How to read a PrivateKey that has been generated using Openssl.

Question

I used openssl to generate the key pairs,,the commands are as follows
openssl req -config openssl.cnf -new -out buyer.csr
openssl rsa -in privkey.pem -out buyer.key
openssl x509 -in buyer.csr -out buyer.cert -req -signkey buyer.key -days 365
openssl x509 -in buyer.cert -out buyer.der.crt -outform DER
now i have buyer.key as my private key,,,i like to read it to sign a file but i get error while doing it,,the code for doing it is as follows
import java.io.*;
import java.security.*;
import java.security.spec.*;
import java.security.spec.X509EncodedKeySpec;
class clientEncrypt {
public static void main(String[] args) {
PrivateKey priv=null;
try{             
FileInputStream in = new FileInputStream("C:/certificates/suepkb");
byte[] encodedKey = new byte[in.available()];
in.read(encodedKey);
in.close();
X509EncodedKeySpec privateKey = new X509EncodedKeySpec(encodedKey);
KeyFactory kf = KeyFactory.getInstance("RSA");
priv = kf.generatePrivate(privateKey);
}catch(Exception e){
System.out.println("subhash"+e.getMessage());
try{  
Signature dsa = Signature.getInstance("SHA1withRSA");
dsa.initSign(priv);
/* Update and sign the data */
FileInputStream fis = new FileInputStream("c:/sub.txt");
BufferedInputStream bufin = new BufferedInputStream(fis);
byte[] buffer = new byte[1024];
int len;
while (bufin.available() != 0) {
len = bufin.read(buffer);
dsa.update(buffer, 0, len);
bufin.close();
/* Now that all the data to be signed has been read in,
generate a signature for it */
byte[] realSig = dsa.sign();
/* Save the signature in a file */
FileOutputStream sigfos = new FileOutputStream("c:/ssig");
sigfos.write(realSig);
sigfos.close();
/* Save the public key in a file */
} catch (Exception e) {
System.err.println("Caught exception " + e.toString());
plz do help me out,,,asap
with regd and thnx in advnce
Subhash

Answer 1

use bouncycastle provider.
there are some classes and a sample code for this.