(VB.NET 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.

Dim crypt As New Chilkat.Crypt2

' This example will use the certificate + private key currently inserted into a smartcard reader.
Dim cert As New Chilkat.Cert

' If we wish to provide the smartcard PIN (otherwise the user will be prompted by the operating system).
cert.SmartCardPin = "000000"
Dim success As Boolean = cert.LoadFromSmartcard("")
If (success <> True) Then
    Debug.WriteLine(cert.LastErrorText)
    Exit Sub
End If


' 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:
Dim attrs As 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()

Dim strToSign As String = "THIS IS MY ID"

Dim bd As 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) Then
    Debug.WriteLine(crypt.LastErrorText)
    Exit Sub
End If


' 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.")