Sign a File to Create a .p7s File (Detached Signature)

Java example to create a detached signature file (.p7s) for any type file. The signature can be verified by calling VerifyP7S and passing the original filename and the .p7s filename.

 Chilkat Java Library Downloads for Windows, Linux, and MAC OS X

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    CkCrypt2 crypt = new CkCrypt2();

    //  Any string argument automatically begins the 30-day trial.
    boolean success;
    success = crypt.UnlockComponent("30-day trial");
    if (success != true) {
        System.out.println("Crypt component unlock failed");
        return;
    }

    //  Find our digital certificate from the Current User certificate store.
    CkCreateCS ccs = new CkCreateCS();
    CkCertStore certStore;
    certStore = ccs.OpenCurrentUserStore();
    CkCert cert;
    cert = certStore.FindCertBySubjectCN("Chilkat Software, Inc.");
    if (cert == null ) {
        System.out.println(cert.lastErrorText());

        return;
    }

    //  Tell the crypt component to use this cert.
    crypt.SetSigningCert(cert);

    //  We can sign any type of file, creating a .p7s as output:
    success = crypt.CreateP7S("license.rtf","license.p7s");
    if (success == false) {
        System.out.println(crypt.lastErrorText());

        return;
    }

    //  Verify the signature:
    crypt.SetVerifyCert(cert);

    success = crypt.VerifyP7S("license.rtf","license.p7s");
    if (success == false) {
        System.out.println(crypt.lastErrorText());

        return;
    }

    System.out.println("Success!");
  }
}