TourIAm/TIAMWebApp/Shared/Services/CustomAuthStateProvider.cs

using AyCode.Interfaces.StorageHandlers;
using Microsoft.AspNetCore.Components.Authorization;
using Newtonsoft.Json;
using System.Net.Http.Headers;
using System.Security.Claims;
using TIAMWebApp.Shared.Application.Models.ClientSide;

namespace TIAMWebApp.Shared.Application.Services
{
    public class CustomAuthStateProvider : AuthenticationStateProvider
    {
        private readonly ISecureStorageHandler _localStorage;
        private readonly HttpClient _http;


        public CustomAuthStateProvider(ISecureStorageHandler localStorage, HttpClient http)
        {
            _localStorage = localStorage;
            _http = http;
        }

        public override async Task<AuthenticationState> GetAuthenticationStateAsync()
        {
            string userDetailsStr = await _localStorage.GetFromSecureStorageAsync(nameof(Setting.UserBasicDetails));
            AuthenticationState state = null;
            if (!string.IsNullOrEmpty(userDetailsStr))
            {

                var userBasicDetail = JsonConvert.DeserializeObject<UserBasicDetails>(userDetailsStr);

                //var handler = new JwtSecurityTokenHandler();
                //var jsontoken = handler.ReadToken(userBasicDetail?.AccessToken) as JwtSecurityToken;
                var token = userBasicDetail?.AccessToken;
                var identity = new ClaimsIdentity();
                _http.DefaultRequestHeaders.Authorization = null;

                if (!string.IsNullOrEmpty(token))
                {
                    identity = new ClaimsIdentity(ParseClaimsFromJwt(token), "jwt");
                    _http.DefaultRequestHeaders.Authorization =
                        new AuthenticationHeaderValue("Bearer", token.Replace("\"", ""));
                }

                var user = new ClaimsPrincipal(identity);
                state = new AuthenticationState(user);

                NotifyAuthenticationStateChanged(Task.FromResult(state));
            }
            else
            {
                state = new AuthenticationState(new ClaimsPrincipal());
                NotifyAuthenticationStateChanged(Task.FromResult(state));
            }

            return state;
        }

        public static IEnumerable<Claim> ParseClaimsFromJwt(string jwt)
        {
            var payload = jwt.Split('.')[1];
            var jsonBytes = ParseBase64WithoutPadding(payload);
            var keyValuePairs = System.Text.Json.JsonSerializer.Deserialize<Dictionary<string, object>>(jsonBytes);
            return keyValuePairs.Select(kvp => new Claim(kvp.Key, kvp.Value.ToString()));
        }

        private static byte[] ParseBase64WithoutPadding(string base64)
        {
            switch (base64.Length % 4)
            {
                case 2: base64 += "=="; break;
                case 3: base64 += "="; break;
            }
            return Convert.FromBase64String(base64);
        }
    }
}