(Perl) Validate Certificate using OCSP Protocol

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

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

# 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 = chilkat::CkCert->new();
$success = $cert->LoadFromFile("qa_data/certs/google.crt");
if ($success != 1) {
    print $cert->lastErrorText() . "\r\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 = chilkat::CkPrng->new();
$json = chilkat::CkJsonObject->new();
$json->put_EmitCompact(0);
# 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() . "\r\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 = chilkat::CkBinData->new();
$http = chilkat::CkHttp->new();

# Convert our JSON to a binary (ASN.1) OCSP request
$success = $http->CreateOcspRequest($json,$ocspRequest);
if ($success == 0) {
    print $http->lastErrorText() . "\r\n";
    exit;
}

# Send the OCSP request to the OCSP server
# resp is a HttpResponse
$resp = $http->PBinaryBd("POST",$ocspUrl,$ocspRequest,"application/ocsp-request",0,0);
if ($http->get_LastMethodSuccess() != 1) {
    print $http->lastErrorText() . "\r\n";
    exit;
}

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

# Convert the binary reply to JSON.
# Also returns the overall OCSP response status.
$jsonReply = chilkat::CkJsonObject->new();
$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." . "\r\n";
    exit;
}

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

# Let's examine the OCSP response (in JSON).
$jsonReply->put_EmitCompact(0);
print $jsonReply->emit() . "\r\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") == 1) {
    $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 . "\r\n";