public static void UseHostedWhitelist(
this IApplicationBuilder app,
string url,
HttpClient client = null)
{
// Shared HTTP client for all requests
if (client == null)
{
// Use IMemoryCache from DI if available, e.g. if configured
// with services.AddMemoryCache()
var cache = (MemoryCache)app.ApplicationServices
.GetService(typeof(IMemoryCache))
?? new MemoryCache(new MemoryCacheOptions());
// Default to 5 minutes caching if not forbidden by NoStore
// or specified by Cache-Control headers.
var handler = new CachingHttpHandler(
new HttpClientHandler(), cache);
handler.DefaultCacheDuration = new TimeSpan(0, 5, 0);
client = new HttpClient(handler);
}
// GetStringAsync is called on every IP check, but HttpClient
// will honour caching headers
app.UseWhitelist(async() =>
Whitelist.Parse(await client.GetStringAsync(url)));
}
void beginRequest(object sender, EventArgs e)
{
var application = (HttpApplication)sender;
if (_whitelist == null)
{
// Have to do this here becase MapPath() isn't allowed in
// Init().
string path = application.Server.MapPath(
ConfigurationManager.AppSettings["whitelist:Path"]);
string data = File.ReadAllText(path);
_whitelist = Whitelist.Parse(data);
}
var request = application.Context.Request;
var ip = IPAddress.Parse(request.UserHostAddress);
if (!_whitelist.Match(ip))
{
var response = application.Context.Response;
response.StatusCode = 403;
response.Output.WriteLine($"Host {ip} is not whitelisted " +
$"for this site.");
response.End();
}
}
public static void UseStaticWhitelist(
this IApplicationBuilder app,
string path)
{
// Shared for all requests
var whitelist = Whitelist.Parse(File.ReadAllText(path));
app.UseWhitelist(() => Task.FromResult <IWhitelist>(whitelist));
}
async Task beginRequest(object sender, EventArgs e)
{
var application = (HttpApplication)sender;
var request = application.Context.Request;
var ip = IPAddress.Parse(request.UserHostAddress);
var data = await _client.GetStringAsync(_url);
var whitelist = Whitelist.Parse(data);
if (!whitelist.Match(ip))
{
var response = application.Context.Response;
response.StatusCode = 403;
response.Output.WriteLine($"Host {ip} is not whitelisted " +
$"for this site.");
response.End();
}
;
}