Authentication/Authorization using ASP.NET authentication and LDAP - c#

I have an existing ASP.NET application that uses LDAP for authentication and ASP.NET membership for authentication and authorization.
So an LDAP user could choose to authenticate either using his LDAP credentials, or ASP.NET membership credentials. A non LDAP user can only authenticate using LDAP credentials.
I now want to create a Web API project that uses a similar approach for authentication and authorization.
Using VS 2013, I created a new Web API project that uses the Individual Accounts option for authentication.
I've modified the GrantResourceOwnerCredentials method in the Providers\ApplicationOAuthProvider.cs file.
Before
...
IdentityUser user = await userManager.FindAsync(context.UserName, context.Password);
if (user == null)
{
context.SetError("invalid_grant", "The user name or password is incorrect.");
return;
}
...
After
...
IdentityUser user;
if (AuthenticateActiveDirectory(context.UserName, context.Password, "MyADDomain"))
{
user = await userManager.FindByNameAsync(context.UserName);
}
else
{
user = await userManager.FindAsync(context.UserName, context.Password);
}
if (user == null)
{
context.SetError("invalid_grant", "The user name or password is incorrect.");
return;
}
...
And the AuthenticateActiveDirectory method is:
private bool AuthenticateActiveDirectory(string userName, string password, string domain)
{
bool validation;
try
{
var lcon = new LdapConnection(new LdapDirectoryIdentifier((string)null, false, false));
var nc = new NetworkCredential(userName, password, domain);
lcon.Credential = nc;
lcon.AuthType = AuthType.Negotiate;
lcon.Bind(nc);
validation = true;
}
catch (LdapException)
{
validation = false;
}
return validation;
}
This works, but is it the best way of doing it or is there a better way?

It's fine. Couple things come to mind:
If you have multiple domains in your forest (or ever will support that), username isn't unique across the forest - just the domain. Looks like you're keying on username today.
For your LdapConnection, I assume the null server name is just for show here? Rather than hardcoding one, you can use the S.DS.AD namespace to find a domain controller for you.
You'd probably want AuthType.Basic rather than Negotiate here. You'll want to make sure your connection is LDAP/S since the creds will be cleartext.

Related

server locking out username after 1 failed login attempt?

I have the following C# method which is used for a custom authentication implementation:
public bool Authenticate(AuthenticateRequest userCredentials)
{
var encoding = Encoding.GetEncoding("iso-8859-1");
var userName = encoding.GetString(Convert.FromBase64String(userCredentials.NetworkUserId));
var password = encoding.GetString(Convert.FromBase64String(userCredentials.Password));
var pc = new PrincipalContext(ContextType.Domain, userCredentials.DomainName);
var isValid = pc.ValidateCredentials(userName, password);
return isValid;
}
This works well when the correct user credentials are provided. This also works well when incorrect user credentials are provided. The problem is that when invalid user credentials are provided only 1 time, the user account gets locked out and subsequent login attempts fail, even when the proper credentials are submitted. Is there a way to configure this code or the server to allow 3 login attempts before the user account lockout happens?

