feat: implement token generation and issuing on successful login

src/Directory.Packages.props

@@ -3,6 +3,7 @@
     <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
   </PropertyGroup>
   <ItemGroup>
+    <PackageVersion Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="10.0.2" />
     <PackageVersion Include="Microsoft.AspNetCore.OpenApi" Version="10.0.1" />
     <PackageVersion Include="Microsoft.EntityFrameworkCore.Design" Version="10.0.2">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

src/FiscalOS.API/FiscalOS.API.csproj

@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" />
     <PackageReference Include="Microsoft.AspNetCore.OpenApi" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Design">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>

src/FiscalOS.API/Login/Endpoint.cs

@@ -14,26 +14,12 @@ internal static class Endpoint
 
   private static async Task<IResult> HandleAsync(
     [FromBody] LoginRequest loginRequest,
+    [FromServices] HttpContext httpContext,
     [FromServices] AppDbContext appDbContext,
-    [FromServices] IPasswordHasher passwordHasher
+    [FromServices] IPasswordHasher passwordHasher,
+    [FromServices] TokenService tokenService
   )
   {
-    // TODO: Implement actual auth flow
-    // 1. We want to make sure that
-    //    the user exists
-    // 2. We want to make sure that
-    //    tha the password is correct
-    // 3. We want to issue an access token
-    //    with a refresh token
-    // 4. We want to store the refresh
-    //    token
-    // 5. We want to set the refresh
-    //    token in a cookie
-
-    // TODO: Things we need
-    // 1. We need a user model
-    // 2. We need a refresh token model
-
     var user = await appDbContext.Users.SingleOrDefaultAsync(u => u.Username == loginRequest.Username);
 
     if (user is null)
@@ -48,6 +34,26 @@ internal static class Endpoint
       return Results.Unauthorized();
     }
 
-    return Results.Ok();
+    var accessToken = tokenService.GenerateAccessToken(user);
+
+    var refreshToken = tokenService.GenerateRefreshToken(user);
+    await appDbContext.RefreshTokens.AddAsync(refreshToken);
+    await appDbContext.SaveChangesAsync();
+
+    httpContext.Response.Cookies.Append(
+      "fiscalos_refresh_cookie",
+      refreshToken.Token,
+      new CookieOptions
+      {
+        HttpOnly = true,
+        Expires = refreshToken.ExpiresAt,
+        // TODO: Revisit when decided
+        // on hosting setup
+        SameSite = SameSiteMode.None,
+        Secure = true
+      }
+    );
+
+    return Results.Ok(new Response(accessToken));
   }
 }

src/FiscalOS.API/Login/JwtOptions.cs

@@ -0,0 +1,27 @@
+using Microsoft.Extensions.Options;
+
+namespace FiscalOS.API.Login;
+
+internal sealed record JwtOptions
+{
+  public string Issuer { get; init; } = string.Empty;
+  public string Audience { get; init; } = string.Empty;
+  public string Secret { get; init; } = string.Empty;
+  public int ExpiryInMinutes { get; init; } = 5;
+}
+
+internal sealed record JwtOptionsSetup : IConfigureOptions<JwtOptions>
+{
+  private const string SectionName = nameof(JwtOptions);
+  private readonly IConfiguration _configuration;
+
+  public JwtOptionsSetup(IConfiguration configuration)
+  {
+    _configuration = configuration;
+  }
+
+  public void Configure(JwtOptions options)
+  {
+    _configuration.GetSection(SectionName).Bind(options);
+  }
+}

src/FiscalOS.API/Login/Response.cs

@@ -0,0 +1,3 @@
+namespace FiscalOS.API.Login;
+
+internal sealed record Response(string AccessToken);

src/FiscalOS.API/Login/TokenService.cs

@@ -0,0 +1,67 @@
+using System.IdentityModel.Tokens.Jwt;
+using System.Security.Claims;
+using System.Security.Cryptography;
+using System.Text;
+
+using FiscalOS.Core.Identity;
+
+using Microsoft.Extensions.Options;
+using Microsoft.IdentityModel.Tokens;
+
+namespace FiscalOS.API.Login;
+
+internal sealed class TokenService(
+  TimeProvider timeProvider,
+  IOptions<JwtOptions> jwtOptions
+)
+{
+  private const int RefreshTokenExpiryInHours = 12;
+  private readonly JwtOptions _jwtOptions = jwtOptions.Value;
+  private readonly TimeProvider _timeProvider = timeProvider;
+
+  public string GenerateAccessToken(User user)
+  {
+    var tokenHandler = new JwtSecurityTokenHandler();
+    var secretKeyBytes = Encoding.UTF8.GetBytes(_jwtOptions.Secret);
+    var issuedAt = _timeProvider.GetUtcNow();
+    var expiresAt = issuedAt.AddMinutes(_jwtOptions.ExpiryInMinutes);
+    List<Claim> claims = [
+      new(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()),
+      new(JwtRegisteredClaimNames.Sub, user.Id.ToString()),
+    ];
+
+    var descriptor = new SecurityTokenDescriptor()
+    {
+      Subject = new(claims),
+      IssuedAt = issuedAt.UtcDateTime,
+      Expires = expiresAt.UtcDateTime,
+      Issuer = _jwtOptions.Issuer,
+      Audience = _jwtOptions.Audience,
+      SigningCredentials = new(
+        new SymmetricSecurityKey(secretKeyBytes),
+        SecurityAlgorithms.HmacSha256Signature
+      ),
+    };
+
+    var securityToken = tokenHandler.CreateJwtSecurityToken(descriptor);
+    var jwtToken = tokenHandler.WriteToken(securityToken);
+
+    return jwtToken;
+  }
+
+  public RefreshToken GenerateRefreshToken(User user)
+  {
+    var expiresAt = _timeProvider
+      .GetUtcNow()
+      .AddHours(RefreshTokenExpiryInHours);
+
+    return RefreshToken.From(user.Id, GenerateToken(), expiresAt);
+  }
+
+  private static string GenerateToken()
+  {
+    var randomBytes = RandomNumberGenerator.GetBytes(32);
+    var token = Convert.ToBase64String(randomBytes);
+    return token;
+  }
+}

src/FiscalOS.Core/Identity/RefreshToken.cs

@@ -2,6 +2,22 @@ namespace FiscalOS.Core.Identity;
 
 public sealed class RefreshToken : Entity
 {
+  public string Token { get; init; } = string.Empty;
+  public DateTimeOffset ExpiresAt { get; init; }
   public Guid UserId { get; init; }
   public User User { get; init; } = new();
+
+  private RefreshToken()
+  {
+  }
+
+  public static RefreshToken From(Guid userId, string token, DateTimeOffset expiresAt)
+  {
+    return new()
+    {
+      UserId = userId,
+      Token = token,
+      ExpiresAt = expiresAt,
+    };
+  }
 }