Spam filtering: where do I start - c#

I have created a new asp.net site (web forms, c#) and looking to make it secure against spam coming through textboxes and being added to the database. Does anyone have any good links on how to implement this?
Thanks

I use ReCaptcha for this.
You can download it from nuget or install with
Install-Package recaptcha
command through package management console
public class NoCache : ActionFilterAttribute
{
public class CaptchaValidatorAttribute : ActionFilterAttribute
{
private const string CHALLENGE_FIELD_KEY = "recaptcha_challenge_field";
private const string RESPONSE_FIELD_KEY = "recaptcha_response_field";
private const string CAPTCHA_MODEL_KEY = "Captcha";
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
var captchaChallengeValue = filterContext.HttpContext.Request.Form[CHALLENGE_FIELD_KEY];
var captchaResponseValue = filterContext.HttpContext.Request.Form[RESPONSE_FIELD_KEY];
var captchaValidtor = new Recaptcha.RecaptchaValidator
{
PrivateKey = "key",
RemoteIP = filterContext.HttpContext.Request.UserHostAddress,
Challenge = captchaChallengeValue,
Response = captchaResponseValue
};
var recaptchaResponse = captchaValidtor.Validate();
if (!recaptchaResponse.IsValid)
{
filterContext.Controller
.ViewData.ModelState
.AddModelError(
CAPTCHA_MODEL_KEY,
"Entered text is invalid");
}
base.OnActionExecuting(filterContext);
}
}
public static class CaptchaExtensions
{
public static string GenerateCaptcha(this HtmlHelper helper)
{
var captchaControl = new Recaptcha.RecaptchaControl
{
ID = "recaptcha",
Theme = "white",
PublicKey = "key",
PrivateKey = "key"
};
var htmlWriter = new HtmlTextWriter(new StringWriter());
captchaControl.RenderControl(htmlWriter);
return htmlWriter.InnerWriter.ToString();
}
}
Than you can use
#using (Html.BeginForm("activate_user", , FormMethod.Post))
{
#Html.HiddenFor(x => x.Email)
<div class="captcha">
#Html.Raw(#Html.GenerateCaptcha())
<div style="text-align:center; margin-left:-25px;">
#Html.ValidationMessage("Captcha")
</div>
</div>
<input type="submit" class="signUpButton active activation" value="Activate" />
}
And in controller:
[ActionName("activate_user")]
[CaptchaValidator]
[HttpPost]
public ActionResult ActivateUser(string email)
{
if (ModelState.IsValid && !string.IsNullOrEmpty(email))
{
FormsAuthentication.SetAuthCookie(email, false);
Repository.ActivateUser(email);
}
return View();
}

If you do not have spam, I wouldn't worry about it.
That being said, if you do have it, you want to know what kind of spam you are getting. Validating the input against the model should prevent most of it assuming you have restrictions on the valid input. If just about anything validates, or you have to accept everything for some reason, you can start with a honey pot, which is a simple, non intrusive method.
To implement a honey pot, you basically add a field, hide it with CSS and and validate that field is null on the server side. Most spam bots fill out all fields and this will identify when something automated has submitted the form.
If you find this ineffective in preventing all spam on your site, you need to see what kind of spam is getting through and find something that prevents that. As a last resort, you can move to intrusive actions such as recaptcha. The real issue with CAPTCHA's (as Eric Lippert's succinctly states it) is that they assume guilt, that the user is trying to do something bad, and that has a negative effect on your users.

I suggest that you take the Growmap Anti-Spam plugin for WordPress and convert its Javascript and PHP implementation to something you can use in your project. It's not as annoying as CAPTCHA to end users and it's been quite effective in stopping automated spam on my WordPress blogs. It shouldn't be a big deal to do the ASP.NET/C# conversion. I started on one but the project I was doing it for got canceled so I didn't complete it.
Of course, it won't help with manual spamming where somebody pays $5 for someone sitting in a third world Internet cafe to enter nonsense onto dozens of sites. This is also a problem for many other anti-spam systems, including CAPTCHA. This activity is primarily done to get links for SEO purposes so screening out links for moderation or preventing them from being entered can curtail this activity.

