Validate a JWS Signature

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.Validate, which validates exactly one signature, identified by a zero-based index, using the key configured at that same index.

<?php

use Chilkat2\Jws;

$jws = new Jws();

// Load the JWS compact serialization.
$jwsCompact = 'eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>';
try {
    $jws->LoadJws($jwsCompact);

    // Provide the key for signature 0 (here an HMAC key).
    $base64Key = 'YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=';
    $jws->SetMacKey(0, $base64Key, 'base64');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

// Validate the signature identified by the zero-based index, using the key configured at that index.
// Validate returns 1 when the signature or MAC is cryptographically valid, 0 when it is not, or a
// negative value on error.
$v = $jws->Validate(0);
if ($v < 0) {
    echo $jws->LastErrorText, "\n";
    exit;
}

if ($v != 1) {
    echo $jws->LastErrorText, "\n";
    echo "The signature is not valid.\n";
    exit;
}

echo "The signature is valid.\n";