.net 5 MVC 6 web api using existing identityDb for authentication - asp.net-web-api

Question

I am working on having native app be able to authenticate to a web api which uses an existing identity db database created from MVC6. I understand this is not a secure way of doing things as per this post. However, until I can figure out how to get IdentityServer3 working with a database I thought I would try a simple web api that authenticates to a database I already created when I built a standard MVC 6 web app. Here is what I did:
Created an asp.net 5 web api from the template and added the following:
Settings:
appsettings.json I added:
"Data": {
"DefaultConnection": {
"ConnectionString": "Server=(localdb)\\mssqllocaldb;Database=aspnet5-TestUsers-eaf0c85f-23e4-4603-97ce-b9f49ee1d167;Trusted_Connection=True;MultipleActiveResultSets=true"
}
},
Startup:
services.AddEntityFramework()
.AddSqlServer()
.AddDbContext<ApiDbContext>(options =>
options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]));
Models:
public class AppUser : IdentityUser
{
}
DBContext:
public class ApiDbContext : IdentityDbContext<AppUser>
{
}
Controller:
private readonly UserManager<AppUser> _userManager;
private readonly SignInManager<AppUser> _signInManager;
private readonly ILogger _logger;
...
public async Task<IEnumerable<string>> Post([FromBody]LoginModel model)
{
if (ModelState.IsValid) {
string user = model.userid;
string passwd = model.password;
var result = await _signInManager.PasswordSignInAsync(model.userid, model.password, false, lockoutOnFailure: false);
if (result.Succeeded)
{
_logger.LogInformation(1, "User logged in.");
return new string[] { user };
}
else
{
return new string[] { "Failed" };
}
}
else
{
return new string[] { "Incorrect format received"};
}
}
However, it bombs at the _signInManager line with the error:
System.NullReferenceException: Object reference not set to an instance
of an object.
So apparently _signInManager is Null because I know the model is fine because I am printing the userid and password and they are there.
What am I missing so I can use the signInManager in a web api?

Answer 1

I went back yet another time to see what was different between the web api and the web app, since the web app auth was working fine. Here is what I added to get it working:
controller needed a constructor:
public AuthController(
SignInManager<AppUser> signInManager,
ILoggerFactory loggerFactory)
{
_signInManager = signInManager;
_logger = loggerFactory.CreateLogger<AuthController>();
}
Which got rid of my other error but produced the following error:
System.InvalidOperationException: No authentication handler is
configured to handle the scheme: Microsoft.AspNet.Identity.Application
So after researching that I needed to add to startup:
configureservices:
services.AddIdentity<AppUser, IdentityRole>()
.AddEntityFrameworkStores<ApiDbContext>()
.AddDefaultTokenProviders();
configure:
app.UseIdentity();
Adding these to the above allowed me to post JSON with userid and password.