PHP Extension Requires Chilkat v11.0.0+

Validate a JWS Using ECDSA P-521 SHA-512

See more JSON Web Signatures (JWS) Examples

Validates a JSON Web Signature (JWS) that uses ECDSA P-521 SHA-512 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.

//  This example takes a JSON signature in compact serialization format,
//  and uses an ECDSA public key to validate and recover the protected header and payload.

//  We only need a public key for signature validation.  This is the ECDSA public key
//  that is used:

//       {"kty":"EC", 
//        "crv":"P-521", 
//        "x":"AekpBQ8ST8a8VcfVOTNl353vSrDCLLJXmPk06wTjxrrjcBpXp5EOnYG_NjFZ6OvLFV1jSfS9tsz4qUxcWceqwQGk", 
//        "y":"ADSmRA43Z1DSNx_RvcLI87cdL07l6jQyyBXMoxVg_l2Th-x3S1WDhjDly79ajL4Kkd0AZMaZmh9ubmf63e3kyMj2" 
//       } 

$sbPubKey = new CkStringBuilder();
$sbPubKey->Append('{\'kty\':\'EC\',');
$sbPubKey->Append('\'crv\':\'P-521\',');
$sbPubKey->Append('\'x\':\'AekpBQ8ST8a8VcfVOTNl353vSrDCLLJXmPk06wTjxrrjcBpXp5EOnYG_NjFZ6OvLFV1jSfS9tsz4qUxcWceqwQGk\',');
$sbPubKey->Append('\'y\':\'ADSmRA43Z1DSNx_RvcLI87cdL07l6jQyyBXMoxVg_l2Th-x3S1WDhjDly79ajL4Kkd0AZMaZmh9ubmf63e3kyMj2\'');
$sbPubKey->Append('}');

$pubKey = new CkPublicKey();
$success = $pubKey->LoadFromString($sbPubKey->getAsString());
if ($success == false) {
    print $pubKey->lastErrorText() . "\n";
    exit;
}

$jws = new CkJws();

//  Set the ECC public key:
$signatureIndex = 0;
$jws->SetPublicKey($signatureIndex,$pubKey);

//  Load the JWS.
$sbJws = new CkStringBuilder();
$sbJws->Append('eyJhbGciOiJFUzUxMiJ9');
$sbJws->Append('.');
$sbJws->Append('UGF5bG9hZA');
$sbJws->Append('.');
$sbJws->Append('AdwMgeerwtHoh-l192l60hp9wAHZFVJbLfD_UxMi70cwnZOYaRI1bKPWROc-mZZq');
$sbJws->Append('wqT2SI-KGDKB34XO0aw_7XdtAG8GaSwFKdCAPZgoXD2YBJZCPEX3xKpRwcdOO8Kp');
$sbJws->Append('EHwJjyqOgzDO7iKvU8vcnwNrmxYbSW9ERBXukOXolLzeO_Jn');

$success = $jws->LoadJwsSb($sbJws);
if ($success == false) {
    print $jws->lastErrorText() . "\n";
    exit;
}

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

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

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

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

//  Examine the protected header:

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

$joseHeader->put_EmitCompact(false);

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

//  Output:
//  (the string "Payload" was the content that was signed.)

//  	Signature validated.
//  	--
//  	Recovered content:
//  	Payload
//  	--
//  	Protected (JOSE) header:
//  	{
//  	  "alg": "ES512"
//  	}

?>