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Topic: Digital Signature in PDF w/o using Adobe products
Conf: (P-PDF) Developers, Msg: 66176
From: hammaas
Date: 6/4/2002 09:34 PM

Hi all,

I want to write an application in Java that adds a digital signature to a pdf doc.

I have to use the profile created by the user, where the private key, certificate & public key are stored.

Problem is... I don't know the structure or format of the apf file in which this profile is stored in, so I tried trial-&-error ...
& ended up with error !!

I get an "Unknown key spec" error. I'm attaching the code & the error that is displayed :

========= CODE START =========
RandomAccessFile rafPrivKey = new RandomAccessFile("PrivKey.txt", "r");
String strPrivKey = rafPrivKey.readLine();
byte[] abPrivKey = ConvertHexStrToByteArr(strPrivKey);

RC4 rc4Tmp = new
byte[] abDecPrivKey = new byte[abPrivKey.length];
rc4Tmp.Update(abPrivKey, abDecPrivKey);

KeyFactory kfTmp = KeyFactory.getInstance("RSA");
PKCS8EncodedKeySpec pkcs8Tmp = new PKCS8EncodedKeySpec(abDecPrivKey);
RSAPrivateKey privKey = (RSAPrivateKey)kfTmp.generatePrivate(pkcs8Tmp); // exception raised here !!!!!!!!!!!!!!!!!!!!!

RandomAccessFile rafDataFile = new RandomAccessFile("Test.pdf", "r");
byte[] abData = new byte[(int)rafDataFile.length()];;

Signature sigTmp = Signature.getInstance("SHA1withRSA");
byte[] abSign = sigTmp.sign();

RandomAccessFile rafHashFile = new RandomAccessFile("Hash.txt", "rw");
========= CODE END =========

========= ERROR START =========
java.lang.reflect.InvocationTargetException: Unknown key spec.
at com.sun.rsajca.JS_KeyFactory.engineGeneratePrivate([DashoPro-V1.2-120198])
at PDFDigSig.Test.PDFDigSigTestAdbPrivKey(
at PDFDigSig.Test.main(
at java.lang.reflect.Method.invoke(Native Method)
at com.borland.jbuilder.util.BootStrap.invokeMain(Unknown Source)
at com.borland.jbuilder.util.BootStrap.main(Unknown Source)
========= ERROR END =========

Any kind of help will be highly appreciated !!!!!!

Thanx in advance...

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