Storing claims on cookie while redirecting to other URL and also without identity authentication - asp.net-core

Question

I just need advise if this is feasible. I am developing an authorization for my Shopify app and I need to somewhat store the access token from shopify auth for future verification of my front-end app.
So the first end-point the shopify is calling is this one:
[HttpGet("install")]
public async Task<IActionResult> Install()
{
try
{
if (ModelState.IsValid)
{
var queryString = Request.QueryString.Value;
var isValid = _shopifyService.VerifyRequest(queryString);
if (isValid)
{
var shopifyUrl = Request.Query["shop"];
var authUrl = _shopifyService.BuildAuthUrl(shopifyUrl,
$"{Request.Scheme}://{Request.Host.Value}/api/shopify/authorize",
Program.Settings.Shopify.AuthorizationScope);
return Redirect(authUrl);
}
}
}
catch (Exception ex)
{
var exceptionMessage = await ApiHelpers.GetErrors(ex, _localizer).ConfigureAwait(false);
ModelState.AddModelError(new ValidationResult(exceptionMessage));
}
ModelState.AddModelError(new ValidationResult(_localizer["InvalidAuthStore"]));
return BadRequest(ModelState.GetErrors());
}
This works fine and the result of this api call will actually redirect to same link to my api, but this one will authorize the app:
[HttpGet("authorize")]
public async Task<IActionResult> AuthorizeStore()
{
try
{
if (ModelState.IsValid)
{
var code = Request.Query["code"];
var shopifyUrl = Request.Query["shop"];
var accessToken = await _shopifyService.AuthorizeStore(code, shopifyUrl).ConfigureAwait(false);
var identity = User.Identity as ClaimsIdentity;
identity.AddClaim(new Claim(Constants.Claims.AccessToken, accessToken));
// genereate the new ClaimsPrincipal
var claimsPrincipal = new ClaimsPrincipal(identity);
// store the original tokens in the AuthenticationProperties
var props = new AuthenticationProperties {
AllowRefresh = true,
ExpiresUtc = DateTimeOffset.UtcNow.AddDays(1),
IsPersistent = false,
IssuedUtc = DateTimeOffset.UtcNow,
};
// sign in using the built-in Authentication Manager and ClaimsPrincipal
// this will create a cookie as defined in CookieAuthentication middleware
await HttpContext.SignInAsync(CookieAuthenticationDefaults.AuthenticationScheme, claimsPrincipal, props).ConfigureAwait(false);
Uri uri = new Uri($"{Program.Settings.Shopify.RedirectUrl}?token={accessToken}");
return Redirect(uri.ToString());
}
}
catch (Exception ex)
{
var exceptionMessage = await ApiHelpers.GetErrors(ex, _localizer).ConfigureAwait(false);
ModelState.AddModelError(new ValidationResult(exceptionMessage));
}
ModelState.AddModelError(new ValidationResult(_localizer["InvalidAuthStore"]));
return BadRequest(ModelState.GetErrors());
}
So the above api will authorize my app in shopify and will return an access token. The accessToken is the one I want to save in the claims identity with Cookie authentication type(this is without authorizing user credentials). Still no errors at that point and after calling the HttpContext.SignInAsync function, I can still view using debugger the newly added claims.
As, you can see in the code, after assigning claims, I call to redirect the app to front-end link(Note: front-end and back-end has different url)
In my front-end app, I have a Nuxt middleware that I put a logic to check the token received from back-end since I only pass the token to the front-end app using query params. Here's my middleware code:
export default function ({ app, route, next, store, error, req }) {
if (process.browser) {
const shopifyAccessToken = store.get('cache/shopifyAccessToken', null)
if (!shopifyAccessToken && route.query.token) {
// if has token on query params but not yet in cache, store token and redirect
store.set('cache/shopifyAccessToken', route.query.token)
app.router.push({
path: '/',
query: {}
})
// verify access token on the route
app.$axios
.get(`/shopify/verifyaccess/${route.query.token}`)
.catch((err) => {
error(err)
})
} else if (!shopifyAccessToken && !route.query.token) {
// if does not have both, throw error
error({
statusCode: 401,
message: 'Unauthorized access to this app'
})
}
} else {
next()
}
}
In my middleware, when the route has query params equal to token= It calls another api to verify the accessToken saved in my claims identity:
[HttpGet("verifyaccess/{accessToken}")]
public async Task<IActionResult> VerifyAccess(string accessToken)
{
try
{
if (ModelState.IsValid)
{
var principal = HttpContext.User;
if (principal?.Claims == null)
return Unauthorized(_localizer["NotAuthenticated"]);
var accessTokenClaim = principal.FindFirstValue(Constants.Claims.AccessToken);
if (accessToken == accessTokenClaim)
{
return Ok();
}
else
{
return Unauthorized(_localizer["NotAuthenticated"]);
}
}
}
catch (Exception ex)
{
var exceptionMessage = await ApiHelpers.GetErrors(ex, _localizer).ConfigureAwait(false);
ModelState.AddModelError(new ValidationResult(exceptionMessage));
}
ModelState.AddModelError(new ValidationResult(_localizer["InvalidAuthStore"]));
return BadRequest(ModelState.GetErrors());
}
Looking at the code above, it always fails me because the claims identity that I saved on the authorize endpoint was not there or in short the ClaimsIdentity is always empty.
Here's how I register the Cookie config:
private void ConfigureAuthCookie(IServiceCollection services)
{
services.AddAuthentication(option =>
{
option.DefaultAuthenticateScheme = CookieAuthenticationDefaults.AuthenticationScheme;
option.RequireAuthenticatedSignIn = false;
})
.AddCookie(options => {
options.ExpireTimeSpan = TimeSpan.FromMinutes(60);
options.SlidingExpiration = true;
options.Cookie.Name = "shopifytoken";
});
services.Configure<CookiePolicyOptions>(options =>
{
options.MinimumSameSitePolicy = SameSiteMode.None;
});
}
and I also put a app.UseAuthentication() and app.UseAuthorization() on my Startup.Configure
Please let me know if this seems confusing so I can revised it. My main goal here is to be able to access that accessToken that I saved in the ClaimsIdentity so that I can verify the token. The reason why I did this because currently the shopify does not have an API for verifying access token. So when a user access my app link like this one http://example.com/?token=<any incorrect token> then they can already access my app.