上传图片的综合验证

#region 私有变量
private static string path = "";
//"script",
private static List<string> chkList = new List<string>();
//private static string[] chkList = {"include","filesystemobject","shell.application","request",".getfolder",".createfolder",".deletefolder",".createdirectory",".deletedirectory",".saveas","wscript.shell","script.encode","server.",".createobject","execute","activexobject","language=","<%","<%","session"};
#endregion

protected void Page_Load(object sender, EventArgs e)
{
if (string.IsNullOrEmpty(path))
{
path = Page.Server.MapPath("~\\Pictrue\\");
}
if (chkList.Count < 1)
{
string chkStr = ConfigurationManager.AppSettings["CodeCheck"];
string[] chks = chkStr.Split(',');
foreach (string str in chks)
{
chkList.Add(str);
}
chkList.Add("<%");
chkList.Add("<%");
}
string result = "<?xml version=\"1.0\" encoding=\"utf-8\"?>\r\n<Data>\r\n";
result = SaveFile(result);
result += "</Data>";
Response.ContentType = "text/xml";
Response.ContentEncoding = Encoding.UTF8;
Response.Write(result);
Response.End();
}

public string SaveFile(string result)
{
try
{
string key = ConfigurationManager.AppSettings["AppKey"];
string type = Request["type"];
string id = Request["id"];
string sign = Request["sign"];
string timestamp = Request["timestamp"];
if ( string.IsNullOrEmpty(type)
|| string.IsNullOrEmpty(id)
|| string.IsNullOrEmpty(sign)
|| string.IsNullOrEmpty(timestamp))
{
result += "<Code>1001</Code>\r\n";
result += "<Message>缺少参数</Message>\r\n";
return result;
}
int minute = int.Parse(timestamp.Substring(10,2));
int second = int.Parse(timestamp.Substring(12,2));
if ((minute * 60 + second + 60) < (DateTime.Now.Minute * 60 + DateTime.Now.Second))
{
result += "<Code>1007</Code>\r\n";
result += "<Message>时间已过期</Message>\r\n";
return result;
}
string newSign = Tools.EncryptMd5UTF8("id=" + id + "&timestamp=" + timestamp + "&type=ts" + key);
if(sign.ToLower() != newSign)
{
result += "<Code>1002</Code>\r\n";
result += "<Message>参数验证错误</Message>\r\n";
return result;
}
string imgPath = path + type.ToUpper() + "\\" + id.ToUpper() + "\\" + timestamp.ToUpper();
if (!Directory.Exists(imgPath))
{
Directory.CreateDirectory(imgPath);
}
for (int i = 0; i < Request.Files.Count; i++)
{
HttpPostedFile filePost = Request.Files[i];
string ImgName = filePost.FileName.Substring(filePost.FileName.LastIndexOf('\\') + 1);

#region 基本验证
int ImgSize = filePost.ContentLength;
if (ImgSize == 0 || string.IsNullOrEmpty(ImgName))
{
continue;
}
string savePath = imgPath + "\\" + ImgName;
#endregion

#region 验证图片大小
if (ImgSize > 2048 * 1024)
{//大于2M
result += "<Code>1003</Code>\r\n";
result += "<Message>图片【" + ImgName + "】大小超过2M</Message>\r\n";
return result;
}
#endregion

#region 验证图片是否附加恶意代码
byte[] buff = new byte[ImgSize];
filePost.InputStream.Read(buff, 0, ImgSize);
filePost.InputStream.Seek(0, SeekOrigin.Begin);
string imgStr = Encoding.Default.GetString(buff);
string strContent = imgStr.ToLower();
foreach (string s in chkList)
{
if (strContent.IndexOf(s) != -1)
{
result += "<Code>1004</Code>\r\n";
result += "<Message>图片【" + ImgName + "】包含恶意代码</Message>\r\n";
Tools.Log("图片【" + ImgName + "】包含恶意代码【" + s + "】原串为【" + strContent + "】");
return result;
}
}
#endregion

#region 验证图片类型
//验证文件后缀名
string ImgType = Path.GetExtension(filePost.FileName);
if (ImgType.ToLower() != ".bmp" && ImgType.ToLower() != ".jpg" && ImgType.ToLower() != ".jpeg")
{
result += "<Code>1005</Code>\r\n";
result += "<Message>图片【" + ImgName + "】格式不正确, 请选择.bmp/.jpg/.jpeg类型的图片</Message>\r\n";
return result;
}

//验证文件内容格式
//8297:RAR|255216:jpg|7173:gif||6677:bmp|13780:png|7790:exe dll|8297:rar|6063:xml|6033:html|239187:aspx|117115:cs|119105:js|210187:txt|255254:sql
//1.Png图片文件包括8字节：89 50 4E 47 0D 0A 1A 0A。即为 .PNG....。
//2.Jpg图片文件包括2字节：FF D8。
//3.Gif图片文件包括6字节：47 49 46 38 39|37 61 。即为 GIF89(7)a。
//4.Bmp图片文件包括2字节：42 4D。即为 BM。
byte[] head = new byte[2];//这里只判断j是否为jpg格式所以获取前两个字节就可以
filePost.InputStream.Read(head, 0, head.Length);
filePost.InputStream.Seek(0, SeekOrigin.Begin);
if ((head[0] == 255 && head[1] == 216)
|| (head[0] == 66 && head[1] == 77))
{//jpg or bmp
filePost.SaveAs(savePath);
}
else
{
result += "<Code>1005</Code>\r\n";
result += "<Message>图片【" + ImgName + "】格式不正确, 请选择.bmp/.jpg/.jpeg类型的图片</Message>\r\n";
return result;
}
#endregion
}
result += "<Code>1000</Code>\r\n";
result += "<Message>图片保存成功</Message>\r\n";
return result;
}
catch (Exception ex)
{
Tools.Log("SaveFile error:" + ex.Message);
result += "<Code>1006</Code>\r\n";
result += "<Message>内部错误，请稍后重试</Message>\r\n";
return result;
}
}