(PowerBuilder) Validate Certificate using OCSP Protocol

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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

integer li_rc
oleobject loo_Cert
integer li_Success
string ls_OcspUrl
string ls_HashAlg
oleobject loo_Prng
oleobject loo_Json
oleobject loo_OcspRequest
oleobject loo_Http
oleobject loo_Resp
oleobject loo_OcspReply
oleobject loo_JsonReply
integer li_OcspStatus
integer li_CertStatus

// 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.
loo_Cert = create oleobject
// Use "Chilkat_9_5_0.Cert" for versions of Chilkat < 10.0.0
li_rc = loo_Cert.ConnectToNewObject("Chilkat.Cert")
if li_rc < 0 then
    destroy loo_Cert
    MessageBox("Error","Connecting to COM object failed")
    return
end if
li_Success = loo_Cert.LoadFromFile("qa_data/certs/google.crt")
if li_Success <> 1 then
    Write-Debug loo_Cert.LastErrorText
    destroy loo_Cert
    return
end if

// Get the cert's OCSP URL.
ls_OcspUrl = loo_Cert.OcspUrl

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

// Possible hash algorithms are sha1, sha256, sha384, sha512.  
ls_HashAlg = "sha256"
loo_Prng = create oleobject
// Use "Chilkat_9_5_0.Prng" for versions of Chilkat < 10.0.0
li_rc = loo_Prng.ConnectToNewObject("Chilkat.Prng")

loo_Json = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_Json.ConnectToNewObject("Chilkat.JsonObject")

loo_Json.EmitCompact = 0
// Read more about OCSP nonce lengths
loo_Json.UpdateString("extensions.ocspNonce",loo_Prng.GenRandom(16,"base64"))
loo_Json.I = 0
loo_Json.UpdateString("request[i].cert.hashAlg",ls_HashAlg)
loo_Json.UpdateString("request[i].cert.issuerNameHash",loo_Cert.HashOf("IssuerDN",ls_HashAlg,"base64"))
loo_Json.UpdateString("request[i].cert.issuerKeyHash",loo_Cert.HashOf("IssuerPublicKey",ls_HashAlg,"base64"))
loo_Json.UpdateString("request[i].cert.serialNumber",loo_Cert.SerialNumber)

Write-Debug loo_Json.Emit()

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

loo_OcspRequest = create oleobject
// Use "Chilkat_9_5_0.BinData" for versions of Chilkat < 10.0.0
li_rc = loo_OcspRequest.ConnectToNewObject("Chilkat.BinData")

loo_Http = create oleobject
// Use "Chilkat_9_5_0.Http" for versions of Chilkat < 10.0.0
li_rc = loo_Http.ConnectToNewObject("Chilkat.Http")

// Convert our JSON to a binary (ASN.1) OCSP request
li_Success = loo_Http.CreateOcspRequest(loo_Json,loo_OcspRequest)
if li_Success = 0 then
    Write-Debug loo_Http.LastErrorText
    destroy loo_Cert
    destroy loo_Prng
    destroy loo_Json
    destroy loo_OcspRequest
    destroy loo_Http
    return
end if

// Send the OCSP request to the OCSP server
loo_Resp = loo_Http.PBinaryBd("POST",ls_OcspUrl,loo_OcspRequest,"application/ocsp-request",0,0)
if loo_Http.LastMethodSuccess <> 1 then
    Write-Debug loo_Http.LastErrorText
    destroy loo_Cert
    destroy loo_Prng
    destroy loo_Json
    destroy loo_OcspRequest
    destroy loo_Http
    return
end if

// Get the binary (ASN.1) OCSP reply
loo_OcspReply = create oleobject
// Use "Chilkat_9_5_0.BinData" for versions of Chilkat < 10.0.0
li_rc = loo_OcspReply.ConnectToNewObject("Chilkat.BinData")

loo_Resp.GetBodyBd(loo_OcspReply)
destroy loo_Resp

// Convert the binary reply to JSON.
// Also returns the overall OCSP response status.
loo_JsonReply = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_JsonReply.ConnectToNewObject("Chilkat.JsonObject")

li_OcspStatus = loo_Http.ParseOcspReply(loo_OcspReply,loo_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 li_OcspStatus < 0 then
    Write-Debug "Invalid OCSP reply."
    destroy loo_Cert
    destroy loo_Prng
    destroy loo_Json
    destroy loo_OcspRequest
    destroy loo_Http
    destroy loo_OcspReply
    destroy loo_JsonReply
    return
end if

Write-Debug "Overall OCSP Response Status: " + string(li_OcspStatus)

// Let's examine the OCSP response (in JSON).
loo_JsonReply.EmitCompact = 0
Write-Debug loo_JsonReply.Emit()

// 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:
li_CertStatus = -1
if loo_JsonReply.HasMember("response.cert[0].status") = 1 then
    li_CertStatus = loo_JsonReply.IntOf("response.cert[0].status")
end if

// Possible certStatus values are:
// -1: No status returned.
// 0: Good
// 1: Revoked
// 2: Unknown.
Write-Debug "Certificate Status: " + string(li_CertStatus)


destroy loo_Cert
destroy loo_Prng
destroy loo_Json
destroy loo_OcspRequest
destroy loo_Http
destroy loo_OcspReply
destroy loo_JsonReply