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PureBasic

RFC3161 Timestamp Client - Fetch from Timestamp Authority (TSA) and Verify

See more HTTP Examples

Sends an RFC 3161 timestamp request to a TSA (Timestamp Authority) server and validates the timestamp token response.

Chilkat PureBasic Downloads

PureBasic
IncludeFile "CkBinData.pb"
IncludeFile "CkHttp.pb"
IncludeFile "CkCrypt2.pb"
IncludeFile "CkHttpResponse.pb"
IncludeFile "CkCert.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkDtObj.pb"

Procedure ChilkatExample()

    success.i = 0

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

    ; First sha-256 hash the data that is to be timestamped.
    ; In this example, the data is the string "Hello World"

    crypt.i = CkCrypt2::ckCreate()
    If crypt.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkCrypt2::setCkHashAlgorithm(crypt, "sha256")
    CkCrypt2::setCkEncodingMode(crypt, "base64")
    base64Hash.s = CkCrypt2::ckHashStringENC(crypt,"Hello World")

    http.i = CkHttp::ckCreate()
    If http.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    requestToken.i = CkBinData::ckCreate()
    If requestToken.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    optionalPolicyOid.s = ""
    addNonce.i = 0
    requestTsaCert.i = 1

    ; Create a time-stamp request token
    success = CkHttp::ckCreateTimestampRequest(http,"sha256",base64Hash,optionalPolicyOid,addNonce,requestTsaCert,requestToken)
    If success = 0
        Debug CkHttp::ckLastErrorText(http)
        CkCrypt2::ckDispose(crypt)
        CkHttp::ckDispose(http)
        CkBinData::ckDispose(requestToken)
        ProcedureReturn
    EndIf

    ; Send the time-stamp request token to the TSA.
    ; This is the equivalent of the following CURL command:
    ; curl -H "Content-Type: application/timestamp-query" --data-binary '@file.tsq' https://freetsa.org/tsr > file.tsr
    tsaUrl.s = "https://freetsa.org/tsr"
    ; Another timestamp server you could try is: http://timestamp.digicert.com
    tsaUrl = "http://timestamp.digicert.com"
    resp.i = CkHttpResponse::ckCreate()
    If resp.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkHttp::ckHttpBd(http,"POST",tsaUrl,requestToken,"application/timestamp-query",resp)
    If success = 0
        Debug CkHttp::ckLastErrorText(http)
        CkCrypt2::ckDispose(crypt)
        CkHttp::ckDispose(http)
        CkBinData::ckDispose(requestToken)
        CkHttpResponse::ckDispose(resp)
        ProcedureReturn
    EndIf

    ; Get the timestamp reply from the HTTP response object.
    timestampReply.i = CkBinData::ckCreate()
    If timestampReply.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkHttpResponse::ckGetBodyBd(resp,timestampReply)

    ; Show the base64 encoded timestamp reply.
    Debug CkBinData::ckGetEncoded(timestampReply,"base64")

    ; Let's verify the timestamp reply against the TSA's cert, which we've previously downloaded.
    ; See https://freetsa.org/index_en.php
    tsaCert.i = CkCert::ckCreate()
    If tsaCert.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success = CkCert::ckLoadFromFile(tsaCert,"qa_data/certs/freetsa.org.cer")
    If success = 0
        Debug CkCert::ckLastErrorText(tsaCert)
        CkCrypt2::ckDispose(crypt)
        CkHttp::ckDispose(http)
        CkBinData::ckDispose(requestToken)
        CkHttpResponse::ckDispose(resp)
        CkBinData::ckDispose(timestampReply)
        CkCert::ckDispose(tsaCert)
        ProcedureReturn
    EndIf

    ; The VerifyTimestampReply method will return one of the following values:
    ; -1:  The timestampReply does not contain a valid timestamp reply.
    ; -2: The  timestampReply is a valid timestamp reply, but failed verification using the public key of the tsaCert.
    ; 0:  Granted and verified.
    ; 1: Granted and verified, with mods (see RFC 3161)
    ; 2: Rejected.
    ; 3: Waiting.
    ; 4: Revocation Warning
    ; 5: Revocation Notification
    pkiStatus.i = CkHttp::ckVerifyTimestampReply(http,timestampReply,tsaCert)
    If pkiStatus < 0
        Debug CkHttp::ckLastErrorText(http)
        CkCrypt2::ckDispose(crypt)
        CkHttp::ckDispose(http)
        CkBinData::ckDispose(requestToken)
        CkHttpResponse::ckDispose(resp)
        CkBinData::ckDispose(timestampReply)
        CkCert::ckDispose(tsaCert)
        ProcedureReturn
    EndIf

    Debug "pkiStatus = " + Str(pkiStatus)

    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkHttp::ckGetLastJsonData(http,json)

    CkJsonObject::setCkEmitCompact(json, 0)
    Debug CkJsonObject::ckEmit(json)

    ; The JSON looks like the following.

