Rust

Verify JWT Using HS256, HS384, or HS512

See more JSON Web Token (JWT) Examples

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.

Rust

// 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.

let jwt = chilkat::Jwt::new();

let token = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwOi8vZXhhbXBsZS5vcmciLCJzdWIiOiJKb2huIiwiYXVkIjoiaHR0cDovL2V4YW1wbGUuY29tIiwiaWF0IjoxNDYzNDMxODEyLCJuYmYiOjE0NjM0MzE4MTIsImV4cCI6MTQ2MzQzNTQxMn0.SHnMJ11qJH5pbp22YchT_9fL2HIx0koHiUHLG67_foU".to_string();

// First verify the signature.
// The password used to create this JWT was "secret".
let mut sig_verified = jwt.verify_jwt(&token, "secret").is_ok();
println!("with correct password: {}", sig_verified);

// Now try with a different password:
sig_verified = jwt.verify_jwt(&token, "secret2").is_ok();
println!("with incorrect password {}", sig_verified);

// 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.
let leeway = 60;
let b_time_valid = jwt.is_time_valid(&token, leeway);
println!("time constraints valid: {}", b_time_valid);

// Now let's recover the original claims JSON (the payload).
let payload = jwt.get_payload(&token).unwrap_or_default();
// The payload will likely be in compact form:
println!("{}", payload);

// We can format for human viewing by loading it into Chilkat's JSON object
// and emit.
let json = chilkat::JsonObject::new();
let _ = json.load(&payload).is_ok();
json.set_emit_compact(false);
println!("{}", json.emit().unwrap_or_default());

// We can recover the original JOSE header in the same way:
let jose_header = jwt.get_header(&token).unwrap_or_default();
// The payload will likely be in compact form:
println!("{}", jose_header);

// We can format for human viewing by loading it into Chilkat's JSON object
// and emit.
let _ = json.load(&jose_header).is_ok();
json.set_emit_compact(false);
println!("{}", json.emit().unwrap_or_default());