Switch WJ over to OAuth for Nexus logins (#2559)

* Switch WJ over to OAuth for Nexus logins

* Remove debug code

* Try and fix the build error

Wabbajack.App.Wpf/LoginManagers/NexusLoginManager.cs

@@ -19,7 +19,7 @@ namespace Wabbajack.LoginManagers;
 public class NexusLoginManager : ViewModel, ILoginFor<NexusDownloader>
 {
     private readonly ILogger<NexusLoginManager> _logger;
-    private readonly ITokenProvider<NexusApiState> _token;
+    private readonly ITokenProvider<NexusOAuthState> _token;
     private readonly IServiceProvider _serviceProvider;
 
     public string SiteName { get; } = "Nexus Mods";
@@ -35,7 +35,7 @@ public Type LoginFor()
     [Reactive]
     public bool HaveLogin { get; set; }
 
-    public NexusLoginManager(ILogger<NexusLoginManager> logger, ITokenProvider<NexusApiState> token, IServiceProvider serviceProvider)
+    public NexusLoginManager(ILogger<NexusLoginManager> logger, ITokenProvider<NexusOAuthState> token, IServiceProvider serviceProvider)
     {
         _logger = logger;
         _token = token;

Wabbajack.App.Wpf/UserIntervention/NexusLoginHandler.cs

@@ -1,92 +1,143 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
+using System.Net;
+using System.Net.Http;
+using System.Net.Sockets;
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
+using System.Web;
 using Fizzler.Systems.HtmlAgilityPack;
+using Microsoft.AspNetCore.WebUtilities;
 using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Primitives;
 using Wabbajack.DTOs.Logins;
+using Wabbajack.DTOs.OAuth;
 using Wabbajack.Messages;
 using Wabbajack.Models;
 using Wabbajack.Networking.Http.Interfaces;
 using Wabbajack.Services.OSIntegrated;
+using Cookie = Wabbajack.DTOs.Logins.Cookie;
 
 namespace Wabbajack.UserIntervention;
 
 public class NexusLoginHandler : BrowserWindowViewModel
 {
-    private readonly EncryptedJsonTokenProvider<NexusApiState> _tokenProvider;
-
-    public NexusLoginHandler(EncryptedJsonTokenProvider<NexusApiState> tokenProvider)
+    private static Uri OAuthUrl = new Uri("https://users.nexusmods.com/oauth");
+    private static string OAuthRedirectUrl = "https://127.0.0.1:1234";
+    private static string OAuthClientId = "wabbajack";
+
+    private readonly EncryptedJsonTokenProvider<NexusOAuthState> _tokenProvider;
+    private readonly ILogger<NexusLoginHandler> _logger;
+    private readonly HttpClient _client;
+
+    public NexusLoginHandler(ILogger<NexusLoginHandler> logger, HttpClient client, EncryptedJsonTokenProvider<NexusOAuthState> tokenProvider)
     {
+        _logger = logger;
+        _client = client;
         HeaderText = "Nexus Login";
         _tokenProvider = tokenProvider;
     }
+
+    private string Base64Id()
+    {
+        var bytes = new byte[32];
+        using var rng = RandomNumberGenerator.Create();
+        rng.GetBytes(bytes);
+        return Convert.ToBase64String(bytes);
+    }
 
     protected override async Task Run(CancellationToken token)
     {
         token.ThrowIfCancellationRequested();
+
+        // see https://www.rfc-editor.org/rfc/rfc7636#section-4.1
+        var codeVerifier = Guid.NewGuid().ToString("N").ToBase64();
 
-        Instructions = "Please log into the Nexus";
+        // see https://www.rfc-editor.org/rfc/rfc7636#section-4.2
+        var codeChallengeBytes = SHA256.HashData(Encoding.UTF8.GetBytes(codeVerifier));
+        var codeChallenge = StringBase64Extensions.Base64UrlEncode(codeChallengeBytes);
 
-        await NavigateTo(new Uri(
-            "https://users.nexusmods.com/auth/continue?client_id=nexus&redirect_uri=https://www.nexusmods.com/oauth/callback&response_type=code&referrer=//www.nexusmods.com"));
 
+        Instructions = "Please log into the Nexus";
 
-        Cookie[] cookies = { };
-        while (true)
+        var state = Guid.NewGuid().ToString();
+
+        await NavigateTo(new Uri("https://nexusmods.com"));
+        var codeCompletionSource = new TaskCompletionSource<Dictionary<string, StringValues>>();
+
+        Browser!.Browser.CoreWebView2.NewWindowRequested += (sender, args) =>
         {
-            cookies = await GetCookies("nexusmods.com", token);
-            if (cookies.Any(c => c.Name.Contains("SessionUser")))
-                break;
-
-            token.ThrowIfCancellationRequested();
-            await Task.Delay(500, token);
+            var uri = new Uri(args.Uri);
+            _logger.LogInformation("New Window Requested {Uri}", args.Uri);
+            if (uri.Host != "127.0.0.1") return;
+            
+            codeCompletionSource.TrySetResult(QueryHelpers.ParseQuery(uri.Query));
+            args.Handled = true;
+        };
+
+        var uri = GenerateAuthorizeUrl(codeChallenge, state);
+        await NavigateTo(uri);
+
+        var ctx = await codeCompletionSource.Task;
+
+        if (ctx["state"].FirstOrDefault() != state)
+        {
+            throw new Exception("State mismatch");
         }
+
+        var code = ctx["code"].FirstOrDefault();
 
