public static bool WinHttpGetProxyForUrl(
SafeWinHttpHandle sessionHandle,
string url,
ref Interop.WinHttp.WINHTTP_AUTOPROXY_OPTIONS autoProxyOptions,
out Interop.WinHttp.WINHTTP_PROXY_INFO proxyInfo)
{
if (TestControl.PACFileNotDetectedOnNetwork)
{
proxyInfo.AccessType = WINHTTP_ACCESS_TYPE_NO_PROXY;
proxyInfo.Proxy = IntPtr.Zero;
proxyInfo.ProxyBypass = IntPtr.Zero;
TestControl.LastWin32Error = (int)Interop.WinHttp.ERROR_WINHTTP_AUTODETECTION_FAILED;
return(false);
}
proxyInfo.AccessType = Interop.WinHttp.WINHTTP_ACCESS_TYPE_NAMED_PROXY;
proxyInfo.Proxy = Marshal.StringToHGlobalUni(FakeRegistry.WinInetProxySettings.Proxy);
proxyInfo.ProxyBypass = IntPtr.Zero;
return(true);
}
/// <summary>
/// Gets the proxy URI. (IWebProxy interface)
/// </summary>
public Uri GetProxy(Uri uri)
{
if (_proxyHelper.ManualSettingsOnly)
{
return(_proxyUri);
}
var proxyInfo = new Interop.WinHttp.WINHTTP_PROXY_INFO();
try
{
if (_proxyHelper.GetProxyForUrl(_sessionHandle, uri, out proxyInfo))
{
return(GetUriFromString(Marshal.PtrToStringUni(proxyInfo.Proxy)));
}
}
finally
{
Marshal.FreeHGlobal(proxyInfo.Proxy);
Marshal.FreeHGlobal(proxyInfo.ProxyBypass);
}
return(null);
}
private void SetRequestHandleProxyOptions(RequestState state)
{
// We've already set the proxy on the session handle if we're using no proxy or default proxy settings.
// We only need to change it on the request handle if we have a specific IWebProxy or need to manually
// implement Wininet-style auto proxy detection.
if (state.WindowsProxyUsePolicy == WindowsProxyUsePolicy.UseCustomProxy ||
state.WindowsProxyUsePolicy == WindowsProxyUsePolicy.UseWinInetProxy)
{
var proxyInfo = new Interop.WinHttp.WINHTTP_PROXY_INFO();
bool updateProxySettings = false;
Uri uri = state.RequestMessage.RequestUri;
try
{
if (state.Proxy != null)
{
Debug.Assert(state.WindowsProxyUsePolicy == WindowsProxyUsePolicy.UseCustomProxy);
updateProxySettings = true;
if (state.Proxy.IsBypassed(uri))
{
proxyInfo.AccessType = Interop.WinHttp.WINHTTP_ACCESS_TYPE_NO_PROXY;
}
else
{
proxyInfo.AccessType = Interop.WinHttp.WINHTTP_ACCESS_TYPE_NAMED_PROXY;
Uri proxyUri = state.Proxy.GetProxy(uri);
string proxyString = string.Format(
CultureInfo.InvariantCulture,
"{0}://{1}",
proxyUri.Scheme,
proxyUri.Authority);
proxyInfo.Proxy = Marshal.StringToHGlobalUni(proxyString);
}
}
else if (_proxyHelper != null && _proxyHelper.AutoSettingsUsed)
{
updateProxySettings = true;
_proxyHelper.GetProxyForUrl(_sessionHandle, uri, out proxyInfo);
}
if (updateProxySettings)
{
GCHandle pinnedHandle = GCHandle.Alloc(proxyInfo, GCHandleType.Pinned);
try
{
SetWinHttpOption(
state.RequestHandle,
Interop.WinHttp.WINHTTP_OPTION_PROXY,
pinnedHandle.AddrOfPinnedObject(),
(uint)Marshal.SizeOf(proxyInfo));
}
finally
{
pinnedHandle.Free();
}
}
}
finally
{
Marshal.FreeHGlobal(proxyInfo.Proxy);
Marshal.FreeHGlobal(proxyInfo.ProxyBypass);
}
}
}
/// <summary>
/// Gets the proxy URI. (IWebProxy interface)
/// </summary>
public Uri GetProxy(Uri uri)
{
if (_proxyHelper.ManualSettingsOnly)
{
if (_bypassLocal)
{
IPAddress address = null;
if (uri.IsLoopback)
{
// This is optimization for loopback addresses.
