Making JSON Web Signature (JWS)

make_jws.pl

#!/usr/bin/env perl

use strict;
use warnings;
use feature qw(say);

use Digest::SHA qw(hmac_sha256);
use JSON;
use MIME::Base64 qw(encode_base64url decode_base64url);

use JSON::WebToken qw(decode_jwt);

our $SHARED_SECRET = "minna_niwa_naisyo_dayo";

my $jws_header = encode_json(+{
    alg => "HS256",
    typ => "JWT"
});

say $jws_header;

my $encoded_jws_header = encode_base64url($jws_header);

say $encoded_jws_header;

my $jws_payload = encode_json(+{
    "iss" => "joe",
    "exp" => 1300819380,
    "http://example.com/is_root" => JSON::true
});

say $jws_payload;

my $encoded_jws_payload = encode_base64url($jws_payload);

say $encoded_jws_payload;

my $signature_base_string = $encoded_jws_header . "." . $encoded_jws_payload;
my $signature = encode_base64url(hmac_sha256($signature_base_string, $SHARED_SECRET));

say $signature;

my $jws = $signature_base_string . "." . $signature;

say $jws;

my $payload = decode_jwt($jws, $SHARED_SECRET);

say encode_json($payload);