Download - Svetlin Nakov

*/
public void init() {
String signButtonCaption = this.getParameter(SIGN_BUTTON_CAPTION_PARAM);
mSignButton = new Button(signButtonCaption);
mSignButton.setLocation(0, 0);
Dimension appletSize = this.getSize();
mSignButton.setSize(appletSize);
mSignButton.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent e) {
signSelectedFile();
}
});
this.setLayout(null);
this.add(mSignButton);
}
/**
* Signs the selected file. The file name comes from a field in the HTML
* document. The result consists of the calculated digital signature and
* certification chain, both placed in fields in the HTML document, encoded
* in Base64 format. The HTML document should contain only one HTML form.
* The name of the field, that contains the name of the file to be signed is
* obtained from FILE_NAME_FIELD_PARAM applet parameter. The names of the
* output fields for the signature and the certification chain are obtained
* from the parameters CERT_CHAIN_FIELD_PARAM and SIGNATURE_FIELD_PARAM.
* The applet extracts the certificate, its chain and its private key from
* a PFX file. The user is asked to select this PFX file and the password
* for accessing it.
*/
private void signSelectedFile() {
try {
// Get the file name to be signed from the form in the HTML document
JSObject browserWindow = JSObject.getWindow(this);
JSObject mainForm = (JSObject) browserWindow.eval("document.forms[0]");
String fileNameFieldName = this.getParameter(FILE_NAME_FIELD_PARAM);
JSObject fileNameField =
(JSObject) mainForm.getMember(fileNameFieldName);
String fileName = (String) fileNameField.getMember("value");
// Perform file signing
CertificationChainAndSignatureInBase64 signingResult=signFile(fileName);
if (signingResult != null) {
// Document signed. Fill the certificate and signature fields
String certChainFieldName=this.getParameter(CERT_CHAIN_FIELD_PARAM);
JSObject certChainField =
(JSObject) mainForm.getMember(certChainFieldName);
certChainField.setMember("value", signingResult.mCertChain);
String signatureFieldName = this.getParameter(SIGNATURE_FIELD_PARAM);
JSObject signatureField =
(JSObject) mainForm.getMember(signatureFieldName);
signatureField.setMember("value", signingResult.mSignature);
} else {
// User canceled signing
}
}
catch (DocumentSignException dse) {
// Document signing failed. Display error message
String errorMessage = dse.getMessage();
JOptionPane.showMessageDialog(this, errorMessage);
}
catch (SecurityException se) {
se.printStackTrace();
JOptionPane.showMessageDialog(this,
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