JCE and binary private keys

[carlos olmos]

Hello:

I'm writing a program to digitally sign documents.

I'm using JCE and keytool to manage the RSA keys and certificates.

Here is my problem:

I need to load the user existing RSA private keys and certificates. I got a sample file for a RSA private key, but it's in binary format (apparently a requirement for this program). I've tried to use the keytool, the JCE KeyFactory class and even openssl rsa utility to open this file without success. Aparently each one of this methods require the file in text format (PEM or DER) to read the key.

Any idea on how to open a RSA Binary private key?

Thanks in advanced.

C.