google authentication stuck when redirecting back to my website - asp.net-core

Question

so i use google authentication to validate the users on our system
here is my code
public IActionResult Login()
{
System.IO.File.WriteAllText("log.txt", Url.Action("ExternalLoginCallback"));
return new ChallengeResult(
GoogleDefaults.AuthenticationScheme,
new AuthenticationProperties
{
RedirectUri = Url.Action("ExternalLoginCallback")
});
}
public IActionResult ExternalLoginCallback()
{
System.IO.File.AppendAllText("log.txt", "I am redirected");
var authenticateResult = HttpContext.AuthenticateAsync("External").Result;
if (!authenticateResult.Succeeded)
return BadRequest(); // TODO: Handle this better.
var claimsIdentity = new ClaimsIdentity("Application");
claimsIdentity.AddClaim(authenticateResult.Principal.FindFirst(ClaimTypes.NameIdentifier));
claimsIdentity.AddClaim(authenticateResult.Principal.FindFirst(ClaimTypes.Email));
var identity = authenticateResult.Principal.Identities.FirstOrDefault();
if (identity != null)
{
var emailClaim = identity.Claims.FirstOrDefault(c => c.Type.ToLower().Contains("emailaddress"));
if (emailClaim == null)
{
return BadRequest();
}
var emailData = emailClaim.Value;
if (string.IsNullOrEmpty(emailData))
{
return BadRequest();
}
var connectionString = _config.GetConnectionString("DefaultConnection");
UserBL userBL = new UserBL(connectionString);
var userModel = userBL.GetUserData(emailData);
if(userModel == null || userModel.HasError)
{
return BadRequest();
}
HttpContext.Session.SetString("UserData", JsonConvert.SerializeObject(userModel.Data));
if (userModel.Data.UserRoles.Any(r => r.Id == (int)UserRolesEnum.ProductOwner
|| r.Id == (int)UserRolesEnum.CopyEditor))
{
return RedirectToAction("Index", "Home");
}
else
{
return RedirectToAction("List", "Translation");
}
return RedirectToAction("UnAuthorized");
}
return BadRequest();
}
it worked fine users were redirected to google to enter their credentials and after that google redirects them back to the website till couple of days back google stopped redirecting back to the website and stays stuck on https://accounts.google.com.eg/accounts/SetSID
any pointers to how i can debug this or how to solve it
any help would be appreciated

Answer 1

Finally after a week i found the problem, it was not in the code it was the server.
The IIS limits the query string character count (i think the default is 260 character) and in my case google responds with a query string with 544 character in which the IIS does not accept or respond to so it stays stuck on the SetSID page
Here is where i found the solution to increase the query string max length
Increase max url length in asp.net core
as of why it was working and then stopped this i could not figure it out