(.NET Core C#) RFC3161 Timestamp Client - Fetch from Timestamp Authority (TSA) and Verify

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

Note: This example requires Chilkat v9.5.0.75 or greater.

Chilkat .NET Downloads Chilkat .NET Assemblies Chilkat for .NET Core Chilkat for Mono

// 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.

// First sha-256 hash the data that is to be timestamped.
// In this example, the data is the string "Hello World"
bool success;
Chilkat.Crypt2 crypt = new Chilkat.Crypt2();
crypt.HashAlgorithm = "sha256";
crypt.EncodingMode = "base64";
string base64Hash = crypt.HashStringENC("Hello World");

Chilkat.Http http = new Chilkat.Http();

Chilkat.BinData requestToken = new Chilkat.BinData();
string optionalPolicyOid = "";
bool addNonce = false;
bool requestTsaCert = true;

// Create a time-stamp request token
success = http.CreateTimestampRequest("sha256",base64Hash,optionalPolicyOid,addNonce,requestTsaCert,requestToken);
if (success != true) {
    Debug.WriteLine(http.LastErrorText);
    return;
}

// 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
string tsaUrl = "https://freetsa.org/tsr";
// Another timestamp server you could try is: http://timestamp.digicert.com
tsaUrl = "http://timestamp.digicert.com";
Chilkat.HttpResponse resp = http.PBinaryBd("POST",tsaUrl,requestToken,"application/timestamp-query",false,false);
if (http.LastMethodSuccess != true) {
    Debug.WriteLine(http.LastErrorText);
    return;
}

// Get the timestamp reply from the HTTP response object.
Chilkat.BinData timestampReply = new Chilkat.BinData();
resp.GetBodyBd(timestampReply);

// Show the base64 encoded timestamp reply.
Debug.WriteLine(timestampReply.GetEncoded("base64"));

// Let's verify the timestamp reply against the TSA's cert, which we've previously downloaded.
// See https://freetsa.org/index_en.php
Chilkat.Cert tsaCert = new Chilkat.Cert();
success = tsaCert.LoadFromFile("qa_data/certs/freetsa.org.cer");
if (success != true) {
    Debug.WriteLine(tsaCert.LastErrorText);
    return;
}

// 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
int pkiStatus = http.VerifyTimestampReply(timestampReply,tsaCert);
if (pkiStatus < 0) {
    Debug.WriteLine(http.LastErrorText);
    return;
}

Debug.WriteLine("pkiStatus = " + Convert.ToString(pkiStatus));

Chilkat.JsonObject json = http.LastJsonData();
json.EmitCompact = false;
Debug.WriteLine(json.Emit());

// The LastJsonData looks like the following.
// Note: The "timestampReply.pkiStatus" portion of the LastJsonData was added in Chilkat v9.5.0.83

// 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="
//             }
//           }
//         }
//       ]
//     }
//   }
// }

Chilkat.DtObj signingTime = new Chilkat.DtObj();
Chilkat.DtObj authAttrSigningTimeUtctime = new Chilkat.DtObj();
string strVal;
string certSerialNumber;
string certIssuerCN;
string certDigestAlgOid;
string certDigestAlgName;
string contentType;
string messageDigest;
string signingAlgOid;
string signingAlgName;
string authAttrContentTypeName;
string authAttrContentTypeOid;
string authAttrSigningTimeName;
string authAttrSigningCertificateName;
string authAttrSigningCertificateDer;
string authAttrMessageDigestName;
string authAttrMessageDigestDigest;

int timestampReplyPkiStatusValue = json.IntOf("timestampReply.pkiStatus.value");
string timestampReplyPkiStatusMeaning = json.StringOf("timestampReply.pkiStatus.meaning");
int i = 0;
int count_i = json.SizeOfArray("pkcs7.verify.digestAlgorithms");
while (i < count_i) {
    json.I = i;
    strVal = json.StringOf("pkcs7.verify.digestAlgorithms[i]");
    i = i + 1;
}

i = 0;
count_i = json.SizeOfArray("pkcs7.verify.signerInfo");
while (i < count_i) {
    json.I = i;
    certSerialNumber = json.StringOf("pkcs7.verify.signerInfo[i].cert.serialNumber");
    certIssuerCN = json.StringOf("pkcs7.verify.signerInfo[i].cert.issuerCN");
    certDigestAlgOid = json.StringOf("pkcs7.verify.signerInfo[i].cert.digestAlgOid");
    certDigestAlgName = json.StringOf("pkcs7.verify.signerInfo[i].cert.digestAlgName");
    contentType = json.StringOf("pkcs7.verify.signerInfo[i].contentType");
    json.DtOf("pkcs7.verify.signerInfo[i].signingTime",false,signingTime);
    messageDigest = json.StringOf("pkcs7.verify.signerInfo[i].messageDigest");
    signingAlgOid = json.StringOf("pkcs7.verify.signerInfo[i].signingAlgOid");
    signingAlgName = json.StringOf("pkcs7.verify.signerInfo[i].signingAlgName");
    authAttrContentTypeName = json.StringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.3\".name");
    authAttrContentTypeOid = json.StringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.3\".oid");
    authAttrSigningTimeName = json.StringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.5\".name");
    json.DtOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.5\".utctime",false,authAttrSigningTimeUtctime);
    authAttrSigningCertificateName = json.StringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.16.2.12\".name");
    authAttrSigningCertificateDer = json.StringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.16.2.12\".der");
    authAttrMessageDigestName = json.StringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.4\".name");
    authAttrMessageDigestDigest = json.StringOf("pkcs7.verify.signerInfo[i].authAttr.\"1.2.840.113549.1.9.4\".digest");
    i = i + 1;
}