// Unfortunately this does not work for all local addresses.
return(null);
}
// Pre-Check if host may be IP address to avoid parsing.
if (uri.HostNameType == UriHostNameType.IPv6 || uri.HostNameType == UriHostNameType.IPv4)
{
// RFC1123 allows labels to start with number.
// Leading number may or may not be IP address.
// IPv6 [::1] notation. '[' is not valid character in names.
if (IPAddress.TryParse(uri.IdnHost, out address))
{
// Host is valid IP address.
// Check if it belongs to local system.
foreach (IPAddress a in _localIp)
{
if (a.Equals(address))
{
return(null);
}
}
}
}
if (uri.HostNameType != UriHostNameType.IPv6 && uri.IdnHost.IndexOf('.') == -1)
{
// Not address and does not have a dot.
// Hosts without FQDN are considered local.
return(null);
}
}
// Check if we have other rules for bypass.
if (_bypass != null)
{
foreach (Regex entry in _bypass)
{
// IdnHost does not have [].
if (entry.IsMatch(uri.IdnHost))
{
return(null);
}
}
}
// We did not find match on bypass list.
return((uri.Scheme == UriScheme.Https || uri.Scheme == UriScheme.Wss) ? _secureProxyUri : _insecureProxyUri);
}
// For anything else ask WinHTTP.
var proxyInfo = new Interop.WinHttp.WINHTTP_PROXY_INFO();
try
{
if (_proxyHelper.GetProxyForUrl(_sessionHandle, uri, out proxyInfo))
{
return(GetUriFromString(Marshal.PtrToStringUni(proxyInfo.Proxy)));
}
}
finally
{
Marshal.FreeHGlobal(proxyInfo.Proxy);
Marshal.FreeHGlobal(proxyInfo.ProxyBypass);
}
return(null);
}
public bool GetProxyForUrl(
SafeWinHttpHandle?sessionHandle,
Uri uri,
out Interop.WinHttp.WINHTTP_PROXY_INFO proxyInfo)
{
proxyInfo.AccessType = Interop.WinHttp.WINHTTP_ACCESS_TYPE_NO_PROXY;
proxyInfo.Proxy = IntPtr.Zero;
proxyInfo.ProxyBypass = IntPtr.Zero;
if (!_useProxy)
{
return(false);
}
bool useProxy = false;
Interop.WinHttp.WINHTTP_AUTOPROXY_OPTIONS autoProxyOptions;
autoProxyOptions.AutoConfigUrl = AutoConfigUrl;
autoProxyOptions.AutoDetectFlags = AutoDetect ?
(Interop.WinHttp.WINHTTP_AUTO_DETECT_TYPE_DHCP | Interop.WinHttp.WINHTTP_AUTO_DETECT_TYPE_DNS_A) : 0;
autoProxyOptions.AutoLoginIfChallenged = false;
autoProxyOptions.Flags =
(AutoDetect ? Interop.WinHttp.WINHTTP_AUTOPROXY_AUTO_DETECT : 0) |
(!string.IsNullOrEmpty(AutoConfigUrl) ? Interop.WinHttp.WINHTTP_AUTOPROXY_CONFIG_URL : 0);
autoProxyOptions.Reserved1 = IntPtr.Zero;
autoProxyOptions.Reserved2 = 0;
// AutoProxy Cache.
// https://docs.microsoft.com/en-us/windows/desktop/WinHttp/autoproxy-cache
// If the out-of-process service is active when WinHttpGetProxyForUrl is called, the cached autoproxy
// URL and script are available to the whole computer. However, if the out-of-process service is used,
// and the fAutoLogonIfChallenged flag in the pAutoProxyOptions structure is true, then the autoproxy
// URL and script are not cached. Therefore, calling WinHttpGetProxyForUrl with the fAutoLogonIfChallenged
// member set to TRUE results in additional overhead operations that may affect performance.
