feat: add JWT auth endpoint

src/AccountTracking.Api/Controllers/AuthController.cs

@@ -0,0 +1,41 @@
+using System.IdentityModel.Tokens.Jwt;
+using System.Security.Claims;
+using AccountTracking.Api.Models.Dtos;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.IdentityModel.Tokens;
+
+namespace AccountTracking.Api.Controllers;
+
+[ApiController]
+[Route("api/auth")]
+public class AuthController : ControllerBase
+{
+    private readonly AppCredentials _credentials;
+
+    public AuthController(AppCredentials credentials)
+        => _credentials = credentials;
+
+    [HttpPost("login")]
+    public IActionResult Login([FromBody] LoginRequest request)
+    {
+        if (request.Username != _credentials.Username
+            || !BCrypt.Net.BCrypt.Verify(request.Password, _credentials.PasswordHash))
+            return Unauthorized();
+
+        var expiry = DateTime.UtcNow.AddDays(30);
+        var token = GenerateToken(expiry);
+
+        return Ok(new LoginResponse(token, expiry.ToString("O")));
+    }
+
+    private string GenerateToken(DateTime expiry)
+    {
+        var key = new SymmetricSecurityKey(_credentials.JwtKeyBytes);
+        var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);
+        var jwt = new JwtSecurityToken(
+            claims: [new Claim(ClaimTypes.Name, _credentials.Username)],
+            expires: expiry,
+            signingCredentials: creds);
+        return new JwtSecurityTokenHandler().WriteToken(jwt);
+    }
+}