begin implementation of token authentication

replacing password authentication ingame
precompile views for webfront
issue #66
issue #52

Application/Misc/TokenAuthentication.cs

@@ -0,0 +1,94 @@
+using SharedLibraryCore.Interfaces;
+using System;
+using System.Collections.Concurrent;
+using System.Security.Cryptography;
+using System.Text;
+
+namespace IW4MAdmin.Application.Misc
+{
+    class TokenAuthentication : ITokenAuthentication
+    {
+        private readonly ConcurrentDictionary<long, TokenState> _tokens;
+        private readonly RNGCryptoServiceProvider _random;
+        private readonly static TimeSpan _timeoutPeriod = new TimeSpan(0, 0, 30);
+        private const short TOKEN_LENGTH = 4;
+
+        private class TokenState
+        {
+            public long NetworkId { get; set; }
+            public DateTime RequestTime { get; set; } = DateTime.Now;
+            public string Token { get; set; }
+        }
+
+        public TokenAuthentication()
+        {
+            _tokens = new ConcurrentDictionary<long, TokenState>();
+            _random = new RNGCryptoServiceProvider();
+        }
+
+        public bool AuthorizeToken(long networkId, string token)
+        {
+            bool authorizeSuccessful = _tokens.ContainsKey(networkId) && _tokens[networkId].Token == token;
+
+            if (authorizeSuccessful)
+            {
+                _tokens.TryRemove(networkId, out TokenState _);
+            }
+
+            return authorizeSuccessful;
+        }
+
+        public string GenerateNextToken(long networkId)
+        {
+            TokenState state = null;
+            if (_tokens.ContainsKey(networkId))
+            {
+                state = _tokens[networkId];
+
+                if ((DateTime.Now - state.RequestTime) < _timeoutPeriod)
+                {
+                    return null;
+                }
+
+                else
+                {
+                    _tokens.TryRemove(networkId, out TokenState _);
+                }
+            }
+
+            state = new TokenState()
+            {
+                NetworkId = networkId,
+                Token = _generateToken()
+            };
+
+            _tokens.TryAdd(networkId, state);
+            return state.Token;
+        }
+
+        public string _generateToken()
+        {
+            bool validCharacter(char c)
+            {
+                // this ensure that the characters are 0-9, A-Z, a-z
+                return (c > 47 && c < 58) || (c > 64 && c < 91) || (c > 96 && c < 123);
+            }
+
+            StringBuilder token = new StringBuilder();
+
+            while (token.Length < TOKEN_LENGTH)
+            {
+                byte[] charSet = new byte[1];
+                _random.GetBytes(charSet);
+
+                if (validCharacter((char)charSet[0]))
+                {
+                    token.Append((char)charSet[0]);
+                }
+            }
+
+            _random.Dispose();
+            return token.ToString();
+        }
+    }
+}