question: public static byte [ ] des_cksum ( byte [ ] ivec , byte [ ] msg , byte [ ] key ) throws KrbCryptoException { Cipher cipher = null ; byte [ ] result = new byte [ 8 ] ; try { cipher = Cipher . getInstance ( "DES/CBC/NoPadding" ) ; } catch ( Exception e ) { KrbCryptoException ke = new KrbCryptoException ( "JCE provider may not be installed. " + e . getMessage ( ) ) ; ke . initCause ( e ) ; throw ke ; } IvParameterSpec params = new IvParameterSpec ( ivec ) ; SecretKeySpec skSpec = new SecretKeySpec ( key , "DES" ) ; try { SecretKeyFactory skf = SecretKeyFactory . getInstance ( "DES" ) ; SecretKey sk = ( SecretKey ) skSpec ; cipher . init ( Cipher . ENCRYPT_MODE , sk , params ) ; for ( int i = 0 ; i < msg . length / 8 ; i ++ ) { result = cipher . doFinal ( msg , i * 8 , 8 ) ; cipher . init ( Cipher . ENCRYPT_MODE , sk , ( new IvParameterSpec ( result ) ) ) ; } } catch ( GeneralSecurityException e ) { KrbCryptoException ke = new KrbCryptoException ( e . getMessage ( ) ) ; ke . initCause ( e ) ; throw ke ; } return result ; }
target:  Encrypts the message blocks using DES CBC and output the final block of 8-byte ciphertext.