seb-win-refactoring/SafeExamBrowser.Browser/Handlers/RequestHandler.cs

77 lines
2.4 KiB
C#

/*
* Copyright (c) 2019 ETH Zürich, Educational Development and Technology (LET)
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
using System;
using System.Collections.Specialized;
using CefSharp;
using CefSharp.Handler;
using SafeExamBrowser.Contracts.Configuration;
namespace SafeExamBrowser.Browser.Handlers
{
/// <remarks>
/// See https://cefsharp.github.io/api/71.0.0/html/T_CefSharp_Handler_DefaultRequestHandler.htm.
/// </remarks>
internal class RequestHandler : DefaultRequestHandler
{
private AppConfig appConfig;
internal RequestHandler(AppConfig appConfig)
{
this.appConfig = appConfig;
}
public override CefReturnValue OnBeforeResourceLoad(IWebBrowser browserControl, IBrowser browser, IFrame frame, IRequest request, IRequestCallback callback)
{
// TODO: CEF does not yet support intercepting requests from service workers, thus the user agent must be statically set at browser
// startup for now. Once CEF has full support of service workers, the static user agent should be removed and the method below
// reactivated. See https://bitbucket.org/chromiumembedded/cef/issues/2622 for the current status of development.
// AppendCustomUserAgent(request);
if (IsMailtoUrl(request.Url))
{
return CefReturnValue.Cancel;
}
ReplaceCustomScheme(request);
return base.OnBeforeResourceLoad(browserControl, browser, frame, request, callback);
}
private void AppendCustomUserAgent(IRequest request)
{
var headers = new NameValueCollection(request.Headers);
var userAgent = request.Headers["User-Agent"];
headers["User-Agent"] = $"{userAgent} SEB/{appConfig.ProgramVersion}";
request.Headers = headers;
}
private bool IsMailtoUrl(string url)
{
return url.StartsWith(Uri.UriSchemeMailto);
}
private void ReplaceCustomScheme(IRequest request)
{
if (Uri.IsWellFormedUriString(request.Url, UriKind.RelativeOrAbsolute))
{
var uri = new Uri(request.Url);
if (uri.Scheme == appConfig.SebUriScheme)
{
request.Url = new UriBuilder(uri) { Scheme = Uri.UriSchemeHttp }.Uri.AbsoluteUri;
}
else if (uri.Scheme == appConfig.SebUriSchemeSecure)
{
request.Url = new UriBuilder(uri) { Scheme = Uri.UriSchemeHttps }.Uri.AbsoluteUri;
}
}
}
}
}