Discuss this help topic in SecureBlackbox Forum

Upgrade CAdES signature to another level

TElCAdESSignatureProcessor offers functionality for upgrading CAdES signatures to a different (normally higher) levels. To upgrade an existing signature:

1. Load the CMS blob into a TElSignedCMSMessage object and get the desired TElCMSSignature: TElCMSSignature sig = cms.get_Signatures(0);
2. Create a TElCAdESSignatureProcessor object passing the signature to its constructor: TElCAdESSignatureProcessor processor = new TElCAdESSignatureProcessor(sig);
3. Call the processor's UpgradeToXXX() method corresponding to the signature level you want to get. Note that some UpgradeXXX() methods require a timestamping client object. In such case you will have to create one before calling UpgradeToXXX(). processor.UpgradeToT(tspClient);
Once the signature is upgraded, save the updated CMS by calling TElSignedCMSMessage.Save().

Note, in some cases it makes sense to check whether the signature can be upgraded to a certain level before trying to upgrade it. You can perform this check using the processor's CanUpgradeToXXX() method:

if (processor.CanUpgradeToBaselineLTA())
{
  processor.UpgradeToBaselineLTA(tspClient);
}

How To articles about CAdES

Discuss this help topic in SecureBlackbox Forum