Can someone help me create an encryption/decryption program in VB.NET with this

Question

Can someone help me create an encryption/decryption program in VB.NET with this form please?

I have been looking for days for the answer to this, but I haven't found anything yet. Please help!

The clear-text message (that will be ‘encrypted’) is stored in a text-file. The text-file is to be selected using an OpenFileDialog Windows control object

Text-file contents are to be displayed in a Textbox control located on the Windows form (you can also use this textbox to input clear-text characters)

Explanation / Answer

public static string Encrypt ( string plainText, string passPhrase, string saltValue, string hashAlgorithm, int passwordIterations, string initVector, int keySize ) { // Convert strings into byte arrays. // Let us assume that strings only contain ASCII codes. // If strings include Unicode characters, use Unicode, UTF7, or UTF8 // encoding. byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector); byte[] saltValueBytes = Encoding.ASCII.GetBytes(saltValue); // Convert our plaintext into a byte array. // Let us assume that plaintext contains UTF8-encoded characters. byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText); // First, we must create a password, from which the key will be derived. // This password will be generated from the specified passphrase and // salt value. The password will be created using the specified hash // algorithm. Password creation can be done in several iterations. PasswordDeriveBytes password = new PasswordDeriveBytes ( passPhrase, saltValueBytes, hashAlgorithm, passwordIterations ); // Use the password to generate pseudo-random bytes for the encryption // key. Specify the size of the key in bytes (instead of bits). byte[] keyBytes = password.GetBytes(keySize / 8); // Create uninitialized Rijndael encryption object. RijndaelManaged symmetricKey = new RijndaelManaged(); // It is reasonable to set encryption mode to Cipher Block Chaining // (CBC). Use default options for other symmetric key parameters. symmetricKey.Mode = CipherMode.CBC; // Generate encryptor from the existing key bytes and initialization // vector. Key size will be defined based on the number of the key // bytes. ICryptoTransform encryptor = symmetricKey.CreateEncryptor ( keyBytes, initVectorBytes ); // Define memory stream which will be used to hold encrypted data. MemoryStream memoryStream = new MemoryStream(); // Define cryptographic stream (always use Write mode for encryption). CryptoStream cryptoStream = new CryptoStream ( memoryStream, encryptor, CryptoStreamMode.Write ); // Start encrypting. cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length); // Finish encrypting. cryptoStream.FlushFinalBlock(); // Convert our encrypted data from a memory stream into a byte array. byte[] cipherTextBytes = memoryStream.ToArray(); // Close both streams. memoryStream.Close(); cryptoStream.Close(); // Convert encrypted data into a base64-encoded string. string cipherText = Convert.ToBase64String(cipherTextBytes); // Return encrypted string. return cipherText; }

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