    ; Use this online tool to generate parsing code from sample JSON: 
    ; Generate Parsing Code from JSON

    ; {
    ;   "timestampReply": {
    ;     "pkiStatus": {
    ;       "value": 0,
    ;       "meaning": "granted"
    ;     }
    ;   },
    ;   "pkcs7": {
    ;     "verify": {
    ;       "digestAlgorithms": [
    ;         "sha256"
    ;       ],
    ;       "signerInfo": [
    ;         {
    ;           "cert": {
    ;             "serialNumber": "04CD3F8568AE76C61BB0FE7160CCA76D",
    ;             "issuerCN": "DigiCert SHA2 Assured ID Timestamping CA",
    ;             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
    ;             "digestAlgName": "SHA256"
    ;           },
    ;           "contentType": "1.2.840.113549.1.9.16.1.4",
    ;           "signingTime": "200405023019Z",
    ;           "messageDigest": "f14zOsdnN9vyyV3HjjBiLzNDi1PF28hAFMODxNkNRZs=",
    ;           "signingAlgOid": "1.2.840.113549.1.1.1",
    ;           "signingAlgName": "RSA-PKCSV-1_5",
    ;           "authAttr": {
    ;             "1.2.840.113549.1.9.3": {
    ;               "name": "contentType",
    ;               "oid": "1.2.840.113549.1.9.16.1.4"
    ;             },
    ;             "1.2.840.113549.1.9.5": {
    ;               "name": "signingTime",
    ;               "utctime": "200405023019Z"
    ;             },
    ;             "1.2.840.113549.1.9.16.2.12": {
    ;               "name": "signingCertificate",
    ;               "der": "MBowGDAWBBQDJb1QXtqWMC3CL0+gHkwovig0xQ=="
    ;             },
    ;             "1.2.840.113549.1.9.4": {
    ;               "name": "messageDigest",
    ;               "digest": "f14zOsdnN9vyyV3HjjBiLzNDi1PF28hAFMODxNkNRZs="
    ;             }
    ;           }
    ;         }
    ;       ]
    ;     }
    ;   }
    ; }

    signingTime.i = CkDtObj::ckCreate()
    If signingTime.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    authAttrSigningTimeUtctime.i = CkDtObj::ckCreate()
    If authAttrSigningTimeUtctime.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    strVal.s
    certSerialNumber.s
    certIssuerCN.s
    certDigestAlgOid.s
    certDigestAlgName.s
    contentType.s
    messageDigest.s
    signingAlgOid.s
    signingAlgName.s
    authAttrContentTypeName.s
    authAttrContentTypeOid.s
    authAttrSigningTimeName.s
    authAttrSigningCertificateName.s
    authAttrSigningCertificateDer.s
    authAttrMessageDigestName.s
    authAttrMessageDigestDigest.s

    timestampReplyPkiStatusValue.i = CkJsonObject::ckIntOf(json,"timestampReply.pkiStatus.value")
    timestampReplyPkiStatusMeaning.s = CkJsonObject::ckStringOf(json,"timestampReply.pkiStatus.meaning")
    i.i = 0
    count_i.i = CkJsonObject::ckSizeOfArray(json,"pkcs7.verify.digestAlgorithms")
    While i < count_i
        CkJsonObject::setCkI(json, i)
        strVal = CkJsonObject::ckStringOf(json,"pkcs7.verify.digestAlgorithms[i]")
        i = i + 1
    Wend
    i = 0
    count_i = CkJsonObject::ckSizeOfArray(json,"pkcs7.verify.signerInfo")
    While i < count_i
        CkJsonObject::setCkI(json, i)
        certSerialNumber = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].cert.serialNumber")
        certIssuerCN = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].cert.issuerCN")
        certDigestAlgOid = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].cert.digestAlgOid")
        certDigestAlgName = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].cert.digestAlgName")
        contentType = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].contentType")
        CkJsonObject::ckDtOf(json,"pkcs7.verify.signerInfo[i].signingTime",0,signingTime)
        messageDigest = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].messageDigest")
        signingAlgOid = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].signingAlgOid")
        signingAlgName = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].signingAlgName")
        authAttrContentTypeName = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].authAttr." + Chr(34) + "1.2.840.113549.1.9.3" + Chr(34) + ".name")
        authAttrContentTypeOid = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].authAttr." + Chr(34) + "1.2.840.113549.1.9.3" + Chr(34) + ".oid")
        authAttrSigningTimeName = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].authAttr." + Chr(34) + "1.2.840.113549.1.9.5" + Chr(34) + ".name")
        CkJsonObject::ckDtOf(json,"pkcs7.verify.signerInfo[i].authAttr." + Chr(34) + "1.2.840.113549.1.9.5" + Chr(34) + ".utctime",0,authAttrSigningTimeUtctime)
        authAttrSigningCertificateName = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].authAttr." + Chr(34) + "1.2.840.113549.1.9.16.2.12" + Chr(34) + ".name")
        authAttrSigningCertificateDer = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].authAttr." + Chr(34) + "1.2.840.113549.1.9.16.2.12" + Chr(34) + ".der")
        authAttrMessageDigestName = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].authAttr." + Chr(34) + "1.2.840.113549.1.9.4" + Chr(34) + ".name")
        authAttrMessageDigestDigest = CkJsonObject::ckStringOf(json,"pkcs7.verify.signerInfo[i].authAttr." + Chr(34) + "1.2.840.113549.1.9.4" + Chr(34) + ".digest")
        i = i + 1
    Wend


    CkCrypt2::ckDispose(crypt)
    CkHttp::ckDispose(http)
    CkBinData::ckDispose(requestToken)
    CkHttpResponse::ckDispose(resp)
    CkBinData::ckDispose(timestampReply)
    CkCert::ckDispose(tsaCert)
    CkJsonObject::ckDispose(json)
    CkDtObj::ckDispose(signingTime)
    CkDtObj::ckDispose(authAttrSigningTimeUtctime)


    ProcedureReturn
EndProcedure