Opt*_*tim 47 .net c# migration encryption .net-6.0
我正在使用与此处提供的类似的字符串加密/解密类作为解决方案。
\n这在 .Net 5 中对我来说效果很好。
\n现在我想将我的项目更新到 .Net 6。
使用 .Net 6 时，解密的字符串确实会根据输入字符串的长度在某个点被截断。
\n\xe2\x96\xb6\xef\xb8\x8f 为了方便调试/重现我的问题，我在这里创建了一个公共重现存储库。
\n两者都使用完全相同的输入"12345678901234567890"和路径短语调用加密方法"nzv86ri4H2qYHqc&m6rL"。
.Net 5 输出："12345678901234567890"
\n.Net 6 输出："1234567890123456"
长度之差为4.
我还查看了.Net 6 的重大更改，但找不到可以指导我找到解决方案的内容。
\n我很高兴就我的问题提出任何建议，谢谢！
\n加密等级
\npublic static class StringCipher\n{\n // This constant is used to determine the keysize of the encryption algorithm in bits.\n // We divide this by 8 within the code below to get the equivalent number of bytes.\n private const int Keysize = 128;\n\n // This constant determines the number of iterations for the password bytes generation function.\n private const int DerivationIterations = 1000;\n\n public static string Encrypt(string plainText, string passPhrase)\n {\n // Salt and IV is randomly generated each time, but is preprended to encrypted cipher text\n // so that the same Salt and IV values can be used when decrypting. \n var saltStringBytes = Generate128BitsOfRandomEntropy();\n var ivStringBytes = Generate128BitsOfRandomEntropy();\n var plainTextBytes = Encoding.UTF8.GetBytes(plainText);\n using (var password = new Rfc2898DeriveBytes(passPhrase, saltStringBytes, DerivationIterations))\n {\n var keyBytes = password.GetBytes(Keysize / 8);\n using (var symmetricKey = Aes.Create())\n {\n symmetricKey.BlockSize = 128;\n symmetricKey.Mode = CipherMode.CBC;\n symmetricKey.Padding = PaddingMode.PKCS7;\n using (var encryptor = symmetricKey.CreateEncryptor(keyBytes, ivStringBytes))\n {\n using (var memoryStream = new MemoryStream())\n {\n using (var cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))\n {\n cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length);\n cryptoStream.FlushFinalBlock();\n // Create the final bytes as a concatenation of the random salt bytes, the random iv bytes and the cipher bytes.\n var cipherTextBytes = saltStringBytes;\n cipherTextBytes = cipherTextBytes.Concat(ivStringBytes).ToArray();\n cipherTextBytes = cipherTextBytes.Concat(memoryStream.ToArray()).ToArray();\n memoryStream.Close();\n cryptoStream.Close();\n return Convert.ToBase64String(cipherTextBytes);\n }\n }\n }\n }\n }\n }\n\n public static string Decrypt(string cipherText, string passPhrase)\n {\n // Get the complete stream of bytes that represent:\n // [32 bytes of Salt] + [16 bytes of IV] + [n bytes of CipherText]\n var cipherTextBytesWithSaltAndIv = Convert.FromBase64String(cipherText);\n // Get the saltbytes by extracting the first 16 bytes from the supplied cipherText bytes.\n var saltStringBytes = cipherTextBytesWithSaltAndIv.Take(Keysize / 8).ToArray();\n // Get the IV bytes by extracting the next 16 bytes from the supplied cipherText bytes.\n var ivStringBytes = cipherTextBytesWithSaltAndIv.Skip(Keysize / 8).Take(Keysize / 8).ToArray();\n // Get the actual cipher text bytes by removing the first 64 bytes from the cipherText string.