// The following steps can be used to improve performance:
// 1. Call WinHttpGetProxyForUrl with the fAutoLogonIfChallenged parameter set to false. The autoproxy
// URL and script are cached for future calls to WinHttpGetProxyForUrl.
// 2. If Step 1 fails, with ERROR_WINHTTP_LOGIN_FAILURE, then call WinHttpGetProxyForUrl with the
// fAutoLogonIfChallenged member set to TRUE.
//
// We match behavior of WINHTTP_ACCESS_TYPE_AUTOMATIC_PROXY and ignore errors.
#pragma warning disable CA1845 // file is shared with a build that lacks string.Concat for spans
// Underlying code does not understand WebSockets so we need to convert it to http or https.
string destination = uri.AbsoluteUri;
if (uri.Scheme == UriScheme.Wss)
{
destination = UriScheme.Https + destination.Substring(UriScheme.Wss.Length);
}
else if (uri.Scheme == UriScheme.Ws)
{
destination = UriScheme.Http + destination.Substring(UriScheme.Ws.Length);
}
#pragma warning restore CA1845
var repeat = false;
do
{
_autoDetectionFailed = false;
if (Interop.WinHttp.WinHttpGetProxyForUrl(
sessionHandle !,
destination,
ref autoProxyOptions,
out proxyInfo))
{
if (NetEventSource.Log.IsEnabled())
{
NetEventSource.Info(this, "Using autoconfig proxy settings");
}
useProxy = true;
break;
}
else
{
var lastError = Marshal.GetLastWin32Error();
if (NetEventSource.Log.IsEnabled())
{
NetEventSource.Error(this, $"error={lastError}");
}
if (lastError == Interop.WinHttp.ERROR_WINHTTP_LOGIN_FAILURE)
{
if (repeat)
{
// We don't retry more than once.
break;
}
else
{
repeat = true;
autoProxyOptions.AutoLoginIfChallenged = true;
}
}
else
{
if (lastError == Interop.WinHttp.ERROR_WINHTTP_AUTODETECTION_FAILED)
{
_autoDetectionFailed = true;
_lastTimeAutoDetectionFailed = Environment.TickCount;
}
break;
}
}
} while (repeat);
private void SetRequestHandleProxyOptions(WinHttpRequestState state)
{
// We've already set the proxy on the session handle if we're using no proxy or default proxy settings.
// We only need to change it on the request handle if we have a specific IWebProxy or need to manually
// implement Wininet-style auto proxy detection.
if (state.WindowsProxyUsePolicy == WindowsProxyUsePolicy.UseCustomProxy ||
state.WindowsProxyUsePolicy == WindowsProxyUsePolicy.UseWinInetProxy)
{
var proxyInfo = new Interop.WinHttp.WINHTTP_PROXY_INFO();
bool updateProxySettings = false;
Uri uri = state.RequestMessage.RequestUri;
try
{
if (state.Proxy != null)
{
Debug.Assert(state.WindowsProxyUsePolicy == WindowsProxyUsePolicy.UseCustomProxy);
updateProxySettings = true;
if (state.Proxy.IsBypassed(uri))
{
proxyInfo.AccessType = Interop.WinHttp.WINHTTP_ACCESS_TYPE_NO_PROXY;
}
else
{
proxyInfo.AccessType = Interop.WinHttp.WINHTTP_ACCESS_TYPE_NAMED_PROXY;
Uri proxyUri = state.Proxy.GetProxy(uri);
string proxyString = string.Format(
CultureInfo.InvariantCulture,
"{0}://{1}",
proxyUri.Scheme,
proxyUri.Authority);
proxyInfo.Proxy = Marshal.StringToHGlobalUni(proxyString);
}
}
else if (_proxyHelper != null && _proxyHelper.AutoSettingsUsed)
{
updateProxySettings = true;
_proxyHelper.GetProxyForUrl(_sessionHandle, uri, out proxyInfo);
}
if (updateProxySettings)
{
GCHandle pinnedHandle = GCHandle.Alloc(proxyInfo, GCHandleType.Pinned);
try
{
SetWinHttpOption(
state.RequestHandle,
Interop.WinHttp.WINHTTP_OPTION_PROXY,
pinnedHandle.AddrOfPinnedObject(),
(uint)Marshal.SizeOf(proxyInfo));
}
finally
{
pinnedHandle.Free();
}
}
}
finally
{
Marshal.FreeHGlobal(proxyInfo.Proxy);
Marshal.FreeHGlobal(proxyInfo.ProxyBypass);
}
}
}
/// <summary>
/// Gets the proxy URIs.
