Java Applet JavaScript Communication
There is a Java Applet which digitally signs files after taking
private key from a smart card.This applet takes external files.
I want to do this "Generate digital signature of a web page with the
help of an applet of which the applet is itself a part"
I am trying using Java Applet to Javascript Communication.
I am able to access the object which represents the HTML document.
That abject is represented by document itself.
Now I have to somehow generate the whole webpage i.e. like we view in a
notepad like this:
<HTML>
<Title>my page</title>
Then write into a file and then that file can be signed.
This is what I feel.
In C#.net there is a method .innerhtml.
Does such kind of a method exists in Java.?
I m searching but cudn't get till now.
Will serialization work?
I tried by adding ur snippet of code but it doesn't work.
JSObject doc = (JSObject)browserWindow.getMember("document");
Here doc represents the object of the HTML document. Somehow from this object the HTML code has to be extracted and written into a file for signing.
CertificationChainAndSignatureBase64 signingResult = signFile(fileName);
this is the line which takes fileName as a parameter.
This is a small part of the whole applet . Just see first 10-30 lines..U will get the idea..
Kindly help me where and how this code should be added so that I can proceed in my work.
I will be highly grateful...
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");
//here we get the document......
JSObject doc = (JSObject)browserWindow.getMember("document");
// String docum = doc.toString();
// Perform the actual file signing
CertificationChainAndSignatureBase64 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.mCertificationChain);
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,
"Unable to access the local file system.\n" +
"This applet should be started with full security permissions.\n" +
"Please accept to trust this applet when the Java Plug-In ask you.");
}
catch (JSException jse) {
jse.printStackTrace();
JOptionPane.showMessageDialog(this,
"Unable to access some of the fields of the\n" +
"HTML form. Please check the applet parameters.");
}
catch (Exception e) {
e.printStackTrace();
JOptionPane.showMessageDialog(this, "Unexpected error: " + e.getMessage());
}
}
/**
* Signs given local file. The certificate and private key to be used for signing
* come from the locally attached smart card. The user is requested to provide a
* PKCS#11 implementation library and the PIN code for accessing the smart card.
* @param aFileName the name of the file to be signed.
* @return the digital signature of the given file and the certification chain of
* the certificatie used for signing the file, both Base64-encoded or null if the
* signing process is canceled by the user.
* @throws DocumentSignException when a problem arised during the singing process
* (e.g. smart card access problem, invalid certificate, invalid PIN code, etc.)
*/
private CertificationChainAndSignatureBase64 signFile(String aFileName)
throws DocumentSignException {
// Load the file for signing
byte[] documentToSign = null;
try {
documentToSign = readFileInByteArray(aFileName);
} catch (IOException ioex) {
String errorMessage = "Can not read the file for signing " + aFileName + ".";
throw new DocumentSignException(errorMessage, ioex);
}
// Show a dialog for choosing PKCS#11 implementation library and smart card PIN
PKCS11LibraryFileAndPINCodeDialog pkcs11Dialog =
new PKCS11LibraryFileAndPINCodeDialog();
boolean dialogConfirmed;
try {
dialogConfirmed = pkcs11Dialog.run();
} finally {
pkcs11Dialog.dispose();
}
if (dialogConfirmed) {
String oldButtonLabel = mSignButton.getLabel();
mSignButton.setLabel("Working...");
mSignButton.setEnabled(false);
try {
String pkcs11LibraryFileName = pkcs11Dialog.getLibraryFileName();
String pinCode = pkcs11Dialog.getSmartCardPINCode();
// Do the actual signing of the document with the smart card
CertificationChainAndSignatureBase64 signingResult =
signDocument(documentToSign, pkcs11LibraryFileName, pinCode);
return signingResult;
} finally {
mSignButton.setLabel(oldButtonLabel);
mSignButton.setEnabled(true);
}
}
else {
return null;
}
}
