private static byte [ ] generateKey ( int size ) throws SymmetricKeyException { if ( size <= 0 ) throw new IllegalArgumentException ( "Size cannot be zero or less than zero." ) ; try { SecureRandom secureRandom = new SecureRandom ( ) ; KeyGenerator keyGenerator = KeyGenerator . getInstance ( "AES" ) ; keyGenerator . init ( size * 8 , secureRandom ) ; return keyGenerator . generateKey ( ) . getEncoded ( ) ; } catch ( NoSuchAlgorithmException e ) { throw new SymmetricKeyException ( e ) ; } }
Generate an AES key of the specifies size in bytes .