auth token endpoint finished

2026-02-06 00:10:00 +01:00
parent c5823dc6fc
commit 81455ab636
7 changed files with 49 additions and 53 deletions
--- a/TimetableDesigner.Backend.Services.Authentication.Core/Helpers/TokenHelper.cs
+++ b/TimetableDesigner.Backend.Services.Authentication.Core/Helpers/TokenHelper.cs
@@ -0,0 +1,96 @@
+using System.IdentityModel.Tokens.Jwt;
+using System.Security.Claims;
+using System.Text;
+using Microsoft.Extensions.Configuration;
+using Microsoft.IdentityModel.Tokens;
+using TimetableDesigner.Backend.Services.Authentication.Database;
+using TimetableDesigner.Backend.Services.Authentication.Database.Model;
+using JwtRegisteredClaimNames = Microsoft.IdentityModel.JsonWebTokens.JwtRegisteredClaimNames;
+
+namespace TimetableDesigner.Backend.Services.Authentication.Core.Helpers;
+
+public class TokenHelper : ITokenHelper
+{
+    private readonly IConfiguration _configuration;
+    
+    public TokenHelper(IConfiguration configuration)
+    {
+        _configuration = configuration;
+    }
+    
+    public string GenerateAccessToken(long accountId)
+    {
+        IConfigurationSection accessTokenSettings = _configuration.GetSection("Tokens")
+                                                                  .GetSection("AccessToken");
+
+        int lifetime = accessTokenSettings.GetSection("Lifetime")
+                                          .GetValue<int>("Normal");
+        DateTimeOffset expirationDate = DateTimeOffset.UtcNow.AddMinutes(lifetime);
+        
+        string stringKey = accessTokenSettings.GetValue<string>("Key")!;
+        byte[] encodedKey = Encoding.UTF8.GetBytes(stringKey);
+        SymmetricSecurityKey key = new SymmetricSecurityKey(encodedKey);
+
+        string algorithm = accessTokenSettings.GetValue<string>("Algorithm")!;
+
+        SecurityTokenDescriptor descriptor = new SecurityTokenDescriptor
+        {
+            Subject = new ClaimsIdentity(
+            [
+                new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()),
+                new Claim(JwtRegisteredClaimNames.Sub, accountId.ToString()),
+                new Claim(JwtRegisteredClaimNames.Exp, expirationDate.UtcTicks.ToString())
+            ]),
+            Issuer = accessTokenSettings.GetValue<string>("Issuer"),
+            Audience = accessTokenSettings.GetValue<string>("Audience"),
+            SigningCredentials = new SigningCredentials(key, algorithm),
+            Expires = expirationDate.UtcDateTime,
+        };
+
+        JwtSecurityTokenHandler handler = new JwtSecurityTokenHandler();
+        handler.InboundClaimTypeMap.Clear();
+        SecurityToken token = handler.CreateToken(descriptor);
+
+        return handler.WriteToken(token);
+    }
+
+    public bool ValidateExpiredAccessToken(string accessToken)
+    {
+        IConfigurationSection accessTokenSettings = _configuration.GetSection("Tokens")
+                                                                  .GetSection("AccessToken");
+        
+        string stringKey = accessTokenSettings.GetValue<string>("Key")!;
+        byte[] encodedKey = Encoding.UTF8.GetBytes(stringKey);
+        SymmetricSecurityKey key = new SymmetricSecurityKey(encodedKey);
+
+        string algorithm = accessTokenSettings.GetValue<string>("Algorithm")!;
+        
+        TokenValidationParameters tokenValidation = new TokenValidationParameters
+        {
+            ValidateIssuerSigningKey = true,
+            ValidateAudience = true,
+            ValidateIssuer = true,
+            ValidateLifetime = false,
+            ValidIssuer = accessTokenSettings.GetValue<string>("Issuer"),
+            ValidAudience = accessTokenSettings.GetValue<string>("Audience"),
+            IssuerSigningKey = key,
+            ClockSkew = TimeSpan.FromMinutes(1),
+        };
+        
+        JwtSecurityTokenHandler tokenHandler = new JwtSecurityTokenHandler();
+        tokenHandler.ValidateToken(accessToken, tokenValidation, out SecurityToken validatedToken);
+        JwtSecurityToken? jwtSecurityToken = validatedToken as JwtSecurityToken;
+        
+        return jwtSecurityToken is not null && jwtSecurityToken.Header.Alg.Equals(algorithm, StringComparison.InvariantCultureIgnoreCase);
+    }
+    
+    public DateTimeOffset CalculateRefreshTokenExpirationDate(bool isExtendable = true)
+    {
+        string lifetimeSection = isExtendable ? "Extended" : "Normal";
+        int lifetime = _configuration.GetSection("Tokens")
+                                     .GetSection("RefreshToken")
+                                     .GetSection("Lifetime")
+                                     .GetValue<int>(lifetimeSection);
+        return DateTimeOffset.UtcNow.AddMinutes(lifetime);
+    }
+}