-        Instructions = "Getting API Key...";
-
-        await NavigateTo(new Uri("https://next.nexusmods.com/settings/api-keys"));
+        var result = await AuthorizeToken(codeVerifier, code, token);
+
+        if (result != null) 
+            result.ReceivedAt = DateTime.UtcNow.ToFileTimeUtc();
 
-        var key = "";
-
-        while (true)
+        await _tokenProvider.SetToken(new NexusOAuthState()
         {
-            try
-            {
-                key = (await GetDom(token)).DocumentNode.QuerySelectorAll("img[alt='Wabbajack']").SelectMany(p => p.ParentNode.ParentNode.QuerySelectorAll("input[aria-label='api key']")).Select(node => node.Attributes["value"]).FirstOrDefault()?.Value;
-            }
-            catch (Exception)
-            {
-                // ignored
-            }
-
-            if (!string.IsNullOrEmpty(key))
-                break;
-
-            try
-            {
-                await EvaluateJavaScript(
-                    "var found = document.querySelector(\"img[alt='Wabbajack']\").parentElement.parentElement.querySelector(\"button[aria-label='Request Api Key']\");" +
-                    "found.onclick= function() {return true;};" +
-                    "found.class = \" \"; " +
-                    "found.click();"
-                );
-                Instructions = "Generating API Key, Please Wait...";
-            }
-            catch (Exception)
-            {
-                // ignored
-            }
-
-            token.ThrowIfCancellationRequested();
-            await Task.Delay(500, token);
+            OAuth = result!
+        });
+    }
+
+    private async Task<JwtTokenReply?> AuthorizeToken(string verifier, string code, CancellationToken cancel)
+    {
+        var request = new Dictionary<string, string> {
+            { "grant_type", "authorization_code" },
+            { "client_id", OAuthClientId },
+            { "redirect_uri", OAuthRedirectUrl },
+            { "code", code },
+            { "code_verifier", verifier },
+        };
+
+        var content = new FormUrlEncodedContent(request);
+
+        var response = await _client.PostAsync($"{OAuthUrl}/token", content, cancel);
+        if (!response.IsSuccessStatusCode)
+        {
+            _logger.LogCritical("Failed to get token {code} - {message}", response.StatusCode,
+                response.ReasonPhrase);
+            return null;
         }
-
-        Instructions = "Success, saving information...";
-        await _tokenProvider.SetToken(new NexusApiState
+        var responseString = await response.Content.ReadAsStringAsync(cancel);
+        return JsonSerializer.Deserialize<JwtTokenReply>(responseString);
+    }
+
+    internal static Uri GenerateAuthorizeUrl(string challenge, string state)
+    {
+        var request = new Dictionary<string, string>
         {
-            Cookies = cookies,
-            ApiKey = key
-        });
+            { "response_type", "code" },
+            { "scope", "public openid profile" },
+            { "code_challenge_method", "S256" },
+            { "client_id", OAuthClientId },
+            { "redirect_uri", OAuthRedirectUrl },
+            { "code_challenge", challenge },
+            { "state", state },
+        };
+
+        return new Uri(QueryHelpers.AddQueryString($"{OAuthUrl}/authorize", request));
     }
 }

Wabbajack.App.Wpf/UserIntervention/OAuth2LoginHandler.cs

@@ -6,6 +6,7 @@
 using System.Threading;
 using System.Threading.Tasks;
 using System.Web;
+using Microsoft.AspNetCore.WebUtilities;
 using Microsoft.Extensions.Logging;
 using ReactiveUI;
 using Wabbajack.Common;
@@ -103,4 +104,5 @@ await _tokenProvider.SetToken(new TLoginType
         });
 