Implementing External Authentication for Mobile App in ASP.NET WebApi 2

I'm trying to build an API (using ASP.NET WebApi) that will be consumed by a native mobile app for a school project. (I'm not concerned about/developing the mobile app, this responsibility falls on a different member)
I'm at a point where I need to implement a token based Facebook login. There are a lot of tutorials available for how to implement this feature for browser based apps (this is pretty straight forward and most of it comes inbuilt), but I don't think I follow how this would work with native apps. What I don't understand is how the redirects would work?
According to this link, nothing needs to be handled specifically by my server. And I don't think I understand how this would work? How would the tokens from Facebook be handled?
Also, what part of token handling should I implement, I couldn't really find good documentation for WebApi external login authentication.
Anyway, if someone could point me to the exact flow of token exchanges that happen and what is implemented by default by ASP.NET, that would be super helpful.
Also, the biggest point of confusion for me is I don't understand how the token returned by Facebook will be handled.
I assume the token will be returned to the client (mobile app), how do I get access to it on my server?
How do I create a local token from facebook's token?
Is this all done internally/auto-magically by ASP.NET?
I'm sorry if this is something I should've been able to figure out. I did do quite a bit of research and I found myself drowning in (related & unrelated) information. I don't think I even know how to search for the information I need.
Some links I've read:
Claims And Token Based Authentication (ASP.NET Web API)
Token Based Authentication using ASP.NET Web API 2, Owin, and Identity
ASP.NET Web API 2 external logins with Facebook and Google in AngularJS app
I had to do pretty much the same thing for an application I was working on. I also had a lot of trouble finding information about it. It seemed like everything I found was close to what I needed, but not exactly the solution. I ended up taking bits and pieces from a bunch of different blog posts, articles, etc. and putting them all together to get it to work.
I remember two of the links you posted "Claims and Token Based Authentication" and "ASP.NET Web API 2 external logins with Facebook and Google in AngularJS app" as being ones that had useful information.
I can't give you a comprehensive answer since I don't remember everything I had to do, nor did I even understand everything I was doing at the time, but I can give you the general idea. You are on the right track.
Essentially I ended up using the token granted by Facebook to confirm that they were logged into their Facebook account, created a user based on their Facebook user ID, and granted them my own bearer token that they could use to access my API.
The flow looks something like this:
Client authenticates with Facebook via whatever method (we used oauth.io)
Facebook returns them a token
Client sends token information to the registration endpoint of my WebApi controller
The token is validated using Facebook's Graph API, which returns user info
A user is created in the database via ASP.NET Identity with their Facebook user ID as the key
Client sends token information to the authentication endpoint of my WebApi controller
The token is validated using Facebook's Graph API, which returns user info
The user info is used to look up the user in the database, confirm they have previously registered
ASP.NET Identity is used to generate a new token for that user
That token is returned to the client
Client includes an Authorization header in all future HTTP requests with the new token granted by my service (ex. "Authorization: Bearer TOKEN")
If the WebApi endpoint has the [Authorize] attribute, ASP.NET Identity will automatically validate the bearer token and refuse access if it is not valid
There ended up being a lot of custom code for implementing the OAuth stuff with ASP.NET Identity, and those links you included show you some of that. Hopefully this information will help you a little bit, sorry I couldn't help more.
I followed this article. The flow is basically this
The server has the facebook keys just like with web login
The app asks for available social logins and displays buttons (you can hardcode this I guess)
When a button is pressed the app opens a browser and sets the URL to the one related to the specified social login. The ASP.NET then redirects the browser to facebook/google/whatever with the appropriate Challenge
