(Node.js) Validate JWS with Multiple Signatures using the General JSON Serialization Format

Validates and recovers data and headers from a JSON Web Signature (JWS) containing 3 signatures.

Note: Chilkat supports all of the following JWS algorithms:

   +--------------+-------------------------------+--------------------+
   | "alg" Param  | Digital Signature or MAC      | Implementation     |
   | Value        | Algorithm                     | Requirements       |
   +--------------+-------------------------------+--------------------+
   | HS256        | HMAC using SHA-256            | Required           |
   | HS384        | HMAC using SHA-384            | Optional           |
   | HS512        | HMAC using SHA-512            | Optional           |
   | RS256        | RSASSA-PKCS1-v1_5 using       | Recommended        |
   |              | SHA-256                       |                    |
   | RS384        | RSASSA-PKCS1-v1_5 using       | Optional           |
   |              | SHA-384                       |                    |
   | RS512        | RSASSA-PKCS1-v1_5 using       | Optional           |
   |              | SHA-512                       |                    |
   | ES256        | ECDSA using P-256 and SHA-256 | Recommended+       |
   | ES384        | ECDSA using P-384 and SHA-384 | Optional           |
   | ES512        | ECDSA using P-521 and SHA-512 | Optional           |
   | PS256        | RSASSA-PSS using SHA-256 and  | Optional           |
   |              | MGF1 with SHA-256             |                    |
   | PS384        | RSASSA-PSS using SHA-384 and  | Optional           |
   |              | MGF1 with SHA-384             |                    |
   | PS512        | RSASSA-PSS using SHA-512 and  | Optional           |
   |              | MGF1 with SHA-512             |                    |
   +--------------+-------------------------------+--------------------+

Note: This example requires Chilkat v9.5.0.66 or greater.

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.

    // Note: This example requires Chilkat v9.5.0.66 or greater.

    // First, prepare the public keys that will be needed for each signature.

    // ---------------------------------------------------
    // Use the following RSA key loaded from JWK format.
    var sbRsaJwk = new chilkat.StringBuilder();
    sbRsaJwk.Append("{\"kty\":\"RSA\",");
    sbRsaJwk.Append("\"n\":\"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx");
    sbRsaJwk.Append("HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs");
    sbRsaJwk.Append("D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH");
    sbRsaJwk.Append("SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV");
    sbRsaJwk.Append("MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8");
    sbRsaJwk.Append("NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ\",");
    sbRsaJwk.Append("\"e\":\"AQAB\"");
    sbRsaJwk.Append("}");

    var rsaKey = new chilkat.PublicKey();
    var success = rsaKey.LoadFromString(sbRsaJwk.GetAsString());
    if (success !== true) {
        console.log(rsaKey.LastErrorText);
        return;
    }

    // ---------------------------------------------------
    // Use the following ECC public key loaded from JWK format.
    var sbEccJwk = new chilkat.StringBuilder();
    sbEccJwk.Append("{\"kty\":\"EC\",");
    sbEccJwk.Append("\"crv\":\"P-256\",");
    sbEccJwk.Append("\"x\":\"f83OJ3D2xF1Bg8vub9tLe1gHMzV76e8Tus9uPHvRVEU\",");
    sbEccJwk.Append("\"y\":\"x_FEzRu9m36HLN_tue659LNpXW6pCyStikYjKIWI5a0\"");
    sbEccJwk.Append("}");

    var eccKey = new chilkat.PublicKey();
    success = eccKey.LoadFromString(sbEccJwk.GetAsString());
    if (success !== true) {
        console.log(eccKey.LastErrorText);
        return;
    }

    // ---------------------------------------------------
    // The HMAC key (in base64url format)
    var hmacKey = "AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow";

    // The code below will verify each of the signatures in this JWS:

    // { 
    //   "payload": "SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu",
    //   "signatures": [
    //     { 
    //       "protected": "eyJhbGciOiJSUzI1NiIsImtpZCI6Im15UnNhS2V5In0",
    //       "signature": "IPMQ02niTQDwLzsRZSCaEm9VEyAX_AVe3HWjniNt9kW-a8d6ZVbd2k6jGae8s1yIh0cgxDnXQ6-p6_sBI0cnMO0xpuJANhh2vFtNJl5lisad94-H3mB3lSfafRqxeYp5D8bh39BPv7y3PrUNVMQdKEJp_D5oJ0ROPTIYx3EG8eJQOx1HO0KqhcUo401XR6KSsIyFm5joBLNKTVzxZUTT1RRZZtwTdeZkbGevugIOX_9gHAtARpV6WaFA4Vvjnq8X9wPgqjWNCQRupadhTPz0JAsa-wy5vXQjsFlXAn43mDPpMfna5Ab3F5pS4yDwkbX6nRn7XBxH1SnnNJRFholQZw"
    //     },
    //     { 
    //       "protected": "eyJhbGciOiJFUzI1NiIsImtpZCI6Im15RWNLZXkifQ",
    //       "signature": "1OQtaT3pgZmkDxvlfghvxL_8kX16WIen6u1MadEq1pA4qytA0--_EwZDNk00GDPWFpoJtKznibMZzLOg_UhHIw"
    //     },
    //     { 
    //       "protected": "eyJhbGciOiJIUzI1NiIsImtpZCI6Im15TWFjS2V5In0",
    //       "signature": "YY8yVjmJJfy7YJOn3uUydG8WCY2PEuCvOLil5Ks5lnw"
    //     }
    //   ]
    // }