     }
+
 }

Wabbajack.App.Wpf/UserIntervention/StringExtensions.cs

@@ -0,0 +1,126 @@
+using System;
+using System.Buffers;
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+using System.Text;
+
+namespace Wabbajack.UserIntervention;
+
+public static class StringBase64Extensions
+{
+    /// <summary>
+    /// Convert string to base 64 encoding
+    /// </summary>
+    public static string ToBase64(this string input)
+    {
+        return ToBase64(Encoding.UTF8.GetBytes(input));
+    }
+
+    /// <summary>
+    /// Convert byte array to base 64 encoding
+    /// </summary>
+    public static string ToBase64(this byte[] input)
+    {
+        return Convert.ToBase64String(input);
+    }
+
+    /// <summary>
+    /// Encodes <paramref name="input"/> using base64url encoding.
+    /// </summary>
+    /// <param name="input">The binary input to encode.</param>
+    /// <returns>The base64url-encoded form of <paramref name="input"/>.</returns>
+    [SkipLocalsInit]
+    public static string Base64UrlEncode(ReadOnlySpan<byte> input)
+    {
+        // TODO: use Microsoft.AspNetCore.WebUtilities when .NET 8 is available
+        // Source: https://github.com/dotnet/aspnetcore/blob/main/src/Shared/WebEncoders/WebEncoders.cs
+        // The MIT License (MIT)
+        //
+        // Copyright (c) .NET Foundation and Contributors
+        //
+        // All rights reserved.
+        //
+        // Permission is hereby granted, free of charge, to any person obtaining a copy
+        // of this software and associated documentation files (the "Software"), to deal
+        // in the Software without restriction, including without limitation the rights
+        // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+        // copies of the Software, and to permit persons to whom the Software is
+        // furnished to do so, subject to the following conditions:
+        //
+        // The above copyright notice and this permission notice shall be included in all
+        // copies or substantial portions of the Software.
+        //
+        // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+        // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+        // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+        // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+        // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+        // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+        // SOFTWARE.
+
+        const int stackAllocThreshold = 128;
+
+        if (input.IsEmpty)
+        {
+            return string.Empty;
+        }
+
+        var bufferSize = GetArraySizeRequiredToEncode(input.Length);
+
+        char[]? bufferToReturnToPool = null;
+        var buffer = bufferSize <= stackAllocThreshold
+            ? stackalloc char[stackAllocThreshold]
+            : bufferToReturnToPool = ArrayPool<char>.Shared.Rent(bufferSize);
+
+        var numBase64Chars = Base64UrlEncode(input, buffer);
+        var base64Url = new string(buffer[..numBase64Chars]);
+
+        if (bufferToReturnToPool != null)
+        {
+            ArrayPool<char>.Shared.Return(bufferToReturnToPool);
+        }
+
+        return base64Url;
+    }
+
+
+    private static int Base64UrlEncode(ReadOnlySpan<byte> input, Span<char> output)
+    {
+        Debug.Assert(output.Length >= GetArraySizeRequiredToEncode(input.Length));
+
+        if (input.IsEmpty)
+        {
+            return 0;
+        }
+
+        // Use base64url encoding with no padding characters. See RFC 4648, Sec. 5.
+
+        Convert.TryToBase64Chars(input, output, out int charsWritten);
+
+        // Fix up '+' -> '-' and '/' -> '_'. Drop padding characters.
+        for (var i = 0; i < charsWritten; i++)
+        {
+            var ch = output[i];
+            switch (ch)
+            {
+                case '+':
+                    output[i] = '-';
+                    break;
+                case '/':
+                    output[i] = '_';
+                    break;
+                case '=':
+                    // We've reached a padding character; truncate the remainder.
+                    return i;
+            }
+        }
+
+        return charsWritten;
+    }
+
+    private static int GetArraySizeRequiredToEncode(int count)
+    {
+        var numWholeOrPartialInputBlocks = checked(count + 2) / 3;
+        return checked(numWholeOrPartialInputBlocks * 4);
+    }
+}

Wabbajack.App.Wpf/Util/FilePickerVM.cs

@@ -159,7 +159,6 @@ public FilePickerVM(object parentVM = null)
                     Filters.Connect().QueryWhenChanged(),
                 resultSelector: (target, type, checkOption, query) =>
                 {
-                    Console.WriteLine("fff");
                     switch (type)
                     {
                         case PathTypeOptions.Either:

Wabbajack.App.Wpf/Wabbajack.App.Wpf.csproj

@@ -90,8 +90,9 @@
     <PackageReference Include="MahApps.Metro" Version="2.4.10" />
     <PackageReference Include="MahApps.Metro.IconPacks" Version="4.11.0" />
     <PackageReference Include="Microsoft-WindowsAPICodePack-Shell" Version="1.1.5" />
+    <PackageReference Include="Microsoft.AspNetCore.WebUtilities" Version="8.0.5" />
     <PackageReference Include="Microsoft.Extensions.Hosting" Version="8.0.0" />
-    <PackageReference Include="Microsoft.Web.WebView2" Version="1.0.2151.40" />
+    <PackageReference Include="Microsoft.Web.WebView2" Version="1.0.2478.35" />
     <PackageReference Include="NLog.Extensions.Logging" Version="5.3.5" />
     <PackageReference Include="Orc.FileAssociation" Version="5.0.0-alpha0061" />
     <PackageReference Include="PInvoke.User32" Version="0.7.124" />