\n var cipherTextBytes = cipherTextBytesWithSaltAndIv.Skip((Keysize / 8) * 2).Take(cipherTextBytesWithSaltAndIv.Length - ((Keysize / 8) * 2)).ToArray();\n\n using (var password = new Rfc2898DeriveBytes(passPhrase, saltStringBytes, DerivationIterations))\n {\n var keyBytes = password.GetBytes(Keysize / 8);\n using (var symmetricKey = Aes.Create())\n {\n symmetricKey.BlockSize = 128;\n symmetricKey.Mode = CipherMode.CBC;\n symmetricKey.Padding = PaddingMode.PKCS7;\n using (var decryptor = symmetricKey.CreateDecryptor(keyBytes, ivStringBytes))\n {\n using (var memoryStream = new MemoryStream(cipherTextBytes))\n {\n using (var cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))\n {\n var plainTextBytes = new byte[cipherTextBytes.Length];\n var decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);\n memoryStream.Close();\n cryptoStream.Close();\n return Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount);\n }\n }\n }\n }\n }\n }\n\n private static byte[] Generate128BitsOfRandomEntropy()\n {\n var randomBytes = new byte[16]; // 16 Bytes will give us 128 bits.\n using (var rngCsp = RandomNumberGenerator.Create())\n {\n // Fill the array with cryptographically secure random bytes.\n rngCsp.GetBytes(randomBytes);\n }\n return randomBytes;\n }\n}\n调用代码
\nvar input = "12345678901234567890";\nvar inputLength = input.Length;\nvar inputBytes = Encoding.UTF8.GetBytes(input);\n\nvar encrypted = StringCipher.Encrypt(input, "nzv86ri4H2qYHqc&m6rL");\n\nvar output = StringCipher.Decrypt(encrypted, "nzv86ri4H2qYHqc&m6rL");\nvar outputLength = output.Length;\nvar outputBytes = Encoding.UTF8.GetBytes(output);\n\nvar lengthDiff = inputLength - outputLength;\nEvk*_*Evk 66
原因是这个重大变化：
DeflateStream、GZipStream 和 CryptoStream 在两个方面与典型的 Stream.Read 和 Stream.ReadAsync 行为不同：
直到传递给读取操作的缓冲区完全填满或到达流末尾时，它们才完成读取操作。
新的行为是：
从 .NET 6 开始，当对具有长度为 N 的缓冲区的受影响流类型之一调用 Stream.Read 或 Stream.ReadAsync 时，操作将在以下情况下完成：
至少已从流中读取了一个字节，或者它们包装的底层流从对其读取的调用中返回 0，表示没有更多数据可用。
在您的情况下，您会因为Decrypt方法中的以下代码而受到影响：
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);
}
您不检查实际读取了多少字节Read以及是否读取了全部字节。在以前的 .NET 版本中，您可以避免这种情况，因为如上所述，CryptoStream行为与其他流不同，而且您的缓冲区长度足以容纳所有数据。但是，情况不再是这样，您需要像检查其他流一样检查它。或者甚至更好 - 只需使用CopyTo：
using (var plainTextStream = new MemoryStream())
{
cryptoStream.CopyTo(plainTextStream);
var plainTextBytes = plainTextStream.ToArray();
return Encoding.UTF8.GetString(plainTextBytes, 0, plainTextBytes.Length);
}
或者甚至更好，正如另一个答案所建议的那样，因为您解密了 UTF8 文本：
using (var plainTextReader = new StreamReader(cryptoStream))
{
return plainTextReader.ReadToEnd();
}
can*_*on7 23
我认为你的问题出在这里：
var decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
即使尚未到达流的末尾，实现也可以自由地返回比请求更少的字节。
因此，单次调用Read不能保证读取所有可用字节（最多plainTextBytes.Length）——读取较少数量的字节完全在其权限之内。
.NET 6 有许多性能改进，如果这是他们以性能名义做出的权衡，我不会感到惊讶。
您必须保持良好状态，并继续调用Read直到返回0，这表明没有更多数据可返回。
但是，使用 a 会容易得多StreamReader，它还会为您处理 UTF-8 解码。
return new StreamReader(cryptoStream).ReadToEnd();