Related

NetSuite SuiteTalk: SavedSearch for "Deleted Record" Type

How does one get the results of a "Saved Search" of Type "Deleted Record" in NetSuite? Other search types are obvious(CustomerSearchAdvanced, ItemSearchAdvanced, etc...) but this one seems to have no reference online, just documentation around deleting records, not running saved searches on them.
Update 1
I should clarify a little bit more what I'm trying to do. In NetSuite you can run(and Save) Saved Search's on the record type "Deleted Record", I believe you are able to access at least 5 columns(excluding user defined ones) through this process from the web interface:
Date Deleted
Deleted By
Context
Record Type
Name
You are also able to setup search criteria as part of the "Saved Search". I would like to access a series of these "Saved Search's" already present in my system utilizing their already setup search criteria and retrieving data from all 5 of their displayed columns.
The Deleted Record record isn't supported in SuiteTalk as of version 2016_2 which means you can't run a Saved Search and pull down the results.
This is not uncommon when integrating with NetSuite. :(
What I've always done in these situations is create a RESTlet (NetSuite's wannabe RESTful API framework) SuiteScript that will run the search (or do whatever is possible with SuiteScript and not possible with SuiteTalk) and return the results.
From the documentation:
You can deploy server-side scripts that interact with NetSuite data
following RESTful principles. RESTlets extend the SuiteScript API to
allow custom integrations with NetSuite. Some benefits of using
RESTlets include the ability to:
Find opportunities to enhance usability and performance, by
implementing a RESTful integration that is more lightweight and
flexible than SOAP-based web services. Support stateless communication
between client and server. Control client and server implementation.
Use built-in authentication based on token or user credentials in the
HTTP header. Develop mobile clients on platforms such as iPhone and
Android. Integrate external Web-based applications such as Gmail or
Google Apps. Create backends for Suitelet-based user interfaces.
RESTlets offer ease of adoption for developers familiar with
SuiteScript and support more behaviors than NetSuite's SOAP-based web
services, which are limited to those defined as SuiteTalk operations.
RESTlets are also more secure than Suitelets, which are made available
to users without login. For a more detailed comparison, see RESTlets
vs. Other NetSuite Integration Options.
In your case this would be a near trivial script to create, it would gather the results and return JSON encoded (easiest) or whatever format you need.
You will likely spend more time getting the Token Based Authentication (TBA) working than you will writing the script.
[Update] Adding some code samples related to what I mentioned in the comments below:
Note that the SuiteTalk proxy object model is frustrating in that it
lacks inheritance that it could make such good use of. So you end with
code like your SafeTypeCastName(). Reflection is one of the best tools
in my toolbox when it comes to working with SuiteTalk proxies. For
example, all *RecordRef types have common fields/props so reflection
