/// <summary>
/// AESDecrypt
/// </summary>
/// <param name="input">待解密数据</param>
/// <param name="key">密钥</param>
/// <param name="kSize">密钥长度 default：8位</param>
/// <returns></returns>
public static string AESDecrypt(this string input, string key, KeySizeEnum kSize = KeySizeEnum.KEY16)
{
if (string.IsNullOrEmpty(input))
{
return(string.Empty);
}
var decrypted = string.Empty;
var dataBytes = Convert.FromBase64String(input.Replace(" ", "+"));
var aes = _genAESProvider(key, kSize);
var mStream = new MemoryStream();
var cStream = new CryptoStream(mStream, aes.CreateDecryptor(), CryptoStreamMode.Write);
try
{
cStream.Write(dataBytes, 0, dataBytes.Length);
cStream.FlushFinalBlock();
decrypted = Encoding.UTF8.GetString(mStream.ToArray());
}
catch
{
return(string.Empty);
}
finally
{
mStream.Close();
cStream.Close();
aes.Clear();
}
return(decrypted);
}
/// <summary>
/// _genAESProvider
/// </summary>
/// <param name="key">密钥</param>
/// <param name="kSize">密钥长度 default：16位</param>
/// <returns></returns>
private static Rijndael _genAESProvider(string key, KeySizeEnum kSize)
{
Rijndael aesProvider = Rijndael.Create();
aesProvider.Mode = CipherMode.CBC;
aesProvider.Padding = PaddingMode.PKCS7;
aesProvider.KeySize = (int)kSize;
aesProvider.BlockSize = (int)kSize;
string strTemp;
int keyLen = (int)kSize / 8;
if (key.Length >= keyLen)//密钥长度足够
{
strTemp = key.Substring(0, keyLen);
}
else//密钥程度不足，为其添加所需要的长度
{
strTemp = key + key.Md5().Substring(0, keyLen - key.Length);
}
byte[] bytKey = Encoding.UTF8.GetBytes(strTemp);
aesProvider.Key = bytKey;
aesProvider.IV = bytKey;
return(aesProvider);
}
