(PHP Extension) Validate Certificate using OCSP Protocol

Demonstrates how to validate a certificate (check the revoked status) using the OCSP protocol.

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<?php

include("chilkat.php");
// Use "chilkat_9_5_0.php" for versions of Chilkat < 10.0.0

// Note: Requires Chilkat v9.5.0.75 or greater.

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

// This example will check the revoked status of a certificate loaded from a file.
$cert = new CkCert();
$success = $cert->LoadFromFile('qa_data/certs/google.crt');
if ($success != true) {
    print $cert->lastErrorText() . "\n";
    exit;
}

// Get the cert's OCSP URL.
$ocspUrl = $cert->ocspUrl();

// Build the JSON that will be the OCSP request.

// Possible hash algorithms are sha1, sha256, sha384, sha512.  
$hashAlg = 'sha256';
$prng = new CkPrng();
$json = new CkJsonObject();
$json->put_EmitCompact(false);
// Read more about OCSP nonce lengths
$json->UpdateString('extensions.ocspNonce',$prng->genRandom(16,'base64'));
$json->put_I(0);
$json->UpdateString('request[i].cert.hashAlg',$hashAlg);
$json->UpdateString('request[i].cert.issuerNameHash',$cert->hashOf('IssuerDN',$hashAlg,'base64'));
$json->UpdateString('request[i].cert.issuerKeyHash',$cert->hashOf('IssuerPublicKey',$hashAlg,'base64'));
$json->UpdateString('request[i].cert.serialNumber',$cert->serialNumber());

print $json->emit() . "\n";

// Our OCSP request looks something like this:
// {
//   "extensions": {
//     "ocspNonce": "qZDfbpO+nUxRzz6c/SPjE5QCAsPfpkQlRDxTnGl0gnxt7iXO"
//   },
//   "request": [
//     {
//       "cert": {
//         "hashAlg": "sha1",
//         "issuerNameHash": "9u2wY2IygZo19o11oJ0CShGqbK0=",
//         "issuerKeyHash": "d8K4UJpndnaxLcKG0IOgfqZ+uks=",
//         "serialNumber": "6175535D87BF94B6"
//       }
//     }
//   ]
// }

$ocspRequest = new CkBinData();
$http = new CkHttp();

// Convert our JSON to a binary (ASN.1) OCSP request
$success = $http->CreateOcspRequest($json,$ocspRequest);
if ($success == false) {
    print $http->lastErrorText() . "\n";
    exit;
}

// Send the OCSP request to the OCSP server
// resp is a CkHttpResponse
$resp = $http->PBinaryBd('POST',$ocspUrl,$ocspRequest,'application/ocsp-request',false,false);
if ($http->get_LastMethodSuccess() != true) {
    print $http->lastErrorText() . "\n";
    exit;
}

// Get the binary (ASN.1) OCSP reply
$ocspReply = new CkBinData();
$resp->GetBodyBd($ocspReply);

// Convert the binary reply to JSON.
// Also returns the overall OCSP response status.
$jsonReply = new CkJsonObject();
$ocspStatus = $http->ParseOcspReply($ocspReply,$jsonReply);

// The ocspStatus can have one of these values:
// -1:  The ARG1 does not contain a valid OCSP reply.
// 0:  Successful - Response has valid confirmations..
// 1: Malformed request - Illegal confirmation request.
// 2: Internal error - Internal error in issuer.
// 3: Try later -  Try again later.
// 4: Not used - This value is never returned.
// 5: Sig required - Must sign the request.
// 6: Unauthorized - Request unauthorized.

if ($ocspStatus < 0) {
    print 'Invalid OCSP reply.' . "\n";
    exit;
}

print 'Overall OCSP Response Status: ' . $ocspStatus . "\n";

// Let's examine the OCSP response (in JSON).
$jsonReply->put_EmitCompact(false);
print $jsonReply->emit() . "\n";

// The JSON reply looks like this:
// (Use the online tool at https://tools.chilkat.io/jsonParse.cshtml
// to generate JSON parsing code.)

// {
//   "responseStatus": 0,
//   "responseTypeOid": "1.3.6.1.5.5.7.48.1.1",
//   "responseTypeName": "ocspBasic",
//   "response": {
//     "responderIdChoice": "KeyHash",
//     "responderKeyHash": "d8K4UJpndnaxLcKG0IOgfqZ+uks=",
//     "dateTime": "20180803193937Z",
//     "cert": [
//       {
//         "hashOid": "1.3.14.3.2.26",
//         "hashAlg": "SHA-1",
//         "issuerNameHash": "9u2wY2IygZo19o11oJ0CShGqbK0=",
//         "issuerKeyHash": "d8K4UJpndnaxLcKG0IOgfqZ+uks=",
//         "serialNumber": "6175535D87BF94B6",
//         "status": 0,
//         "thisUpdate": "20180803193937Z",
//         "nextUpdate": "20180810193937Z"
//       }
//     ]
//   }
// }
// 

// The certificate status:
$certStatus = -1;
if ($jsonReply->HasMember('response.cert[0].status') == true) {
    $certStatus = $jsonReply->IntOf('response.cert[0].status');
}

// Possible certStatus values are:
// -1: No status returned.
// 0: Good
// 1: Revoked
// 2: Unknown.
print 'Certificate Status: ' . $certStatus . "\n";

?>