(Java) Create S/MIME with Detached Signature

Java example to create a simple S/MIME message with a detached digital signature.

Important: This example is specific to the Windows operating system because it obtains the certificate and private key from the Windows registry-based certificate store. For other operating systems, see the PKCS7 signature examples that use PFX (.p12) files.

 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[])
  {
    CkMime mime = new CkMime();

    //  Any string argument automatically begins the 30-day trial.
    boolean success;
    success = mime.UnlockComponent("30-day trial");
    if (success != true) {
        System.out.println(mime.lastErrorText());
        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;
    }

    //  Our MIME object is currently empty.  Add some header fields
    //  and a body:
    mime.AddHeaderField("subject","this is a test");
    mime.AddHeaderField("test123","this is a test 123");
    mime.put_ContentType("text/plain");
    mime.put_Charset("iso-8859-1");
    mime.SetBodyFromPlainText("This is the body");

    System.out.println("Original MIME message:");
    System.out.println(mime.getMime());

    //  The original MIME looks like this:
    //  ----------------------------------
    //  subject: this is a test
    //  test123: this is a test 123
    //  content-type: text/plain;
    //  	 charset="iso-8859-1"
    // 
    //  This is the body
    //  ----------------------------------

    //  Add a detached signature.  Transfer the header fields
    //  from our existing MIME to what will become the new outer
    //  envelope.
    boolean transferHeaderFields;
    transferHeaderFields = true;
    success = mime.AddDetachedSignature2(cert,transferHeaderFields);
    if (success != true) {
        System.out.println(mime.lastErrorText());
        return;
    }

    System.out.println("----------------------------------");
    System.out.println("S/MIME with detached signature:");
    System.out.println(mime.getMime());

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

    //  The signed MIME looks like this:
    //  --------------------------------
    //  content-type: multipart/signed;
    //  	boundary="----=_NextPart_e7c_2b68_282042d9.6ba23d56";
    //  	protocol="application/x-pkcs7-signature";
    //  	micalg=SHA1
    //  subject: this is a test
    //  test123: this is a test 123
    // 
    //  This is a multi-part message in MIME format.
    // 
    //  ------=_NextPart_e7c_2b68_282042d9.6ba23d56
    //  content-type: text/plain;
    //  	 charset="iso-8859-1"
    // 
    //  This is the body
    //  ------=_NextPart_e7c_2b68_282042d9.6ba23d56
    //  content-transfer-encoding: base64
    //  content-type: application/x-pkcs7-signature;
    //  	name="smime.p7s"
    //  content-disposition: attachment;
    //  	 filename="smime.p7s"
    // 
    //  MIIGAAYJKoZIhvcNAQcCoIIF8TCCBe0CAQExCzAJBgUrDgMCGgUAMAsGCSqGSIb3DQEHAaCC
    //  A9kwggPVMIIDPqADAgECAhB4ouTcAmLszrGi170k1deSMA0GCSqGSIb3DQEBBQUAMFUxCzAJ
    //  BgNVBAYTAlpBMSUwIwYDVQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5KSBMdGQuMR8wHQYD
    //  VQQDExZUaGF3dGUgQ29kZSBTaWduaW5nIENBMB4XDTA3MDExNTAwMDAwMFoXDTA4MDExNTIz
    //  NTk1OVowgZ0xCzAJBgNVBAYTAlVTMREwDwYDVQQIEwhJbGxpbm9pczEQMA4GA1UEBxMHV2hl
    //  YXRvbjEfMB0GA1UEChMWQ2hpbGthdCBTb2Z0d2FyZSwgSW5jLjEnMCUGA1UECxMeU2VjdXJl
    //  IEFwcGxpY2F0aW9uIERldmVsb3BtZW50MR8wHQYDVQQDExZDaGlsa2F0IFNvZnR3YXJlLCBJ
    //  bmMuMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwR2t6b/Kn4VzNCOlj1YGkHxD
    //  YPVnfZNIeO7hmutreK6kr94xm9RlQn+vkN1uRMhvSbOdds+B25o+AyAeuBmLsuxoNRCC9AUb
    //  a37pY8eL04AaTEAm350tfnHGT44joSdFPoW5D91TDare6q5UaaccdEtXU4/LGqh+nHB9Idft
    //  0S/rIpP2PK9TAwQ5V8dlMuBQQA+BUCg5MY9oqZgtnkX7O6OJSk8MT0lUhVg7EAge9iUx7Eu4
    //  oWK88fkOo81pqHogTpGfy4nibWg72XkPk135leMw/Jme37q7OR/zm6HceFlyyO0WL1fYx09P
    //  pYbj1lYNvVo8n38ohT8T/7h3N4GUlQIDAQABo4HYMIHVMAwGA1UdEwEB/wQCMAAwPgYDVR0f
    //  BDcwNTAzoDGgL4YtaHR0cDovL2NybC50aGF3dGUuY29tL1RoYXd0ZUNvZGVTaWduaW5nQ0Eu
    //  Y3JsMB8GA1UdJQQYMBYGCCsGAQUFBwMDBgorBgEEAYI3AgEWMB0GA1UdBAQWMBQwDjAMBgor
    //  BgEEAYI3AgEWAwIHgDAyBggrBgEFBQcBAQQmMCQwIgYIKwYBBQUHMAGGFmh0dHA6Ly9vY3Nw
    //  LnRoYXd0ZS5jb20wEQYJYIZIAYb4QgEBBAQDAgQQMA0GCSqGSIb3DQEBBQUAA4GBAAUMcxUb
    //  eo5HTDKMaxMFFy3iA9i/ke4VLFw97yEG3raLTHZUlRwVxwLGLmW81dY/64nEDEgKi3Ifuohf
    //  A0a3N3Ld7zwL1f/hdG2pQigLcvMymP9jj6DEQxOs03iADFguMpqkb79hbbURzsKX7pvWuNjQ
    //  VGiowTuo1JXuSbsqaW7vMYIB7zCCAesCAQEwaTBVMQswCQYDVQQGEwJaQTElMCMGA1UEChMc
    //  VGhhd3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEfMB0GA1UEAxMWVGhhd3RlIENvZGUgU2ln
    //  bmluZyBDQQIQeKLk3AJi7M6xote9JNXXkjAJBgUrDgMCGgUAoF0wGAYJKoZIhvcNAQkDMQsG
    //  CSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMDcwNDA0MTkzMDUyWjAjBgkqhkiG9w0BCQQx
    //  FgQUevptGkutc0lb6gI3NPHovx4Di34wDQYJKoZIhvcNAQEBBQAEggEAk4jqKMsn7D+MjGtY
    //  M9bnLdekBSxMVWPpKxk6hWg0NVOoiBOd/OOyH8FO/r7trmzr2Z9eJf1zpdjzpSPCwnGJzIy9
    //  RunBBTJ+BxCbDXfjwJJTYVy1Uhsedv+o7Gfj9LlAVysNLjda5VcU7x/OOBVst034X+map3ds
    //  85yBrfcJ/LyQs/lyZYmSPgOpFIBSy3oULPzYt45EUVsuk5qSZ1MA4HeIDW37b8OfQOW8pLEL
    //  cBRducU19lpDOp5hBRZDR3zu+/9ddWKxKvcH04WitYRBi5TtqhQxpep+vRhJX8EPY6cgenJ+
    //  lbDURg552YftF4EpDGALADR41j6sUMzb0QOz4A==
    // 
    //  ------=_NextPart_e7c_2b68_282042d9.6ba23d56--
    // 
    // 

  }
}