saves you type checking all over the place to work with the object you
suspect you have.
public static TType GetProperty<TType>(object record, string propertyID)
{
PropertyInfo pi = record.GetType().GetProperty(propertyID);
return (TType)pi.GetValue(record, null);
}
public static string GetInternalID(Record record)
{
return GetProperty<string>(record, "internalId");
}
public static string GetInternalID(BaseRef recordRef)
{
PropertyInfo pi = recordRef.GetType().GetProperty("internalId");
return (string)pi.GetValue(recordRef, null);
}
public static CustomFieldRef[] GetCustomFieldList(Record record)
{
return GetProperty<CustomFieldRef[]>(record, CustomFieldPropertyName);
}
Credit to #SteveK for both his revised and final answer. I think long term I'm going to have to implement what is suggested, short term I tried implementing his first solution("getDeleted") and I'd like to add some more detail on this in case anyone needs to use this method in the future:
//private NetSuiteService nsService = new DataCenterAwareNetSuiteService("login");
//private TokenPassport createTokenPassport() { ... }
private IEnumerable<DeletedRecord> DeletedRecordSearch()
{
List<DeletedRecord> results = new List<DeletedRecord>();
int totalPages = Int32.MaxValue;
int currentPage = 1;
while (currentPage <= totalPages)
{
//You may need to reauthenticate here
nsService.tokenPassport = createTokenPassport();
var queryResults = nsService.getDeleted(new GetDeletedFilter
{
//Add any filters here...
//Example
/*
deletedDate = new SearchDateField()
{
#operator = SearchDateFieldOperator.after,
operatorSpecified = true,
searchValue = DateTime.Now.AddDays(-49),
searchValueSpecified = true,
predefinedSearchValueSpecified = false,
searchValue2Specified = false
}
*/
}, currentPage);
currentPage++;
totalPages = queryResults.totalPages;
results.AddRange(queryResults.deletedRecordList);
}
return results;
}
private Tuple<string, string> SafeTypeCastName(
Dictionary<string, string> customList,
BaseRef input)
{
if (input.GetType() == typeof(RecordRef)) {
return new Tuple<string, string>(((RecordRef)input).name,
((RecordRef)input).type.ToString());
}
//Not sure why "Last Sales Activity Record" doesn't return a type...
else if (input.GetType() == typeof(CustomRecordRef)) {
return new Tuple<string, string>(((CustomRecordRef)input).name,
customList.ContainsKey(((CustomRecordRef)input).internalId) ?
customList[((CustomRecordRef)input).internalId] :
"Last Sales Activity Record"));
}
else {
return new Tuple<string, string>("", "");
}
}
public Dictionary<string, string> GetListCustomTypeName()
{
//You may need to reauthenticate here
nsService.tokenPassport = createTokenPassport();
return
nsService.search(new CustomListSearch())
.recordList.Select(a => (CustomList)a)
.ToDictionary(a => a.internalId, a => a.name);
}
//Main code starts here
var results = DeletedRecordSearch();
var customList = GetListCustomTypeName();
var demoResults = results.Select(a => new
{
DeletedDate = a.deletedDate,
Type = SafeTypeCastName(customList, a.record).Item2,
Name = SafeTypeCastName(customList, a.record).Item1
}).ToList();
I have to apply all the filters API side, and this only returns three columns:
Date Deleted
Record Type(Not formatted in the same way as the Web UI)
Name

