AES cipher cann't generate required IV in encrypt mode

If this cipher requires any algorithm parameters and params is null, the underlying cipher implementation is supposed to generate the required parameters itself (using provider-specific default or random values) if it is being initialized for encryption. But the AES cipher can not. The following program demonstrates this.


import java.io.PrintStream;
import java.security.*;
import java.security.spec.*;
import java.util.Random;

import javax.crypto.*;
import javax.crypto.spec.*;
import java.security.Provider;
import com.sun.advcrypto.provider.SunAES;

public class test {

     public static void main( String argv[] ) {
     try{
    
byte[] iv = null;
         String algorithm = "AES";
     String mode = "CBC";
    String padding = "NoPadding";
  int keyStrength=128;
  AlgorithmParameterSpec aps = null;
 
  Cipher ci = Cipher.getInstance( algorithm + "/" + mode + "/" + padding, "SunAES" );
 
  KeyGenerator kg = KeyGenerator.getInstance( algorithm, "SunAES" );
     kg.init(keyStrength);
     SecretKey key = kg.generateKey();

     ci.init( Cipher.ENCRYPT_MODE, key, aps);

     }catch(Exception ex){
     System.out.println("FAILED");
     ex.printStackTrace();
    
     }
     }
}


lwang:/home/lw129730/AES/testcode/test( 172 )%java test
FAILED
java.security.InvalidAlgorithmParameterException: Wrong parameter type: IV expected
        at cryptix.jce.provider.cipher.SunAES_j.b(DashoA6275)
        at cryptix.jce.provider.cipher.SunAES_i.a(DashoA6275)
        at cryptix.jce.provider.cipher.SunAES_h.a(DashoA6275)
        at cryptix.jce.provider.cipher.BlockCipher.engineInit(DashoA6275)
        at javax.crypto.Cipher.init(DashoA6275)
        at test.main(test.java:30)