/// </summary>
public MultiProxy GetMultiProxy(Uri uri)
{
// We need WinHTTP to detect and/or process a PAC (JavaScript) file. This maps to
// "Automatically detect settings" and/or "Use automatic configuration script" from IE
// settings. But, calling into WinHTTP can be slow especially when it has to call into
// the out-of-process service to discover, load, and run the PAC file. So, we skip
// calling into WinHTTP if there was a recent failure to detect a PAC file on the network.
// This is a common error. The default IE settings on a Windows machine consist of the
// single checkbox for "Automatically detect settings" turned on and most networks
// won't actually discover a PAC file on the network since WPAD protocol isn't configured.
if (_proxyHelper.AutoSettingsUsed && !_proxyHelper.RecentAutoDetectionFailure)
{
Interop.WinHttp.WINHTTP_PROXY_INFO proxyInfo = default;
try
{
if (_proxyHelper.GetProxyForUrl(_sessionHandle, uri, out proxyInfo))
{
// If WinHTTP just specified a Proxy with no ProxyBypass list, then
// we can return the Proxy uri directly.
if (proxyInfo.ProxyBypass == IntPtr.Zero)
{
if (proxyInfo.Proxy != IntPtr.Zero)
{
string proxyStr = Marshal.PtrToStringUni(proxyInfo.Proxy) !;
return(MultiProxy.CreateLazy(_failedProxies, proxyStr, IsSecureUri(uri)));
}
else
{
return(MultiProxy.Empty);
}
}
// A bypass list was also specified. This means that WinHTTP has fallen back to
// using the manual IE settings specified and there is a ProxyBypass list also.
// Since we're not really using the full WinHTTP stack, we need to use HttpSystemProxy
// to do the computation of the final proxy uri merging the information from the Proxy
// and ProxyBypass strings.
}
else
{
return(MultiProxy.Empty);
}
}
finally
{
Marshal.FreeHGlobal(proxyInfo.Proxy);
Marshal.FreeHGlobal(proxyInfo.ProxyBypass);
}
}
// Fallback to manual settings if present.
if (_proxyHelper.ManualSettingsUsed)
{
if (_bypassLocal)
{
IPAddress?address;
if (uri.IsLoopback)
{
// This is optimization for loopback addresses.
// Unfortunately this does not work for all local addresses.
return(MultiProxy.Empty);
}
// Pre-Check if host may be IP address to avoid parsing.
if (uri.HostNameType == UriHostNameType.IPv6 || uri.HostNameType == UriHostNameType.IPv4)
{
// RFC1123 allows labels to start with number.
// Leading number may or may not be IP address.
// IPv6 [::1] notation. '[' is not valid character in names.
if (IPAddress.TryParse(uri.IdnHost, out address))
{
// Host is valid IP address.
// Check if it belongs to local system.
foreach (IPAddress a in _localIp !)
{
if (a.Equals(address))
{
return(MultiProxy.Empty);
}
}
}
}
if (uri.HostNameType != UriHostNameType.IPv6 && !uri.IdnHost.Contains('.'))
{
// Not address and does not have a dot.
