(JavaScript) Verify JWT Using HS256, HS384, or HS512
Demonstrates how to verify a JWT that was signed using HS256, HS384, or HS512. (HS256 is JWT's acronym for HMAC-SHA256.)
This example verifies the signature. It also does the following:
- Checks to see if the time constraints ("nbf" and "exp") are valid.
- Recovers the original JOSE header.
- Recovers the original claims JSON.
var success = false;
// Demonstrates how to verify an HMAC JWT using a shared secret (password).
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
var jwt = new CkJwt();
var token = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwOi8vZXhhbXBsZS5vcmciLCJzdWIiOiJKb2huIiwiYXVkIjoiaHR0cDovL2V4YW1wbGUuY29tIiwiaWF0IjoxNDYzNDMxODEyLCJuYmYiOjE0NjM0MzE4MTIsImV4cCI6MTQ2MzQzNTQxMn0.SHnMJ11qJH5pbp22YchT_9fL2HIx0koHiUHLG67_foU";
// First verify the signature.
// The password used to create this JWT was "secret".
var sigVerified = jwt.VerifyJwt(token,"secret");
console.log("with correct password: " + sigVerified);
// Now try with a different password:
sigVerified = jwt.VerifyJwt(token,"secret2");
console.log("with incorrect password " + sigVerified);
// Let's see if the time constraints, if any, are valid.
// The above JWT was created on the afternoon of 16-May-2016, with an expiration of 1 hour.
// If the current system time is before the "nbf" time, or after the "exp" time,
// then IsTimeValid will return false/0.
// Also, we'll allow a leeway of 60 seconds to account for any clock skew.
// Note: If the token has no "nbf" or "exp" claim fields, then IsTimeValid is always true.
var leeway = 60;
var bTimeValid = jwt.IsTimeValid(token,leeway);
console.log("time constraints valid: " + bTimeValid);
// Now let's recover the original claims JSON (the payload).
var payload = jwt.GetPayload(token);
// The payload will likely be in compact form:
console.log(payload);
// We can format for human viewing by loading it into Chilkat's JSON object
// and emit.
var json = new CkJsonObject();
success = json.Load(payload);
json.EmitCompact = false;
console.log(json.Emit());
// We can recover the original JOSE header in the same way:
var joseHeader = jwt.GetHeader(token);
// The payload will likely be in compact form:
console.log(joseHeader);
// We can format for human viewing by loading it into Chilkat's JSON object
// and emit.
success = json.Load(joseHeader);
json.EmitCompact = false;
console.log(json.Emit());
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