(Go) Sign String to create a CAdES-T Signature, using HTTP Proxy to Access Timestamp Server

This example will sign a string to create a CAdEST-T signature. It will use an HTTP proxy to access the timestamp server.

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    crypt := Crypt2_Ref.html">chilkat.NewCrypt2()

    cert := Cert_Ref.html">chilkat.NewCert()
    cert.SetSmartCardPin("123456")
    success := cert.LoadFromSmartcard("")
    if success != true {
        fmt.Println(cert.LastErrorText())
        crypt.DisposeCrypt2()
        cert.DisposeCert()
        return
    }

    success = crypt.SetSigningCert(cert)

    // Use SHA-256 rather than the default of SHA-1
    crypt.SetHashAlgorithm("sha256")

    // Create JSON that tells Chilkat what signing attributes to include:
    attrs := JsonObject_Ref.html">chilkat.NewJsonObject()
    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.SetSigningAttributes(attrs.Emit())

    strToSign := "Hello World!"

    bd := BinData_Ref.html">chilkat.NewBinData()
    bd.AppendString(strToSign,"utf-8")

    // -------------------------------------------------------------------------
    // The purpose of this example is to show how an HTTP object with custom
    // settings can be used to access the Internet when signing.
    // Access to the Internet is needed to communicate with the timestamp server.
    http := Http_Ref.html">chilkat.NewHttp()
    // This can be a domain name, hostname, or IP address.
    http.SetProxyDomain("172.16.16.56")
    http.SetProxyPort(808)
    http.SetProxyLogin("myProxyLogin")
    http.SetProxyPassword("myProxyPassword")
    crypt.SetTsaHttpObj(http)
    // -------------------------------------------------------------------------

    // 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 = crypt.OpaqueSignBd(bd)
    if success != true {
        fmt.Println(crypt.LastErrorText())
        crypt.DisposeCrypt2()
        cert.DisposeCert()
        attrs.DisposeJsonObject()
        bd.DisposeBinData()
        http.DisposeHttp()
        return
    }

    // Get the signature in base64 format:
    fmt.Println(*bd.GetEncoded("base64_mime"))

    fmt.Println("Success.")

    crypt.DisposeCrypt2()
    cert.DisposeCert()
    attrs.DisposeJsonObject()
    bd.DisposeBinData()
    http.DisposeHttp()