public ActionResult GetImageBytes(string code)
{
try
{
var protectedTokenBytes = Convert.FromBase64String(code);
var tokenBytes = MachineKey.Unprotect(protectedTokenBytes, typeof(CaptchaImageToken).Name);
var token = CaptchaImageToken.FromBytes(tokenBytes);
if (!CheckGetImageBytesTimeout(token.Timestamp))
{
return(InvalidCaptchaParamImage());
}
var image = new CaptchaImage();
ApplyCaptchaImageProperties(image);
image.Text = token.ImageContent;
var resultStream = new MemoryStream();
using (Bitmap bitmap = image.RenderImage())
bitmap.Save(resultStream, ImageFormat.Jpeg);
return(File(resultStream.ToArray(), "image/jpeg"));
}
catch (Exception)
{
return(InvalidCaptchaParamImage());
}
}
public ActionResult ViewImage()
{
var token = new CaptchaImageToken(GenerateRandomText());
var protectedTokenBytes = MachineKey.Protect(token.ToBytes(), typeof(CaptchaImageToken).Name);
var protectedTokenString = Convert.ToBase64String(protectedTokenBytes);
return(PartialView((object)protectedTokenString));
}
public static CaptchaImageToken FromBytes(byte[] bytes)
{
if (bytes == null || bytes.Length <= 8)
{
return(null);
}
var result = new CaptchaImageToken
{
Timestamp = BitConverter.ToInt64(bytes, 0),
ImageContent = Encoding.UTF8.GetString(bytes, 8, bytes.Length - 8)
};
return(result);
}