(C# UWP/WinRT) Sign JSON to Create CAdES P7S Bytes

Demonstrates how to sign JSON using a certificate + private key from a .p12/.pfx to create a CAdES P7S byte array.

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

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

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

Chilkat.Cert cert = new Chilkat.Cert();
bool success = cert.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123");
if (success != true) {
    Debug.WriteLine(cert.LastErrorText);
    return;
}

// Tell the crypt component to use this cert.
success = crypt.SetSigningCert(cert);
if (success != true) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

// The CadesEnabled property applies to all methods that create PKCS7 signatures. 
// To create a CAdES-BES signature, set this property equal to true. 
crypt.CadesEnabled = true;

crypt.HashAlgorithm = "sha256";

Chilkat.JsonObject jsonSigningAttrs = new Chilkat.JsonObject();
jsonSigningAttrs.UpdateInt("contentType",1);
jsonSigningAttrs.UpdateInt("signingTime",1);
jsonSigningAttrs.UpdateInt("messageDigest",1);
jsonSigningAttrs.UpdateInt("signingCertificateV2",1);
crypt.SigningAttributes = jsonSigningAttrs.Emit();

// By default, all the certs in the chain of authentication are included in the signature.
// If desired, we can choose to only include the signing certificate:
crypt.IncludeCertChain = false;

// Create the CAdES-BES attached signature, which contains the original data.
crypt.Charset = "utf-8";
byte[] cadesP7s = null;
cadesP7s = await crypt.OpaqueSignStringAsync("{ \"abc\": 123}");
if (crypt.LastMethodSuccess == false) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

// Verify the signature and extract the original JSON:
string originalJson = crypt.OpaqueVerifyString(cadesP7s);
if (crypt.LastMethodSuccess == false) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

Debug.WriteLine("Original JSON: " + originalJson);

Debug.WriteLine("Success!");