PHP Extension

JWS Using HMAC SHA-256

See more JSON Web Signatures (JWS) Examples

Creates a JSON Web Signatures (JWS) using HMAC SHA-256. PHP Extension

<?php

include("chilkat.php");

$success = false;

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

// First create the JWS Protected Header
$jwsProtHdr = new CkJsonObject();
$jwsProtHdr->AppendString('typ','JWT');
$jwsProtHdr->AppendString('alg','HS256');
print 'JWS Protected Header: ' . $jwsProtHdr->emit() . "\n";

// Output:
// JWS Protected Header: {"typ":"JWT","alg":"HS256"}

$jws = new CkJws();

// Set the HMAC key:
$hmacKey = 'AyM1SysPpbyDfgZld3umj1qzKObwVMkoqQ-EstJQLr_T-1qS0gZH75aKtMN3Yj0iPS4hcgUuTwjAzZr1Z9CAow';
$signatureIndex = 0;
$jws->SetMacKey($signatureIndex,$hmacKey,'base64url');

// Set the protected header:
$jws->SetProtectedHeader($signatureIndex,$jwsProtHdr);

// Set the payload.
$bIncludeBom = false;
$payloadStr = 'In our village, folks say God crumbles up the old moon into stars.';
$jws->SetPayload($payloadStr,'utf-8',$bIncludeBom);

// Create the JWS
// By default, the compact serialization is used.
$jwsCompact = $jws->createJws();
if ($jws->get_LastMethodSuccess() == false) {
    print $jws->lastErrorText() . "\n";
    exit;
}

print 'JWS: ' . $jwsCompact . "\n";

// sample output:
// JWS: eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.SW4gb3VyIHZpbGxhZ2UsIGZvbGtzIHNheSBHb2QgY3J1bWJsZXMgdXAgdGhlIG9sZCBtb29uIGludG8gc3RhcnMu.bsYsi8HJ0N6OqGI1hKQ9QQRNPxxA5qMpcHLtOvXatk8

// Now load the JWS, validate, and recover the original text.
$jws2 = new CkJws();

// Load the JWS.
$success = $jws2->LoadJws($jwsCompact);

// Set the MAC key used for validation.
$signatureIndex = 0;
$jws2->SetMacKey($signatureIndex,$hmacKey,'base64url');

// Validate the 1st (and only) signature at index 0..
$v = $jws2->Validate($signatureIndex);
if ($v < 0) {
    // Perhaps Chilkat was not unlocked or the trial expired..
    print 'Method call failed for some other reason.' . "\n";
    print $jws2->lastErrorText() . "\n";
    exit;
}

if ($v == 0) {
    print 'Invalid signature.  The MAC key was incorrect, the JWS was invalid, or both.' . "\n";
    exit;
}

// If we get here, the signature was validated..
print 'Signature validated.' . "\n";

// Recover the original content:
print $jws2->getPayload('utf-8') . "\n";

// Examine the protected header:

$joseHeader = new CkJsonObject();
$success = $jws2->GetProtectedH($signatureIndex,$joseHeader);
if ($success == false) {
    print $jws2->lastErrorText() . "\n";
    exit;
}

$joseHeader->put_EmitCompact(false);

print 'Protected (JOSE) header:' . "\n";
print $joseHeader->emit() . "\n";

// Output:

// 	Signature validated.
// 	In our village, folks say God crumbles up the old moon into stars.
// 	Protected (JOSE) header:
// 	{ 
// 	  "typ": "JWT",
// 	  "alg": "HS256"
// 	} 

?>