Losing Cookies and Session Variables during AuthorizeCore

I'm currently working on getting a test environment stood up (it is currently called DEV) and am experiencing some weird issues.
When you first come to the site, we have an agreement page. Hitting the "I Agree" button will force the user through an Action to check to see if they are a member of the site already or not. We do use a demo mode also, but that is not part of the issue.
The issue I'm currently experiencing is the following. Initially in the Action, we create a Cookie called "siteaccept". Once that is created, we determine if the site is in demo mode or not, then move on to getting the user (actual user or demo user). Once the user is found, we log their Id in a Cookie called "cntPOC", and also create a Session variable by the same name with the same data (original developers wrote much of this convoluted logic which I want to change before someone asks why keep a Session and Cookie). We then do a RedirectToAction to the Action to bring up the main page of the site.
Here is where the issue comes into play. The main page of the site's Action has a CustomAuthorizeAttribute decoration on it. In our CustomAuthorizeAttribute class, we have OnAuthorizion and AuthorizeCore being overrode. OnAuthorizion fires off first, however, it uses base.OnAuthorization. Once that is called, AuthorizeCore is called. In AuthorizeCore, we check for the "siteaccept" Cookie, followed by a check on the "cntPOC" Session variable. If both are there, we return true, otherwise false if either fails.
On not only my local environment but the DBA's, this works without a hitch. I see our Cookies and Session variable. However, on our DEV environment, both the Cookies and Session variable are missing. We have IE 11 configured to allow Cookies, yet we cannot get them once we leave the Action and proceed into the CustomAuthorizeAttribute.
I did find I can find the Cookie today if I check HttpContext.Current.Response instead of HttpContext.Current.Request, but that is the incorrect way to do it obviously.
Below is my code. I'm fairly certain since the code works on my local environment, it should be fine in our DEV environment. Also a quick note, our production environment does work, so the code obviously functions. It's a question now of why does the DEV environment not.
MainController.cs
[HttpPost]
public ActionResult Index(FormCollection frmCollection)
{
try
{
Response.Cookies.Remove("bracmisaccept");
HttpCookie cookie = new HttpCookie("bracmisaccept");
cookie.Value = "true";
Response.Cookies.Add(cookie);
...
//Demo Mode
var poc = new HttpCookie("cntPOC");
cookie.Value = "7578";
Response.Cookies.Add(poc);
Session["cntPOC"] = 7578;
return RedirectToAction("ApplicationSelection");
}
catch (Exception ex)
{
logger.LogError("Main Index", ex);
return PartialView(#"../Error/ExceptionHandling");
}
}
[CustomAuthorizeAttribute]
public ActionResult ApplicationSelection()
{
return View();
}
CustomAuthorizeAttribute.cs
public string RedirectUrl = "~/Main/SessionTimeout";
public string CookieExpiredRedirectUrl = "~/Main/Index";
public string AjaxRedirectUrl = "~/Error/AjaxError";
private bool _isAuthorized;
private bool _isCookieExpired;
protected override bool AuthorizeCore(HttpContextBase httpContext)
{
if (HttpContext.Current.Request.Cookies["siteaccept"] == null)
{
_isAuthorized = false;
_isCookieExpired = true;
return false;
}
if (HttpContext.Current.Session["cntPOC"] == null)
{
_isAuthorized = false;
return false;
}
return true;
}
public override void OnAuthorization(AuthorizationContext filterContext)
{
base.OnAuthorization(filterContext);
if (!_isAuthorized)
{
if (filterContext.RequestContext.HttpContext.Request.IsAjaxRequest())
{
filterContext.HttpContext.Response.StatusCode = 401;
filterContext.HttpContext.Response.End();
}
else
{
if(_isCookieExpired)
filterContext.RequestContext.HttpContext.Response.Redirect(CookieExpiredRedirectUrl);
else
filterContext.RequestContext.HttpContext.Response.Redirect(RedirectUrl);
}
}
}
I'm fairly certain the code is fine, but I did read in a few articles that AuthorizeCore may or may not have the Cookies and Session variables at times. I just wanted to find out if I'm wasting my time with changing the code or if it's the box we have this site on. The server is super locked down, so yeah, kind of annoying...
Edit: I have yet to figure out how to fix this yet, however, I did find if I do a publish on this code, I can enter into the site properly. I still cannot run localhost to inspect the site, but a publish fixes a few minor issues of whether things will work on this site.

