Perl

Verify JWT Using an RSA Public Key (RS256, RS384, RS512)

Demonstrates how to verify a JWT that was signed using an RSA private key.

This example verifies the RSA 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.

Chilkat Perl Downloads

Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

# Demonstrates how to verify an JWT using an RSA public key.

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

my $pubKey = Chilkat2::PublicKey->new;
my $success = $pubKey->LoadFromFile('qa_data/pem/rsa_public.pem');

my $jwt = Chilkat2::Jwt->new;

my $token = 'eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJodHRwOi8vZXhhbXBsZS5vcmciLCJzdWIiOiJKb2huIiwiYXVkIjoiaHR0cDovL2V4YW1wbGUuY29tIiwiaWF0IjoxNDYzNDQ1MjM4LCJuYmYiOjE0NjM0NDUyMzgsImV4cCI6MTQ2MzQ0ODgzOH0.XRtqed6nuJ9lrp0wbNdDX3fCkSh_d9cHAniPbNcqm7G-5N3mtI5ntQvZBDP3pHtECVqufuDwW7XgUtzAi0ZXhyiRm1iZ3wMSN5lHWv52OQJmMHPA7VPd8Q1hDG-tx-QswzJKd75OEUHP7wIXq2Mg_YVElfDvJI6TGjGyS1y-RLHlz-ldlGsEwIBkO0PtzIYTVov97x8p9KCsPNhS4lZUIqKOYoTZUV5LpuAWARl-636DfMEB_A5_IEaw_W8leh2suP2ULVZxwE-Tk1kBC9tsSGrBrPTtg7sziaV4Lbb0JRANmh98uTRu5f8ji9CVOnpbMiAzjsJSy56kz_olweXSuA';

# First verify the signature.
my $sigVerified = $jwt->VerifyJwtPk($token, $pubKey);
print 'verified: ', ($sigVerified ? 1 : 0), "\n";

# 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.
my $leeway = 60;
my $bTimeValid = $jwt->IsTimeValid($token, $leeway);
print 'time constraints valid: ', ($bTimeValid ? 1 : 0), "\n";

# Now let's recover the original claims JSON (the payload).
my $payload = $jwt->GetPayload($token);
# The payload will likely be in compact form:
print $payload, "\n";

# We can format for human viewing by loading it into Chilkat's JSON object
# and emit.
my $json = Chilkat2::JsonObject->new;
$success = $json->Load($payload);
$json->EmitCompact(0);
print $json->Emit(), "\n";

# We can recover the original JOSE header in the same way:
my $joseHeader = $jwt->GetHeader($token);
# The payload will likely be in compact form:
print $joseHeader, "\n";

# We can format for human viewing by loading it into Chilkat's JSON object
# and emit.
$success = $json->Load($joseHeader);
$json->EmitCompact(0);
print $json->Emit(), "\n";