为什么RijndaelManaged在加密后返回垃圾数据
本文关键字:数据 返回 RijndaelManaged 加密 为什么 | 更新日期: 2024-07-27 11:54:56
我从http://msdn.microsoft.com/en-us/library/system.security.cryptography.cryptostream.aspx并将其修改如下。我有一个加密的例子,它在解码时工作得很好。但当使用加密函数时,它会返回带有奇怪符号的垃圾字符串。以下是加密/解密的功能。
加密字符串"嘿"的示例:"???U?b??z?Y??"
再次解码时:"ûc{ÁpÅ`ñ""
我正在使用此代码将字节数组转换为字符串:
private string ByteArrayToString(byte[] input)
{
ASCIIEncoding dec = new ASCIIEncoding();
return dec.GetString(input);
}
以下是加密/解密功能。解密功能运行良好。
private string DecryptStringFromBytesAes(byte[] cipherText, byte[] Key, byte[] IV)
{
// Check arguments.
if (cipherText == null || cipherText.Length <= 0)
throw new ArgumentNullException("cipherText");
if (Key == null || Key.Length <= 0)
throw new ArgumentNullException("Key");
// Declare the string used to hold
// the decrypted text.
string plaintext = null;
// Create an RijndaelManaged object
// with the specified key and IV.
using (RijndaelManaged aesAlg = new RijndaelManaged())
{
aesAlg.Key = Key;
aesAlg.Padding = PaddingMode.Zeros;
aesAlg.Mode = CipherMode.ECB;
// Create a decrytor to perform the stream transform.
ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for decryption.
using (MemoryStream msDecrypt = new MemoryStream(cipherText))
{
using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
{
using (StreamReader srDecrypt = new StreamReader(csDecrypt))
{
// Read the decrypted bytes from the decrypting stream
// and place them in a string.
plaintext = srDecrypt.ReadToEnd();
}
}
}
}
return plaintext;
}
private byte[] EncryptStringToBytesAes(string plainText, byte[] Key, byte[] IV)
{
// Check arguments.
if (plainText == null || plainText.Length <= 0)
throw new ArgumentNullException("plainText");
if (Key == null || Key.Length <= 0)
throw new ArgumentNullException("Key");
byte[] encrypted;
// Create an RijndaelManaged object
// with the specified key and IV.
using (RijndaelManaged aesAlg = new RijndaelManaged())
{
aesAlg.Key = Key;
aesAlg.Padding = PaddingMode.Zeros;
aesAlg.Mode = CipherMode.ECB;
// Create a decrytor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
using (MemoryStream msEncrypt = new MemoryStream())
{
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
//Write all data to the stream.
swEncrypt.Write(plainText);
}
encrypted = msEncrypt.ToArray();
}
}
}
return encrypted;
}
您观察到的是将任意字节(在0-255范围内)映射到字符的问题。有意义的字符仅在32-255范围内,甚至仅在32-127(ASCII)范围内。低于32的值是所谓的不可打印字符,高于127的值取决于您使用的字符编码。这就是为什么加密文本看起来像垃圾的原因。因此,Mast加密系统将字节转换为可感知的ASCII范围。一种这样的算法是BASE64。因此,通过BASE64对加密的字节进行篡改,可以获得所有可打印的字符,并且通过电子邮件也不会出现问题。在解密之前,您必须撤消BASE64编码。
另一种使加密结果看起来更好的方法是显示它的十六进制表示。例如,如果字节值为15
,则打印0F
。您可以使用它来表示十六进制的字节数组:
private string ByteArrayToHexString(byte[] data)
{
return String.Concat(data.Select(b => b.ToString("x2")));
}
为了将输出作为数据的十六进制编码,请遵循此处的方法。我将它们稍微修改为扩展方法:
public static string ToHexString(this byte[] bytes)
{
return bytes == null ? string.Empty : BitConverter.ToString(bytes).Replace("-", string.Empty);
}
public static byte[] FromHexString(this string hexString)
{
if (hexString == null)
{
return new byte[0];
}
var numberChars = hexString.Length;
var bytes = new byte[numberChars / 2];
for (var i = 0; i < numberChars; i += 2)
{
bytes[i / 2] = Convert.ToByte(hexString.Substring(i, 2), 16);
}
return bytes;
}
加密的字符串看起来像乱码。测试加密是否正常工作的方法是通过解密将字符串传回。如果它能解密,那么你就知道这个字符串是正确的,尽管它看起来像垃圾。