// Hosts without FQDN are considered local.
return(MultiProxy.Empty);
}
}
// Check if we have other rules for bypass.
if (_bypass != null)
{
foreach (string entry in _bypass)
{
// IdnHost does not have [].
if (SimpleRegex.IsMatchWithStarWildcard(uri.IdnHost, entry))
{
return(MultiProxy.Empty);
}
}
}
// We did not find match on bypass list.
return(IsSecureUri(uri) ? _secureProxy : _insecureProxy);
}
return(MultiProxy.Empty);
}
public void GetProxyForUrl(SafeWinHttpHandle sessionHandle, Uri uri, out Interop.WinHttp.WINHTTP_PROXY_INFO proxyInfo)
{
Interop.WinHttp.WINHTTP_AUTOPROXY_OPTIONS autoProxyOptions;
autoProxyOptions.AutoConfigUrl = AutoConfigUrl;
autoProxyOptions.AutoDetectFlags = AutoDetect ? (Interop.WinHttp.WINHTTP_AUTO_DETECT_TYPE_DHCP | Interop.WinHttp.WINHTTP_AUTO_DETECT_TYPE_DNS_A) : 0;
autoProxyOptions.AutoLoginIfChallenged = false;
autoProxyOptions.Flags =
(AutoDetect ? Interop.WinHttp.WINHTTP_AUTOPROXY_AUTO_DETECT : 0) |
(!string.IsNullOrEmpty(AutoConfigUrl) ? Interop.WinHttp.WINHTTP_AUTOPROXY_CONFIG_URL : 0);
autoProxyOptions.Reserved1 = IntPtr.Zero;
autoProxyOptions.Reserved2 = 0;
// AutoProxy Cache.
// http://msdn.microsoft.com/en-us/library/windows/desktop/aa383153(v=vs.85).aspx
// If the out-of-process service is active when WinHttpGetProxyForUrl is called, the cached autoproxy
// URL and script are available to the whole computer. However, if the out-of-process service is used,
// and the fAutoLogonIfChallenged flag in the pAutoProxyOptions structure is true, then the autoproxy
// URL and script are not cached. Therefore, calling WinHttpGetProxyForUrl with the fAutoLogonIfChallenged
// member set to TRUE results in additional overhead operations that may affect performance.
// The following steps can be used to improve performance:
// 1. Call WinHttpGetProxyForUrl with the fAutoLogonIfChallenged parameter set to false. The autoproxy
// URL and script are cached for future calls to WinHttpGetProxyForUrl.
// 2. If Step 1 fails, with ERROR_WINHTTP_LOGIN_FAILURE, then call WinHttpGetProxyForUrl with the
// fAutoLogonIfChallenged member set to TRUE.
var repeat = false;
do
{
if (Interop.WinHttp.WinHttpGetProxyForUrl(sessionHandle, uri.AbsoluteUri, ref autoProxyOptions, out proxyInfo))
{
repeat = false;
}
else
{
var lastError = Marshal.GetLastWin32Error();
if (lastError == Interop.WinHttp.ERROR_WINHTTP_AUTODETECTION_FAILED)
{
// Fall back to manual settings if available.
if (!string.IsNullOrEmpty(Proxy))
{
proxyInfo.AccessType = Interop.WinHttp.WINHTTP_ACCESS_TYPE_NAMED_PROXY;
proxyInfo.Proxy = Marshal.StringToHGlobalUni(Proxy);
proxyInfo.ProxyBypass = string.IsNullOrEmpty(ProxyBypass) ? IntPtr.Zero : Marshal.StringToHGlobalUni(ProxyBypass);
}
else
{
proxyInfo.AccessType = Interop.WinHttp.WINHTTP_ACCESS_TYPE_NO_PROXY;
proxyInfo.Proxy = IntPtr.Zero;
proxyInfo.ProxyBypass = IntPtr.Zero;
}
repeat = false;
}
else if (lastError == Interop.WinHttp.ERROR_WINHTTP_LOGIN_FAILURE)
{
if (repeat)
{
throw WinHttpException.CreateExceptionUsingError(lastError);
}
repeat = true;
autoProxyOptions.AutoLoginIfChallenged = true;
}
else
{
WinHttpException.ThrowExceptionUsingLastError();
}
}
} while (repeat);
}
public bool GetProxyForUrl(
SafeWinHttpHandle sessionHandle,
Uri uri,
out Interop.WinHttp.WINHTTP_PROXY_INFO proxyInfo)
{
proxyInfo.AccessType = Interop.WinHttp.WINHTTP_ACCESS_TYPE_NO_PROXY;
proxyInfo.Proxy = IntPtr.Zero;
proxyInfo.ProxyBypass = IntPtr.Zero;
if (!_useProxy)
{
return(false);
}
bool useProxy = false;
Interop.WinHttp.WINHTTP_AUTOPROXY_OPTIONS autoProxyOptions;
autoProxyOptions.AutoConfigUrl = AutoConfigUrl;
autoProxyOptions.AutoDetectFlags = AutoDetect ?
