@ -7,6 +7,8 @@
using System.ComponentModel ;
using System.Globalization ;
using System.Net ;
using System.Net.Sockets ;
using System.Runtime.InteropServices ;
using Microsoft.Extensions.Hosting ;
using Microsoft.Extensions.Logging ;
using Microsoft.Extensions.Options ;
@ -44,6 +46,14 @@ public sealed class OpenIddictClientSystemIntegrationHttpListener : BackgroundSe
/// <inheritdoc/>
protected override async Task ExecuteAsync ( CancellationToken stoppingToken )
{
// Note: the RFC8252 specification recommends starting the web server only when an authorization request is
// about to be sent and closing it when the response is received. Unfortunately, such an approach has important
// downsides, as it increases the delay seen by the user before the browser is launched and differs potential
// server initialization errors. To avoid degrading the user experience, the embedded web server is started in
// parallel to the host and unsollicted callback requests are always rejected (as they don't include a valid
// state token). Whenever possible, the HTTP listener is configured to only listen on loopback IP endpoints
// and rejects unknown requests with an HTTP 404, making attacks targeting the embedded web server unlikely.
// If the embedded web server instantiation was not enabled, signal the task completion source with a
// null value to inform the handlers that no HTTP listener is going to be created and return immediately.
if ( _ options . CurrentValue . EnableEmbeddedWebServer is not true )
@ -58,14 +68,14 @@ public sealed class OpenIddictClientSystemIntegrationHttpListener : BackgroundSe
// To ensure the host initialization is not blocked, the whole process is offloaded to the thread pool.
await Task . Run ( cancellationToken : stoppingToken , function : async ( ) = >
{
var ( listener , port ) = CreateHttpListener ( stoppingToken ) ? ?
throw new InvalidOperationException ( SR . GetResourceString ( SR . ID0391 ) ) ;
// Inform the handlers that the HTTP listener was created and can now be accessed via the specified port.
_ source . SetResult ( port ) ;
var ( listener , port ) = CreateHttpListener ( _ options . CurrentValue . AllowedEmbeddedWebServerPorts , stoppingToken ) ;
using ( listener )
{
// Inform the handlers that the HTTP listener was created and can
// now be accessed via the static port configured in the options
// or dynamically chosen at runtime in the IANA dynamic ports range.
_ source . SetResult ( port ) ;
// Note: while the received load should be minimal, 3 task workers are used
// to be able to process multiple requests at the same time, if necessary.
var tasks = new Task [ 3 ] ;
@ -87,32 +97,89 @@ public sealed class OpenIddictClientSystemIntegrationHttpListener : BackgroundSe
return ;
}
static ( HttpListener Listener , int Port ) ? CreateHttpListener ( CancellationToken cancellationToken )
static ( HttpListener Listener , int Port ) CreateHttpListener ( List < int > ports , CancellationToken cancellationToken )
{
// Note: HttpListener doesn't offer a native way to select a random, non-busy port.
// To work around this limitation, this local function tries to bind an HttpListener
// on the first free port in the IANA dynamic ports range (typically: 49152 to 65535).
// Note: HttpListener doesn't offer a native way to select a non-busy port from
// an arbitrary list. To work around this limitation, this local function tries
// to bind an HttpListener on the first free port in the specified list or in
// the IANA dynamic ports range if the list doesn't contain any explicit port.
//
// For more information, see
// https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml.
for ( var port = 4 9 1 5 2 ; port < 6 5 5 3 5 ; port + + )
Stack < Exception > ? exceptions = null ;
for ( var port = IPEndPoint . MinPort ; port < = IPEndPoint . MaxPort ; port + + )
{
cancellationToken . ThrowIfCancellationRequested ( ) ;
// If one or more explicit ports were specified, ignore ports that are not listed.
