private void test(int keyLength, int messageLegth)
{
//setup
string message = new string('a', messageLegth); //creates stirng of "a" of length <messageLength>
int tests = 1000; //how many tests to run
TestResult[] testResults = new TestResult[tests];
CryptoUtility.AESkeyLength = keyLength; //set up CryptoUtility to use correct key length
AESKey = CryptoUtility.GenerateAESRandomKey(); //gets random key for set of tests
//first run done seporately because of set up time
TestResult firstRun = process(message);
//Console.WriteLine("First run:");
//Console.WriteLine($"Total time: {firstRun.totalLength} ms");
Console.WriteLine($"First Run - Total: {firstRun.totalTime} ms Encryption: {firstRun.encryptionTime}ms Decryption: {firstRun.decryptionTime}ms");
Console.WriteLine($"Number of tests: {tests}");
for (int i = 0; i < testResults.Length; i += 1)
{
testResults[i] = process(message);
}
displayResults(testResults, keyLength, messageLegth); //send results to be displayed
Console.WriteLine();
//write results to excel file (in memory)
excelWriter.addRow(keyLength, messageLegth, testResults);
}
/// <summary>
/// Returns the key whos date field is equal to todays date. If a key does not yet exist for todays date, it is created
/// and stored.
/// </summary>
/// <returns>byte[] containing todays key</returns>
public Key getTodaysKey()
{
SQLiteDataReader reader = db.retrieve("SELECT keyID, AESKey, IV FROM Keys WHERE date = CURRENT_DATE"); //gets key with todays date
if (reader.HasRows) //if there were any keys with todays date
{
reader.Read(); //prepares reader to extract data
int keyID = Convert.ToInt32((long)reader["keyID"]); //sqlite stored primary keys as int64s
byte[] encKey = (byte[])reader["AESKey"]; //extract encrypted key
byte[] IV = (byte[])reader["IV"]; //extract initialisation vector it was encrypted with
byte[] keyBytes = decryptKey(encKey, IV); //decrypt key
Key key = new Key(keyID, keyBytes); //creates key object to return
return(key);
}
else //must generate new key and create DB entry
{
byte[] newKey = CryptoUtility.GenerateAESRandomKey(); //generate random AES key
byte[] masterKey = Globals.getMasterKey(); //gets master key to encrypt the new key
Tuple <byte[], byte[]> encResult = CryptoUtility.AESEncrypt(newKey, masterKey); //encrypts new key with master key
byte[] encNewKey = encResult.Item1; //extract encrypted key
byte[] IV = encResult.Item2; //extract initialisation vector
insertNewKey(encNewKey, IV); //insert it into database
return(getTodaysKey()); //1 level of recursion, creates entry then fetches and returns it
}
}
//this method tests the creation of a random AES key, then using it encrypt and decrypt a message
public void testRandomKeyEncryption()
{
string data = "hello, good morning, I hope all is well. blahblahblahblahblah";
byte[] dataBytes = Encoding.UTF8.GetBytes(data); //convert data to bytes
byte[] keyBytes = CryptoUtility.GenerateAESRandomKey(); //gets randomly generated
//tuple contains encrypted bytes plus initialisation vector needed to decrypt it
Tuple <byte[], byte[]> enc = CryptoUtility.AESEncrypt(dataBytes, keyBytes); //encypts and gets encrypted bytes + IV
byte[] encBytes = enc.Item1; //encrypted bytes
byte[] IV = enc.Item2; //Instantiation vector
string decryptedString = CryptoUtility.AESDecrypt(encBytes, keyBytes, IV);
Assert.AreEqual <string>(data, decryptedString); //compare original data to the decrypted string
}
