(C# UWP/WinRT) Sign String to create a CAdES-T Signature

This example will sign a string to create a CAdEST-T signature.

Note: This example requires Chilkat v9.5.0.78 or greater.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

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

Chilkat.Crypt2 crypt = new Chilkat.Crypt2();

// This example will use the certificate + private key currently inserted into a smartcard reader.
Chilkat.Cert cert = new Chilkat.Cert();

// If we wish to provide the smartcard PIN (otherwise the user will be prompted by the operating system).
cert.SmartCardPin = "000000";
bool success = cert.LoadFromSmartcard("");
if (success != true) {
    Debug.WriteLine(cert.LastErrorText);
    return;
}

// Note: It is also possible to use certs from .pfx/.p12, .pem, or other sources such as 
// pre-installed Windows certificates.

success = crypt.SetSigningCert(cert);

// Use SHA-256 rather than the default of SHA-1
crypt.HashAlgorithm = "sha256";

// Create JSON that tells Chilkat what signing attributes to include:
Chilkat.JsonObject attrs = new Chilkat.JsonObject();
attrs.UpdateBool("contentType",true);
attrs.UpdateBool("signingTime",true);
attrs.UpdateBool("messageDigest",true);
attrs.UpdateBool("signingCertificateV2",true);

// A CAdES-T signature is one that includes a timestampToken created by an online TSA (time stamping authority).
// We must include the TSA's URL, as well as a few options to indicate what is desired.
// Except for the TSA URL, the options shown here are typically what you would need.
attrs.UpdateBool("timestampToken.enabled",true);
attrs.UpdateString("timestampToken.tsaUrl","https://freetsa.org/tsr");
attrs.UpdateBool("timestampToken.addNonce",false);
attrs.UpdateBool("timestampToken.requestTsaCert",true);
attrs.UpdateString("timestampToken.hashAlg","sha256");

crypt.SigningAttributes = attrs.Emit();

string strToSign = "THIS IS MY ID";

Chilkat.BinData bd = new Chilkat.BinData();
bd.AppendString(strToSign,"utf-8");

// This creates the CAdES-T signature.  During the signature creation, it
// communicates with the TSA to get a timestampToken.
// The contents of bd are signed and replaced with the CAdES-T signature (which embeds the original content).
success = await crypt.OpaqueSignBdAsync(bd);
if (success != true) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

// Get the signature in base64 format:
Debug.WriteLine(bd.GetEncoded("base64_mime"));

// Or save the signature to a file.
bd.WriteFile("qa_output/cades-t_sample.p7m");

Debug.WriteLine("Success.");