1NTkm8Pj

1using System;
2using System.Collections.Generic;
3using System.Linq;
4using System.Security.Cryptography;
5using System.Text;
6
7namespace Campus.Core.Social
8{
9	public class TelegramAuthResponse
10	{
11		public int auth_date { get; set; }
12		public string first_name { get; set; }
13		public string hash { get; set; }
14		public int id { get; set; }
15		public string photo_url { get; set; }
16		public string username { get; set; }
17	}
18
19	public class TelegramClient
20	{
21		private readonly string _botKey;
22
23		public TelegramClient(string botKey)
24		{
25			_botKey = botKey;
26		}
27
28		public bool CheckTelegramAuthorization(TelegramAuthResponse response)
29		{
30			var checkList = new List<string>
31			{
32				$"auth_date={response.auth_date}",
33				$"first_name={response.first_name}",
34				$"id={response.id}",
35				$"photo_url={response.photo_url}",
36				$"username={response.username}"
37			};
38
39			checkList.Sort();
40
41			var dataCheckString = string.Join("\n", checkList);
42
43			var secretKey = HashString(_botKey);
44			var hash = GetHashSha256(secretKey, dataCheckString);
45
46			return response.hash == hash;
47		}
48
49		private static byte[] HashString(string text) => 
50			new SHA256Managed().ComputeHash(Encoding.UTF8.GetBytes(text));
51		
52		
53
54		public static string GetHashSha256(byte[] secretKey, string text)
55		{
56			var hash = new HMACSHA256(secretKey).ComputeHash(Encoding.UTF8.GetBytes(text));
57			return hash.Aggregate(string.Empty, (current, x) => current + $"{x:x2}");
58		}
59	}
60}