У нас есть вспомогательный класс для шифрования, который, если честно, был, вероятно, скопирован из Stack Overflow несколько лет назад.
В настоящее время мы пытаемся перенести часть этого кода на .NET Core и обнаруживаем, что он не работает, потому что реализация .NET Core RijndaelManaged не поддерживает размер блока 256.Из того, что я прочитал, кажется, что BouncyCastle все еще должен поддерживать его, но я не могу заставить его работать.«Незашифрованный» текст - это просто чепуха.Я уверен, что делаю что-то не так, но, судя по всему, я не могу понять это.
Вот оригинальная версия класса .Net Framework:
internal static class StringEncryptor
{
private const int Keysize = 256;
private const int _iterations = 1000;
private const int _hashLenth = 20;
public static string Encrypt(string plainText, string superSecretPassPhrase)
{
// Salt and IV is randomly generated each time, but is preprended to encrypted cipher text
// so that the same Salt and IV values can be used when decrypting.
var saltStringBytes = Generate256BitsOfRandomEntropy();
var ivStringBytes = Generate256BitsOfRandomEntropy();
var plainTextBytes = Encoding.UTF8.GetBytes(plainText);
using (var password = new Rfc2898DeriveBytes(superSecretPassPhrase, saltStringBytes, _iterations))
{
var keyBytes = password.GetBytes(Keysize / 8);
using (var symmetricKey = new RijndaelManaged())
{
symmetricKey.BlockSize = 256;
symmetricKey.Mode = CipherMode.CBC;
symmetricKey.Padding = PaddingMode.PKCS7;
using (var encryptor = symmetricKey.CreateEncryptor(keyBytes, ivStringBytes))
{
using (var memoryStream = new MemoryStream())
{
using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
{
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);
cryptoStream.FlushFinalBlock();
// Create the final bytes as a concatenation of the random salt bytes, the random iv bytes and the cipher bytes.
var cipherTextBytes = saltStringBytes;
cipherTextBytes = cipherTextBytes.Concat(ivStringBytes).ToArray();
cipherTextBytes = cipherTextBytes.Concat(memoryStream.ToArray()).ToArray();
memoryStream.Close();
cryptoStream.Close();
return WebEncoders.Base64UrlEncode(cipherTextBytes);
//return System.Web.HttpServerUtility.UrlTokenEncode(cipherTextBytes);
}
}
}
}
}
}
public static string Decrypt(string cipherText, string superSecretPassPhrase)
{
if (cipherText == null)
{
throw new ArgumentNullException(nameof(cipherText));
}
// Get the complete stream of bytes that represent:
// [32 bytes of Salt] + [32 bytes of IV] + [n bytes of CipherText]
var cipherTextBytesWithSaltAndIv = WebEncoders.Base64UrlDecode(cipherText);
// Get the saltbytes by extracting the first 32 bytes from the supplied cipherText bytes.
var saltStringBytes = cipherTextBytesWithSaltAndIv.Take(Keysize / 8).ToArray();
// Get the IV bytes by extracting the next 32 bytes from the supplied cipherText bytes.
var ivStringBytes = cipherTextBytesWithSaltAndIv.Skip(Keysize / 8).Take(Keysize / 8).ToArray();
// Get the actual cipher text bytes by removing the first 64 bytes from the cipherText string.
var cipherTextBytes = cipherTextBytesWithSaltAndIv.Skip((Keysize / 8) * 2).Take(cipherTextBytesWithSaltAndIv.Length - ((Keysize / 8) * 2)).ToArray();
using (var password = new Rfc2898DeriveBytes(superSecretPassPhrase, saltStringBytes, _iterations))
{
var keyBytes = password.GetBytes(Keysize / 8);
using (var symmetricKey = new RijndaelManaged())
{
symmetricKey.BlockSize = 256;
symmetricKey.Mode = CipherMode.CBC;
symmetricKey.Padding = PaddingMode.PKCS7;
using (var decryptor = symmetricKey.CreateDecryptor(keyBytes, ivStringBytes))
{
using (var memoryStream = new MemoryStream(cipherTextBytes))
{
using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
{
var plainTextBytes = new byte[cipherTextBytes.Length];
var decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
memoryStream.Close();
cryptoStream.Close();
return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);
}
}
}
}
}
}
private static byte[] Generate256BitsOfRandomEntropy()
{
var randomBytes = new byte[32]; // 32 Bytes will give us 256 bits.
using (var rngCsp = new RNGCryptoServiceProvider())
{
// Fill the array with cryptographically secure random bytes.
rngCsp.GetBytes(randomBytes);
}
return randomBytes;
}
}
И вот моя попытка заставить метод Decrypt работать с BouncyCastle:
/// <summary>
/// Decrypt a string
/// </summary>
/// <param name="cipherText"></param>
/// <returns></returns>
public static string Decrypt(string cipherText)
{
if (cipherText == null)
{
throw new ArgumentNullException(nameof(cipherText));
}
// Get the complete stream of bytes that represent:
// [32 bytes of Salt] + [32 bytes of IV] + [n bytes of CipherText]
var cipherTextBytesWithSaltAndIv = WebEncoders.Base64UrlDecode(cipherText);
// Get the saltbytes by extracting the first 32 bytes from the supplied cipherText bytes.
var saltStringBytes = cipherTextBytesWithSaltAndIv.Take(Keysize / 8).ToArray();
// Get the IV bytes by extracting the next 32 bytes from the supplied cipherText bytes.
var ivStringBytes = cipherTextBytesWithSaltAndIv.Skip(Keysize / 8).Take(Keysize / 8).ToArray();
// Get the actual cipher text bytes by removing the first 64 bytes from the cipherText string.
var cipherTextBytes = cipherTextBytesWithSaltAndIv.Skip((Keysize / 8) * 2).Take(cipherTextBytesWithSaltAndIv.Length - ((Keysize / 8) * 2)).ToArray();
using (var password = new Rfc2898DeriveBytes(superSecretPassPhrase, saltStringBytes, _iterations))
{
var keyBytes = password.GetBytes(Keysize / 8);
var engine = new RijndaelEngine(256);
var blockCipher = new CbcBlockCipher(engine);
var cipher = new PaddedBufferedBlockCipher(blockCipher, new Pkcs7Padding());
var keyParam = new KeyParameter(keyBytes);
var keyParamWithIV = new ParametersWithIV(keyParam, ivStringBytes, 0, 32);
cipher.Init(true, keyParamWithIV);
var outputBytes = new byte[cipher.GetOutputSize(cipherTextBytes.Length)];
var length = cipher.ProcessBytes(cipherTextBytes, outputBytes, 0);
var finalBytes = cipher.DoFinal(outputBytes, 0, length);
var final = Encoding.UTF8.GetString(finalBytes);
return final;
}
}
}
Заранее спасибо!Я уверен, что делаю что-то глупое, но я не эксперт по криптографии, и у меня возникают проблемы с поиском хороших примеров BouncyCastle.