Java

Get an S/MIME Signing Time

Demonstrates the Chilkat Mime.GetSignatureSigningTimeStr method, which returns the CMS signingTime attribute for the signer at a zero-based index, as an RFC 822-style date string in GMT. The only argument is the signer index.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: This is the timestamp the signer asserted at signing — useful for "when was this signed" audit trails and for evaluating whether the signing certificate was valid at that moment. Because it is a signed attribute, it is tamper-evident. Guard the call with HasSignatureSigningTime, since the attribute is optional. Note it is the signer's claim, not a trusted third-party timestamp.

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import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Mime;

public class ChilkatExample {

    public static void main(String[] args) {
        Mime mime = new Mime();
        try {
            mime.loadMimeFile("qa_data/signed.eml");

            // After verifying, get the CMS signingTime for each signer that has one, as an RFC 822 date string
            // in GMT.  The only argument is the zero-based signer index.
            mime.verify();
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        int n = mime.getNumSignerCerts();
        for (int i = 0; i < n; i++) {
            // Only signers that included a signing time have one to retrieve.
            if (mime.hasSignatureSigningTime(i)) {
                String signingTime;
                try {
                    signingTime = mime.getSignatureSigningTimeStr(i);
                } catch (ChilkatException e) {
                    System.out.println(e.getLastErrorText());
                    return;
                }

                System.out.println("Signer " + i + " signing time: " + signingTime);
            }
        }
    }
}