simpleioexample.java

sip CMSEnvelopedData

package chapter2;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;

import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

/**
 * Basic IO example with CTR using AES
 */
public class SimpleIOExample
{   
    public static void main(
        String[]    args)
        throws Exception
    {
        byte[]          input = new byte[] { 
                            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
                            0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
                            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06 };
        byte[]		    keyBytes = new byte[] {
                            0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
                            0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
                            0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17 };
        byte[]		    ivBytes = new byte[] { 
                            0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x02, 0x03,
                            0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 };
        
        SecretKeySpec   key = new SecretKeySpec(keyBytes, "AES");
        IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
        Cipher          cipher = Cipher.getInstance("AES/CTR/NoPadding", "BC");
        

        System.out.println("input : " + Utils.toHex(input));
        
        // encryption pass
        
        cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
        
        ByteArrayInputStream	bIn = new ByteArrayInputStream(input);
        CipherInputStream		cIn = new CipherInputStream(bIn, cipher);
        ByteArrayOutputStream	bOut = new ByteArrayOutputStream();
        
        int	ch;
        while ((ch = cIn.read()) >= 0)
        {
            bOut.write(ch);
        }
        
        byte[] cipherText = bOut.toByteArray();
        
        System.out.println("cipher: " + Utils.toHex(cipherText));
        
        // decryption pass
        
        cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
        
        bOut = new ByteArrayOutputStream();
        
        CipherOutputStream      cOut = new CipherOutputStream(bOut, cipher);

        cOut.write(cipherText);
        
        cOut.close();
        
        System.out.println("plain : " + Utils.toHex(bOut.toByteArray()));
    }
}