(Go) Create a CAdES-T Signature

Demonstrates how to create a signature with an external timestamp that certifies the time of signing. This requires an online TSA (Time Stamping Authority) service that is capable of producing RFC 3161 compliant timestamps.

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

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

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

    crypt := chilkat.NewCrypt2()

    // This example will use a certificate + private key from a .pfx/.p12 file.
    // On Windows systems, it is also possible to use certs on smartcards/usb tokens or certs pre-installed in the Windows registry.
    cert := chilkat.NewCert()

    pfxPath := "qa_data/pfx/myCertAndKey.p12"
    pfxPassword := "test123"

    success := cert.LoadPfxFile(pfxPath,pfxPassword)
    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 := 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())

    inFile := "qa_data/json/sample.json"
    outFile := "qa_output/sample_cades_t.p7m"

    // This creates the CAdES-T signature.  During the signature creation, it
    // communicates with the TSA to get a timestampToken.
    success = crypt.CreateP7M(inFile,outFile)
    if success != true {
        fmt.Println(crypt.LastErrorText())
        crypt.DisposeCrypt2()
        cert.DisposeCert()
        attrs.DisposeJsonObject()
        return
    }

    fmt.Println("Success.")

    crypt.DisposeCrypt2()
    cert.DisposeCert()
    attrs.DisposeJsonObject()