Added auth/authenticate endpoint

Birdmap/Services/AuthService.cs

@@ -0,0 +1,78 @@
+using Birdmap.Models;
+using Birdmap.Services.Interfaces;
+using Microsoft.Extensions.Configuration;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Security.Authentication;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Birdmap.Services
+{
+    public class AuthService : IAuthService
+    {
+        private readonly IConfiguration _configuration;
+
+        public AuthService(IConfiguration configuration)
+        {
+            _configuration = configuration;
+        }
+
+        public async Task<User> AuthenticateUserAsync(string username, string password)
+        {
+            if (string.IsNullOrWhiteSpace(username) || string.IsNullOrEmpty(password))
+                throw new ArgumentException("Username or password cannot be null or empty.");
+
+            //var user = await _context.Users.SingleOrDefaultAsync(u => u.Name == username)
+            var user = await Temp_GetUserAsync(_configuration)
+                ?? throw new AuthenticationException();
+
+            if (!VerifyPasswordHash(password, user.PasswordHash, user.PasswordSalt))
+                throw new AuthenticationException();
+
+            return user;
+        }
+
+        private Task<User> Temp_GetUserAsync(IConfiguration configuration)
+        {
+            var name = configuration["BasicAuth:Username"];
+            var pass = configuration["BasicAuth:Password"];
+
+            CreatePasswordHash(pass, out var hash, out var salt);
+            return Task.FromResult(new User
+            {
+                Name = name,
+                PasswordHash = hash,
+                PasswordSalt = salt,
+            });
+        }
+
+        private static void CreatePasswordHash(string password, out byte[] passwordHash, out byte[] passwordSalt)
+        {
+            if (string.IsNullOrWhiteSpace(password)) throw new ArgumentException("Value cannot be null or empty.", "password");
+
+            using var hmac = new System.Security.Cryptography.HMACSHA512();
+
+            passwordSalt = hmac.Key;
+            passwordHash = hmac.ComputeHash(Encoding.UTF8.GetBytes(password));
+        }
+
+        private static bool VerifyPasswordHash(string password, byte[] storedHash, byte[] storedSalt)
+        {
+            if (string.IsNullOrWhiteSpace(password)) throw new ArgumentException("Value cannot be null or empty.", "password");
+            if (storedHash.Length != 64) throw new ArgumentException("Invalid length of password hash (64 bytes expected).", "passwordHash");
+            if (storedSalt.Length != 128) throw new ArgumentException("Invalid length of password salt (128 bytes expected).", "passwordHash");
+
+            using var hmac = new System.Security.Cryptography.HMACSHA512(storedSalt);
+
+            var computedHash = hmac.ComputeHash(Encoding.UTF8.GetBytes(password));
+            for (int i = 0; i < computedHash.Length; i++)
+            {
+                if (computedHash[i] != storedHash[i]) return false;
+            }
+
+            return true;
+        }
+    }
+}

Birdmap/Services/Interfaces/IAuthService.cs

@@ -0,0 +1,10 @@
+using Birdmap.Models;
+using System.Threading.Tasks;
+
+namespace Birdmap.Services.Interfaces
+{
+    public interface IAuthService
+    {
+        Task<User> AuthenticateUserAsync(string username, string password);
+    }
+}