Node.js

JWS Using HMAC SHA-256

See more JSON Web Signatures (JWS) Examples

Creates a JSON Web Signatures (JWS) using HMAC SHA-256. Node.js

NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

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

    // First create the JWS Protected Header
    var jwsProtHdr = new chilkat.JsonObject();
    jwsProtHdr.AppendString("typ","JWT");
    jwsProtHdr.AppendString("alg","HS256");
    console.log("JWS Protected Header: " + jwsProtHdr.Emit());

    // Output:
    // JWS Protected Header: {"typ":"JWT","alg":"HS256"}

    var jws = new chilkat.Jws();

    // Set the HMAC key:
    var hmacKey = "AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow";
    var signatureIndex = 0;
    jws.SetMacKey(signatureIndex,hmacKey,"base64url");

    // Set the protected header:
    jws.SetProtectedHeader(signatureIndex,jwsProtHdr);

    // Set the payload.
    var bIncludeBom = false;
    var payloadStr = "In our village, folks say God crumbles up the old moon into stars.";
    jws.SetPayload(payloadStr,"utf-8",bIncludeBom);

    // Create the JWS
    // By default, the compact serialization is used.
    var jwsCompact = jws.CreateJws();
    if (jws.LastMethodSuccess == false) {
        console.log(jws.LastErrorText);
        return;
    }

    console.log("JWS: " + jwsCompact);

    // sample output:
    // JWS: eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.bsYsi8HJ0N6OqGI1hKQ9QQRNPxxA5qMpcHLtOvXatk8

    // Now load the JWS, validate, and recover the original text.
    var jws2 = new chilkat.Jws();

    // Load the JWS.
    success = jws2.LoadJws(jwsCompact);

    // Set the MAC key used for validation.
    signatureIndex = 0;
    jws2.SetMacKey(signatureIndex,hmacKey,"base64url");

    // Validate the 1st (and only) signature at index 0..
    var v = jws2.Validate(signatureIndex);
    if (v < 0) {
        // Perhaps Chilkat was not unlocked or the trial expired..
        console.log("Method call failed for some other reason.");
        console.log(jws2.LastErrorText);
        return;
    }

    if (v == 0) {
        console.log("Invalid signature.  The MAC key was incorrect, the JWS was invalid, or both.");
        return;
    }

    // If we get here, the signature was validated..
    console.log("Signature validated.");

    // Recover the original content:
    console.log(jws2.GetPayload("utf-8"));

    // Examine the protected header:

    var joseHeader = new chilkat.JsonObject();
    success = jws2.GetProtectedH(signatureIndex,joseHeader);
    if (success == false) {
        console.log(jws2.LastErrorText);
        return;
    }

    joseHeader.EmitCompact = false;

    console.log("Protected (JOSE) header:");
    console.log(joseHeader.Emit());

    // Output:

    // 	Signature validated.
    // 	In our village, folks say God crumbles up the old moon into stars.
    // 	Protected (JOSE) header:
    // 	{ 
    // 	  "typ": "JWT",
    // 	  "alg": "HS256"
    // 	} 

}

chilkatExample();