add auth files

api/src/Services/JwtService.cs

@@ -0,0 +1,42 @@
+
+using Microsoft.IdentityModel.Tokens;
+using System.Text;
+using System.Security.Claims;
+using System.IdentityModel.Tokens.Jwt;
+
+using agologumApi.Models;
+
+public class JwtService {
+
+    private readonly IConfiguration config_;
+
+    public JwtService(IConfiguration config) { // why the heck does c# not have initializer lists ?
+        config_ = config;
+    }
+
+    public string? GenerateJwt(User user) {
+
+        string? jwtKey = config_["Jwt:Key"];
+        if(jwtKey == null) return null;
+        var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(jwtKey));
+
+        var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);
+
+        // not too sure
+        var claims = new[] {
+            new Claim(ClaimTypes.Name, user.Name),
+            new Claim(ClaimTypes.NameIdentifier, user.Id.ToString())
+        };
+
+        var token = new JwtSecurityToken(
+            claims: claims,
+            expires: DateTime.UtcNow.AddHours(2), // will add a refresher later
+            signingCredentials: creds
+        );
+
+        return new JwtSecurityTokenHandler().WriteToken(token);
+
+    }
+
+
+}