我收到“要解密的数据长度无效”。当我尝试解密内存流时出现异常。我是初学者,无法弄清楚什么是错的。怎么了?
public bool EncryptStream()
{
string password = @"myKey123"; // Your Key Here
UnicodeEncoding UE = new UnicodeEncoding();
byte[] key = UE.GetBytes(password);
s_EncryptedStream = new MemoryStream();
int NoOfBytes;
byte[] b_Buffer = new byte[8192];
s_MemoryStream.Seek(0, SeekOrigin.Begin);
RijndaelManaged RMCrypto = new RijndaelManaged();
s_CrytpoStream = new CryptoStream(s_EncryptedStream,
RMCrypto.CreateEncryptor(key, key),
CryptoStreamMode.Write);
while (s_MemoryStream.Length < s_MemoryStream.Position)
{
NoOfBytes = s_MemoryStream.Read(b_Buffer, 0, 8192);
s_CrytpoStream.Write(b_Buffer, 0, NoOfBytes);
}
s_MemoryStream.Seek(0, SeekOrigin.Begin);
while (s_EncryptedStream.Position < s_EncryptedStream.Length)
{
NoOfBytes = s_EncryptedStream.Read(b_Buffer, 0, 8192);
s_MemoryStream.Write(b_Buffer, 0, NoOfBytes);
}
s_CrytpoStream.Flush();
s_CrytpoStream.Close();
return true;
}
public bool DecryptStream()
{
string password = @"myKey123"; // Your Key Here
UnicodeEncoding UE = new UnicodeEncoding();
byte[] key = UE.GetBytes(password);
int NoOfBytes;
byte[] b_Buffer = new byte[8192];
s_DecryptedStream = new MemoryStream();
RijndaelManaged RMCrypto = new RijndaelManaged();
s_CrytpoStream = new CryptoStream(s_MemoryStream,
RMCrypto.CreateDecryptor(key, key),
CryptoStreamMode.Read);
s_MemoryStream.Seek(0, SeekOrigin.Begin);
while (s_MemoryStream.Length > s_MemoryStream.Position)
{
NoOfBytes = s_CrytpoStream.Read(b_Buffer, 0, 8192);
s_DecryptedStream.Write(b_Buffer, 0, NoOfBytes);
}
s_DecryptedStream.Seek(0, SeekOrigin.Begin);
s_MemoryStream.Seek(0, SeekOrigin.Begin);
while (s_DecryptedStream.Position < s_DecryptedStream.Length)
{
NoOfBytes = s_DecryptedStream.Read(b_Buffer, 0, 8192);
s_MemoryStream.Write(b_Buffer, 0, NoOfBytes);
}
s_CrytpoStream.Flush();
s_CrytpoStream.Close();
return true;
}
最佳答案
首先,这个 while 循环条件永远不会正确:
while (s_MemoryStream.Length < s_MemoryStream.Position)
位置怎么会超出长度?
复制流的常用模式不是使用流的长度,而是重复读取,直到返回的值不为正。无论如何,当您在此代码中执行两次此操作时,您不妨将其封装:
public static void CopyStream(Stream input, Stream output)
{
byte[] buffer = new byte[8192];
int read;
while ( (read = input.Read(buffer, 0, buffer.Length)) > 0)
{
output.Write(buffer, 0, read);
}
}
最好使用
using
语句来清理字符串。此外,Encoding.Unicode
属性意味着您不必创建新的 UnicodeEncoding
你自己。另外,我一般发现设置Position
属性比使用 Seek
更具可读性.最后,如果返回值总是 true
,则方法返回值毫无意义。 .因此,您的代码将变为:public void EncryptStream()
{
string password = @"myKey123"; // Your Key Here
byte[] key = Encoding.Unicode.GetBytes(password);
s_EncryptedStream = new MemoryStream();
s_MemoryStream.Position = 0;
RijndaelManaged RMCrypto = new RijndaelManaged();
using (Stream crytpoStream = new CryptoStream(s_EncryptedStream,
RMCrypto.CreateEncryptor(key, key),
CryptoStreamMode.Write))
{
CopyStream(s_MemoryStream, cryptoStream);
}
s_MemoryStream.Position = 0;
s_EncryptedStream.Position = 0;
CopyStream(s_EncryptedStream, s_MemoryStream);
}
public void DecryptStream()
{
string password = @"myKey123"; // Your Key Here
byte[] key = Encoding.Unicode.GetBytes(password);
s_DecryptedStream = new MemoryStream();
s_MemoryStream.Position = 0;
RijndaelManaged RMCrypto = new RijndaelManaged();
using (Stream crytpoStream = new CryptoStream(s_MemoryStream,
RMCrypto.CreateDecryptor(key, key),
CryptoStreamMode.Read))
{
CopyStream(cryptoStream, s_DecryptedStream);
}
s_DecryptedStream.Position = 0;
s_MemoryStream.Position = 0;
CopyStream(s_DecryptedStream, s_MemoryStream);
}
即使修改了这段代码,你也感觉这里有太多的非局部变量。我不明白为什么这些都应该在实例变量中。使要加密或解密的流成为一个参数(连同密码),并返回一个带有加密/解密数据的内存流,或者只是一个字节数组。
关于exception - "Length of the data to decrypt is invalid."Rijndael 解密期间的异常,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/845971/