    "d": "jZCffzVqJjryBH4EoaN0oD-TyLXrW2XHoDdIuPZnk8c",
    "use": "enc",
    "crv": "P-256",
    "kid": "evEK2thJMsWxBYRivXI8ykUf6n6zizLiLCGH3s58wKs",
    "x": "LOakgGvxWBsWbCPLY6Vq6OuBktIqG8POXFXe7ngQ2oM",
    "y": "voJvS6I-Mc4qqmEA_G2hLQqBck3a3vqaJbmzY7YPUD4",
    "alg": "ECDH-ES+A256KW"
}

Also shows how to decrypt.

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

var os = require('os');
if (os.platform() == 'win32') {  
  var chilkat = require('@chilkat/ck-node23-win64'); 
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node23-linux-arm');
    } else if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node23-linux-arm64');
    } else {
        var chilkat = require('@chilkat/ck-node23-linux-x64');
    }
} else if (os.platform() == 'darwin') {
  var chilkat = require('@chilkat/ck-node23-mac-universal');
}

function chilkatExample() {

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

    var success;

    // Create the following JSON:
    // {
    //     "kty": "EC",
    //     "d": "jZCffzVqJjryBH4EoaN0oD-TyLXrW2XHoDdIuPZnk8c",
    //     "use": "enc",
    //     "crv": "P-256",
    //     "kid": "evEK2thJMsWxBYRivXI8ykUf6n6zizLiLCGH3s58wKs",
    //     "x": "LOakgGvxWBsWbCPLY6Vq6OuBktIqG8POXFXe7ngQ2oM",
    //     "y": "voJvS6I-Mc4qqmEA_G2hLQqBck3a3vqaJbmzY7YPUD4",
    //     "alg": "ECDH-ES+A256KW"
    // }

    var json = new chilkat.JsonObject();
    json.UpdateString("kty","EC");
    json.UpdateString("d","jZCffzVqJjryBH4EoaN0oD-TyLXrW2XHoDdIuPZnk8c");
    json.UpdateString("use","enc");
    json.UpdateString("crv","P-256");
    json.UpdateString("kid","evEK2thJMsWxBYRivXI8ykUf6n6zizLiLCGH3s58wKs");
    json.UpdateString("x","LOakgGvxWBsWbCPLY6Vq6OuBktIqG8POXFXe7ngQ2oM");
    json.UpdateString("y","voJvS6I-Mc4qqmEA_G2hLQqBck3a3vqaJbmzY7YPUD4");
    json.UpdateString("alg","ECDH-ES+A256KW");

    var pubkey = new chilkat.PublicKey();

    success = pubkey.LoadFromString(json.Emit());
    if (success == false) {
        console.log(pubkey.LastErrorText);
        return;
    }

    // Build our protected header:

    // 	{
    // 	  "alg": "ECDH-ES+A256KW",
    // 	  "enc": "A256GCM",
    // 	  "exp": 1621957030,
    // 	  "cty": "NJWT",
    // 	  "epk": {
    // 	    "kty": "EC",
    // 	    "x": "QLpJ_LpFx-6yJhsb4OvHwU1khLnviiOwYOvmf5clK7w"
    // 	    "y": "AJh7pJ3zZKDJkm8rbeG69GBooTosXJgSsvNFH0i3Vxnu"
    // 	    "crv": "BP-256"
    // 	  }
    // 	}

    // Use jwt only for getting the current date/time + 3600 seconds.
    var jwt = new chilkat.Jwt();

    var jweProtHdr = new chilkat.JsonObject();
    jweProtHdr.UpdateString("alg","ECDH-ES+A256KW");
    jweProtHdr.UpdateString("enc","A256GCM");
    jweProtHdr.UpdateInt("exp",jwt.GenNumericDate(3600));
    jweProtHdr.UpdateString("cty","NJWT");
    jweProtHdr.UpdateString("epk.kty","EC");
    jweProtHdr.UpdateString("epk.x","LOakgGvxWBsWbCPLY6Vq6OuBktIqG8POXFXe7ngQ2oM");
    jweProtHdr.UpdateString("epk.y","voJvS6I-Mc4qqmEA_G2hLQqBck3a3vqaJbmzY7YPUD4");
    jweProtHdr.UpdateString("epk.crv","P-256");

    var jwe = new chilkat.Jwe();
    jwe.SetProtectedHeader(jweProtHdr);
    jwe.SetPublicKey(0,pubkey);

    var plainText = "This is the text to be encrypted.";
    var strJwe = jwe.Encrypt(plainText,"utf-8");
    if (jwe.LastMethodSuccess !== true) {
        console.log(jwe.LastErrorText);
        return;
    }

    console.log(strJwe);

    // Let's decrypt...
    var privkey = new chilkat.PrivateKey();

    success = privkey.LoadJwk(json.Emit());
    if (success == false) {
        console.log(privkey.LastErrorText);
        return;
    }

    var jwe2 = new chilkat.Jwe();
    success = jwe2.LoadJwe(strJwe);
    if (success == false) {
        console.log(jwe2.LastErrorText);
        return;
    }

    jwe2.SetPrivateKey(0,privkey);

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

    console.log(decryptedText);

}

chilkatExample();