ASP.NET Security: single entry of role names

We're building an ASP.NET app, and have a requirement to use the corporate LDAP system (Siteminder) for authentication (upside: no login dialogs). Roles are created in the LDAP tool, and users are assigned to the roles by userland managers (read: the structure has to be easily understood). Currently, all apps that use the system use a dual-entry process whereby the roles identified in the app are hand-entered into the LDAP system and users are assigned, then app functions are assigned to their role mirrors in an app-based control panel. This works, but it bothers me that dual-entry is required.
What I would like to achieve is something where the app queries the LDAP system to get a list of roles that are assigned to the app (which is identified in the LDAP system) and populate the role:function control panel with them. This part seems really straightforward. However, I lose clarity when it comes to figuring out what to put in the Authorize attribute:
[Authorize(Roles = "Admin, Moderator")]
would become... what?
[Authorize(LoadedRoles(r => r.FindAll("some expression that describes the roles that have a particular permission")))]
I'm seriously into blue sky territory here. I read this question, and liked - from an architectural standpoint - the answer that suggested making the permissions the roles. But that might not be acceptable to the userland managers that needed to manage users. On the other hand, this question turns things into non-string resources, but I can't conceive of how to translate that into "roles that have this sort of function included".
Any suggestions?
Update:
Based on the advice of #venerik below, I've made some progress. For the time being, I'm encapsulating everything in the [AuthorizeFunctionAttribute], and will farm the individual pieces out where they belong later. To that end, I created three variables:
private IList<KeyValuePair<long, string>> Roles;
private IList<KeyValuePair<long, string>> Functions;
private IList<RoleFunction> RoleFunctions;
...then put static data in them:
Roles = new ICollection<KeyValuePair<long, string>>();
Roles.Add(KeyValuePair<long, string>(1, "Basic User"));
Roles.Add(KeyValuePair<long, string>(2, "Administrator"));
Functions = new ICollection<KeyValuePair<long, string>>();
Functions.Add(KeyValuePair<long,string>(1,"List Things"));
Functions.Add(KeyValuePair<long,string>(2,"Add Or Edit Things"));
Functions.Add(KeyValuePair<long,string>(3,"Delete Things"));
...and finally bound them together (in a complicated manner that lays the groundwork for the future):
RoleFunctions = new IList<RoleFunction>();
RoleFunctions.Add(
new RoleFunction
{
RoleId = Roles.Where( r => r.Value == "Basic User").FirstOrDefault().Key,
FunctionId = Functions.Where( f => f.Value == "List Things" ).FirstOrDefault().Key,
isAuthorized = true
},
new RoleFunction
{
RoleId = Roles.Where( r => r.Value == "Administrator").FirstOrDefault().Key,
FunctionId = Functions.Where( f => f.Value == "Add or Edit Things" ).FirstOrDefault().Key,
isAuthorized = true
},
// More binding...
);
I feel good about this so far. So I went researching AuthorizeCore to see what I needed to do there. However, per the comment at the bottom of the page, it's not very helpful. I more or less get that at the end, the method needs to return a bool value. And I get that I need to check that one of the User.Roles array fits the permission that's passed in through [AuthorizeFunction("List Things")].
Update (again):
I've got the following code, which seems like it will do what I need (one method needs fleshing out):
/// <summary>An authorization attribute that takes "function name" as a parameter
/// and checks to see if the logged-in user is authorized to use that function.
/// </summary>
public class AuthorizeFunctionAttribute : AuthorizeAttribute
{
private IList<KeyValuePair<long, string>> Roles;
private IList<KeyValuePair<long, string>> Functions;
private IList<RoleFunction> RoleFunctions;
public string Function { get; private set; }
public AuthorizeFunctionAttribute(string FunctionName)
{
Function = FunctionName;
Roles = SetApplicationRoles();
Functions = SetApplicationFunctions();
RoleFunctions = SetRoleFunctions();
}
protected virtual bool AuthorizeCore(HttpContextBase httpContext)
{
bool userIsAuthorized = false;
foreach (string ur in GetUserRoles(httpContext.Current.Request.Headers["SM_USER"]))
{
long roleId = Roles.Where( sr => sr.Value == ur )
.First().Key;
long functionId = Functions.Where( sf => sf.Value == Function )
.First().Key;
// If any role is authorized for this function, set userIsAuthorized to true.
// DO NOT set userIsAuthorized to false within this loop.
if (RoleFunctions.Where(rf => rf.RoleId == roleId && rf.FunctionId == functionId)
.First().isAuthorized)
{
userIsAuthorized = true;
}
}
return userIsAuthorized;
}
Previously I didn't know enough about the underlying bits of creating a custom attribute to get out of my own way. However, this MSDN article told me what should have been obvious to me in the beginning: build it yourself. So, once I get the GetUserRoles() method put together, I should be underway.
I think you can solve this using a custom AuthorizeAttribute. In a project I worked close to they used that to access Active Directory (as described in this answer).
In your case it would look something like:
public class AuthorizeWithLDAPAttribute(string functionName) : AuthorizeAttribute
{
protected virtual bool AuthorizeCore(HttpContextBase httpContext)
{
// check LDAP to verify that user has
// a role that's linked to `functionName`
}
}
Next you can use this attribute on your controllers and/or methods:
[AuthorizeWithLDAP("functionName1")]
public class BlogController : Controller
{
....
[AuthorizeWithLDAP("functionName2")]
public ViewResult Index()
{
return View();
}
}
The controller is now only accessible to users whose role are linked to functionName1 and the method is only accessible to users whose role are linked to functionName1 and functionName2

