Xbase++ Requires Chilkat v11.0.0+

Validate Certificate using OCSP Protocol

See more Certificates Examples

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

LOCAL nSuccess
LOCAL oCert
LOCAL cOcspUrl
LOCAL cHashAlg
LOCAL oPrng
LOCAL oJson
LOCAL oOcspRequest
LOCAL oHttp
LOCAL oResp
LOCAL oOcspReply
LOCAL oJsonReply
LOCAL nOcspStatus
LOCAL nCertStatus

nSuccess := 0

//  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.
oCert := CreateObject("Chilkat.Cert")
nSuccess := oCert:LoadFromFile("qa_data/certs/google.crt")
IF (nSuccess == 0)
    ? oCert:LastErrorText
    oCert:destroy()
    RETURN
ENDIF

//  Get the cert's OCSP URL.
cOcspUrl := oCert:OcspUrl

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

//  Possible hash algorithms are sha1, sha256, sha384, sha512.  
cHashAlg := "sha256"
oPrng := CreateObject("Chilkat.Prng")
oJson := CreateObject("Chilkat.JsonObject")
oJson:EmitCompact := 0
//  Read more about OCSP nonce lengths
oJson:UpdateString("extensions.ocspNonce", oPrng:GenRandom(16, "base64"))
oJson:I := 0
oJson:UpdateString("request[i].cert.hashAlg", cHashAlg)
oJson:UpdateString("request[i].cert.issuerNameHash", oCert:HashOf("IssuerDN", cHashAlg, "base64"))
oJson:UpdateString("request[i].cert.issuerKeyHash", oCert:HashOf("IssuerPublicKey", cHashAlg, "base64"))
oJson:UpdateString("request[i].cert.serialNumber", oCert:SerialNumber)

? oJson:Emit()

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

oOcspRequest := CreateObject("Chilkat.BinData")
oHttp := CreateObject("Chilkat.Http")

//  Convert our JSON to a binary (ASN.1) OCSP request
nSuccess := oHttp:CreateOcspRequest(oJson, oOcspRequest)
IF (nSuccess == 0)
    ? oHttp:LastErrorText
    oCert:destroy()
    oPrng:destroy()
    oJson:destroy()
    oOcspRequest:destroy()
    oHttp:destroy()
    RETURN
ENDIF

//  Send the OCSP request to the OCSP server
oResp := CreateObject("Chilkat.HttpResponse")
nSuccess := oHttp:HttpBd("POST", cOcspUrl, oOcspRequest, "application/ocsp-request", oResp)
IF (nSuccess == 0)
    ? oHttp:LastErrorText
    oCert:destroy()
    oPrng:destroy()
    oJson:destroy()
    oOcspRequest:destroy()
    oHttp:destroy()
    oResp:destroy()
    RETURN
ENDIF

//  Get the binary (ASN.1) OCSP reply
oOcspReply := CreateObject("Chilkat.BinData")
oResp:GetBodyBd(oOcspReply)

//  Convert the binary reply to JSON.
//  Also returns the overall OCSP response status.
oJsonReply := CreateObject("Chilkat.JsonObject")
nOcspStatus := oHttp:ParseOcspReply(oOcspReply, oJsonReply)

//  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 (nOcspStatus < 0)
    ? "Invalid OCSP reply."
    oCert:destroy()
    oPrng:destroy()
    oJson:destroy()
    oOcspRequest:destroy()
    oHttp:destroy()
    oResp:destroy()
    oOcspReply:destroy()
    oJsonReply:destroy()
    RETURN
ENDIF

? "Overall OCSP Response Status: " + Str(nOcspStatus)

//  Let's examine the OCSP response (in JSON).
oJsonReply:EmitCompact := 0
? oJsonReply: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:
nCertStatus := -1
IF (oJsonReply:HasMember("response.cert[0].status") == 1)
    nCertStatus := oJsonReply:IntOf("response.cert[0].status")
ENDIF

//  Possible certStatus values are:
//  -1: No status returned.
//  0: Good
//  1: Revoked
//  2: Unknown.
? "Certificate Status: " + Str(nCertStatus)

oCert:destroy()
oPrng:destroy()
oJson:destroy()
oOcspRequest:destroy()
oHttp:destroy()
oResp:destroy()
oOcspReply:destroy()
oJsonReply:destroy()