IW4M-Admin/Application/Misc/TokenAuthentication.cs
2022-06-16 10:07:03 -05:00

101 lines
2.9 KiB
C#

using SharedLibraryCore.Helpers;
using SharedLibraryCore.Interfaces;
using System;
using System.Collections.Concurrent;
using System.Security.Cryptography;
using System.Text;
namespace IW4MAdmin.Application.Misc
{
internal class TokenAuthentication : ITokenAuthentication
{
private readonly ConcurrentDictionary<int, TokenState> _tokens;
private readonly RandomNumberGenerator _random;
private static readonly TimeSpan TimeoutPeriod = new(0, 0, 120);
private const short TokenLength = 4;
public TokenAuthentication()
{
_tokens = new ConcurrentDictionary<int, TokenState>();
_random = RandomNumberGenerator.Create();
}
public bool AuthorizeToken(ITokenIdentifier authInfo)
{
var authorizeSuccessful = _tokens.ContainsKey(authInfo.ClientId) &&
_tokens[authInfo.ClientId].Token == authInfo.Token;
if (authorizeSuccessful)
{
_tokens.TryRemove(authInfo.ClientId, out _);
}
return authorizeSuccessful;
}
public TokenState GenerateNextToken(ITokenIdentifier authInfo)
{
TokenState state;
if (_tokens.ContainsKey(authInfo.ClientId))
{
state = _tokens[authInfo.ClientId];
if (DateTime.Now - state.RequestTime > TimeoutPeriod)
{
_tokens.TryRemove(authInfo.ClientId, out _);
}
else
{
return state;
}
}
state = new TokenState
{
Token = _generateToken(),
TokenDuration = TimeoutPeriod
};
_tokens.TryAdd(authInfo.ClientId, state);
// perform some housekeeping so we don't have built up tokens if they're not ever used
foreach (var (key, value) in _tokens)
{
if (DateTime.Now - value.RequestTime > TimeoutPeriod)
{
_tokens.TryRemove(key, out _);
}
}
return state;
}
private 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);
}
var token = new StringBuilder();
var charSet = new byte[1];
while (token.Length < TokenLength)
{
_random.GetBytes(charSet);
if (ValidCharacter((char)charSet[0]))
{
token.Append((char)charSet[0]);
}
}
_random.Dispose();
return token.ToString();
}
}
}