The user might be logged in or not and might have given permission to your app or not. After he gives the permissions facebook redirects back to the provided callback URL
At that point you can get the external login info from the SignInManager and check if the user already exists and if you should create a new account
Finally a token is generated and the browser is redirected to a URL in which the token is placed. The app gets the token from the URL and closes the browser. Uses the token to proceed with API requests.
Honestly I have no idea if this approach is legit...
The code of the action buttons should redirect to:
public async Task<IEnumerable<ExternalLoginDto>> GetExternalLogins(string returnUrl, bool generateState = false)
{
IEnumerable<AuthenticationScheme> loginProviders = await SignInManager.GetExternalAuthenticationSchemesAsync();
var logins = new List<ExternalLoginDto>();
string state;
if (generateState)
{
const int strengthInBits = 256;
state = RandomOAuthStateGenerator.Generate(strengthInBits);
}
else
{
state = null;
}
foreach (AuthenticationScheme authenticationScheme in loginProviders)
{
var routeValues = new
{
provider = authenticationScheme.Name,
response_type = "token",
client_id = Configuration["Jwt:Issuer"],
redirect_uri = $"{Request.Scheme}//{Request.Host}{returnUrl}",
state = state
};
var login = new ExternalLoginDto
{
Name = authenticationScheme.DisplayName,
Url = Url.RouteUrl("ExternalLogin", routeValues),
State = state
};
logins.Add(login);
}
return logins;
}
The code for the callback action:
[Authorize(AuthenticationSchemes = "Identity.External")]
[Route("ExternalLogin", Name = "ExternalLogin")]
public async Task<IActionResult> GetExternalLogin(string provider, string state = null, string client_id = null, string error = null)
{
if (error != null)
{
ThrowBadRequest(error);
}
if (!User.Identity.IsAuthenticated)
{
return new ChallengeResult(provider);
}
string providerKey = User.FindFirstValue(ClaimTypes.NameIdentifier);
var externalLoginInfo = new ExternalLoginInfo(User, User.Identity.AuthenticationType, providerKey, User.Identity.AuthenticationType);
if (externalLoginInfo.LoginProvider != provider)
{
await HttpContext.SignOutAsync(IdentityConstants.ExternalScheme);
return new ChallengeResult(provider);
}
var userLoginInfo = new UserLoginInfo(externalLoginInfo.LoginProvider, externalLoginInfo.ProviderKey, externalLoginInfo.ProviderDisplayName);
User user = await UserManager.FindByLoginAsync(externalLoginInfo.LoginProvider, externalLoginInfo.ProviderKey);
if (client_id != Configuration["Jwt:Issuer"])
{
return Redirect($"/#error=invalid_client_id_{client_id}");
}
if (user != null)
{
return await LoginWithLocalUser(user, state);
}
else
{
string email = null;
string firstName = null;
string lastName = null;
IEnumerable<Claim> claims = externalLoginInfo.Principal.Claims;
if (externalLoginInfo.LoginProvider == "Google")
{
email = claims.FirstOrDefault(c => c.Type == ClaimTypes.Email)?.Value;
firstName = claims.FirstOrDefault(c => c.Type == ClaimTypes.GivenName)?.Value;
lastName = claims.FirstOrDefault(c => c.Type == ClaimTypes.Surname)?.Value;
}
else if (externalLoginInfo.LoginProvider == "Facebook")
{
email = claims.FirstOrDefault(c => c.Type == ClaimTypes.Email)?.Value;
string[] nameParts = claims.First(c => c.Type == ClaimTypes.Name)?.Value.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
firstName = nameParts?.First();
lastName = nameParts?.Last();
}
//some fallback just in case
firstName ??= externalLoginInfo.Principal.Identity.Name;
lastName ??= externalLoginInfo.Principal.Identity.Name;
user = new User
{
UserName = email,
Email = email,
FirstName = firstName,
LastName = lastName,
EmailConfirmed = true //if the user logs in with Facebook consider the e-mail confirmed
};
IdentityResult userCreationResult = await UserManager.CreateAsync(user);
if (userCreationResult.Succeeded)
{
userCreationResult = await UserManager.AddLoginAsync(user, userLoginInfo);
if (userCreationResult.Succeeded)
{
return await LoginWithLocalUser(user, state);
}
}
string identityErrrors = String.Join(" ", userCreationResult.Errors.Select(ie => ie.Description));
Logger.LogWarning($"Error registering user with external login. Email:{email}, Errors:" + Environment.NewLine + identityErrrors);
return Redirect($"/#error={identityErrrors}");
}
}
private async Task<RedirectResult> LoginWithLocalUser(User user, string state)
{
await HttpContext.SignOutAsync(IdentityConstants.ExternalScheme);
DateTime expirationDate = DateTime.UtcNow.AddDays(365);
string token = user.GenerateJwtToken(Configuration["Jwt:Key"], Configuration["Jwt:Issuer"], expirationDate);
return Redirect($"/#access_token={token}&token_type=bearer&expires_in={(int)(expirationDate - DateTime.UtcNow).TotalSeconds}&state={state}");
}

