/// <summary>
/// Calculating public exp, private exp and cypher module
/// </summary>
/// <param name="keyLength">Key length</param>
/// <param name="pNumeric">First decimal prime number</param>
/// <param name="qNumeric">Second decimal prime number</param>
/// <param name="generator">prime numbers generator</param>
/// <returns>Возвращает структуру, хранящую ключи и модуль</returns>
private static KeysHolder CalculateKeysValues(int keyLength, BigInteger pNumeric, BigInteger qNumeric, PrimeNumbersGenerator generator)
{
var keysToReturn = new KeysHolder();
// Cypher module
var N = pNumeric * qNumeric;
keysToReturn.cypherModule = N;
// Euler function
var phi = (pNumeric - 1) * (qNumeric - 1);
var exponentHelper = new ExponentHelper();
// public exp
var e = exponentHelper.GetPublicExp(phi, keyLength, generator);
keysToReturn.publicKey = e;
// private exp
var d = exponentHelper.GetPrivateExp(e, phi);
keysToReturn.privateKey = d;
return(keysToReturn);
}
/// <summary>
/// Task 2. RSA Encryption and decryption
/// </summary>
/// <param name="keys">keys</param>
/// <param name="fileName"></param>
/// <param name="keyLength">Key length</param>
private static void RsaCrypt(KeysHolder keys, string fileName, int keyLength)
{
var plainText = FileWorker.GetBinaryFile(fileName);
var encodedText = new List <short>();
var decryptedText = new List <short>();
var rsaEncoder = new RsaEncoder();
// encrypting
encodedText = Encode(keys.publicKey, keys.cypherModule, plainText, rsaEncoder, keyLength / 4, keyLength, false);
// saving encrypted message
FileWorker.CreateTextFileForBinaryNumber(encodedText, "crypted.txt");
Console.WriteLine(String.Format("Encryption has finished. Check crypted.txt"));
// decrypting
decryptedText = Encode(keys.privateKey, keys.cypherModule, encodedText, rsaEncoder, keyLength, keyLength / 4, true);
// saving decrypted message
FileWorker.GetNEWFile(decryptedText, "decrypted_" + fileName);
Console.WriteLine(String.Format("DEcryption has finished. Check decrypted{0}", fileName));
Console.WriteLine("-------------------------------------------------------------");
}