How to maintain culture through session variable

I have a multilingual web-forms web application which I am using resource files and a BasePage class which sets the culture based on the QueryString that was included in the page which is inheriting from this class. This is all working well, if a tad clunky as I am having to do this sort of thing for every button which takes the user to a different page to maintain the culture:
if (Thread.CurrentThread.CurrentCulture.ToString() == "cy-GB")
{
return "~/Secure/Details.aspx?lang=cy-GB&PersonId=" + currentPersonId;
}
else
{
return "~/Secure/Details.aspx?PersonId=" + currentPersonId;
}
I knew there was probably a better way of doing this but being a novice as it worked I simply made do.
This was until I had to implement an asp:SiteMapPath control. I initially assumed that I could simply create a resource entry for the url property like I had done for the title:
<siteMapNode
title="$resources:SiteMapLocalizations,HomePageTitle"
description="Home"
url="~$resources:SiteMapLocalizations,HomePageUrl">
However this resulted in a server error:
A potentially dangerous Request.Path value was detected from the client (:).
I've done some reading and I believe I need to somehow store the current culture to a session variable which will follow the user around so when they click 'Home' on the breadcrumb it will be consistent with the culture and grab the appropriate text from the resource files, I'm also hoping this will allow me to remove all of the IF ELSE statements I've had to write to maintain the current language throughout the application.
My question is however, where do I start with this, I cannot find any guide step by step to follow in order to achieve this, can anyone provide some instructions?
Make sure you have a button of some sort which triggers the change of language. In my case I have two versions of the header, one with an English link which will append the Query String to English and one for Welsh, something like:
ASP
<a id="languagelink" runat="server" title="Cymraeg">Cymraeg</a>
C#
if (Thread.CurrentThread.CurrentCulture.ToString() == "en-GB")
{
Uri uri = new Uri(currentPage);
languagelink.HRef = String.Format(uri.GetLeftPart(UriPartial.Path)+"?lang=cy-GB");
}
Every page which requires the language switch needs to inherit from my custom BasePage like so:
Inheritance
public partial class Secure_CustomerSummary : BasePage
Base_Page
public partial class BasePage : System.Web.UI.Page
{
protected override void InitializeCulture()
{
if (Session["language"] == null)
{
Session["language"] = "en-GB";
}
else
{
if (Request.QueryString["lang"] == null)
{
SetSessionCulture();
}
if (Request.QueryString["lang"] != null)
{
string qs = Request.QueryString["lang"];
Session["language"] = qs;
}
SetSessionCulture();
}
SetSessionCulture();
}
private void SetSessionCulture()
{
Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(Session["language"].ToString());
Thread.CurrentThread.CurrentUICulture = new CultureInfo(Session["language"].ToString());
base.InitializeCulture();
}
}

asp.net mvc 3 silverlight like validation

MAIN QUESTION
As the title says, i'm asking if anyone knows how to create a validation structure similar to silverlight's dataform. Any hints, materials , ideas would be welcome. I'd like to do a validation like this:
(You can check this out here)
DETAILS
I've been trying to something like the example above, but without results until now. Mostly because i dont' know how the validation message helper works. I've managed to a single validation message by taking the data-val-number attribute and set it into a link title (using a third party jquery plugin callled qTip to show a tooltip error message). However, i can't do the same thing if there are more than one validation.
So, is it possible to rewrite the validation message helper? I'd like to understand more how it shows the validation messages so i can put them on any html content. This would do the tooltip part and i could set as many messages as i want, with any formatting i desire.
And i'd like to be able to show the validation messages through any jquery events (mouseover, click, dblclick, ready, etc.). As far as i understand on it's actual implementation, the validation only occurs when the user changes focus from the actual input to another html element.
I highly recommend that you checkout the validation rules section in Professional ASP.NET MVC. It shows how to do exactly what you describe with ASP.NET MVC v1 and it works all the way up through v3.
The displayed user interface is slightly different; however, you can check the output and write your own CSS to make it look just like your screenshot.
For a quick example:
Action Result
try
{
// code
}
catch
{
foreach (var issue in std.GetRuleViolations())
{
ModelState.AddModelError(issue.PropertyName, issue.ErrorMessage);
}
}
Model
public IEnumerable<RuleViolation> GetRuleViolations()
{
if (!String.IsNullOrEmpty(this.Phone) && !Utility.IsValidPhoneNumber(this.Phone))
{
yield return new RuleViolation("Phone is invalid. Try this format: ###-###-####.", "HomePhone");
}
yield break;
}
Edit View
<%
using (Html.BeginForm())
{
%>
<fieldset>
<legend>Edit</legend>
<%= Html.ValidationSummary("Create was unsuccessful. Please correct the errors and try again.") %>
<%= Html.TextBox("Phone", Model.Phone)%>
<%= Html.ValidationMessage("Phone", "*")%>
<!-- more fields go here -->
</fieldset>
<% } %>
rule violation class -- lifted from link
public class RuleViolation
{
public string ErrorMessage { get; private set; }
public string PropertyName { get; private set; }
public RuleViolation(string errorMessage)
{
ErrorMessage = errorMessage;
}
public RuleViolation(string errorMessage, string propertyName)
{
ErrorMessage = errorMessage;
PropertyName = propertyName;
}
}

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