(PHP ActiveX) Validate a JWS Using ECDSA P-521 SHA-512

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

Note: This example requires Chilkat v9.5.0.66 or greater.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows Note: The php_com_dotnet.dll may need to be enabled inside of php.ini.

<?php

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

// Note: This example requires Chilkat v9.5.0.66 or greater.

// 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" 
//      } 

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.StringBuilder')
$sbPubKey = new COM("Chilkat.StringBuilder");
$sbPubKey->Append('{\'kty\':\'EC\',');
$sbPubKey->Append('\'crv\':\'P-521\',');
$sbPubKey->Append('\'x\':\'AekpBQ8ST8a8VcfVOTNl353vSrDCLLJXmPk06wTjxrrjcBpXp5EOnYG_NjFZ6OvLFV1jSfS9tsz4qUxcWceqwQGk\',');
$sbPubKey->Append('\'y\':\'ADSmRA43Z1DSNx_RvcLI87cdL07l6jQyyBXMoxVg_l2Th-x3S1WDhjDly79ajL4Kkd0AZMaZmh9ubmf63e3kyMj2\'');
$sbPubKey->Append('}');

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.PublicKey')
$pubKey = new COM("Chilkat.PublicKey");
$success = $pubKey->LoadFromString($sbPubKey->getAsString());
if ($success != 1) {
    print $pubKey->LastErrorText . "\n";
    exit;
}

// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.Jws')
$jws = new COM("Chilkat.Jws");

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

// Load the JWS.
// For versions of Chilkat < 10.0.0, use new COM('Chilkat_9_5_0.Chilkat.StringBuilder')
$sbJws = new COM("Chilkat.StringBuilder");
$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 != 1) {
    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 is a Chilkat.JsonObject
$joseHeader = $jws->GetProtectedHeader($signatureIndex);
if ($jws->LastMethodSuccess != 1) {
    print 'No protected header found at the given index.' . "\n";
    exit;
}

$joseHeader->EmitCompact = 0;

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"
// 	}

?>