    var sbJws = new chilkat.StringBuilder();
    sbJws.Append("{ ");
    sbJws.Append("  \"payload\": \"SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu\",");
    sbJws.Append("  \"signatures\": [");
    sbJws.Append("    { ");
    sbJws.Append("      \"protected\": \"eyJhbGciOiJSUzI1NiIsImtpZCI6Im15UnNhS2V5In0\",");
    sbJws.Append("      \"signature\": \"IPMQ02niTQDwLzsRZSCaEm9VEyAX_AVe3HWjniNt9kW-a8d6ZVbd2k6jGae8s1yIh0cgxDnXQ6-p6_sBI0cnMO0xpuJANhh2vFtNJl5lisad94-H3mB3lSfafRqxeYp5D8bh39BPv7y3PrUNVMQdKEJp_D5oJ0ROPTIYx3EG8eJQOx1HO0KqhcUo401XR6KSsIyFm5joBLNKTVzxZUTT1RRZZtwTdeZkbGevugIOX_9gHAtARpV6WaFA4Vvjnq8X9wPgqjWNCQRupadhTPz0JAsa-wy5vXQjsFlXAn43mDPpMfna5Ab3F5pS4yDwkbX6nRn7XBxH1SnnNJRFholQZw\"");
    sbJws.Append("    },");
    sbJws.Append("    { ");
    sbJws.Append("      \"protected\": \"eyJhbGciOiJFUzI1NiIsImtpZCI6Im15RWNLZXkifQ\",");
    sbJws.Append("      \"signature\": \"1OQtaT3pgZmkDxvlfghvxL_8kX16WIen6u1MadEq1pA4qytA0--_EwZDNk00GDPWFpoJtKznibMZzLOg_UhHIw\"");
    sbJws.Append("    },");
    sbJws.Append("    { ");
    sbJws.Append("      \"protected\": \"eyJhbGciOiJIUzI1NiIsImtpZCI6Im15TWFjS2V5In0\",");
    sbJws.Append("      \"signature\": \"YY8yVjmJJfy7YJOn3uUydG8WCY2PEuCvOLil5Ks5lnw\"");
    sbJws.Append("    }");
    sbJws.Append("  ]");
    sbJws.Append("}");

    var jws = new chilkat.Jws();

    success = jws.LoadJwsSb(sbJws);
    if (success !== true) {
        console.log(jws.LastErrorText);
        return;
    }

    // The payload is easily accessible:
    console.log("Payload: " + jws.GetPayload("utf-8"));

    // protHeader: JsonObject
    var protHeader;
    var sbKeyId = new chilkat.StringBuilder();
    var bCaseSensitive = false;

    var numSignatures = jws.NumSignatures;
    var i = 0;
    while (i < numSignatures) {
        protHeader = jws.GetProtectedHeader(i);

        console.log("--------------------------");
        console.log(i + ": ");

        // Get the protected header.
        protHeader.EmitCompact = false;
        console.log(protHeader.Emit());

        // Get the key ID ("kid") member.

        // Note: In this example, the "kid" values are contained in the protected headers.
        // They could've just as easily been located in unprotected headers.  In that case,
        // we would've called GetUnprotectedHeader(i) instead of GetProtectedHeader(i).

        sbKeyId.Clear();
        sbKeyId.Append(protHeader.StringOf("kid"));

        // Set the key based on key ID.
        if (sbKeyId.ContentsEqual("myRsaKey",bCaseSensitive) == true) {
            jws.SetPublicKey(i,rsaKey);
        }

        if (sbKeyId.ContentsEqual("myEcKey",bCaseSensitive) == true) {
            jws.SetPublicKey(i,eccKey);
        }

        if (sbKeyId.ContentsEqual("myMacKey",bCaseSensitive) == true) {
            jws.SetMacKey(i,hmacKey,"base64url");
        }

        // Validate this signature.
        var v = jws.Validate(i);
        if (v < 0) {
            // Perhaps Chilkat was not unlocked or the trial expired..
            console.log("Validate failed for some other reason.");
            console.log(jws.LastErrorText);
        }
        else {
            if (v == 0) {
                console.log("Invalid signature.  The key was incorrect, the JWS was invalid, or both.");
            }
            else {
                console.log("Signature validated.");
            }

        }

        i = i+1;
    }

    // The output of this program is:

    // 	Payload: In our village, folks say God crumbles up the old moon into stars.
    // 	--------------------------
    // 	0: 
    // 	{
    // 	  "alg": "RS256",
    // 	  "kid": "myRsaKey"
    // 	}
    // 
    // 	Signature validated.
    // 	--------------------------
    // 	1: 
    // 	{
    // 	  "alg": "ES256",
    // 	  "kid": "myEcKey"
    // 	}
    // 
    // 	Signature validated.
    // 	--------------------------
    // 	2: 
    // 	{
    // 	  "alg": "HS256",
    // 	  "kid": "myMacKey"
    // 	}
    // 
    // 	Signature validated.

}

chilkatExample();