检索加密数据的实际大小
在.NET框架中，我试图加密一些二进制数据（使用RijndaelManaged），为了解密，我使用了以下示例代码（C++/.NET）：
RijndaelManaged^ rjdAlg= gcnew RijndaelManaged;
rjdAlg->IV= IV;
rjdAlg->Key=this->key;
ICryptoTransform^ decryptor= rjdAlg->CreateDecryptor();
MemoryStream^ msDecrypt = gcnew MemoryStream(encryptedData);
CryptoStream^ csDecrypt = gcnewCryptoStream(msDecrypt,decryptor,CryptoStreamMode::Read);
array<unsigned char>^ decryptedData= gcnew array<unsigned char>(encryptedData->Length);
csDecrypt->Read(decryptedData,0,decryptedData->Length);
现在，decryptedData除了空值之外还包含有用的数据（作为数组初始化） ，我怎样才能获得加密数据的实际大小（如果它是字符串，我可以停在第一个空值！）。
In .NET framework, I'm trying to encrypt some binary data (using RijndaelManaged), for decrypting I used the following sample code (C++/.NET):
RijndaelManaged^ rjdAlg= gcnew RijndaelManaged;
rjdAlg->IV= IV;
rjdAlg->Key=this->key;
ICryptoTransform^ decryptor= rjdAlg->CreateDecryptor();
MemoryStream^ msDecrypt = gcnew MemoryStream(encryptedData);
CryptoStream^ csDecrypt = gcnewCryptoStream(msDecrypt,decryptor,CryptoStreamMode::Read);
array<unsigned char>^ decryptedData= gcnew array<unsigned char>(encryptedData->Length);
csDecrypt->Read(decryptedData,0,decryptedData->Length);
Now, decryptedData contains useful data in addition to nulls (as the array initialization), how can I get the actual size of encrypted data ( if it was string I can just stop at the first null!).
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您需要单独存储长度，或者作为加密数据的前 N 位/字节，或者在加密数据之外。
Rijndael 是一种分组密码，这意味着它始终会加密整个块，并且解密时您总是会得到整个块。
You need to store the length separately, either as the first N bits/bytes of your encrypted data, or outside of the encrypted data.
Rijndael is a block cipher, which means it will always encrypt whole blocks, and you always get whole blocks back when decrypting.