feat: offload jwt generation to guhf, move auth code to new controller

Controllers/GeneralUseHelperFunctions.cs

@@ -0,0 +1,34 @@
+using Microsoft.IdentityModel.Tokens;
+using System.IdentityModel.Tokens.Jwt;
+using System.Security.Claims;
+using System.Text;
+
+namespace QuotifyBE.Controllers;
+
+public class GeneralUseHelpers
+{
+    public string GenerateJwtToken(string username, IConfiguration appsettings)
+    {
+        var claims = new[]
+        {
+            new Claim(JwtRegisteredClaimNames.Sub, username),
+            new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString())
+        };
+
+        var key = new SymmetricSecurityKey(
+            Encoding.UTF8.GetBytes(appsettings["JwtSecret"]!)
+            // won't be null here - otherwise Program.cs wouldn't start
+        );
+        var creds = new SigningCredentials(key, SecurityAlgorithms.HmacSha256);
+
+        var token = new JwtSecurityToken(
+            issuer: appsettings["DomainName"]!,
+            audience: appsettings["DomainName"]!,
+            claims: claims,
+            expires: DateTime.Now.AddDays(7),
+            signingCredentials: creds
+        );
+
+        return new JwtSecurityTokenHandler().WriteToken(token);
+    }
+}