Go 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. Go

    success := false

    //  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.NewCert()
    success = cert.LoadFromFile("qa_data/certs/google.crt")
    if success == false {
        fmt.Println(cert.LastErrorText())
        cert.DisposeCert()
        return
    }

    //  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.NewPrng()
    json := chilkat.NewJsonObject()
    json.SetEmitCompact(false)
    //  Read more about OCSP nonce lengths
    json.UpdateString("extensions.ocspNonce",*prng.GenRandom(16,"base64"))
    json.SetI(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())

    fmt.Println(*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"
    //        }
    //      }
    //    ]
    //  }

    ocspRequest := chilkat.NewBinData()
    http := chilkat.NewHttp()

    //  Convert our JSON to a binary (ASN.1) OCSP request
    success = http.CreateOcspRequest(json,ocspRequest)
    if success == false {
        fmt.Println(http.LastErrorText())
        cert.DisposeCert()
        prng.DisposePrng()
        json.DisposeJsonObject()
        ocspRequest.DisposeBinData()
        http.DisposeHttp()
        return
    }

    //  Send the OCSP request to the OCSP server
    resp := chilkat.NewHttpResponse()
    success = http.HttpBd("POST",ocspUrl,ocspRequest,"application/ocsp-request",resp)
    if success == false {
        fmt.Println(http.LastErrorText())
        cert.DisposeCert()
        prng.DisposePrng()
        json.DisposeJsonObject()
        ocspRequest.DisposeBinData()
        http.DisposeHttp()
        resp.DisposeHttpResponse()
        return
    }

    //  Get the binary (ASN.1) OCSP reply
    ocspReply := chilkat.NewBinData()
    resp.GetBodyBd(ocspReply)

    //  Convert the binary reply to JSON.
    //  Also returns the overall OCSP response status.
    jsonReply := chilkat.NewJsonObject()
    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 {
        fmt.Println("Invalid OCSP reply.")
        cert.DisposeCert()
        prng.DisposePrng()
        json.DisposeJsonObject()
        ocspRequest.DisposeBinData()
        http.DisposeHttp()
        resp.DisposeHttpResponse()
        ocspReply.DisposeBinData()
        jsonReply.DisposeJsonObject()
        return
    }

    fmt.Println("Overall OCSP Response Status: ", ocspStatus)

    //  Let's examine the OCSP response (in JSON).
    jsonReply.SetEmitCompact(false)
    fmt.Println(*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:
    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.
    fmt.Println("Certificate Status: ", certStatus)

    cert.DisposeCert()
    prng.DisposePrng()
    json.DisposeJsonObject()
    ocspRequest.DisposeBinData()
    http.DisposeHttp()
    resp.DisposeHttpResponse()
    ocspReply.DisposeBinData()
    jsonReply.DisposeJsonObject()