(Interop.WinHttp.WINHTTP_AUTO_DETECT_TYPE_DHCP | Interop.WinHttp.WINHTTP_AUTO_DETECT_TYPE_DNS_A) : 0;
autoProxyOptions.AutoLoginIfChallenged = false;
autoProxyOptions.Flags =
(AutoDetect ? Interop.WinHttp.WINHTTP_AUTOPROXY_AUTO_DETECT : 0) |
(!string.IsNullOrEmpty(AutoConfigUrl) ? Interop.WinHttp.WINHTTP_AUTOPROXY_CONFIG_URL : 0);
autoProxyOptions.Reserved1 = IntPtr.Zero;
autoProxyOptions.Reserved2 = 0;
// AutoProxy Cache.
// http://msdn.microsoft.com/en-us/library/windows/desktop/aa383153(v=vs.85).aspx
// If the out-of-process service is active when WinHttpGetProxyForUrl is called, the cached autoproxy
// URL and script are available to the whole computer. However, if the out-of-process service is used,
// and the fAutoLogonIfChallenged flag in the pAutoProxyOptions structure is true, then the autoproxy
// URL and script are not cached. Therefore, calling WinHttpGetProxyForUrl with the fAutoLogonIfChallenged
// member set to TRUE results in additional overhead operations that may affect performance.
// The following steps can be used to improve performance:
// 1. Call WinHttpGetProxyForUrl with the fAutoLogonIfChallenged parameter set to false. The autoproxy
// URL and script are cached for future calls to WinHttpGetProxyForUrl.
// 2. If Step 1 fails, with ERROR_WINHTTP_LOGIN_FAILURE, then call WinHttpGetProxyForUrl with the
// fAutoLogonIfChallenged member set to TRUE.
//
// We match behavior of WINHTTP_ACCESS_TYPE_AUTOMATIC_PROXY and ignore errors.
var repeat = false;
do
{
_autoDetectionFailed = false;
if (Interop.WinHttp.WinHttpGetProxyForUrl(
sessionHandle,
uri.AbsoluteUri,
ref autoProxyOptions,
out proxyInfo))
{
WinHttpTraceHelper.Trace("WinInetProxyHelper.GetProxyForUrl: Using autoconfig proxy settings");
useProxy = true;
break;
}
else
{
var lastError = Marshal.GetLastWin32Error();
WinHttpTraceHelper.Trace("WinInetProxyHelper.GetProxyForUrl: error={0}", lastError);
if (lastError == Interop.WinHttp.ERROR_WINHTTP_LOGIN_FAILURE)
{
if (repeat)
{
// We don't retry more than once.
break;
}
else
{
repeat = true;
autoProxyOptions.AutoLoginIfChallenged = true;
}
}
else
{
if (lastError == Interop.WinHttp.ERROR_WINHTTP_AUTODETECTION_FAILED)
{
_autoDetectionFailed = true;
_lastTimeAutoDetectionFailed = Environment.TickCount;
}
break;
}
}
} while (repeat);
// Fall back to manual settings if available.
if (!useProxy && !string.IsNullOrEmpty(Proxy))
{
proxyInfo.AccessType = Interop.WinHttp.WINHTTP_ACCESS_TYPE_NAMED_PROXY;
proxyInfo.Proxy = Marshal.StringToHGlobalUni(Proxy);
proxyInfo.ProxyBypass = string.IsNullOrEmpty(ProxyBypass) ?
IntPtr.Zero : Marshal.StringToHGlobalUni(ProxyBypass);
WinHttpTraceHelper.Trace(
"WinInetProxyHelper.GetProxyForUrl: Fallback to Proxy={0}, ProxyBypass={1}",
Proxy,
ProxyBypass);
useProxy = true;
}
WinHttpTraceHelper.Trace("WinInetProxyHelper.GetProxyForUrl: useProxy={0}", useProxy);
return(useProxy);
}