Token-based Authorization in Existing ASP.NET MVC App

I have inherited an existing application. This application uses ASP.NET MVC 3. It has some APIs. Those APIs look like the following:
[AcceptVerbs(HttpVerbs.Post)]
[Endpoint]
public ActionResult AuthenticatePlayer(string username, string password)
{
// Ensure that the user entered valid credentials
if (Membership.ValidateUser(username, password) == false)
return Json(new { statusCode = StatusCodes.INVALID_CREDENTIALS, message = "You entered an invalid username or password. Please try again." });
// Get the profile of the person that just logged in.
ProfileCommon userProfile = (ProfileCommon)(ProfileCommon.Create(username));
if (userProfile != null)
{
string name = username;
if (String.IsNullOrEmpty(userProfile.FirstName) == false)
name = userProfile.FirstName;
return Json(new {
statusCode = StatusCodes.SUCCESS,
payload = name,
username = username.ToLower(),
});
}
}
[AcceptVerbs(HttpVerbs.Get)]
[Endpoint]
public ActionResult SomeUserAction(string q)
{
// TODO: Ensure the user is authorized to perform this action via a token
// Do something
return Json(new { original = q, response = DateTime.UtcNow.Millisecond }, JsonRequestBehavior.AllowGet);
}
I'm trying to figure out how to integrate a token-based authorization schema into this process. From my understanding, a token-based system would return a short-lived token and a refresh token to a user if they successfully login. Then, each method can check to see if a user is authorized to perform the action by looking at the token. I'm trying to learn if this is built-in to ASP.NET MVC or if there is a library I can use. I need to figure out the shortest way to get this done.
Thank you so much!
I've built a WebAPI Token Authentication library a year ago, providing Token based authentication:
WebAPI Token Auth Bootstrap is out of the box Token based User Auth for WebAPI applications, Provides ready to use 'TokenAuthorize'
Attribute and 'TokenAuthApiController' Controller.
Among its features - Token Based User Authentication User Property inside the
TokenAuthApiController (Id, Username, Role, LastAccess).
Token Based User Authorization TokenAuthorizeAttribute with Access
Level - Public, User, Admin or Anonymous.
Built-in Functionality Login(), Logoff(), Error(), Unauthorized()
Responses with various overloads.
You can read more about here and in its own wiki in GitHub.
Nowadays I am working on a Node.js application and I am using Json Web Tokens (JWT) using Node.js library and it is very easy and straightforward.. its Node.js after all ;)
I saw there is a .NET implementation of JWT explained on this article which I recommend you to look at.
You can use Owin ... i.e. Microsoft.owin.security
I haven't tried this implementation but this is just to give you an idea:
var identity = new ClaimsIdentity(Startup.OAuthBearerOptions.AuthenticationType);
var currentUtc = new SystemClock().UtcNow;
ticket.Properties.IssuedUtc = currentUtc;
ticket.Properties.ExpiresUtc = currentUtc.Add(TimeSpan.FromMinutes(30));
DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", accessToken);
return Json(new {
statusCode = StatusCodes.SUCCESS,
payload = name,
username = username.ToLower(),
accessToken = Startup.OAuthBearerOptions.AccessTokenFormat.Protect(ticket)
});

Get domain chosen by PrincipalContext

I'm creating a custom login functionality for asp.net which validates against active directory. The user must be able to login with only his username or with his username and a domain (and a password in both cases).
Code:
AuthUser user = Authentication.getDomainAndUserName(givenUsername);
bool validAccount = false;
PrincipalContext network = null;
if (user.domain != "") network = new PrincipalContext(ContextType.Domain, user.domain);
else network = new PrincipalContext(ContextType.Domain);
if (UserPrincipal.FindByIdentity(network, IdentityType.SamAccountName, user.username) != null) {
validAccount = network.ValidateCredentials(givenUsername, givenPassword, ContextOptions.Negotiate);
}
The "AuthUser" contains the username and, if given, the domain. Now if a user didn't explicitly specify the domain the above still works fine.
So if you call
new PrincipalContext(ContextType.Domain);
It seems that the domain is set automatically.
In that case, how can i find out the domain it used?
You always can get the domain used from the user principal returned from UserPrincipal.FindByIdentity()

Sitecore extranet check logged in user roles in HttpHandler

How do I get the roles for an authenticated logged in extranet user in sitecore 6.4? I'm trying to check the roles to restrict access.
The Sitecore.Context.User.Roles is coming back with default\Anonynous not extranet\WebsiteUser.
UPDATE: When checking the roles directly after login all appears fine. However it's when I check the roles from within a httphandler that the Sitecore.Context.User.Roles is lost and defaults to default\Anonynous.
Create extranet user code:
using (new SecurityStateSwitcher(SecurityState.Disabled))
{
var domainUsername = Context.Domain.GetFullName(user.Email);
Sitecore.Security.Accounts.User sitecoreUser = Sitecore.Security.Accounts.User.Create(domainUsername, user.Password);
Database dbCore = Factory.GetDatabase("core");
Item profileItem = dbCore.GetItem(CustomUserProfilePath);
List<Role> roles = Sitecore.Context.Domain.GetRoles().Where(role => role.Name == "extranet\WebsiteUser").ToList();
if (roles.Any())
{
sitecoreUser.Roles.Add(roles.First());
}
sitecoreUser.Profile.ProfileItemId = profileItem.ID.ToString();
sitecoreUser.Profile.FullName = string.Format("{0} {1}", user.FirstName, user.LastName);
sitecoreUser.Profile.Email = user.Email;
sitecoreUser.Profile.Comment = "Created by the register system";
sitecoreUser.Profile.Save();
}
I have now found a solution through using IIS7 url rewrites instead of routing the handler through the web.config. This keeps the Sitecore.Context so I can check the logged in users roles.

Categories

Resources