Test.hpp // Write a preprocessor guard which will prevent this header file from

Question

Test.hpp

// Write a preprocessor guard which will prevent this header file from being included more than once. The name
// used in the preprocessor guard must be unique, so a common C++ convention is to use the name of the source
// code file, written in all uppercase letters, with an underscore replacing the dot.
???

// Write the class declaration for a class named 'Test' using the class diagram in the lab project document as
// a guide. The class shall declare two function members: (1) the default constructor; and (2) a void function
// named run(). Both functions are public and neither function has input parameters. There are no data members
// or private functions.
???

// Write the preprocessor directive that ends the preprocessor guard.
???

Test.cpp

#include "Decryptor.hpp" // For Decryptor class declaration
#include "Encryptor.hpp" // For Encryptor class declaration
#include "Test.hpp" // For Test class declaration

using namespace std;

//----- Test() -------------------------------------------------------------------------------------------------
// Default constructor. Every class must have at least one constructor even if there are no data members to
// initialize. This particular constructor does nothing so just write a pair of empty braces with no statements
// inside them.
//--------------------------------------------------------------------------------------------------------------
???

//----- run() --------------------------------------------------------------------------------------------------
// Performs the testing of the Encryptor and Decryptor classes. We instantiate an Encryptor object and use it to
// encrypt the secret message stored in the file "plain.txt", writing the encrypted message to a file named
// "cipher.txt". Then we instantiate a Decryptor object and use it to decrypt the encrypted message stored in
// "cipher.txt", writing the output to a file named "plain-new.txt". To verify the program works correctly, load
// both "plain.txt" and "plain-new.txt" into the editor pane, and verify the two files are identical (except
// that "plain-new.txt" will not contain the whitespace characters that are in "plain.txt").
//--------------------------------------------------------------------------------------------------------------
// Write the function header and the left brace
???
// Define and instantiate an Encryptor object named 'encryptor' calling the default constructor to
// initialize the object.
???

// Call the encryptFile() function on 'encryptor' and pass "plain.txt" as the plaintext file name and
// "cipher.txt" as the ciphertext file name.
???

// Define and instantiate a Decryptor object named 'decryptor' calling the default constructor to
// initialize the object.
???

// Call the decryptFile() function on 'decryptor' and pass "cipher.txt" as the ciphertext file name and
// "plain-new.txt" as the new plaintext file name.
???

// End the function
???

Explanation / Answer

import java.security.Security; import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; public class MainClass { public static void main(String[] args) throws Exception { Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider()); byte[] input = "www.java2s.com".getBytes(); 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 }; SecretKeySpec key = new SecretKeySpec(keyBytes, "AES"); Cipher cipher = Cipher.getInstance("AES/ECB/PKCS7Padding", "BC"); System.out.println(new String(input)); // encryption pass cipher.init(Cipher.ENCRYPT_MODE, key); byte[] cipherText = new byte[cipher.getOutputSize(input.length)]; int ctLength = cipher.update(input, 0, input.length, cipherText, 0); ctLength += cipher.doFinal(cipherText, ctLength); System.out.println(new String(cipherText)); System.out.println(ctLength); // decryption pass cipher.init(Cipher.DECRYPT_MODE, key); byte[] plainText = new byte[cipher.getOutputSize(ctLength)]; int ptLength = cipher.update(cipherText, 0, ctLength, plainText, 0); ptLength += cipher.doFinal(plainText, ptLength); System.out.println(new String(plainText)); System.out.println(ptLength); } }

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