JavaScript

Validate JWS Using RSASSA-PKCS1-v1_5 SHA-256

See more JSON Web Signatures (JWS) Examples

Validates a JSON Web Signature (JWS) that uses RSASSA-PKCS1-v1_5 SHA-256. JavaScript

var success = false;

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

// This example takes a JSON signature in compact serialization format,
// and uses an RSA public key to validate and recover the protected header and payload.

// We only need a public key for signature validation.  This is the RSA public key
// that is used:

//      {"kty":"RSA", 
//       "n":"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx
//            HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs
//            D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH
//            SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV
//            MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8
//            NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ", 
//       "e":"AQAB"
//      }

var sbPubKey = new CkStringBuilder();
sbPubKey.Append("{\"kty\":\"RSA\",");
sbPubKey.Append("\"n\":\"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx");
sbPubKey.Append("HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs");
sbPubKey.Append("D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH");
sbPubKey.Append("SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV");
sbPubKey.Append("MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8");
sbPubKey.Append("NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ\",");
sbPubKey.Append("\"e\":\"AQAB\"");
sbPubKey.Append("}");

var pubKey = new CkPublicKey();
success = pubKey.LoadFromString(sbPubKey.GetAsString());
if (success == false) {
    console.log(pubKey.LastErrorText);
    return;
}

var jws = new CkJws();

// Set the RSA public key:
var signatureIndex = 0;
jws.SetPublicKey(signatureIndex,pubKey);

// Load the JWS.
var sbJws = new CkStringBuilder();
sbJws.Append("eyJhbGciOiJSUzI1NiJ9");
sbJws.Append(".");
sbJws.Append("eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt");
sbJws.Append("cGxlLmNvbS9pc19yb290Ijp0cnVlfQ");
sbJws.Append(".");
sbJws.Append("cC4hiUPoj9Eetdgtv3hF80EGrhuB__dzERat0XF9g2VtQgr9PJbu3XOiZj5RZmh7");
sbJws.Append("AAuHIm4Bh-0Qc_lF5YKt_O8W2Fp5jujGbds9uJdbF9CUAr7t1dnZcAcQjbKBYNX4");
sbJws.Append("BAynRFdiuB--f_nZLgrnbyTyWzO75vRK5h6xBArLIARNPvkSjtQBMHlb1L07Qe7K");
sbJws.Append("0GarZRmB_eSN9383LcOLn6_dO--xi12jzDwusC-eOkHWEsqtFZESc6BfI7noOPqv");
sbJws.Append("hJ1phCnvWh6IeYI2w9QOYEUipUTI8np6LbgGY9Fs98rqVt5AXLIhWkWywlVmtVrB");
sbJws.Append("p0igcN_IoypGlUPQGe77Rw");

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

// Validate the 1st (and only) signature at index 0..
var v = jws.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(jws.LastErrorText);
    return;
}

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

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

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

// Examine the protected header:

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

joseHeader.EmitCompact = false;

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

// Output:

// 	Signature validated.
// 	--
// 	Recovered content:
// 	{"iss":"joe", 
// 	 "exp":1300819380,
// 	 "http://example.com/is_root":true}
// 	--
// 	Protected (JOSE) header:
// 	{ 
// 	  "alg": "RS256"
// 	}