// Otherwise, ignore all the ports outside the IANA dynamic ports range.
if ( ports . Count is 0 )
{
if ( port < 4 9 1 5 2 )
{
continue ;
}
}
else if ( ! ports . Contains ( port ) )
{
continue ;
}
var listener = new HttpListener
{
AuthenticationSchemes = AuthenticationSchemes . Anonymous ,
IgnoreWriteExceptions = true ,
// Note: the prefix registration is deliberately not configurable to ensure
// only the "localhost" authority is used, which enforces the built-in host
// validation performed by HTTP.sys (or the managed .NET implementation on
// non-Windows operating systems) and doesn't require running the application
// as an administrator or adding a namespace reservation/ACL rule on Windows.
Prefixes = { $"http://localhost:{port.ToString(CultureInfo.InvariantCulture)}/" }
IgnoreWriteExceptions = true
} ;
// Note: the prefix registration is deliberately not configurable to ensure
// only loopback authorities are used, which enforces the built-in host header
// validation performed by HTTP.sys (or the managed .NET implementation on
// non-Windows operating systems) and doesn't require running the application
// as an administrator or adding a namespace reservation/ACL rule on Windows.
if ( RuntimeInformation . IsOSPlatform ( OSPlatform . Windows ) )
{
// On Windows 10 1511 and higher, listening on 127.0.0.1 and ::1 is preferred
// to localhost as it allows ignoring requests that are sent by other machines
// located on the same network (even if the firewall is not enabled or not
// configured to reject such requests) without requiring administrator rights.
//
// See https://www.rfc-editor.org/rfc/rfc8252#section-8.3 for more information.
if ( OpenIddictClientSystemIntegrationHelpers . IsWindowsVersionAtLeast ( 1 0 , 0 , 1 0 5 8 6 ) )
{
if ( Socket . OSSupportsIPv4 )
{
listener . Prefixes . Add ( $"http://{IPAddress.Loopback}:{port.ToString(CultureInfo.InvariantCulture)}/" ) ;
}
if ( Socket . OSSupportsIPv6 )
{
listener . Prefixes . Add ( $"http://[{IPAddress.IPv6Loopback}]:{port.ToString(CultureInfo.InvariantCulture)}/" ) ;
}
}
// On older versions, listening on 127.0.0.1 and ::1 requires administrator rights.
else
{
listener . Prefixes . Add ( $"http://localhost:{port.ToString(CultureInfo.InvariantCulture)}/" ) ;
}
}
else
{
// Note: the managed HttpListener implementation doesn't support IPv6 and
// doesn't allow sending a Host header containing the "localhost" authority
// when binding on the 127.0.0.1 address. To keep using "localhost" instead of
// being forced to use 127.0.0.1, the embedded web server is configured to listen
// on "localhost" on platforms that use the managed HttpListener implementation.
//
// See https://github.com/dotnet/runtime/issues/34399 for more information.
listener . Prefixes . Add ( $"http://localhost:{port.ToString(CultureInfo.InvariantCulture)}/" ) ;
}
try
{
listener . Start ( ) ;
@ -120,19 +187,31 @@ public sealed class OpenIddictClientSystemIntegrationHttpListener : BackgroundSe
return ( listener , port ) ;
}
catch ( HttpListenerException )
catch ( HttpListenerException exception )
{
listener . Close ( ) ;
exceptions ? ? = new ( capacity : 3 ) ;
exceptions . Push ( new InvalidOperationException ( SR . FormatID0384 ( port ) , exception ) ) ;
}
catch ( Exception exception )
{
listener . Close ( ) ;
throw new InvalidOperationException ( SR . GetResourceString ( SR . ID0391 ) , exception ) ;
}
}
return null ;
throw exceptions is { Count : > 0 } ?
new InvalidOperationException ( SR . GetResourceString ( SR . ID0391 ) , new AggregateException ( exceptions . Take ( 3 ) ) ) :
new InvalidOperationException ( SR . GetResourceString ( SR . ID0391 ) ) ;
}
static async Task ProcessRequestsAsync ( HttpListener listener , OpenIddictClientSystemIntegrationService service ,
ILogger < OpenIddictClientSystemIntegrationHttpListener > logger , CancellationToken cancellationToken )
{
while ( true )
while ( listener . IsListening )
{
cancellationToken . ThrowIfCancellationRequested ( ) ;
Kévin Chalet
3 years ago