Java

Check if a MIME Entity is Signed (S/MIME)

Demonstrates the Chilkat Mime.IsSigned method, which returns whether the entity is a complete CMS/PKCS #7 signed S/MIME wrapper, including detached multipart/signed and opaque forms. It takes no arguments.

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

Background: Before verifying a signature you need to know one is present, and this is the check. A signed S/MIME message comes in two shapes — detached (multipart/signed, signature alongside the content) and opaque (application/pkcs7-mime, content wrapped inside the signature) — and this recognizes both. Follow a true result with Verify.

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Chilkat2 Java

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

public class ChilkatExample {

    public static void main(String[] args) {
        // Demonstrates the Mime.IsSigned method, which returns whether the entity is a complete CMS/PKCS #7 signed S/MIME wrapper.  It takes no arguments.

        Mime mime = new Mime();
        try {
            mime.loadMimeFile("qa_data/signed.eml");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        if (mime.isSigned()) {
            System.out.println("This is a signed S/MIME message.");
        } else {
            System.out.println("This is not a signed S/MIME message.");
        }
    }
}